Anti-lipoapoptotic effects of Alisma orientalis extract on non-esterified fatty acid-induced HepG2 cells

BACKGROUND: Liver steatosis was caused by lipid accumulation in the liver. Alisma orientale (AO) is recognized as a promising candidate with therapeutic efficacy for the treatment of nonalcoholic fatty liver disease (NAFLD). HepG2 hepatocyte cell line is commonly used for liver disease cell model. METHOD: The HepG2 cells were cultured with the NEFAs mixture (oleic and palmitic acids, 2:1 ratio) for 24 h to induce hepatic steatosis. Then different doses of Alisma orientale extract (AOE) was treated to HepG2 for 24 h. Incubated cells were used for further experiments. RESULTS: The AOE showed inhibitory effects on lipid accumulation in the Oil Red O staining and Nile red staining tests with no cytotoxicity at a concentration of 300 μg/mL. Fatty acid synthase (FASN) and acetyl-CoA carboxylase 1 (ACC1) mRNA and protein expression level were down-regulated after AOE treatment. Bcl-2 associated X protein (Bax) and c-Jun N-terminal kinase (JNK) mRNA expression level were decreased as well as p-JNK (activated form of JNK), Bax, cleaved caspase-9, caspase-3 protein expression level. Anti-apopototic B-cell lymphoma 2 (Bcl-2) protein level increased after AOE treatment. In addition, inflammatory protein expression including p-p65, p65, COX-2 and iNOS were inhibited by AOE treatment. CONCLUSION: The results suggest that AOE has anti-steatosis effects that involve lipogenesis, anti-lipoapoptosis, and anti-inflammation in the NEFA-induced NAFLD pathological cell model.