Salmonella enterica, Cryptococcus, Influenza A virus (IAV) and Zika virus (ZIKV) have been observed to impact the regulatory mechanisms of ATP7A/B, either directly or indirectly, as a means of survival. This review summarizes the key features and trafficking mechanisms of the copper transporters ATP7A/B, and examines the intricate interplay between microbes and copper metabolism. Ultimately, it highlights how microbes can perturb copper homeostasis through interactions with host factors, offering valuable insights into the mechanistic aspects of host-microbe interactions.Copper, a vital element in various physiological processes, is transported from the gastrointestinal tract to tissues and cells through diverse copper transporters. Among these transporters, ATP7A and ATP7B play significant roles in regulating systemic copper metabolism and exhibit precise regulation in their intracellular trafficking. These transporters undergo dynamic shuttling between the trans-Golgi network (TGN) and the plasma membrane via the endocytic recycling mechanism, which involves the retromer and other associated factors. Interestingly, the antimicrobial attribute of copper implies a potential connection between microbial infection and copper metabolism. Several microbes, including  Those enzymes play vital roles in respiration (cytochrome c oxidase), peptide processing (peptidylglycine α-amidating mono-oxygenase), and protection of oxidative stress (superoxide dismutase SOD). (+) are incorporated into cells by the copper transporter 1 (Ctr1) and subsequently assigned to different utilization pathways: cytosolic, mitochondrial, and Golgi routes. .  However,se SOD).  Additionse SOD).  In order routes. .+ is transported to P-type ATPases, including ATPase copper-transporting α (ATP7A) and ATPase copper-transporting β (ATP7B), by the copper chaperone antioxidant protein 1 (Atox1). (Cu(Atox1).  ATP7A an(Atox1).  ATP7A is(Atox1).  Therefor(Atox1). .Salmonella enteric (S. enteric), serovar Typhimurium (S. Typhimurium), Mycobacterium tuberculosis (M. tuberculosis), and Candida albicans  has suggested that copper-deficient conditions enhance mortality rates and enable bacteria to survive better. , re-emerging pathogens like invasive nontyphoidal Salmonella causing public health concerns, and recent outbreaks of mpox. To tackle these challenges, it is crucial to develop effective strategies for the prevention and control of infectious diseases. In this context, exploring the relationship between copper metabolism and microbial infections may provide novel insights into how the human body can effectively combat microbial invasions. This review summarizes the functions and features of copper-dependent ATPases and sheds light on the interplay between microbes and copper. We specially focused on the interaction between microorganisms and ATP7A/B, to uncover potential links paving the way for further research.2ATP7A and ATP7B are copper-dependent and copper-transporting proteins that employ adenosine 5′-triphosphate (ATP) to pump copper ions. They share the conserved structure with other P-type ATPases and both transport ions from intracellular compartments with low concentrations to extracellular fluid with high concentrations.  The pumpThe trafficking of ATP7A/B largely relies on copper concentration. The ATPases, located on the trans-Golgi network (TGN) at basal copper levels, are stimulated by elevated copper, followed which they accumulate at cell periphery to expel excess Cu+  where thThe membrane trafficking of ATP7A has also been explored.  The retrBesides the retromer complex, there are other factors engaged in ATP7A/B transports. Adaptor protein (AP) 1 and 2 function in secretion and endosomal recycling of ATP7A/B mediated by clathrin-coated vesicles.  The C-te3+) and oxidized(Cu2+) forms, it is required by the development of immune function. Copper status strongly influences several aspects of neutrophils and monocytes,  copp+ is imported by CTR1, accompanied by Atox1, and finally delivered to phagosomes through ATP7A. , and Klebsiella pneumoniae (K. pneumoniae) share common characteristics when it comes to combating copper attacks and interacting with host ATP7A. M. tuberculosis has been found to interact with host ATP7A through its prokaryotic ATPases. Fungi such as Cryptococcus can directly impact the expression levels of ATP7A. In terms of viruses, IAV and its association with ATP7A have been extensively studied and discussed. Other viruses, such as ZIKV, have garnered attention due to the potential link between copper deficiency and nervous system damage.Several bacteria and viruses that interact with ATP7A/B have been extensively studied, but there is still a need to gain a better understanding of the relationship between microbes and copper metabolism mediated by these two proteins. 4.1S. enterica can be transmitted through animal-based foods and contaminated water or food sources.  via upregulating Atp7a gene 10 to 15 folds at 14 h post-infection.  residue on the cell surface to enter the host cell, while NA cleaves the sialic acid, facilitating virion excretion. Another outer layer protein, Matrix 2 (M2) tetramer, forms a proton channel to maintain a suitable pH for viral entry. , a dominant cis-acting regulatory element of SOD1, which reduces the quantity and activity of SOD1.  Knockdowes SOD1.  Therefores SOD1. .4.5Flaviviridae family, is an enveloped single-stranded RNA virus transmitted by various Aedes mosquitoes. The symptoms are mostly self-limiting, including fever, headache, arthralgia, myalgia, and maculopapular rash. However, newborns whose mothers are infected with ZIKV during pregnancy are reportedly born with a severe abnormality of the central nervous system (CNS). .  The virum (CNS). .In the CNS, astrocytes maintain brain copper homeostasis. Copper-dependent ATPase, mostly ATP7A, controls astrocyte copper excretion.  Copper d5The copper metabolism of mammals largely depends on various transporters, including copper importer CTR1, copper exporter ATP7A/B, and copper chaperones, to maintain an intracellular and systemic balance. CRT1 is incorporated with cuprous ions in a high-affinity manner to transmit the kations into cells. ATP7A and ATP7B share some regulators and co-transporters, such as COMMD1 and Vps35. However, they have different distributions in tissues, resulting in slightly diverse functions in copper secretion. Copper homeostasis is crucial for the human body, especially the nervous system, and its dysmetabolism might be associated with neurodegeneration. .S. enterica and M. tuberculosis leads to an upregulation of ATP7A. These bacteria employ copper pumps, such as CopA/GolT and ctpV/ctpB, to counteract the elevated copper levels. Other microbes, including Cryptococcus neoformans, IAV and ZIKV directly influence the regulation or localization of ATP7A/B. Recently, the endocytic recycling of angiotensin converting enzyme 2 (ACE2), glucose transporter type 1 (GLUT1), hydroxytryptamine receptor 4 (HTR4) and adrenoceptor beta 1 (ADRB1) was inhibited by SARS-CoV-2 S, possibly explaining some COVID symptoms associated with deficiency of those surface proteins. , using CopA to maintain copper levels, demonstrates high toxicity on the depletion of lung macrophages, which proves to be a main source of lung copper. (Candida albicans senses copper levels via two distinct copper regulators, Mac1 and Cup2, which can induce CTR1 and the gene of MTs, to cope with host copper starvation or accumulation. (Similar to SARS-CoV-2, some viruses target the protein sorting process of host cells and disrupt ion balance by influencing ion transporters. For instance, IAV targets ATP7A to disturb the host cellular copper balance, particularly causing loss of smell,  consiste copper.  And Candulation.  The inteIn conclusion, our review has focused on the characteristics and trafficking mechanisms of ATP7A/B, as well as the role of copper in antimicrobial responses, with a particular emphasis on the interplay between host copper-dependent ATPase and microbial infections. Additionally, we suggest that viral infections may disrupt the endocytic recycling process, leading to disturbances in copper metabolism. We believe that the link between microbial infections and copper metabolism can help elucidate specific clinical syndromes and provide new avenues for the prevention and treatment of infectious diseases.YZ: Writing – original draft. LZ: Conceptualization, Writing – review & editing.


Nevertheless, there has been little synthesis of the strength and quality of this evidence in aggregate.Systematic reviews and meta-analyses of randomized clinical trials (RCTs) have reported the benefits of ketogenic diets (KD) in various participants such as patients with epilepsy and adults with overweight or obesityTo grade the evidence from published meta-analyses of RCTs that assessed the association of KD, ketogenic low-carbohydrate high-fat diet (K-LCHF), and very low-calorie KD (VLCKD) with health outcomes, PubMed, EMBASE, Epistemonikos, and Cochrane database of systematic reviews were searched up to February 15, 2023. Meta-analyses of RCTs of KD were included. Meta-analyses were re-performed using a random-effects model. The quality of evidence per association provided in meta-analyses was rated by the GRADE  criteria as high, moderate, low, and very low.n = 2), seizure frequency (n = 1) and increased low-density lipoprotein cholesterol (LDL-C) (n = 1)) and four associations supported by moderate-quality evidence , hemoglobin A1c, and increased total cholesterol). The remaining associations were supported by very low (26 associations) to low (17 associations) quality evidence. In overweight or obese adults, VLCKD was significantly associated with improvement in anthropometric and cardiometabolic outcomes without worsening muscle mass, LDL-C, and total cholesterol. K-LCHF was associated with reduced body weight and body fat percentage, but also reduced muscle mass in healthy participants.We included 17 meta-analyses comprising 68 RCTs  and 115 unique associations. There were 51 statistically significant associations (44%) of which four associations were supported by high-quality evidence (reduced triglyceride (This umbrella review found beneficial associations of KD supported by moderate to high-quality evidence on seizure and several cardiometabolic parameters. However, KD was associated with a clinically meaningful increase in LDL-C. Clinical trials with long-term follow-up are warranted to investigate whether the short-term effects of KD will translate to beneficial effects on clinical outcomes such as cardiovascular events and mortality.The online version contains supplementary material available at 10.1186/s12916-023-02874-y. The  unclear , 11.Several systematic reviews and meta-analyses of randomized clinical trials (RCTs) have reported on the use of KD in patients with obesity or type 2 diabetes mellitus (T2DM) to control weight and improve cardiometabolic parameters , 12–15, The protocol of this study was registered with PROSPERO CRD42022334717). We reported following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA)  from the database inception to February 15, 2023  independently performed data extraction and quality assessment  of individual studies included in each meta-analysis and performed the meta-analyses to calculate the pooled effect sizes and 95% CIs using a random-effects model under DerSimonian and Laird , or the try test . Statisttry test , 26–30.We assessed the quality of evidence per association by applying the GRADE criteria  in five domains, including (1) risk of bias in the individual studies, (2) inconsistency, (3) indirectness, (4) imprecision, and (5) publication bias . We gradth percentile) [Sensitivity analyses were performed by excluding small-size studies (< 25centile)  and exclcentile) –21, 33.Seventeen meta-analyses were included  KD, which limits carbohydrate intake to < 50 g/day or < 10% of the total energy intake (TEI) , (2) ketWe identified 115 unique associations of KD with health outcomes , 6 (5%) exercise performance , 5 (4%) blood pressure outcomes , 1 (1%) outcome associated with seizure frequency reduction ≥ 50% from baseline, and 3 other outcomes . In addition, there is 1 association (1%) of adverse events.The associations involved 40 (35%) anthropometric measures , 37 (32%) lipid profile outcomes , 22 (19%) glycemic profile outcomes  associations in adults with overweight or obesity with or without T2DM or dyslipidemia, 15 (13%) athletes or resistance-trained adults, 12 (10%) adults with T2DM, 11 (10%) healthy participants ≥ 16 years old, 8 (7%) cancer patients, and 1 (1%) in children and adolescents with epilepsy.n = 66, 57%), with the remaining being low , moderate , and high quality of evidence   [Eight out of 13 associations supported by moderate to high-quality evidence were statistically significant Table . There wld 0.5%) , 35, (2)ld 0.5%) , 15, (3)ld 0.5%) , and (4)ld 0.5%) , 17.Tabl1c; however, KD for 12 months led to a clinically meaningful increase in LDL-C by 6.35 mg/dL  [Types of KD showed different effects on health outcomes with changes more than the MCID thresholds in different populations Fig. . KD or M7 mg/dL) , 35. In 7 mg/dL) , 15. VLC7 mg/dL) .Fig. 2AsExcluding RCTs with small sizes in 7 associations found that the strength of evidence of one association was downgraded to very low quality, i.e., KD for 12 months, and the increase of LDL-C in adults with T2DM compared with a control diet. Another association was downgraded to low quality, i.e., KD for 12 months and the reduction of triglyceride in adults with T2DM compared with the control diet  for up to 16 months , 11, 16.In adults, KD was associated with improved anthropometric measures, cardiometabolic parameters, and exercise performance. Our findings, however, demonstrated differences in the level of associations with type of KD. On the one hand, VLCKD is very effective in producing weight loss while preserving muscle mass in adults with overweight or obesity, with specific benefits on anthropometric and cardiometabolic parameters , 42. On Our findings demonstrated that KD could induce a rapid weight loss in the initial phase of 6 months, after which time further weight loss was hardly achieved . FurtherKD is one of the dietary interventions