A new promising simultaneous approach for attenuating type II diabetes mellitus induced neuropathic pain in rats: iNOS inhibition and neuroregeneration.

In view of the pathologic basis for the treatment of diabetic neuropathy, it is important to enhance nerve regeneration as well as prevent nerve degeneration. So, in the present study, we have investigated the effect of S-Methylisothiourea Sulfate (selective iNOS inhibitor) and Citicoline, alone and in combination, on Type II diabetes mellitus induced neuropathic pain in wistar rats. Type II diabetes was induced by providing high fat diet and low dose of Streptozotocin for 35 days in rats. Type II diabetes mellitus was assessed in terms of increased glucose, triglycerides, cholesterol, LDL levels, glucose tolerance and decrease in HDL levels. Neuropathy as the complication of type II diabetes was assessed in terms of decreased nerve conduction velocity, mechanical and thermal hyperalgesia and cold allodynia. Oxidative stress was assessed in sciatic nerve and showed increase in LPO and nitrite levels whereas decrease was shown in GSH and catalase activity. Axonal degeneration marked by nerve fibre dearrangement and demyelination was observed in histopathological studies. SMT (iNOS inhibitor), Citicoline and low dose combination of both drugs significantly attenuates the diabetic neuropathic pain assessed in terms of parameters employed. Thus, it may be concluded that simultaneous administration of SMT and Citicoline may provide potential therapeutics for diabetic neuropathic pain.