Dietary quercetin ameliorates nonalcoholic steatohepatitis induced by a high-fat diet in gerbils

Dietary quercetin is highly abundant in edible plants, which possesses a wide range of pharmacological properties. This study was to investigate hepatoprotective effects of quercetin in the nonalcoholic steatohepatitis (NASH) gerbils induced by a high-fat diet (HFD), and to evaluate its regulatory mechanism on hepatic inflammatory response. The gerbils were fed with HFD for 28 days to induce NASH. From 15th day to 28th day, the treated drugs were given daily to each animal, respectively. The lipid profiles and biochemical markers were determined at the end of the experiment. The expressions of Sirt1, NF-kappa B p65 and iNOS were detected by immunohistochemistry and Western blot analysis. The results showed that oral administration of quercetin at doses of 30-60 mg/kg to hyperlipidemia rats for 14 days were highly effective in decreasing the levels of serum total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). It could decrease lipid accumulation in the hepatocytes, and reduce serum levels of pro-inflammatory cytokines TNF-alpha and IL-6 via regulating the expressions of Sirt1, NF-kappa B p65 and iNOS. Thus, dietary quercetin had significant therapeutic benefits and could be explored as a potential promising candidate for the prevention of NASH. (C) 2012 Elsevier Ltd. All rights reserved.