employed by individuals to achieve rapid weight loss, which usually comes with reduced muscle mass . HoweverWith regards to KD effects on lipid profiles, our results demonstrate an effective reduction in serum triglyceride levels with 3 months of lowered dietary carbohydrate intake, with even further reduction by month 12 . TriglycMost RCTs of KD were conducted in patients with a limited group of participants, such as those with overweight, obesity, metabolic syndrome, cancer, and refractory epilepsy. In addition, most outcomes measured were limited to only surrogate outcomes. Thus, more clinical trials with a broader scope in populations and outcomes associated with KD would expand the role of KD in a clinical setting. For example, participant selection could be expanded from previous trials to include elderly patients, nonalcoholic fatty live disease (NAFLD) patients, and polycystic ovarian syndrome patients. Outcomes of interest of could be expanded to include (1) clinical outcomes such as cardiovascular events and liver outcomes, (2) short- and long-term safety outcomes such as adverse events , eating disorder syndrome, sleep parameters, lipid profiles, and thyroid function and (3) other outcomes such as adherence and quality of life. More importantly, long-term studies are needed to investigate the sustainability of the clinical benefits of KD.Our findings are useful to support the generation of evidence-based recommendations for clinicians contemplating use of KD in their patients, as well as for the general population. We further emphasize the importance of consultation with healthcare professionals before utilizing KD and any other dietary interventions. We demonstrated the benefits of KD on various outcomes in the short term. However, these improvements may prove difficult to sustain in the long term because of challenges in adherence. As for any diet interventions to achieve sustainable weight loss, factors of success include adherence, negative energy balance, and high-quality foods. Thus, communication and education with KD practitioners are important to ensure their adherence to the diet. Some individuals might benefit from switching from KD to other dietary interventions to maintain long-term weight loss.This umbrella review has several limitations. Firstly, we focused on published meta-analyses which confined us from assessing the associations of KD on outcomes and populations that were not included in existing meta-analyses. Secondly, most of the included meta-analyses were rated with AMSTAR-2 as critically low confidence, mainly due to a lack of study exclusion reasons, unexplained study heterogeneity, and unassessed publication bias. However, these domains unlikely affected our findings. Thirdly, we could not perform a dose–response analysis to understand the effects of different levels of carbohydrate intake on health outcomes because of insufficient details of carbohydrate intake reported in the meta-analyses. Fourthly, most RCTs of KD were limited to a relatively small number of participants with a short-term follow-up period, which limited our assessment of sustained beneficial effects after stopping KD. Lastly, due to decreased adherence, carbohydrate intake most likely increased across the course of the trials. For example, subjects in the KD arm of the A TO Z Weight Loss Study , started1c, RER, and decreased seizure frequency. However, KD was associated with a clinically meaningful increase in LDL-C. Clinical trials with long-term follow-up are warranted to investigate whether these short-term effects of KD will translate to beneficial effects on more long-term clinical outcomes such as cardiovascular events and mortality.Beneficial associations of practicing KD were supported by moderate- to high-quality evidence, including weight loss, lower triglyceride levels, decreased HbAAdditional file 1. PRISMA 2020 Main Checklist. Additional file 2:Method S1. Data extraction. Table S1. Difference from original review protocol. Table S2. Search strategy. Table S3. Excluded studies with reasons. Table S4. Quality assessment. Table S5. Summary of associations. Table S6. Sensitivity analyses.


Aim and Objectives: Direct-acting antiviral (DAA) therapy can cure chronic hepatitis C (CHC), and daclatasvir (DCV)/asunaprevir (ASV) was the first interferon-free DAA therapy introduced in Korea. Patients who achieve sustained virologic response (SVR) after DAA treatment are expected to have good prognoses. Therefore, in this study, we aimed to investigate the prognosis of these patients. Materials and Methods: This multicenter prospective observational study included patients with CHC who achieved SVR after DCV/ASV treatment. The primary endpoint was hepatocellular carcinoma (HCC) occurrence, which was reviewed annually. Results: We included 302 patients  in the study. Cirrhosis was observed in 103 patients (34.1%), and the median Child–Pugh score was 5.0. HCC occurred in 16 patients (5.3%) within six years post-SVR; these patients were older and had higher cirrhosis prevalence, alpha-fetoprotein levels, and fibrosis-4 index scores than did those without HCC development. Cox proportional hazards analysis revealed that age > 71 years (p = 0.005) and cirrhosis (p = 0.035) were significant risk factors for HCC occurrence. Conclusions: Although the prognoses of patients who achieved SVR with DCV/ASV therapy were generally good, the risk for HCC was present, especially in older patients and in those with cirrhosis. Hence, early treatment at younger ages and regular follow-up surveillance after achieving SVR are warranted. Hepatitis C virus (HCV) infection results in a substantial medical and economic burden globally; in 2019, 58 million people worldwide were estimated to have a chronic HCV (CHC) infection . From a therapeutic point of view, the development of direct-acting antivirals (DAAs) has been a turning point in CHC treatment. DAAs have a high efficacy for viral eradication and an excellent safety profile; hence, they have replaced interferon-based treatments as the first-line therapy for HCV. In particular, combination therapy with daclatasvir (DCV) and asunaprevir (ASV), the first interferon-free regimen, was developed to overcome the shortcomings of interferon therapy and has replaced interferon-based therapy in clinical practice ,5,6. ThePatients with CHC that achieve an SVR have demonstrated decreased rates of life-threatening complications, all-cause mortality, decompensated cirrhosis, and HCC ,8. In paRecently, Fujii et al. demonstrated that DSV/ASV combination treatment was a critical factor for the surveillance of HCC development in Japan . HoweverThis prospective observational multicenter study included six teaching hospitals in South Korea and was approved by the ethics committees of each hospital. Informed consent was obtained from all participants. Patients with CHC who achieved SVR after DCV/ASV treatment were enrolled between March 2016 and February 2021; the final follow-up month was August 2022. The inclusion criteria were as follows: (1) the presence of CHC with the achievement of SVR after DCV/ASV treatment and (2) age ≥ 18 years. The exclusion criteria were as follows: (1) unwillingness to be enrolled in the study; (2) inability to understand or provide informed consent; (3) presence of malignant tumors, including HCC; (4) coinfection with chronic hepatitis B or human immunodeficiency virus; (5) a history of liver transplantation; and (6) a history of CHC treatment. Patients with compensated cirrhosis were included in the study.9/L]) × 100; FIB-4 index = age (years) × AST (IU/L)/(platelet count (109/L) ×  1/2) ,18. APRIThe clinical outcomes were as follows: (1) HCC occurrence as the primary endpoint and (2) HCV recurrence or reinfection as the secondary endpoint. Hepatic decompensation was defined as overt ascites, hepatic encephalopathy, variceal bleeding, bacterial infection, or deterioration of liver dysfunction, defined as serum bilirubin levels ≥ 3 mg/dL. During the follow-up period, all enrolled patients underwent liver function tests, tests for HCV-RNA and alpha-fetoprotein (AFP) levels, and radiologic examinations, such as abdominal ultrasonography or computed tomography, at least once annually.Continuous variables are expressed as median (interquartile range), while categorical variables are presented as numbers (%). The Mann–Whitney U, chi-squared, and Fisher’s exact tests were conducted to compare variables between groups, as appropriate. The Wilcoxon signed-rank test was used to assess significant changes in liver function and noninvasive fibrosis scores at two different time points. Cumulative HCC occurrence was evaluated using the Kaplan–Meier method, and differences were determined using the log-rank test. ® software. Statistical significance was set at p < 0.05, and all analyses were performed using SPSS  and MedCalc version 22.005 .Univariate and multivariate analyses were performed to identify independent predictors of HCC occurrence using a Cox regression hazard model (forward). Significant factors that predicted HCC development after treatment in patients with CHC who achieved SVR were extracted. Continuous variables were categorized according to the area under the receiver operating characteristic (ROC) curve to predict HCC development. New cutoff values were defined using the Youden index set to the maximum level and generated automatically using MedCalcThis study enrolled 302 patients, including 148 (49.0%) males, and the median age was 58 years . The medDuring the follow-up period, HCC occurred in 16 patients: in 5 (1.7%), 7 (2.3%), 9 (3.0%), 12 (4.0%), 13 (4.3%), and 16 (5.3%) patients within 1, 2, 3, 4, 5, and 6 years, respectively . Recurrep = 0.011) than the rest of the patients. Furthermore, these patients had higher MELD , APRI , and FIB-4  scores than the rest of the patients.Decompensation events occurred in 8 patients: 2 (0.7%), 4 (1.3%), 7 (2.3%), 7 (2.3%), 7 (2.3%), and 8 (2.6%) patients within 1, 2, 3, 4, 5, and 6 years, respectively. These patients either had cirrhosis or were older .The APRI and FIB-4 scores were compared annually with the pre-treatment scores ; both APp < 0.001) and had a higher cirrhosis incidence , higher AFP levels , and higher pre-FIB-4 , APRI , and FIB-4  scores  scores  than didp < 0.1) in the univariate analysis. Additionally, age and cirrhosis were significant variables in the multivariate analysis (According to the area under the ROC curve and Youden index (J) analysis, cutoff levels for risk factors were as follows: (1) age, 71 years; (2) AFP, 3.85 ng/mL; (3) pre-FIB-4, 2.227; (4) APRI, 0.556; and (5) FIB-4, 2.123. These variables were all significant  during 38 months of follow-up after achieving SVR. The patients demonstrated improved reserve liver function after achieving SVR. However, 5.3% of the enrolled patients developed HCC. Among the factors associated with HCC development, age > 71 years and the presence of cirrhosis were observed to be closely related in the multivariate analysis. If patients with cirrhosis were excluded, age > 71 years was the only risk factor.There have been no previous reports regarding the long-term recurrence or reinfection rates after HCV elimination with DCV/ASV. To the best of our knowledge, the present study is the first to report long-term follow-up results of HCV recurrence or reinfection rates after SVR achievement with DCV/ASV. Furthermore, this study demonstrated a persistent virologic response without recurrence or reinfection for more than three years in most patients (99.3%). Two women, each aged 69 years, who underwent 24 weeks of DCV/ASV therapy for HCV genotype 1b infection experienced HCV recurrence or reinfection at three and eight months, respectively, after achieving SVR. Both patients had underlying compensated cirrhosis and high HCV-RNA levels. The presence of cirrhosis and a high HCV-RNA viral load have been proposed as risk factors for DAA treatment failure. Previous studies have reported a reversal effect on liver function impairment and fibrosis after hepatitis C elimination ,22. SimiThere has been ongoing successful HCV eradication with the introduction of DAAs, and the number of patients who have achieved SVR is also increasing. However, eventual HCC development, which is difficult to avoid, is the main burden in patients with successful SVR, especially in those with high-risk features . In the The present study had several limitations. First, the total number of patients diagnosed with HCC during follow-up after SVR achievement was limited. Despite enrolling a sizeable number of patients from multiple institutions and following up for more than three years, HCC developed in only 5.3% of the enrolled patients. Hence, further studies with a larger number of patients and a longer observation period than those of the present study may be necessary to investigate the risk factors for HCC development. Second, the present study included patients with an HCV genotype 1b infection treated with DCV/ASV. Therefore, this study’s results may not apply to patients with an HCV infection of other genotypes and those who received other DAAs. Third, our study has limited data about potential confounding factors such as comorbidities, medication use, and environmental factors that may influence the association between DCV/ASV treatment and prognosis. To overcome this limitation, larger data analyses are warranted. Finally, many guidelines recommend pan-genotypic agents with simplified treatment algorithms after the introduction of pan-genotypic DAA agents, such as sofosbuvir with velpatasvir or glecaprevir with pibrentasvir ,31. AlthThe current data lacked information about genetic and environmental factors related to the prognosis of such patients and HCC screening strategy treatment modalities. Therefore, future research should include these factors.In conclusion, patients who underwent 24 weeks of DCV/ASV treatment demonstrated a very low HCV recurrence/reinfection rate, improved liver function, and improved fibrotic burden after achieving SVR. However, patients with risk factors for HCC, such as old age (>71 years) and cirrhosis, should undergo close surveillance for HCC development. Further studies are warranted to determine the efficacy of post-SVR treatment and the factors associated with HCC development.


