Pomegranate reverses methotrexate-induced oxidative stress and apoptosis in hepatocytes by modulating Nrf2-NF-κB pathways.
The clinical efficacy of the widely used chemotherapeutic drug methotrexate (MTX) is limited due to its associated hepatotoxicity. Pomegranate polyphenols are of huge health benefits and known to possess remarkable antioxidant properties capable of protecting normal cells from various stimuli-induced oxidative stress and cell death. In this study, we explored the protective role of pomegranate fruit extract (PFE) in ameliorating MTX-induced hepatic damage. Male Swiss albino mice exposed to MTX (20 mg/kg body weight) exhibited distinct markers of toxicity such as increased activities of enzymes alanine transaminase, aspartate transaminase, lactate dehydrogenase and alkaline phosphatase and also increased oxidative stress in liver evidenced by increased ROS generation and lipid peroxidation. Decrease in reduced glutathione levels, superoxide dismutase, catalase, hepatic heme oxygenase 1 and NQO-1 activities were also observed. Tracing the signal transduction pathways, it was seen that MTX exposure significantly increased nuclear translocation of NF-κB coupled with increase in phosphorylated Iκ-B and down-regulation of NF-kappaB-dependent antiapoptotic protein Bcl-2. Treatment with MTX increased the expression of the apoptotic enhancer Rho/Cdc42 as well as the phosphorylation of SAPK/JNK. A shift in the Bax/Bcl-2 ratio towards apoptosis and increase in the caspase 3 level was also evident. Administration of PFE for 7 consecutive days before and after MTX challenge suppressed MTX-induced cell death, mitigated the injurious effects of MTX and offered protection against apoptosis. PFE was shown to reduce ROS generation in hepatocytes by activating the Nrf2-ARE pathway and inhibiting NF-κB as a consequence of which the antioxidant defense mechanism in the liver was up-regulated, thereby conferring protection against MTX-induced hepatotoxicity and apoptosis.
['Mukherjee|Sudeshna|S|', 'Ghosh|Sayan|S|', 'Choudhury|Sreetama|S|', 'Adhikary|Arghya|A|', 'Manna|Krishnendu|K|', 'Dey|Sanjit|S|', 'Sa|Gaurisankar|G|', 'Das|Tanya|T|', 'Chattopadhyay|Sreya|S|']
D000818:Animals D000975:Antioxidants D017209:Apoptosis D053148:Caspase 3 D002374:Catalase D002470:Cell Survival D015536:Down-Regulation D005978:Glutathione D051547:Heme Oxygenase-1 D022781:Hepatocytes D015227:Lipid Peroxidation D008099:Liver D029561:Lythraceae D008297:Male D008565:Membrane Proteins D008727:Methotrexate D051379:Mice D016660:NAD(P)H Dehydrogenase (Quinone) D051267:NF-E2-Related Factor 2 D016328:NF-kappa B D018384:Oxidative Stress D010766:Phosphorylation D059808:Polyphenols D015398:Signal Transduction D013482:Superoxide Dismutase D051028:bcl-2-Associated X Protein
Pomegranate Oxidative stress Apoptosis Methotrexate Hepatotoxicity NF-κB Nrf2