Effective control of blood glucose status and toxicity in streptozotocin-induced diabetic rats by orally administration of vanadate in an herbal decoction.

Vanadium compounds have been well recognized for hypoglycemic effects, but questions remain on gastrointestinal disturbance and possible tissue vanadium accumulation thus slowing the acceptance of vanadium compounds as diabetic therapeutic agents. Our intestinal permeability and toxicity studies of vanadium compounds have suggested that the co-administration of vanadate with Salvia miltiorrhiza Bunge decoction could benefit the therapeutic use of hypoglycemic vanadium compounds. In the present paper, we tested the hypoglycemic effects of vanadate ingested in an aqueous extract of S. Bunge using a streptozocin (STZ)-induced diabetic rat model. Oral administration of vanadate in S. Bunge herbal decoction produced a stable (free of hypoglycemic shock) and long-lasting ( approximately 70day) control of blood glucose status. Effective protection of animal organs from hyperglycemic damage was also observed. As expected, the herbal extract significantly alleviated vanadium toxicity, i.e. GI stress and metal accumulation. In addition, the result suggesting that vanadium-induced amelioration of the diabetic state appears to be secondary to the preservation of a functional portion of the pancreatic beta-cells which initially survived STZ-toxicity. These studies provide new insight into the therapeutic treatment of diabetics with vanadium compounds.