Protective effects of bamboo (Sasa borealis) leaf extracts against oxidative stress induced by t‐BHP in HepG2 cells

Abstract

Bamboo (Sasa borealis) has been widely utilized as a medicinal plant in Korea. In this study, hepato‐protective effects of bamboo leaf extracts against oxidative damage induced by tert‐butyl hydroperoxide (t‐BHP) were evaluated using HepG2 cells. Two crude extracts and five fractions of the 70% ethanol (EtOH) extract of the bamboo leaves were prepared by extracting using water or 70% ethanol and by fractionating sequentially. The two crude extracts and the five fractions were non toxic up to 150 ¥ì g/mL concentration, as determined by the 3‐(4,5)‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide (MTT) assay. Decreased cell viability (%), increased leakage of lactate dehydrogenase (LDH), increased activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR), and raised concentration of malonedialdehyde (MDA) and decreased reduced glutathione (GSH) by t‐BHP were restored dose‐dependently by adding the crude extract of water or 70% EtOH or each fraction of the 70% EtOH extract. Among the two crude extract and five fractions, chloroform, ethyl acetate, and n‐butanol fractions showed the highest protective potential against oxidative damage. The results indicate that bamboo leaf extracts protect against oxidative damage in HepG2 cells.