Pneumococcal disease remains one of the major causes of severe disease in both children and adults. Severe disease may be prevented by pneumococcal polysaccharide and conjugate vaccines, which currently cover more than 20 serotypes. However, unlike routine pneumococcal vaccination in children, guidelines promote only limited pneumococcal vaccination in adults, and do not cater for decision-making for individual patients. In this narrative review, considerations for individualized decision-making are identified and discussed. This review identifies and discusses considerations for individualized decision-making, including the risk of severe disease, immunogenicity, clinical efficacy, mucosal immunity, herd immunity, concomitant administration with other vaccines, waning immunity, and replacement strains. Streptococcus pneumoniae. The bacterium possesses a surface polysaccharide capsule that inhibits ingestion and killing by leukocytes. Each capsular polysaccharide is antigenically unique and represents a different serotype. More than 90 serotypes of S. pneumoniae exist [Pneumococcal disease is caused by a gram-positive pathogenic diplococcus bacterium called ae exist , with vaae exist . In anotae exist .S. pneumoniae occurs via intimate contact or aerosol exposure. Infection by S. pneumoniae can lead to asymptomatic nasopharyngeal carriage, localized respiratory disease  or severe systemic disease. Pneumococcal disease remains one of the major causes of severe disease in both children and adults, especially when invasive pneumococcal disease  or severe non-bacteremic pneumonia occur. Annually, in the United States, invasive pneumococcal disease has an incidence of 10.6/100,000, while pneumococcal pneumonia accounts for 900,000 cases and 400,000 hospitalizations [S. pneumoniae is the leading bacterial cause of pneumonia globally [Human-to-human transmission of izations . Additioglobally .Severe pneumococcal disease may be prevented by pneumococcal vaccines. In severe infection, proinflammatory cytokines produced by systemic infections may trigger endothelial dysfunction, atheroma instability, plaque rupture, and myocardial infarction . By prevLike for children, vaccination in adults aims to prevent severe disease. However, unlike routine pneumococcal vaccination in children, guidelines only promote routine pneumococcal vaccination in older adults aged ≥ 65 years. For other adults, pneumococcal vaccination is recommended only for those who are at higher risk of severe disease due to chronic medical conditions, anatomical risk for meningitis, or immunocompromise . These rIn this review, considerations for individualized decision-making are therefore identified and discussed. Knowing these considerations will allow individualized decision-making as societal perspectives adopted by guidelines do not always apply to individual patients. Apart from risk of severe disease, these considerations include immunogenicity, clinical efficacy, mucosal immunity, herd immunity, concomitant administration with other vaccines, waning immunity, and replacement strains.®  of contemporary trials over the past 5 years from 2018–2023 was performed using the term “pneumococcal vaccination randomized trials”. This was done to update the author’s personal library of articles. Articles relevant to the considerations covered in this narrative review were included.A search of PubMedNot surprisingly, patients at risk of invasive pneumococcal disease or severe nonbacteremic pneumonia include those at the extremes of age (age < 2 or ≥ 65 years), and those with chronic medical conditions  or at a very high cardiovascular risk, a systematic review and pooled analysis of 5 observational studies showed that pneumococcal vaccination was associated with a 22% decrease of all-cause mortality  .S. pneumoniae. Vaccination should induce antibodies directed to the capsular polysaccharide, and pneumococcal vaccines use capsular polysaccharides from pneumococcal serotypes that commonly cause invasive disease. The response to pneumococcal vaccine in adults is measured by the rise in antibody levels (immunoglobin G) or serum opsonophagocytic activity titres  after vaccine administration.Humoral immunity is key to the host defence against Two types of pneumococcal vaccine are available for clinical use: the pneumococcal polysaccharide vaccine (PPSV) and the pneumococcal conjugate vaccine (PCV). PPSV consists of partially purified pneumococcal capsular polysaccharides, with the only available formulation being PPSV23. PPSV23 contains 23 pneumococcal polysaccharides derived from the 23 serotypes that most frequently caused invasive pneumococcal disease in United States adults in the 1980s .S. pneumoniae and human-to-human transmission of vaccine-serotypes. A variety of PCVs exist with numbers indicating the number of pneumococcal capsule types included in the vaccine, resulting in varying extents of serotype coverage:PCV13 serotype coverage: 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23FPCV15 serotype coverage: 22F and 33F, in addition to PCV13 serotypesPCV20 serotype coverage: 8, 10A, 11A, 12F, 15B, 22F, and 33F, in addition to PCV13 serotypes ,25,26PCV21 serotype coverage : 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 19A, 20, 22F, 23A, 23B, 24F, 31, 33F, 35B. These serotypes contribute to 74–94% of invasive pneumococcal disease in adults aged ≥65 years . Eight oPCV23 serotype coverage : 2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20, 22F, and 33F, in addition to PCV13 serotypes (except for 6A). Serotypes 9N, 17F, and 20 are included in PPSV23 and are absent from PCV20PCV24 serotype coverage : 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F (shared PCV13 serotypes) plus 2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 22F, and 33F (shared PPSV23 serotypes) and 20B. This vaccine also incorporates a fusion protein consisting of two highly conserved pneumococcal proteins (sp1500 and sp0785) that may help protect against both vaccine and nonvaccine serotypes In contrast to PPSV23, PCVs are inactivated vaccines that consist of type-specific pneumococcal capsular polysaccharides conjugated to a carrier protein or proteins. This carrier protein elicits a T cell-dependent memory response, which improves vaccine effectiveness during the first two years of life. Immunogenicity does not seem greatly different between the two vaccine types ,22, thouWhen both PPSV and PCV are given, the sequence of administration may be important. In older adults, prior administration of PPSV23 blunts the opsonophagocytic antibody response to subsequent administration of PCV13 . NonetheThe protective efficacy of PPSV23 has been consistently shown by several trials ,34,35, aGiven the huge expense required to run large vaccine efficacy trials with relatively small event rates, studies of newer vaccines tend to compare immunogenicity to PCV13, and infer clinical efficacy from immunogenicity  . ExampleLittle reason exists to avoid pneumococcal vaccination in immunocompromised patients. For instance, PCV15 and PPSV23 are both well tolerated and immunogenic for persons living with human immunodeficiency virus (HIV) ,56. PCV7Among pregnant mothers, PPSV23 may be preferred in HIV-infected mothers, as PCV10 was associated with decreased antibody responses to PCV10 and seroprotection rates in infants who subsequently received PCV10 . AlthougS. pneumoniae. Since successfully vaccinated individuals cannot be infected, they would not be able to spread infection to others. Mucosal immunity thus reduces the potential for human-to-human transmission of S. pneumoniae, which causes an indirect effect  at the population level. Vaccination of invasive pneumococcal disease in South Africa was shown to have both direct and indirect effects in the GERMS-SA study [Unlike PPSV, PCV stimulates mucosal immunity and prevents nasal colonization of SA study . In thisIndirect effect of childhood pneumococcal vaccination was also found in the United States, where the routine schedule for PCV (either PCV13 or PCV15) includes a three-dose primary series and a booster dose ,32. UsinCoadministration of pneumococcal vaccines with other vaccines have demonstrated little cross-interference, especially with the inactivated influenza vaccine. Coadministration of PPSV23 and trivalent inactivated influenza vaccine (IIV3) or quadrivalent inactivated influenza vaccine (IIV4) yielded no worsening of antibody responses and no increased adverse reactions in two separate trial populations: 162 adults aged ≥ 65 years  and 41 aPCV15 administered concomitantly with IIV4 is generally well tolerated and immunologically non-inferior to non-concomitant administration, supporting coadministration of both vaccines, according to a trial involving 1200 participants (about 50% aged ≥ 65 years) . SimilarCoadministration of pneumococcal vaccine with recombinant zoster vaccine (RZV) has also showed no immunologic interference in a trial of 865 participants ≥ 50 years of age, who were randomly assigned into two groups: Group 1 received coadministration of PPSV23 and recombinant zoster vaccine (RZV), then RZV 2 months later, while Group 2 received PPSV23, then RZV 2 and 4 months later . An analThough coadministration of pneumococcal vaccine with COVID-19 vaccines would be desirable to improve vaccination coverage, published data on immunologic interference are not available . Such daNevertheless, coadministration of pneumococcal vaccines with tetanus-diphtheria vaccine (Td) may not be desirable. In a trial of 448 adults aged ≥ 50 years, the coadministration of PCV13 with Td lead to similar immunogenicity and safety for PCV13 but decreased immunogenicity for Td when co-administered . On a siAdministration of additional pneumococcal vaccines among adults may be required due to waning immunity and the emergence of replacement strains, both of which erode the protection afforded by existing pneumococcal vaccines. For PPSV23, effectiveness wanes over several years ,76, and S. pneumoniae type 19A (not included in PCV7) became the commonest cause of pneumococcal disease in both children and adults. Similarly, for PCV13, non-vaccine serotypes have increased in prevalence since PCV13 was introduced [Emergence of replacement strains  creates an epidemiological moving target for pneumococcal vaccination, necessitating development of vaccines that cover new serotypes or that do not depend on specific capsular polysaccharides for protection. For example, a few years after universal vaccination with PCV7 commenced in the United States, troduced ,82,83.The clinical impact of replacement strains was demonstrated in the GERMS-SA study, which investigated the direct and indirect effects of pneumococcal vaccination . Among cp = 0.008), but similar in TR [Two areas of adult pneumococcal vaccination require further research. Firstly, vaccination strategies with the existing vaccines require clarification. It remains uncertain how vaccine immunogenicity and efficacy will wane over the long-term in either healthy or immunocompromised patients. These will have implications for revaccination intervals. Furthermore, for immunocompromised patients who have blunted immune responses , vaccinaar in TR ,86. Nonear in TR .S. pneumoniae serotypes . However, for unclear reasons, a recent clinical trial of a protein-based pneumococcal vaccine co-administered with PCV13 in infants did not demonstrate incremental efficacy in preventing acute otitis media or acute lower respiratory tract infection [S. pneumoniae whole cell vaccine, which relies on killed cells from a nonencapsulated strain of S. pneumoniae, coupled with an aluminium hydroxide adjuvant. A whole cell vaccine could potentially protect against more diverse serotypes than existing capsular polysaccharide-based vaccines [S. pneumoniae whole cell vaccine (3 doses 4 weekly) was well-tolerated and induced pneumococcal antigen-specific antibody and T-cell cytokine responses [Secondly, new vaccines are needed to mitigate the emergence of replacement strains. Existing vaccines that use capsular polysaccharides as antigens are limited by the number of serotypes covered. A novel vaccine development approach taps on highly conserved pneumococcal proteins  ,89,90,91nfection . Non-servaccines . In a raesponses .Guidelines currently recommend pneumococcal vaccination among patients at risk of severe disease, identifying age and comorbidity as the main risk factors. Decision-making for individuals additionally require clinicians to consider risk of exposure to infection, immunogenicity, clinical efficacy, mucosal immunity, herd immunity, concomitant administration with other vaccines, waning immunity, and replacement strains . In gene


