Supplementation of standardized extract from fermented Smilax china L. leaf containing secondary metabolites moderated diet‐induced obesity by modulating the activity antioxidant enzymes and hepatic lipogenesis

This study investigated the effects of non-fermented Smilax china L. (SC) and fermented Smilax china L. leaf extract by Aspergillus oryzae (FSC) on lipogenesis and antioxidant activities in diet induced-obese mice. While principal bioactive constituents in SC were decreased by fermentation, diverse secondary metabolites were identified. Both SC and FSC supplementation reduced body weight and epididymal fat mass in mice fed a high-fat diet. Hepatic triglyceride and cholesterol levels were lowered by SC treatment and the degree of lipid reduction was higher in FSC-treated group due to hepatic upregulation of lipogenic genes. SC and FSC improved hepatic function by lowering the activity of serum biomarker enzymes. In contrast, the activities of antioxidant enzymes were elevated and cellular lipid peroxide were decreased in liver. Taken together, FSC is more potent in preventing obesity and ameliorating hepatic function by fermentation-mediated production of bioactive constituents that have higher antioxidant and anti-obese efficacy. Practical applications The studies revealing that specific mechanism regarding anti-obesity effect of consumption of SC leaf in animal models is limited. Extract of fermented SC by Aspergillus oryzae (FSC) could be used as a bioactive ingredient for functional food products that can have a health claim for reducing hepatic lipogenesis in the liver in high-fat diet induced-obese mice.