Context: Amla [Emblica officinalis Gaertn. (Euphorbiaceae)], a major constituent of several herbal formulations, is a well-known hepatoprotectant. Despite its extensive use, mechanistic understanding of its antioxidant action is rather limited.
Objective: In the current study, we investigated the effects of E. officinalis extracts (from dried fruits) on cellular oxidative state using a hepatocyte cell line (HepG2). We hypothesize that E. officinalis aqueous extracts have potency to modulate basal oxidative markers and enhance endogenous antioxidant defenses.
Materials and methods: Cells were incubated with aqueous extracts of E. officinalis (1-100 μg/ml) for varied time points (4-24 h) and biochemical markers of oxidative stress were determined in cell lysate.
Discussion: Aqueous extracts of E. officinalis at 100 μg/ml can significantly modulate the basal levels of oxidative markers and enhance antioxidant defenses of the cells.
Conclusions: Our findings clearly indicate the propensity of E. officinalis aqueous extracts to improve endogenous antioxidant defenses in HepG2 cells. Although further studies are required to assess their efficacy under experimentally induced oxidative, our data suggest that the hepatoprotective effects of E. officinalis reported earlier may be largely due to its potential to enhance the antioxidant defenses in vivo.
Results: Because E. officinalis up to 100 μg/ml concentrations had no effect on cell viability; it was considered noncytotoxic. Incubation with E. officinalis for 24 h resulted in significant diminution in the levels of lipid hydroperoxide (18-42%) and reactive oxygen species (11-29%). Furthermore; E. officinalis increased the levels of glutathione (GSH; 18-32%); antioxidant capacity (19-31%); and activities of antioxidant enzymes (superoxide dismutase; 25-41%; catalase; 39-50%; GSH peroxidase; 20-35%; GSH reductase; 26-35%; and GSH S-transferase; 12-30%).