Gammaproteobacteria, Alphaproteobacteria, Campylobacterota, and Chlorobia above the anoxic zone I and sulfate-reducing bacteria were dominated by Desulfobacterota in anoxic zones. Metagenomic analyses showed that the sulfide-oxidation-related gene sqr and genes encoding the Sox system were mainly distributed in the anoxic zone I, while genes related to dissimilatory sulfate reduction and sulfur intermediate metabolite reduction were mainly distributed in the anoxic zone II, indicating different sulfur metabolic processes between these two zones. Moreover, sulfur-metabolism-related genes were identified in 81 metagenome-assembled genomes (MAGs), indicating a high diversity of microbial communities involved in sulfur cycling. Among them, three MAGs from the candidate phyla JdFR-76 and AABM5-125-24 with genes related to dissimilatory sulfate reduction exhibited distinctive metabolic features. Our results showed unique and novel microbial populations in the SYBH sulfur cycle correlated to the sharp redox gradients, revealing complex biogeochemical processes in this extreme environment.The Sansha Yongle Blue Hole (SYBH), the deepest blue hole in the world, is an excellent habitat for revealing biogeochemical cycles in the anaerobic environment. However, how sulfur cycling is mediated by microorganisms in the SYBH hasn’t been fully understood. In this study, the water layers of the SYBH were divided into oxic zone, hypoxic zone, anoxic zone I and II, and microbial-mediated sulfur cycling in the SYBH was comprehensively interpreted. The 16S rRNA genes/transcripts analyses showed that the microbial community structures associated with the sulfur cycling in each zone had distinctive features. Sulfur-oxidizing bacteria were mostly constituted by Oxygen-deficient regions in the global ocean are expanding rapidly and affect the growth, reproduction and ecological processes of marine organisms. The anaerobic water body of about 150 m in the Sansha Yongle Blue Hole (SYBH) provided a suitable environment to study the specific microbial metabolism in anaerobic seawater. Here, we found that the vertical distributions of the total and active communities of sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) were different in each water layer of the SYBH according to the dissolved oxygen content. Genes related to sulfur metabolism also showed distinct stratification characteristics. Furthermore, we have obtained diverse metagenome-assembled genomes, some of which exhibit special sulfur metabolic characteristics, especially candidate phyla JdFR-76 and AABM5-125-24 were identified as potential novel SRB. The results of this study will promote further understanding of the sulfur cycle in extreme environments, as well as the environmental adaptability of microorganisms in blue holes. Sulfur plays an important role in the biochemistry of marine ecosystems, which can be further linked to other important element cycles. Affected by factors such as global warming and the eutrophication of offshore waters, the dissolved oxygen (DO) content in seawater has continued to decrease recently, resulting in the rapid expansion of marine anoxic environments around the world, such as the oxygen minimum zones (OMZs) –3. Rec2S)  , 14. In Thiomicrospira and Sulfurimonas) accounting for at most 37% of the total bacteria in winter  were enriched in anoxic layers  of the SYBH for 16S rRNA genes/transcripts sequencing and seven depths for metagenome sequencing. The composition and distribution of microbial communities involved in the sulfur cycle in the SYBH were examined based on 16S rRNA amplicons to elucidate the interaction of microbial communities and environmental factors in depth. In addition, 16S rRNA transcripts were analyzed for the first time, demonstrating that sulfur-associated microorganisms were not only highly abundant in the SYBH but also active. Moreover, the vertical distribution patterns of sulfur metabolic genes and the main groups of SOB and SRB were determined by metagenomic analyses. This investigation reveals the diversity of sulfur-associated microorganisms in the SYBH and potential mechanisms driving the sulfur cycling in marine anoxic environments.3− and NO2−), ammonium (NH4+), sulfate (SO42-), and H2S also showed significant stratifications at different depths  and decreased to a similar level of that in the hypoxic zone. The SO42− concentration fluctuated sharply in the anoxic zone I and decreased significantly in the anoxic zone II. H2S concertation began to increase in the anoxic zone I (90 m below), which showed a sharp elevation at 130–150 m and remained at a high level of ~250 µmol/L below 150 m in the anoxic zone II. The variation trend of NH4+ concertation was similar to that of H2S. NO3− and NO2− concertation began to increase at 40 m and showed the highest concentration in the hypoxic zone.DO in the SYBH reduced from 192 µmol/L at the surface (0 m) to 8 µmol/L at 100 m and dropped to nearly 0 µmol/L at 105 m. The water of the SYBH was highly stratified according to DO and was divided into oxic zone (0–40 m), hypoxic zone (50–85 m), anoxic zone I (90–110 m), and anoxic zone II (115–190 m) . In addit depths . The conProteobacteria, Bacteroidota, Desulfobacterota, Planctomycetota, Chloroflexi, SAR406 clade, Actinobacteriota, Firmicutes, Patescibacteria, and Latescibacterota, which accounted for 47.92%–92.26% of the total sequences in different samples . The relative abundance of Desulfobacterota obviously increased in anoxic zones, with the highest abundance reaching 37.81% (F150). The 16S rRNA transcripts showed a similar distribution pattern of the microbial community across the water column compared with that based on 16S rRNA genes.A total of 2,096,476,770 high-quality 16S rRNA genes and 175,305,600,296 16S rRNA transcripts sequences were obtained from the 115 seawater samples , whereas Thiomicrospirales, which belonged to CSB, was dominant both in the hypoxic zone and anoxic zone I  samples compared with particle-associated  samples. In addition, other CSB groups like Arcobacteraceae, Sulfurimonadaceae, Sulfurospirillaceae, and Sulfurovaceae from the phylum Campylobacterota were mainly active in the anoxic zone I . Th. ThAlphac zone I  28). Pr. PrAlphac zone I , which cnditions , 30.Desulfobacterota, whose relative abundance displayed an obviously increasing trend below 90 m, and were consistently high in anoxic zones  and Shannon (reflecting diversity) were calculated. The rarefaction curves of the Shannon index of total OTUs indicated that the amount of sequencing data could reflect the diversity of the microbial community . The ric2r (DNA) = 0.8329, 2r (RNA) = 0.8522] and DOC  were the main factors separating the populations of the oxic zone from those of the deeper zones. The sulfur-associated microbes of the hypoxic zone were separated from other groups by high concentrations of NO3−, NO2−  and SO42- . The sulfur-associated microbes in the anoxic zone II were mainly influenced by high levels of H2S , NH4+  and PO43- .For both total prokaryotes and sulfur-associated bacteria, distinct communities between four zones and different lifestyles (FL and PA) were observed on the DNA and RNA levels , consistsqr and genes for sulfate and other intermediate metabolites reduction were at high levels in layers below 90 m  (2O32−) to SO42−  encoding gene ic zones . Howeverse (Fcc) , which ao SO42− , 33, as 2− , aprAB (adenylylsulfate reductase), and dsrAB (dissimilatory sulfite reductase) were mainly distributed in Desulfobacteraceae at the anoxic zone II. In addition, based on phylogenetic analysis, the reverse DsrAB (rDsrAB), which is responsible for the oxidation of S0 for energy  pathway is a common way for all known SRB to perform sulfate reduction , 36. As r energy , 38, bashlorobia . Genes h zone II .sqr, Sox system, soeABC, sat, aprAB, dsrAB, hydABDG, and phsABC). We finally screened out 81 sulfur-associated MAGs, which were affiliated with 21 phyla, including 24 sulfur-oxidizing MAGs and 18 sulfate-reducing MAGs , Alphaproteobacteria (4), Bacteroidota (9), Marinisomatota (4), Chloroflexota (2), and Actinobacteriota (1). The SOB of Bacteroidota were divided into Chlorobia (1) from the anoxic zone I and Bacteroidia (8) generated from the anoxic zone II. The selected MAGs distributed in the oxic zone were only MAG10  and MAG11 . Among these MAGs, genes encoding rDsrA were identified in Gammaproteobacteria, Alphaproteobacteria, and Chlorobia. Besides, the abundance of MAGs belonging to Alphaproteobacteria in FL samples was higher than that in PA samples. Moreover, other SOB of Bacteroidia, Chloroflexota, and archaeal MAG185 (Thermoproteota) were mainly distributed in anoxic zone II. Dominant SRB MAGs were affiliated with Desulfobacterota (7), Planctomycetota (4), AABM5-125-24 (2), JdFR-76 (1), Myxococcota (2), Krumholzibacteriota (1), and Abyssubacteria (1). All SRB MAGs from this study were enriched in anoxic zone II.From the 14 metagenomic samples in the SYBH, a total of 108 non-redundant metagenome-assembled genomes (MAGs) were recovered, representing 26 known phyla . MAGs being MAGs . The arcPrevious phylogenetic inferences suggested that the candidate phyla AABM5-125-24  and JdFR-76 (MAG371) might be affiliated with the Fibrobacteres-Chlorobi-Bacteroidetes (FCB) superphylum, and the JdFR-76 was previously affiliated with KSB1 , 41. Botsat, aprAB, and dsrAB) were present in MAG371, whereas genomes of JdFR-76 collected from other environments lacked these genes. Genes acsA and ackA, encoding acetyl-CoA synthetase and acetate kinase, were key genes related to acetate metabolism . The complete dissimilatory sulfate reduction pathway was present in MAGs of AABM5-125-24 clade II, which was absent in the clade I. acsA was found in both clades of AABM5-125-24, while ackA existed only in the clade II. In addition, MAGs in AABM5-125-24 contained most genes associated with denitrification  and dissimilatory nitrate reduction .The metabolic functions of MAGs from candidate phyla JdFR-76 and AABM5-125-24 were further investigated . The gentabolism , 44. BotThe sharp redox gradient and anoxia condition resulted in high concentrations of sulfates and sulfides in the water column of the SYBH, which indicated that SRB and SOB might be core members