Effect of Rheum undulatum Linne extract and Glycyrriza uralensis Fischer extract against arachidonic acid and iron-induced oxidative stress in HepG2 cell and CCl4-induced liver injury in mice

Objectives : Rheum undulatum Linne and Glycyrriza uralensis Fischer are widely used herbal medicine. In this study, anti-oxidant and liver protective effects of R. undunlatum extract (RUE) and G. uralensis extract (GUE) were investigated in HepG2 cells, respectively. Oxidative stress and liver fibrosis were induced by arachidonic acid (AA) and iron, and CCl4.Methods : MTT assay was assessed for cell viability, and immunoblotting analysis was performed to detect expression of apoptosis related proteins. In addition, reactive oxygen species (ROS) and mitochondrial dysfunction were measured. In vivo, BALB/c mouse were orally administrated with the aqueous extract of 10 mg/kg RUE and 100 mg/kg GUE for 3 days and then, injected with CCl4 0.5 ml/kg body weight to induce acute liver damage. Serum ALT level was measured, and histological change was observed in Harris's hematoxylin and eosin stainResults : RUE and GUE pre-treatment increased relative cell viability in concentration dependent manner and altered the expression levels of apoptosis-related proteins such as procaspase 3, PARP and Bcl-xL. RUE and GUE also inhibited the mitochondrial dysfunction and excessive reactive oxygen species (ROS) production induced by AA and iron. In addition, RUE and GUE activated liver kinase B1 (LKB1), by increasing phosphorylation. Moreover, RUE and GUE treatment decreased liver injuries induced by CCl4, as evidenced by decreases in histological liver damage as well as serum alanine amino transferase (ALT) level.Conclusions : These data suggest that RUE and GUE has anti-oxidant and liver protective effects against AA and iron-induced oxidative stress and CCl4-induced liver injury.