Ameliorating effects of casein glycomacropeptide on obesity induced by high-fat diet in male Sprague-Dawley rats

The effect of casein glycomacropeptide (GMP) as a specific regulating mediator in obese rats induced by high-fat (HF) diet was investigated. Male obese Sprague-Dawley (SD) rats induced by high-fat diet for 8 weeks period were fed high-fat, high-fat with GMP of 100 mg/kg BW (HFLG), 200 mg/kg BW (HFMG) and 400 mg/kg BW (HFHG) for 6 weeks. Compared with the high-fat control (HFC) group GMP supplementation significantly decreased adipose tissue weight, activity of fatty acid synthase (FAS) and glycerol-3-phosphate dehydrogenase (GPDH). Hepatic lipid droplet size, plasma and hepatic lipid levels markedly reduced. Moreover, GMP reduces plasma total cholesterol and low-density lipoprotein (LDL) cholesterol as well as hepatic-cholesterol and triglycerides. The liver steatosis observed in obese rats was also prevented by GMP supplement. In addition, GMP significantly diminished mitochondrial and liver malondialdehyde (MDA) production, and obviously elevated the activities of mitochondrial and hepatic superoxidase dismutase (SOD) and glutathione peroxidase (GSH-Px). Leptin production and proinflammatory cytokines such as TNF-α and IL-6 secretion decreased. Taken together, GMP can reduce lipid accumulation and enhance antioxidant capability of obese rats. It suggests that GMP can counteract high-fat diet-induced obesity, which might make it a potential ingredient with anti-obesity activity.