in this environment , 46. TheThiopontia belonging to Gammaproteobacteria , and no novel candidate phylum has been discovered among these MAGs  and SRB (Desulfobacterota and Planctomycetota) MAGs was similar with the results of 16S rRNA genes/transcripts analyses. As a poorly studied SOB in Gammaproteobacteria, except for the Sox system, MAG79  also encodes narGHI in the denitrification pathway, which is consistent with the MAGs assigned to Pseudomonadales in the sediment of Siberian soda lake, reflecting the coupling mechanism of sulfur oxidation and nitrate reduction under anaerobic environments  was also determined on-site using a spectrophotometer at 670 nm after color development  were obtained by Niskin bottles in the SYBH  during 24–25 October 2019. To compare the 16S rRNA gene abundance and diversity between microbial communities with FL and PA lifestyles, the seawater samples (1 L) in Niskin bottles from each sampling depth were pooled and subsequently filtered through 3 µm  and 0.22 µm  polycarbonate membranes. Microbial samples collected on 3 µm filters were designated as PA microbes, while samples collected on 0.22 µm filters were defined as FL microbes. Seawater samples from 0, 30, 50, 90, 120, 140, and 170 m were chosen for further metagenomic sequencing . Fifty lelopment . Sampleselopment . Sulfateelopment .DNA and RNA for amplicon sequencing were extracted by the DNeasy PowerSoil Pro Kit  and RNeasy PowerSoil Total RNA Kit  according to the manufacturer’s instructions, respectively. The DNA and RNA samples were sequenced by Majorbio Bio-pharm Technology Co., Ltd. . The V4 regions of the 16S rRNA genes/transcripts were amplified using the primer pairs 515F and 806R  and thenThe paired-end reads generated from the Illumina Miseq PE300 platform (MiSeq Reagent Kit v3) were processed by trimming the barcodes and primers and then merged using Fast Length Adjustment of Short Reads (FLASH version 1.2.11) . Reads sHigh-quality clean data were obtained after removing the low-quality sequences and adaptors in the raw metagenomic sequencing data by fastp . For eacContigs from each sample were used for metagenome binning with MetaWRAP integrated with MaxBin2 (model 2.2.4), metaBAT2 (model 2.12.1), and CONCOCT (model 0.4.0) –103. MdsrA gene, after multiple sequence alignment by MAFFT (version 7) and trimming by TrimAl (version 1.2)  and AABM5-125-24 were downloaded from GTDB . A phyloion 1.2) , 115, ition 1.2) , and theion 1.2) .


Additionally, myrcene, icariin, and tenuigenin prevented the nod-like receptor family pyrin domain-containing 3 inflammasome and microglial neurotoxicity, while a-cyperone, citronellol, nobiletin, and taurine prevented NADPH oxidase 2 and nuclear factor kappa B activation. Furthermore, other nutraceuticals like plantamajoside, swertiamarin, urolithin A, kurarinone, Daphne genkwa flower, and Boswellia serrata extracts showed promising neuroprotection in treating Parkinson’s disease. In Huntington’s disease, elderberry, curcumin, iresine celosia, Schisandra chinensis, gintonin, and pomiferin showed promising results against microglial activation and improved patient symptoms. Meanwhile, linolenic acid, resveratrol, Huperzia serrata, icariin, and baicalein protected against activated macrophages and microglia in experimental autoimmune encephalomyelitis and multiple sclerosis. Additionally, emodin, esters of gallic and rosmarinic acids, Agathisflavone, and sinomenine offered promising multiple sclerosis treatments. This review highlights the therapeutic potential of using nutraceuticals to treat neurodegenerative diseases involving microglial-related pathways.The pathophysiology of different neurodegenerative illnesses is significantly influenced by the polarization regulation of microglia and macrophages. Traditional classifications of macrophage phenotypes include the pro-inflammatory M1 and the anti-inflammatory M2 phenotypes. Numerous studies demonstrated dynamic non-coding RNA modifications, which are catalyzed by microglia-induced neuroinflammation. Different nutraceuticals focus on the polarization of M1/M2 phenotypes of microglia and macrophages, offering a potent defense against neurodegeneration. Caeminaxin A, curcumin, aromatic-turmerone, myricetin, aurantiamide, 3,6′-disinapoylsucrose, and resveratrol reduced M1 microglial inflammatory markers while increased M2 indicators in Alzheimer’s disease. Amyloid beta-induced microglial M1 activation was suppressed by andrographolide, sulforaphane, triptolide, xanthoceraside, piperlongumine, and novel plant extracts which also prevented microglia-mediated necroptosis and apoptosis. Asarone, galangin, baicalein, and  Microglia are specialized macrophages, that constitute the primary central nervous system (CNS) innate immune cells. They are the first glial cells that enter the CNS during prenatal development. They represent approximately 10%–15% of all CNS cells. Microglia control CNS homeostasis at rest by eliminating pathogens and cell residue through phagocytic activity. Resting microglia become activated and generate inflammatory mediators, thus providing neurons protection and defense against infections. In addition to supporting the CNS, they are linked to the development of many inflammatory and neurodegenerative disorders . Dependiß (TGF-β), IL-1, and IL-4, which suppress inflammatory responses, encourage repair and regeneration and have neuroprotective effects , NOD-like receptors, toll-like receptors (TLRs), and multiple scavenger receptors. They are activated by interferon-gamma (IFN-γ) and lipopolysaccharide (LPS). After activation, microglial cells are motivated to release pro-inflammatory factors with neurotoxic effects. Furthermore, IFN-γ stimulates the transcription factor signal transducer and activator of transcription 1 (STAT1) via Janus kinase (JAK)1/JAK2 signaling and stimulates the production of reactive oxygen species (ROS) and nitric oxide (NO) in addition to pro-inflammatory chemotactic factors and cytokines, like tumor necrosis factor-alpha (TNF-α), interleukin-23 (IL-23), IL-2, IL-1β, C-X-C motif chemokine ligand-9 (CXCL9), and CXCL10 . Activat effects . The impNon-coding RNAs (ncRNAs) are a diverse class of ncRNA transcripts that do not play any role in protein coding. Nevertheless, it has been proven that they are key factors in many biological processes, including disease progression . RegulatncRNAs play key roles at the post-transcriptional level in different pathways and diseases, including neurodegenerative disorders  Table 1.a-synuclein (α-syn) nucleoprotein. As a result, microglia may exhibit impaired autophagy and inflammatory reactions. Consequently, this provides a new treatment target for PD (Metastatic-associated lung adenocarcinoma transcript 1 (MALAT1), also known as the nuclear-enriched abundant transcript 2, is a lncRNA that is a crucial factor in the pathogenesis of Parkinson’s disease (PD) . PD onset for PD . Due to In the CNS, miRNA-124 is highly expressed and perfectly conserved . It playNeurodegenerative disorders such as AD, PD, Huntington’s disease (HD), amyotrophic lateral sclerosis, and multiple sclerosis (MS) are distinguished by neurodegeneration in particular parts of the CNS and share very similar pathophysiological processes . MicroglIn various neurodegenerative disorders, neuroinflammation caused by microglia, macrophages that are found in the brain, is a prevalent hallmark, and various inflammatory mediators generated by M1 microglia have a role in the development of neurodegeneration and myelin damage in these diseases. Nevertheless, M2 microglia activation is required for tissue maintenance and repair . MultiplAlzheimer’s disease is the prevailing type of dementia, associated with damaged locomotor ability, thinking, judgment ability, increasing memory loss, and cognitive decline . It is dIn vivo, amyloid plaques can attract and stimulate microglia cells , which is enhanced by presenilin-1 (PS1) . In vivoia cells , while ipeptides .Furthermore, neuroinflammation has an important role in the etiology of AD . In the Microglia also can respond to potentially damaging stimuli such as misfolded Aβ proteins . M2 micrAt the outset of Aβ pathology, the microglia that encircle the Aβ plaques are typical of the neuroprotective phenotype, identified as Ym1. Thus, Microglia perform an important role in reducing the accumulation of potentially neurotoxic Aβ aggregates while also protecting neurons from localized toxicity . HoweverPro-inflammatory cytokines reduce microglia phagocytic activity and additionally are likely to shift microglia into pro-inflammatory phenotypes. Consequently, pro-inflammatory microglia promote tau phosphorylation . FurtherThe dynamic nature of microglial activation involves constant transitions between different phenotypes. In a study conducted by Fan et al., it was suggested that microglial activation in AD may exhibit two distinct peaks . The firThe impact of different natural products and nutraceuticals on AD through regulation of M1/M2 microglia polarization is presented in Origanum majorana L. is an aromatic plant used to treat various diseases in folk medicine, including intestinal antispasmodic, intestinal hypertension, allergies, respiratory infections, diabetes, and stomach pain  in mouse brain tissue  (tipation . Chinesetiflorum . The mai20H22O9) . TSG cau20H22O9) .Myricaceae, Polygonaceae, Primulaceae, Pinaceae, and Anacardiaceae. Previous studies have demonstrated that myricetin has various pharmacological effects, including its anticancer, anti-diabetic, anti-obesity, cardiovascular, anti-osteoporosis, anti-inflammatory, and hepatoprotective (in vitro AD model (BV-2 microglia cells stimulated with Aβ25–35), myricetin prevented the hyperactivation of microglia and the conversion from the M2 to the M1 type and inhibited NLRP3 activation by inhibiting the activation of the P38 MAPK signaling pathway. In 3 × Tg-AD mice, myricetin reduced microglia hyperactivation, encouraged microglia conversion from M1 type to M2 type, and effectively reduced neuroinflammation through reduced IL-1β, TNF-α, and IL-6 expression, whereas increased IL-4 and IL-10. In addition, it could significantly enhance memory loss, spatial learning capacity, Aβ plaque formation, and neuronal and synaptic damage . It has a rich history of traditional use as a food and herbal medicine in Asia and has emerged as a highly promising phytochemical candidate for treating AD owing to its notable anti-inflammatory and immunomodulatory properties  as demonstrated in the in vivo studies  pathway with a wide range of biological and pharmacological actions, including anti-inflammatory and antioxidant properties . An in vechanism . Furtheresponses .Tripterygium wilfordii, is well-known for its medicinal promise in the treatment of inflammatory and autoimmune conditions such as systemic lupus erythematosus, rheumatoid arthritis, and nephrotic syndrome. Additionally, multiple in vitro studies have shown that triptolide at 5 and 25 μg/mL doses successfully prevented neuronal death caused by Aβ1-40 in cultures of primary hippocampal neurons and microglial cells (in vivo study using an AD mouse model (APP/PS1 mice) discovered that triptolide  effectively reduced TNF-α and IL-1β production and restricted the activation of microglia towards the pro-inflammatory M1 state. These results were obtained by inhibiting the phosphorylation of the MAPK signaling pathway  significantly restricted the generation of inflammatory cytokines and