Preventive Effects of Ilex Cornuta Aqueous Extract on High-Fat Diet-Induced Fatty Liver of Mice

To investigate the preventive effects of Ilex cornuta aqueous extract (ICAE) on high-fat diet (HFD)-induced fatty liver of mice and its mechanisms.

Twenty-six male KM (Kunming) mice were divided into 3 groups, including the control group (n = 9), fed with normal diet; HFD group (n = 9), fed with HFD; ICAE + HFD group (n = 8), fed with HFD and administered with ICAE (3 g·kg^-1·d^-1) at the same time for 10 weeks. Body weight, liver weight, intra-abdominal and subcutaneous fat weight, serum triglyceride (TG), total cholesterol (TC), and blood glucose were determined to evaluate the preventive effects of ICAE on obesity. The average 24 h food consumption of the mice was monitored for 5 times in the 9th week of the experiment to investigate the effects of ICAE on food intake. Serum alanine transaminase (ALT) and aspartate aminotransferase (AST) were assayed to observe the influences of HFD and ICAE on liver function. HE staining was adopted to observe the influence of ICAE on the morphology of adipose tissue and liver tissue. Hepatic TG and TC content assay and oil red O staining were used to evaluate the influences of ICAE on HFD-induced fatty liver, and the protein expression of peroxisome proliferator-activated receptors γ (PPARγ) and adipose differentiation-related protein (ADRP) in liver were examined by immunoblotting.

ICAE treatment significantly reduced the increase of body weight, intra-abdominal, and subcutaneous fat and liver weight induced by HFD (P < 0.001), but has no influence on food intake; ICAE treatment attenuated the elevation of serum TG, TC, and glucose, as well as serum ALT and AST (P < 0.01, P < 0.05, P < 0.001) and dramatically decreased the content of TG in liver (P < 0.01), but has no influence on hepatic TC content. HE staining and oil red O staining showed that ICAE significantly reduced HFD-induced white adipocyte hypertrophy and significantly inhibited lipid accumulation in liver. Immunoblotting showed that the protein levels of PPARγ and ADRP were significantly increased by HFD induction, which can be dramatically reduced by ICAE treatment (P < 0.05, P < 0.0001).

ICAE has preventive effects on HFD-induced obesity and fatty liver in mice, exerted beneficial effects upon HFD-induced hepatic injury. The preventive effects of ICAE on fatty liver are concerned with the downregulation of PPARγ and ADRP protein expression in liver.