Insulin-sensitizing and cholesterol-lowering effects of chromium (d-Phenylalanine)3

Low-molecular weight organic chromium complexes are thought to play a key role in carbohydrate and lipid metabolism and therefore have been gaining popularity as nutritional supplement for patients with diabetes and concomitant lipid disorders. The aim of the present study was to evaluate the effects of a novel synthetic chromium (d-phenylalanine)3 complex on insulin-sensitivity, plasma lipid-profile and oxidant stress in a mouse model of type II diabetes. Plasma glucose levels following intraperitoneal insulin-challenge (1 U/kg) to obese ob/ob(+/+) mice treated with Cr(d-Phe)3 (150 μg/kg/day for 6 weeks) were significantly lower compared to vehicle-control (control: 175.8 ± 43.2 mg/dL versus Cr(d-Phe)3 115.3 ± 18.0 mg/dL, p < 0.01, n = 12). Total serum cholesterol to high-density lipoprotein ratio was significantly reduced following Cr(d-Phe)3-treatment (control: 2.19 ± 0.08 versus Cr(d-Phe)3 1.63 ± 0.05; p < 0.05). Hepatic oxidant stress, assessed as malondialdehyde equivalents and protein-carbonyl content were significantly attenuated following Cr(d-Phe)3 treatment. The complex also inhibited lipid-peroxidation in vitro, in a concentration dependent manner. Taken together, these data suggest that Cr(d-Phe)3 may be of potential value in the therapy or prophylaxis of insulin-resistance and dyslipidemia associated with obesity.