the activation of microglia towards the pro-inflammatory M1 state in the hippocampus of mice injected with Aβ1-42. Blocking the translocation of NFκB p50 and p65 into the nucleus and suppressing the phosphorylation of MAPK signaling pathways is considered the main xanthoceraside inhibitory mechanism , which is native to southern India and Southeast Asia, has piqued the interest of pharmacologists due to its possible medicinal qualities  and A1 neurotoxic astrocyte activation. Lewy bodies (LBs), which are primarily composed of filamentous he brain . Throughhe brain . Dopamintrocytes . Dopaminth in PD . Furtherth in PD .a-syn in dopaminergic cells has been associated with increased amounts of ROS. This implies that a-syn may contribute to oxidative damage by influencing mitochondrial activity. Overexpression of mutant a-syn has been demonstrated to make dopaminergic neurons more susceptible to mitochondrial toxins such as 6-hydroxydopamine (6-OHDA) and mitochondrial processing peptidases 1-methyl-4-phenylpyridinium ion (MPP+), leading to elevated protein carbonylation and lipid peroxidation. These results demonstrate that a-syn may regulate oxidative stress and mitochondrial dysfunction in dopaminergic cells . Furthermore, a-Cyperone substantially reduced microglia activation and the production of many neuroinflammatory factors, including IL-6, IL-1β, TNF-α, iNOS, ROS, and COX-2  have previously been investigated for their anti-inflammatory and antioxidant properties  orally over 3 days. LPS (4 mg/kg) intraperitoneal injection induced neuroinflammation 1 hour after the initial oral therapy. GFE inhibited the production of inflammatory factors  in microglial and primary glial cells, resulting in significant anti-inflammatory and neuroprotective effects. It also stimulated phagocytosis in microglia and boosted the expression of neuroprotective markers (Arg-1 and brain-derived neurotrophic factor mRNA) in primary glial cells, emphasizing its potential as a PD treatment  is a monoterpene alcohol found in the essential oils of various plants that are used in cooking and traditional medicine . ROT wasand mTOR .Boswellia serrata , has been employed in religious, cultural, and medical traditions  was given for 2 weeks, and Western blotting was used to identify neuroprotective compounds. In Phase II, to explore the neuroprotective effects of Boswellia extract on ROT neurotoxicity, four groups were studied: one as a control, one receiving oral Boswellia extract group, one receiving ROT , and one receiving both Boswellia extract and ROT. Boswellia enhanced AMPK phosphorylation, decreased p-mTOR and p-α-synuclein in the striatum, and raised the expression of Beclin1 and brain-derived neurotrophic factor. Boswellia reduced dopaminergic neuron loss, microglial activation, and formance .Sophora flavescens  did not affect the generation of pro-inflammatory cytokines caused by LPS. However, it inhibited the elongated changes in the morphology of M1 microglia generated by LPS by lowering monocyte chemotactic protein-1 (MCP-1) expression. An in vivo study using transgenic Tg (Apo-E:eGFP) zebrafish infected with E. coli found that at the same dosage, a-asarone reduced the proportion of M1 microglia and the number of microglial tips. These findings emphasize a-asarone’s neuroprotective potential, specifically its potential to modulate inflammation and morphological alterations in microglia . This molecule was widely investigated and has been shown to stimulate PPAR-γ, a receptor involved in cellular process regulation. Galangin suppressed inflammatory responses of M1 microglia in tests employing BV-2 cells treated with LPS. This was accomplished by activating the Nrf2/cAMP response element-binding protein (CREB) signaling pathway at doses ranging from 10 to 50 μM , has the potential to be used as a treatment for inflammatory conditions. Baicalein significantly suppressed the expression of iNOS in experiments involving BV-2 cells and primary microglia activated with LPS and IFN-γ. The effect mentioned was obtained by blocking the MAPKs and NFκB signaling pathways  showed neuroprotective properties against the neurotoxicity induced by primary microglia activated with LPS. Additional research into the underlying mechanisms showed that icariin, in a manner dependent on the dosage used, suppressed the JNK, p38 MAPK, and NFκB signaling pathways by inhibiting the production of ROS and pro-inflammatory cytokines, including IL-6, TNF-α, and IL-1β in M1-activated microglia  in primary rat midbrain neuroglia co-cultures . It has neuroprotective benefits such as antioxidant, anti-aging, and anti-inflammatory capabilities. An in vitro study using different doses of tenuigenin  revealed a dose-dependent decrease in LPS-induced microglial M1 activation. The activation of the Nrf2/HO-1 pathway was directly linked to this neuroprotective significance  gave significant protection to DA neurons located in the SNpc. Nobiletin has also been shown to decrease M1 microglia activation, lowering inflammatory cytokines release (Nobiletin is a flavonoid compound in Tangerine peel (Citri reticulatae pericarpium). Numerous studies have demonstrated its antioxidant, anti-atherogenic, and anti-inflammatory qualities. Nobiletin administration at various doses (range from 1 to 50 μM) significantly suppressed the generation of pro-inflammatory cytokines, including IL-1β and TNF-α in a dose-dependent manner in a previous  nucleus . One not nucleus . Further release .in vivo research employing a maneb and paraquat-induced model of PD. The researchers discovered that mice who received maneb and paraquat suffered from severe dopaminergic neurotoxicity and motor impairments, which were considerably relieved by taurine administration. Notably, taurine reduced the accumulation of a-syn, a characteristic protein linked with PD, in maneb and paraquat-intoxicated rats  located in the midbrain region on the right side. The researchers discovered that Plantamajoside substantially alleviated the behavioral impairment caused by LPS in Parkinson’s disease rats. In addition, Plantamajoside has been shown to reduce SN damage produced by LPS and to decrease microglial cell over-activation in PD rats. Further investigation revealed that Plantamajoside exerted its effects in both PD mice and BV-2 cells by suppressing the activation of the histone deacetylase-2 (HDAC2)/MAPK pathway. Notably, Plantamajoside demonstrated its ability to reduce microglia polarization by inhibiting HDAC2  substantially inhibited the activation of microglial and astroglial cells in the SN. Furthermore, swertiamarin reduced ROT-induced a-syn overexpression in the striatum and the SN. Notably, swertiamarin improved motor impairment caused by ROT-induced neurotoxicity and reduced the loss of dopaminergic neurons in the nigrostriatal pathway. These data suggest that swertiamarin has tremendous promise as an additional treatment for PD  of chromosome 4 and mutated to cause the disease . The CAGThe impact of different natural products and nutraceuticals on HD through regulation of M1/M2 microglia polarization is presented in Maclura pomifera fruits are prenylated isoflavones, osajin, and pomiferin  is used for a variety of health problems, including respiratory, hepatic, gastrointestinal, and stress-related diseases. Additionally, it may help with menopausal symptoms, diabetes, polycystic ovarian syndrome, obesity, hepatitis, cognitive function, physical stamina, and as a preventative step for estrogen-dependent malignancies  before or after 3-NPA therapy, Neuroprotective effects were investigated both before and after therapy, with pre-treatment being more beneficial. Schisandra chinensis extract decreased inflammatory markers, lesion area, cell death, and microglial activation. It inhibited the MAPK and NFκB signaling pathways while promoting the Nrf-2 pathway. Schizandrin and gomisin A, two Schisandra chinensis extract ingredients, reduced 3-NPA-induced brain damage and mortality  was performed in recent investigations. The results showed that rats given elderberry had significantly decreased microgliosis. The study concluded that elderberry’s antioxidant action increased GSH concentration and reduced ROS production in the tissue that had been damaged. Additionally, by reducing microglia’s production of TNF-α, this study sheds new illumination on using elderberry as neuroprotective medicine to treat HD by improving neuron survival due to microglial inactivation .in vivo study in YAC128 HD mice, solid lipid nanoparticles of curcumin reduced HD-like neurodegeneration. By boosting glutathione levels and reducing superoxide dismutase activity, solid lipid nanoparticles of curcumin greatly reduced protein carbonyl formation, lipid peroxidation, ROS levels, and mitochondrial swelling  and neurodegeneration are the two pathological hallmarks of MS . In the ma cells . Microglma cells . Using ama cells .The presence of myelin and axonal remains, the elevated levels of major histocompatibility complex-II and co-stimulatory molecules, and the release of several inflammatory and neurotoxic mediators through activated macrophages and microglia in MS and experimental autoimmune encephalomyelitis (EAE) lesions are all consistent findings. Additionally, studies using bone marrow chimeras demonstrated that the activation and proliferation of microglia preceded the beginning of EAE and that suppressing their activation prevents the growth and maintenance of inflammatory lesions in the CNS. It is important to observe that MS patients have active microglia clusters dispersed throughout their generally normal-looking white matter .The impact of different natural products and nutraceuticals on MS through regulation of M1/M2 microglia polarization is presented in + T cells has neuroprotective effects , a chemical derived from herbs such as rhubarb, has a neuroprotective effect . Emodin  effects . In vitrh emodin . COX-2 ih emodin . Treatmeh emodin . Furtherh emodin . Howeverh emodin .in vivo study of its effects on encephalitogenic cells , a secondary metabolite abundant in many plants, nuts, and fruits, has been associated with anti-inflammatory activities. GA’s anti-inflammatory activities have been attributed to its capacity to interfere with MAPK and NFκB signaling, restricting immune cell activation and effector qualities . The pheic cells  PEGA lowin vivo and in vitro studies   .in vivo study, and greatly reduced inflammatory responses in the CNS and peripheral system, by affecting microglia  while significantly downregulating the mRNA expression of genes related to pro-inflammatory microglia (ation H. . It has icroglia .in vitro, there were considerably fewer NeuN + neurons than in the control group (Icariin is a naturally present flavonoid glucoside that has been identified in the family of Epimedium that is frequently utilized in traditional Chinese medicine . Degenerol group . Glial col group .S. baicalensis Georgi, a traditional Chinese medicine, is called baicalein. It exhibits antioxidant, anti-inflammatory, anticancer, antiviral, and neuroprotective pharmacological activities. (in vivo and in vitro studies, the number of microglia and macrophages that were both iNOS- and Iba-1-positive decreased considerably after baicalein therapy. In addition, resulting from baicalein treatment, Iba-1, and iNOS expression significantly lowered in comparison to the EAE model group. Nonetheless, qRT-PCR was applied to identify the expression of M1 inflammatory markers