Standardized rice bran extract improves hepatic steatosis in HepG2 cells and ovariectomized rats

BACKGROUD/OBJECTIVES: Hepatic steatosis is the most common liver disorder, particularly in postmenopausal women. This study investigated the protective effects of standardized rice bran extract (RBS) on ovariectomized (OVX)-induced hepatic steatosis in rats. MATERIALS/METHODS: HepG2 cells were incubated with 200 µM oleic acid to induce lipid accumulation with or without RBS and γ-oryzanol. OVX rats were separated into three groups and fed a normal diet (ND) or the ND containing 17β-estradiol (E2; 10 µg/kg) and RBS (500 mg/kg) for 16 weeks. RESULTS: RBS supplementation improved serum triglyceride and free fatty acid levels in OVX rats. Histological analysis showed that RBS significantly attenuated hepatic fat accumulation and decreased hepatic lipid, total cholesterol, and triglyceride levels. Additionally, RBS suppressed the estrogen deficiency-induced upregulation of lipogenic genes, such as sterol regulatory element-binding protein 1 (SREBP1), acetyl-CoA carboxylase 1, fatty acid synthase, glycerol-3-phosphate acyltransferase, and stearoyl-CoA desaturase 1. CONCLUSIONS: RBS and γ-oryzanol effectively reduced lipid accumulation in a HepG2 cell hepatic steatosis model. RBS improves OVX-induced hepatic steatosis by regulating the SREBP1-mediated activation of lipogenic genes, suggesting the benefits of RBS in preventing fatty liver in postmenopausal women.