Moringa oleifera Leaves Extract Attenuates Neuropathic Pain Induced by Chronic Constriction Injury

Problem statement: Neuropathic pain, a challenge of this decade, has been reported to be associated with the diversity conditions including diabetes. At present, there are no conventional analgesics that can effectively treat neuropathic pain with a satisfactory outcome. Due to the limitation of therapeutic efficacy, the searching for novel effective remedies in the management of neuropathic pain is required. Approach: Male Wistar rats, weighing 180-220 g were induced diabetes mellitus by Streptozotocin (STZ) (single injection, 65 mg kg^-1 BW, i.p). Diabetic rats were induced neuropathic pain by Constricting the right sciatic nerve (CCI) at permanently. Then, all rats were administered the extract of M. oleifera leaves at doses of 100, 200 and 300 mg kg^-1 BW once daily in a period of 21 days. The analgesic effect of the plant extract was evaluated using Von Frey filament and hot plate tests every 3 days after CCI throughout 21-day experimental period. In addition, at the end of the experiment, the alteration of oxidative damage markers including MDA level and the activities of SOD, CAT and GSH-PX in the injured sciatic nerve were also evaluated. Results: The current results showed that rats subjected to M.oleifera leaves extract at doses of 100 and 200 mg kg^-1 BW significantly reversed the decreased withdrawal threshold intensity and withdrawal latency in Von Frey filament and hot plate tests respectively. In addition, rats subjected to the medium dose extract also reversed the decreased activities of SOD and GSH-Px and the elevation of MDA level in the injured nerve. Taken all together, our data suggest that M. oleifera leaves extract can attenuate neuropathic pain in diabetic condition. The possible underlying mechanism may occur partly via the decreased oxidative stress. However, other mechanisms may also involve. Conclusion: Our results suggest that M. oleifera leaves may be the potential novel adjuvant therapy for neuropathic pain management.