in each group’s mouse spinal cord. The outcomes demonstrated that animals receiving baicalein or dexamethasone had significantly lower mRNA levels of iNOS, CD86, IL-12p35, IL-12p40, and IL-18 in their spinal cords than the EAE model group (The primary flavonoid found in ivities. . Iba-1 iel group .Concerning human data, a few randomized clinical trials have been conducted for neurodegenerative disorders after natural product administration. Only a small number of clinical research has looked at the impact of curcumin on human cognitive performance in AD, compared with animal studies. The findings of these investigations are contradictory. Some studies show no cognitive enhancing benefits of curcumin , whilst Regarding resveratrol, a phase II clinical trial evidenced the safety and well-tolerated effects of 500 mg orally once daily resveratrol on mild to moderate AD patients for 52 weeks, with no observed effects on AD biomarkers . HoweverH. serrata appears to positively impact the restoration of cognitive function, performing everyday tasks, and overall clinical assessment (a-Linolenic acid is associated with improved magnetic resonance imaging lesions activity in 87 multiple sclerosis patients (Furtherly, in patients with AD, sessment . In addisessment . A prosppatients .D. cochinchinensis stemwood and O. majorana L. Microglia-mediated apoptosis was prohibited because of andrographolide, sulforaphane, triptolide, xanthoceraside, and piperlongumine inhibition of Aβ-induced microglial M1 activation. In PD, urolithin A, kurarinone, asarone, galangin, baicalein, and mangostin hindered ROS and pro-inflammatory cytokines in M1-activated microglia. Further, icariin and tenuigenin suppressed microglial neurotoxicity via inhibiting NLRP3 inflammasome. Likewise, citronellol, myrcene, a-cyperone, nobiletin, taurine, plantamajoside, and swertiamarin showed neuroprotective effects in Parkinson’s. Similarly, elderberry, curcumin, iresine celosia, Schisandra chinensis, gintonin, and pomiferin showed promising results in improved symptoms in HD patients. In MS, linolenic acid, resveratrol, H. serrata, icariin, and baicalein are potent inhibitors of microglial activation, in addition to emodin, PEGA, FAB, sinomenine, and PERA, which all showed improved disease outcomes. Therefore, additional studies are required to resolve the significant enigma surrounding microglia polarization. It is important to note that these studies in the particular context of neurodegenerative illnesses clearly demand additional research. Moreover, several regulators of the microglia phenotype, which connects cytokine and signal pathways, may be linked to one another. It is still unknown how other risk genes affect microglia polarization in neurodegenerative disorders. Finally, the available findings encourage incorporating the natural product in treatment guidelines for neurodegenerative diseases, but more proof from randomized controlled studies on their effectiveness is highly warranted.In our review, we emphasized the role and polarization control of microglia in the pathophysiology of neurodegenerative disorders and briefly introduced the function and phenotype of microglia to explore prospective therapeutic approaches. Transcription factors, receptors, and cytokines are merely a few examples of the numerous categories that modulate microglia polarization from M1 to M2. TNF-α, ILs, CXCLs, ROS, and NO, which have pro-inflammatory and neurotoxic effects, are released when the M1 phenotype is activated by IFN- γ, LPS, and TLR pathways. Meanwhile, M2 microglia are activated by different types of ILs to release abrineurin and anti-inflammatory cytokines, such as TGF-β, which suppress inflammatory responses and have neuroprotective effects. NcRNAs, such as miRNA-155, miR-23b-3p, and circHIPK3, seem to represent key factors in shifting microglia from M1 to M2. Consequently, inhibiting M1 microglia and promoting M2 microglial activation is required for neurodegenerative cure. In AD, curcumin, aromatic-turmerone, caeminaxin A, myricetin, aurantiamide, 3,6′-disinapoylsucrose, and resveratrol restored the normal balance of M1/M2 markers in microglia, which was also achieved by plant extracts of


Nuclear receptors (NRs) constitute a superfamily of ligand-activated transcription factors with a paramount role in ubiquitous physiological functions such as metabolism, growth, and reproduction. Owing to their physiological role and druggability, NRs are deemed attractive and valid targets for medicinal chemists. Pentacyclic triterpenes (PTs) represent one of the most important phytochemical classes present in higher plants, where oleanolic acid (OA) is the most studied PTs representative owing to its multitude of biological activities against cancer, inflammation, diabetes, and liver injury. PTs possess a lipophilic skeleton that imitates the NRs endogenous ligands. Herein, we report a literature overview on the modulation of metabolic NRs by OA and its semi-synthetic derivatives, highlighting their health benefits and potential therapeutic applications. Indeed, OA exhibited varying pharmacological effects on FXR, PPAR, LXR, RXR, PXR, and ROR in a tissue-specific manner. Owing to these NRs modulation, OA showed prominent hepatoprotective properties comparable to ursodeoxycholic acid (UDCA) in a bile duct ligation mice model and antiatherosclerosis effect as simvastatin in a model of New Zealand white (NZW) rabbits. It also demonstrated a great promise in alleviating non-alcoholic steatohepatitis (NASH) and liver fibrosis, attenuated alpha-naphthol isothiocyanate (ANIT)-induced cholestatic liver injury, and controlled blood glucose levels, making it a key player in the therapy of metabolic diseases. We also compiled OA semi-synthetic derivatives and explored their synthetic pathways and pharmacological effects on NRs, showcasing their structure-activity relationship (SAR). To the best of our knowledge, this is the first review article to highlight OA activity in terms of NRs modulation. Nuclear receptors (NRs) are ligand-activated transcription factors encoded by 48 genes in humans and classified into seven subfamilies . They arMost NRs function as dimers, either homodimers, such as steroid receptors including GR, androgen receptors , mineralocorticoid receptors , and estrogen receptors  ,14, or hThe typical structure of NRs is shown in It is noteworthy that the resulting NR modulation occurs in a tissue-specific manner depending on the type of recruited cofactor, which makes it more complex to obtain a selective NR modulator. For example, tamoxifen works as an ER antagonist in breast tissue but as an agonist in the uterus and bone, which may trigger uterus cancer. A better selective modulator is raloxifene, which is an agonist of bone ER but an antagonist for both breast and uterus ER, making it a safer choice with better clinical outcomes than tamoxifen for hormonal breast cancer therapy ,2,4.Natural products are privileged structures and rich sources of approved pharmaceutical products ,23. PentCelastrus orbicalatus Thunb., was identified as an effective and selective FXR agonist over other metabolic NRs with hepatoprotective properties against paracetamol-induced injury. Indeed, hedragonic acid was co-crystalized with FXR (protein data bank accession code: 5WZX) [De facto, many natural products of both plant and marine origin have been proven effective with respect to NRs modulation ,50,51,52e: 5WZX) . Its cone: 5WZX) ,59. Celae: 5WZX) . OA and In a similar vein, among PTs, OA garnered the highest interest as a ligand of nuclear receptors with potential application in the treatment of metabolic diseases. This provoked us to compile and summarize the previous results in a review article that would be a cornerstone for future studies on NRs modulation by PTs and OA as a representative. There are different reviews on OA highlighting its ubiquitous bioactivities ,39,61; hWe used the keywords pentacyclic triterpenes or oleanolic acid and nuclear receptors for our search in the Web of Science database. This resulted in approximately 110 research articles, review articles, and patents, of which 70 were considered for this review. The other articles were excluded as they mainly focused on other types of receptors or other PTs.FXR is implicated in bile acid, lipid, and glucose homeostasis, and hepatic inflammation, regeneration, and fibrosis, and is widely distributed in organs such as the liver, kidney, intestinal tract, and adrenal gland ,63,64,65FXR expression is found to be decreased in human intestinal tumors due to the promotion of Wnt signaling, while the reactivation of FXR in a xenograft model via adenoviral infection induced cytotoxicity through the induction of apoptosis and inhibition of proinflammatory and antiapoptotic genes . On the The first report relating OA with FXR was disclosed by Liu and Wong in 2010 . They suAnother interesting work showcased the effect of OA on mice models with obstructive cholestasis by bile duct ligation (BDL) . Basical1–4. These esters were afforded through reacting free OA or protected benzyl OA ester with the appropriate activated acid, followed by catalytic hydrogenolysis for deprotection. In human embryonic kidney 293T cells, compounds 1–4 suppressed FXR transactivation in a concentration-dependent manner with respective IC50 19.41, 7.03, 13.74, and 9.03 μM as settled by a dual-luciferase reporter assay. This is in agreement with their predicted docking energy values pKi  for 24 h . BasicalAnother study explored the underlying mechanism of OA in alleviating alpha-naphthol isothiocyanate (ANIT)-induced cholestatic liver damage in rats instead of BDL ,80. As aThe same research group conducted an extensive mechanistic study . They coBy virtue of the cellular context effect of NRs modulators, Fallon et al. studied the effect of hederagenin and OA on FXR in human colonic epithelial cells T84 in comparison to the GW4064, a synthetic FXR agonist. Surprisingly, they found that both hederagenin and OA compounds do not have direct agonistic FXR activity in this model. Having said that, they induced the overexpression of FXR mRNA and protein and upregulated GW4064-induced FXR signaling. This opens the way for the potential application of OA in colon cancer and secretory diarrheas .t-butylmethylsilyl (TBS). Olefin of the double-protected derivative was oxidized by meta-chloroperoxybenzoic acid (m-CPBA), affording a 12-oxo derivative. The latter was reduced by sodium borohydride (NaBH4) to a mixture of 12β- and 12α-hydroxyl derivatives in ca. 2:1 ratio. The 12β-OH compound was reacted with the corresponding carboxylic acids in the presence of N,N’-diisopropylcarbodiimide (DIC) or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) and 4-dimethylaminopyridine (DMAP), followed by deprotection of TBS and Bn groups with BF3.Et2O and Pd/C hydrogenolysis, respectively, to furnish a series of 12-OA alkyl esters. Various aliphatic and aromatic substituents were used with different polarities.The same research group of Fang reported a class of 12β-oxygenated oleanolic alkyl esters with FXR modulation properties . In brie5 with an acetopropionyl group and 6 with a 4-acetobutanoyl group of the 12-O-alkanoic acid esters are pronounced FXR antagonists opposing the CDCA effect without observable cytotoxicity at 10 µM  against FXR and inconsiderable antagonism (10–20%) against LXRα and PPARα.In HEK293T cells, screening of the synthesized series at 10 μM showed that compound