The effects of gliclazide, methylcobalamin, and gliclazide+methylcobalamin combination therapy on diabetic peripheral neuropathy in rats.

AIMS: This study investigated the efficacies of gliclazide (GLZ), methylcobalamin (MCA), and GLZ+MCA combination therapy on DPN by evaluating the treatment-related changes in peripheral nerve function, the polyol pathway, and oxidative stress in the sciatic nerve of streptozotocin-induced diabetic rats.

MATERIALS AND METHODS: The rat model of streptozotocin-induced diabetes was orally given GLZ (25mg/kg/day), MCA (175μg/kg/day), and GLZ+MCA (25mg/kg/day+175μg/kg/day) combination therapy for 8weeks, in order to observe its effects on the motor nerve conduction velocity (MNCV), on the activities of Na(+), K(+)-ATPase, aldose reductase(AR), AR mRNA expression, on the polyol contents, antioxidative enzyme activities and peroxidation products in the sciatic never tissue.

KEY FINDINGS: Most of the indicators of DPN, such as delayed MNCV, altered/damaged nerve structure, inhibited Na(+),K(+)-ATPase activity, enhanced AR activity and AR mRNA expression, increased polyol contents, altered Cu,Zn-superoxide dismutase, catalase, and glutathione-peroxidase activities, and elevated malondialdehyde level in the sciatic nerves of the diabetic rats, were significantly ameliorated by treatment with either GLZ or MCA. Moreover, the combination of GLZ and MCA was found to enhance the curative effect on DPN in parts of above-mentioned parameters as compared to monotherapy.

SIGNIFICANCE: Monotherapy with GLZ or MCA, and especially the combined application of GLZ and MCA, could be efficient therapeutic strategies for combating experimental DPN in diabetic rats.