The effects of soy isoflavone on insulin sensitivity and adipocytokines in insulin resistant rats administered with high-fat diet.

The effects of soy isoflavone (SIF) on insulin sensitivity and adipocytokines in high-fat-diet-induced insulin resistant (IR) rats were studied. Male Sprague Dawley rats (n = 80) were randomly assigned into a basal diet fed group and high-fat diet fed group. The high-fat-diet-induced IR rats were assigned into IR model control group and three SIF-treated groups with different dosages. Thirty days later, the fasting blood glucose, insulin and adipocytokines in serum and mRNA expressions of adipocytokines in perirenal white adipose tissue were measured. The Homeostasis Model Assessment of IR was calculated. The administration of 450 mg kg(-1) d(-1) SIF decreased the body weights and depositions of visceral adipose tissue as well as improved insulin resistance in high-fat-diet-induced IR rats. The mechanisms were associated with SIF regulating the expression of adipocytokines, including adiponectin, leptin, resistin and TNF-alpha. SIF supplements may have favourable effects on insulin resistance in high-fat-diet-induced IR rats.