Betulin prevents high fat diet-induced non-alcoholic fatty liver disease by mitigating oxidative stress and upregulating Nrf2 and SIRT1 in rats

Non-alcoholic fatty liver disease (NAFLD) is a common chronic hepatic disorder characterized by hepatic lipid accumulation. This study explored the effect of betulin (BE), a terpenoid with promising antioxidant, anti-inflammatory and insulin sensitizing effects, on NAFLD induced by high fat diet (HFD). Rats received HFD and BE (15 and 30 mg/kg) for 12 weeks and blood and liver samples were collected for analyses. HFD caused hyperlipidemia, cholesterol and triglycerides accumulation in the liver, hepatocellular ballooning, fibrosis, in-sulin resistance (IR), lipid peroxidation (LPO), and NF-kB p65 upregulation. BE ameliorated serum and liver lipids, blood glucose and insulin, liver LPO, prevented steatosis and fibrosis, suppressed NF-kB p65 and enhanced antioxidants in HFD-fed rats. BE downregulated acetyl-CoA carboxylase (ACC1) and fatty acid synthase (FAS), and upregulated Nrf2, HO-1 and SIRT1 in the liver of HFD-fed rats. In silico investigations revealed the binding affinity of BE towards FAS, NF-kB, Keap1, HO-1 and SIRT1. In conclusion, BE attenuated HFD-induced NAFLD ameliorating hyperlipidemia, IR, lipogenesis, liver lipid accumulation, and oxidative stress. The protective effect of BE was associated with enhanced Nrf2/HO-1 signaling and SIRT1.