Anti-diabetic activity and mechanism of action of chromium chloride.

Though supplementation of chromium has been found to improve deranged carbohydrate and lipid metabolism associated with suboptimal chromium intake in patients, its usefulness in the treatment of diabetes mellitus of variable etiology remains questionable. In the present investigation, the effect of 6 wk oral administration of chromium chloride (CC) on the glucose and lipid metabolism was studied in streptozotocin (STZ) diabetic and neonatal-STZ (nSTZ) diabetic rats. Further, its cellular mechanism was studied using 3T3-L1 adipocyte and C2C12 myoblast cell lines. Treatment with CC significantly improved the impaired glucose tolerance and insulin sensitivity of both STZ diabetic and nSTZ diabetic rats without any change in basal or glucose stimulated insulin response indicating insulin-sensitizing action of chromium. CC treatment also significantly improved deranged lipid metabolism. CC per se did not produce any effect in vitro, however, significantly increased insulin stimulated glucose uptake in C2C12 myoblasts and differentiation of 3T3-L1 preadipocytes into mature adipocytes supporting the in vivo insulin-sensitizing action of chromium. This study shows that CC exhibited significant anti-diabetic potential in chemically-induced diabetes in rats, the mechanism of which appears to be potentiation of insulin actions at the target tissues leading to improved peripheral insulin sensitivity.