Holarrhena antidysenterica Extract Promotes Recovery of Peripheral Neuropathy In Diabetic Rats

This study explored the effect of bark of Holarrhena antidysenterica Linn in management of diabetic neuropathy in experimental animals. Adult Wistar rats (either sex; 250-275 g) were injected with streptozotocin (50 mg/kg; i.p.) to induce diabetes. Methanol extract of bark of Holarrhena antidysenterica was administered in 3 doses (200, 400 and 600 mg/kg; p.o.) to rats for 28 successive days daily after 4 weeks of STZ administration. After 8 weeks, the neuropathic activity was evaluated using Open field test, Tail Flick test, Cold Allodynia and Formalin test. Afterwards, sciatic nerve was used for TBARS, GSH, Nitrite, Catalase and protein estimations. STZ induced diabetic neuropathy caused decrease in tail-flick latency time in radiant heat test and decreased allodynic response in tail-immersion (cold water) test. STZ caused increase in blood glucose, Glycosylated Haemoglobin and blood Cholesterol levels. Furthermore, activity of endogenous antioxidants like GSH and catalase significantly decreased; however, TBARS and nitrite levels were increased. Administration of MEHA for 28 days prevented the development of diabetic neuropathy as evident from reversed (p< 0.05) cold allodynia and tail flick latency (p< 0.05) as compared to diabetic control group. Glycosylated haemoglobin and cholesterol levels were significantly decreased (p< 0.05) in rats as compared to diabetic control group. MEHA treated rats showed significant decreased TBARS and nitrite levels and increased GSH and Catalase level. Thus, Holarrhena antidysenterica not only improved the diabetic condition but also reversed neuropathic pain through modulation of oxidative–nitrosative stress.