Hepatic fibroblast growth factor 21 is required for two polyphenols in exerting their metabolic beneficial effect in mice

Recent studies have shown that FGF21 is a common target for dietary polyphenol intervention and nutritional restriction. FGF21 is also a newly recognized target of GLP-1R agonists (GLP-1RAs). Here we ask whether hepatic FGF21 is required for dietary polyphenols in exerting their metabolic beneficial effects. Liver-specific FGF21 null mice (lFgf21-/-) were utilized in current study. We found that on chow diet, no appreciable defect on glucose disposal was observed in male or female lFgf21-/- mice, while fat tolerance was impaired in male but not female lFgf21-/- mice, associated with elevated serum TG level, reduced hepatic expression of Ehhadh and Ppargc1. On high-fat-high-fructose (HFHF) diet challenge, Fgf21fl/fl mice but not lFgf21-/- mice exhibited response to curcumin intervention on reducing body weight and serum TG, and on improving fat tolerance. Resveratrol intervention also affected hepatic FGF21 expression and its downstream effectors. Metabolic beneficial effects of resveratrol intervention observed in HFHF diet challenged Fgf21fl/fl mice were either absent or attenuated in lFgf21-/- mice. Thus, hepatic FGF21 is required for curcumin and resveratrol in exerting their metabolic beneficial effect. Recognition that FGF21 is the common target of GLP-1RAs and dietary intervention brings us a novel angle in studying metabolic disease treatment and prevention. To investigate the beneficial effects of resveratrol in high fat high fructose (HFHF) diet-challenged mice, we fed male mice with normal chow diet (LFD), HFHF diet, and HFHF diet with Resveratrol for 16 weeks. Liver was collected at the end of the experiment and subjected to RNA isolation.