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Fibrates, including fenofibrate, are a class of hypolipidemic drugs that activate peroxisome proliferator-activated receptor α (PPARα), which in-turn regulates the expression of lipid and lipoprotein metabolism genes. We investigated whether fenofibrate can reduce visceral obesity and nonalcoholic fatty liver disease via adipose tissue PPARα activation in female ovariectomized (OVX) C57BL/6J mice fed a high-fat diet (HFD), a mouse model of obese postmenopausal women. Fenofibrate reduced body weight gain (−38%, p < 0.05), visceral adipose tissue mass (−46%, p < 0.05), and visceral adipocyte size (−20%, p < 0.05) in HFD-fed obese OVX mice. In addition, plasma levels of alanine aminotransferase and aspartate aminotransferase, as well as free fatty acids, triglycerides, and total cholesterol, were decreased. Fenofibrate also inhibited hepatic lipid accumulation (−69%, p < 0.05) and infiltration of macrophages (−72%, p < 0.05), while concomitantly upregulating the expression of fatty acid β-oxidation genes targeted by PPARα and decreasing macrophage infiltration and mRNA expression of inflammatory factors in visceral adipose tissue. These results suggest that fenofibrate inhibits visceral obesity, as well as hepatic steatosis and inflammation, in part through visceral adipose tissue PPARα activation in obese female OVX mice.

Vitamin C (ascorbic acid) supplementation has been suggested to negatively correlate with obesity in humans and other animals. Previous studies, including ours, have demonstrated that a high-fat diet (HFD) induces obesity and related diseases such as hyperlipidemia, hyperglycemia, insulin resistance, and nonalcoholic fatty liver disease. Here, we investigated the effects of vitamin C on visceral adipocyte hypertrophy and glucose intolerance in C57BL/6J mice. Mice received a low-fat diet (LFD, 10% kcal fat), HFD (45% kcal fat), or the same HFD supplemented with vitamin C (HFD-VC, 1% w/w) for 15 weeks. Visceral adiposity and glucose intolerance were examined using metabolic measurements, histology, and gene expression analyses. Mice in the HFD-VC supplementation group had reduced body weight, mesenteric fat mass, and mesenteric adipocyte size compared with HFD-fed mice. Vitamin C intake in obese mice also decreased the mRNA levels of lipogenesis-related genes (i.e., stearoyl-CoA desaturase 1 and sterol regulatory element-binding protein 1c) in mesenteric adipose tissues, inhibited hyperglycemia, and improved glucose tolerance. In addition, vitamin C attenuated the HFD-induced increase in the size of pancreatic islets. These results suggest that vitamin C suppresses HFD-induced visceral adipocyte hypertrophy and glucose intolerance in part by decreasing the visceral adipose expression of genes involved in lipogenesis.

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