Anti-inflammatory, free radical scavenging and alpha-glucosidase inhibitory activities of Hamelia patens and its chemical constituents.
Context Hamelia patens Jacq. (Rubiaceae) is traditionally used to treat wounds, inflammation and diabetes. However, there is still a lack of scientific evidence to support these applications. Objective The objective of this study is to evaluate the anti-inflammatory, antioxidant and antidiabetic activities of Hamelia patens, and identify its bioactive compounds. Materials and methods Four extracts were obtained by maceration and liquid-liquid extraction: HEX, DCM-EtOAc, MeOH-EtOAc and MeOH-Aq. The anti-inflammatory effect was evaluated orally on rat paw carrageenan-induced oedema over 6 h (50, 200 and 500 mg/kg), and topically in mouse ear oedema induced by 12-tetradecanoylphorbol-13-acetate (TPA) after 4 h (0.5 and 1 mg/ear). We also evaluated myeloperoxidase levels in ear tissue, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and in vitro α-glucosidase inhibition. The chemical compounds were separated by column chromatography and identified by spectroscopic analysis. Results We found that the oral administration of the HEX extract at 500 and 200 mg/kg significantly decreased the carrageenan-induced inflammation after 1 and 3 h, respectively. The MeOH-EtOAc extract significantly inhibited myeloperoxidase activity (83.5%), followed by the DCM-EtOAc extract (76%), β-sitosterol/stigmasterol (72.7%) and the HEX extract (55%), which significantly decreased oedema induced by TPA at both doses, giving a similar effect to indomethacin. We also found that the MeOH-EtOAc, MeOH-Aq and DCM-EtOAc extracts showed good DPPH scavenging activity (IC50 values of 18.6, 93.9 and 158.2 μg/mL, respectively). The HEX extract showed the lowest α-glucosidase inhibition (an IC50 value of 26.07 μg/mL), followed by the MeOH-EtOAc extract (an IC50 value of 30.18 μg/mL), β-sitosterol/stigmasterol (IC50 34.6 μg/mL) and compound A ((6E,10E,14E,18E)-2,6,10,14,18,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, an IC50 value of 114.6 μg/mL), which were isolated for the first time from Hamelia patens. Discussion and conclusion Hamelia patens possesses anti-inflammatory, antioxidant and α-glucosidase inhibitory activities, which support its traditional use. These effects can be attributed to the identified compounds.
['Jiménez-Suárez|Verónica|V|', 'Nieto-Camacho|Antonio|A|', 'Jiménez-Estrada|Manuel|M|', 'Alvarado Sánchez|Brenda|B|']
D000818:Animals D000893:Anti-Inflammatory Agents D001713:Biphenyl Compounds D002351:Carrageenan D004195:Disease Models, Animal D004305:Dose-Response Relationship, Drug D004487:Edema D005260:Female D016166:Free Radical Scavengers D065089:Glycoside Hydrolase Inhibitors D032063:Hamelia D009195:Peroxidase D008517:Phytotherapy D010851:Picrates D018515:Plant Leaves D010946:Plants, Medicinal D017208:Rats, Wistar D029701:Saccharomyces cerevisiae Proteins D012997:Solvents D013755:Tetradecanoylphorbol Acetate D013997:Time Factors D000520:alpha-Glucosidases
antioxidant Antidiabetic 12-tetradecanoylphorbol-13-acetate myeloperoxidase β-sitosterol stigmasterol carrageenan squalene isomer