at 10 µM . Compounmulation . To asse6 efficiently reversed the induction of small heterodimeric partner (SHP) and BSEP by 50 μM of the endogenous agonist CDCA without significant effect on sterol regulatory element-binding protein-1c (SREBP-1c and CYP7A1). This is controversial due to the discrepancy with the effect of the parent OA, which suppresses CYP7A1 expression [6 clearly hindered SHP, BSEP, and CYP7A1 at 10 μM but did not affect the expression of SREBP-1c, revealing a unique FXR downstream regulation.Transcription of FXR downstream genes was then evaluated in HepG2 cells. An amount of 10 μM of pression . Intrigu6 on FXR-controlled genes that regulate blood glucose level and gluconeogenesis [6 significantly decreased fasting and non-fasting blood glucose levels. Concomitantly, 6 improved glucose tolerance and insulin sensitivity and lowered HbA1c levels [Upon exploring the possible effect of ogenesis , it was c levels .O-β-aspartyl or 12β-O-γ-glutamyl moiety trying to enhance the affinity of compound 6 towards FXR-LBD as shown for compounds 7–10 [6 terminal chain, thus aimed at using more branched chains. The authors adopted similar synthetic procedures for OA 12β-OH esterification that were used for the synthesis of compound 6, as mentioned above. Among the new series, compound 10 with S-γ-glutamyl moiety possesses the highest antagonism to FXR with IC50 0.44 µM in HEK293T cells. Using the R-γ-glutamyl chain lowered the activity . OA-bearing S-aspartyl chain, compound 7, is slightly less active than 10 with IC50 0.95 µM. Protection of the terminal amino- group by tert-butyloxycarbonyl (Boc) and the terminal carboxyl with tert-butyl (t-Bu) group is crucial for activity; for example, compound 8 with both free terminal groups dramatically lost activity. In general, OA derivatives bearing (S) configuration side chains outperform those bearing (R) configuration ones, and glutamyl derivatives outperform aspartyl derivatives. In a similar fashion to compound 6, 10 showed favorable selectivity against FXR with much less effect on LXRα and PPARα and no effect on other tested metabolic NRs. Consequently, 10 significantly inhibited the expression of PEPCK and G6Pase at 1 and 10 µM concentrations. In hepatic stellate cell line LX-2, compound 10 lowered mRNA expressions of liver fibrosis marker genes, including collagen type I α-1, actin-α-2, transforming growth factor β-1, connective tissue growth factor, and integrin α-V, whereas guggulsterone lowered expression of only collagen type I α-1, actin-α-2.In continuation of their work, Fang’s group designed and synthesized more OA hybrids with 12β-nds 7–10 ,84. The 10 for two weeks effectively decreased the levels of AST, ALT, TBA, and TBiL, which means less liver fibrosis. Liver histopathology using hematoxylin and eosin (H&E) staining showed that compound 10 intake alleviated bile duct hyperplasia and parenchymal necrosis that accompany BDL. The collagen-specific Sirius red staining showed less collagen accumulation in the compound 10 treated group. These in vitro data of reducing hepatic fibrosis markers were further validated in vivo. Interestingly, in a NASH mice model, the titled compound reduced intrahepatic steatosis and hepatic lobular inflammation, indicating less liver fat accumulation. This is accompanied by a reduction in mRNA expression of fibrosis marker genes. Collectively, compound 10 is an OA derivative and a promising FXR modulator with NASH and diabetes therapeutic potential [In a bile duct ligation (BDL) rat model, the oral administration of compound otential .Collectively, OA reprograms the liver to protect against hepatotoxic chemicals, but its intake should be with care since its high doses are reported to be hepatotoxic and can develop cholestatic liver injury ,86,87. IPPARs comprise three different subtypes, α, β, and γ, that orchestrate lipid homeostasis and insulin sensitivity, making them attractive targets for controlling metabolic syndrome and diabetes ,90,91,92officinalis extract [In 2005, Huang et al. revealed that OA is a concentration-dependent PPARα activator through luciferase reporter assay in human embryonic kidney 293 cells, unlike ursolic acid and gallic acid. The OA-induced activation of PPARα was demolished upon adding a selective PPARα antagonist MK-886 . The ant extract ,98. Such extract .The generation of a pharmacophore model of PPARγ partial agonists using the Chinese natural product database led to the identification of OA as a PPARγ modulator . Chios mThe synthetic derivative of oleanolic acid, 2-Cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO) , is endoLXR  are naturally activated by oxysterols and implicated in glucose homeostasis, lipid homeostasis, cancer, atherosclerosis, and NASH ,105. LXROA was identified as an LXR antagonist, which is similar to the effect of its congener ursolic acid ,109. In On the contrary, in rats, another cellular model, OA oral administration promoted mRNA expression and protein levels of liver detoxification enzymes, including hydroxylation, glucuronidation, sulfation, and glutathione conjugation enzymes. This helped protect the liver from bile acids-induced toxicity in BDL rats. OA hepatoprotective effect is basically attributed to increasing the mRNA expression of LXRα and other transcription factors. At the protein level, not only LXRα was elevated but also PXR, RAR, and VDR .RXR, with three subtypes  expression, including the two major types CYP3A4 and CYP2B6 ,114. AddOA was identified as a PXR/CAR modulator that competes with the strong agonist rifampicin. In this regard, the possible increase in CYP3A4-mediated drug metabolism by rifampicin could be reversed by OA, which reduced the inducible forms of CYP3A4 and CYP2B6 mRNA and protein in the presence of rifampicin. OA significantly attenuated rifampicin-isoniazide-induced cytotoxicity and enhanced glutathione concentration HepaRG Cells at ten µM in comparison with OA-untreated cells . Hence, Interestingly, Lin et al. assessed the OA effect on PXR transcriptional activation of genes implicated in lipogenesis, including S14 and SCD. A reporter assay showed that activation of promoters S14 and SCD by rifampicin could be efficiently reversed by OA. mRNA and protein expression of S14, FAS, SCD, ACC, ACLY, and FAE genes was reduced by OA even in the presence of rifampicin. HepaRG cells staining Oil Red O and observation by phase-contrast microscope revealed rifampicin-induced lipid accumulation, which was remarkably reduced by treatment with OA .ROR controls Th17 lymphocyte differentiation, which, in turn, secrets interleukins (IL) that fight pathogens. However, the overactivation of Th17 cells is observed in different autoimmune disorders such as multiple sclerosis, psoriasis, and rheumatoid arthritis, which confers a potential role in controlling these diseases to ROR modulation . Of inteFinding selective modulators for NRs with efficient health benefits and minimal deleterious effects is like finding a needle in a haystack and is a real challenge in the hard-fought battle against metabolic syndromes that are directly related to heart and cardiovascular disease. Befitting their pivotal role in physiological homeostasis, and also their druggability, we aimed to review NRs with respect to modulation by one of the most prominent phytochemicals, OA. Indeed, OA demonstrated pronounced pharmacodynamic activities against metabolic NRs, holding a clinical promise for the treatment of a batch of metabolic disorders, including NASH, diabetes, and atherosclerosis. It was normal to witness varying effects of OA on NRs, which are cell- and gene-type-specific, confirming the importance of considering the cellular context of each NR target. So far, a few OA derivatives have been semi-synthesized and benchmarked against NRs; hence, screening of more rationally designed derivatives is still required and may open the way for the discovery of selective NRs modulators.


CKX genes from monocotyledons, PCR primers were designed to synthesize a probe for screening a bamboo genomic library. Cloned results of three genes encoding cytokinin oxidase were named as follows: BoCKX1, BoCKX2, and BoCKX3. In comparing the exon-intron structures among the above three genes, there are three exons and two introns in BoCKX1 and BoCKX3 genes, whereas BoCKX2 contains four exons and three introns. The amino acid sequence of BoCKX2 protein shares 78% and 79% identity with BoCKX1 and BoCKX3 proteins, respectively. BoCKX1 and BoCKX3 genes are particularly closely related given that the amino acid and nucleotide sequence identities are more than 90%. These three BoCKX proteins carried putative signal peptide sequences typical of secretion pathway, and a GHS-motif was found at N-terminal flavin adenine dinucleotide (FAD) binding domain, suggesting that BoCKX proteins might covalently conjugate with an FAD cofactor through a predicted histidine residue.Cytokinin oxidase/dehydrogenase (CKX) catalyzes the irreversible breakdown of active cytokinins, which are a class of plant hormones that regulate cell division. According to conserved sequences of  Cytokinin is a phytohormone of plant growth regulators, playing an important role in the control of plant division. Many developmental events, such as shoot and root branching, leaf development, delay of senescence, and chloroplast ripening are directly regulated by the physiological functions of cytokinins ,2,3,4,5.CKX gene-encoded cytokinin oxidase/dehydrogenase enzyme  catalyzes the turnover of the cytokinins, isopentenyl-adenine, zeatin, and their ribosides by a unique enzymatic reaction by cleaving and oxidizing its side chain for converting isopentenyladenine to unsaturated 3-methyl-2-butenal and adenine . Se. Se® II KX probe . Phage Dn enzyme , followey BoCKX1 A, lane 1  and encoded a 525 amino acid polypeptide or a 57.0 kDa protein  was obtained  [To better understand the potential transcriptional regulations, the upstream sequence of the obtained . PlantPrdon ATG, . Promotedon ATG, . Among t (−1289)  were ideBoCKX3 was completely sequenced and ~1.2 kb promoter region was obtained (BoCKX2, which was situated 79 base pairs from the translational start codon (ATG, To better understand the potential transcriptional regulations, the upstream sequence of the obtained . PlantPrdon ATG, . Promotedon ATG, .BoCKX genes in B. oldhamii.CKX proteins had been reported to localize at different compartments ,23,36,37CKX functions are regulated by post-translational modifications, e.g., glycosylation. All CKX proteins were predicted to be glycoproteins , and maiBoCKX1 and BoCKX3 genes had identical exon-intron structures (BoCKX2 was slightly different in comparison with the above two genes (BoCKX genes showed similar exon-intron organizations between other CKX genes (A multi-gene family of CKX in plants has been reported previously ,36. In tructures A as wellructures . The exowo genes A. All thKX genes B. In thecis-acting elements were predicted from promoter regions of the BoCKX1–3 genes (BoCKX genes contained a conserved TATA box and a typical CAAT box was identified in the upstream site of TATA box of the BoCKX2 [CKX gene expression is induced by abiotic stress and plant hormones, such as abscisic acid and cytokinins [BoCKX genes, suggesting that the BoCKX gene expressions may be affected by different plant hormones and cytokinin response regulator proteins.Several putative –3 genes , and thee BoCKX2 . CKX gentokinins . As-1 botokinins ,56,57 antokinins ,58,59 we