Prevention and treatment effect of total flavonoids in Stellera chamaejasme L. on nonalcoholic fatty liver in rats

BACKGROUND: The incidence of nonalcoholic fatty liver disease (NAFLD) has been increasing worldwide in parallel with the obesity epidemic. This study aims to investigate the effects of the total flavonoids in Stellera chamaejasme L. (TFSC) on the experimental NAFLD in high fat diet fed (HFD) rats. METHODS: NAFLD model was induced in male Wistar rats by high-fat diet, and the rats in NAFLD group were randomized into NAFLD group (n = 20) and TFSC-treated group (n = 60). Both groups were given high-fat diet, and the normal group (n = 20) was given normal diet. In addition, the TFSC treated group was administered TFSC orally once a day at a low dose of 100 mg/kg (n = 20), medium dose of 200 mg/kg (n = 20), and high dose of 400 mg/kg (n = 20) for 6 weeks. Subsequently, the rats were sacrificed and body weight changes, lipid profiles in plasma and liver pathology were examined. The relative levels of fatty acid synthesis and β-oxidation gene expression in hepatic tissues were measured by quantitative real-time polymerase chain reaction (RT-PCR). RESULTS: After the HFD administration for 4 weeks, the body weight,serum TC and TG levels in the rat of model group were significantly higher than in normal group (P < 0.05), and which Showed that the experimental NAFLD model was successfully established. While continual feeding with HFD deteriorated NAFLD and hyperlipidemia, and treatment with the different doses of TFSC effectively improved serum and liver lipid metabolism and liver function. A linear relationship between the dose of TFSC and blood lipid level was observed. The mRNA expression of hepatic acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), Leptin (LEP) and sterol regulatory element binding protein (SREBP)-1c as well as peroxisome proliferator-activated receptor (PPAR) –γ were significantly lower in high-dose group compared to the positive control group (P < 0.05). The hepatic mRNA expression of Cholesterol 7α-hydroxylase1 (CYP7A1), Carnitine palmitoyltransferase-1 (CPT1) and peroxisome proliferator-activated receptor (PPAR) –α were significantly higher in the high-dose group compared to the positive control group (P < 0.05). However, no difference was detected in the middle-dose group or the low-dose group compared to the positive control group (P > 0.05). CONCLUSION: TFSC treatment effectively improved NAFLD-related hyperlipidemia and inhibited liver steatosis in rats, and accompanied by modulating the expression of genes for regulating lipid metabolism.