Ameliorative potential of cannabis sativa extract on diabetes induced neuropathic pain in rats

Abstract

Diabetes induced neuropathic pain is recognized as one of the most difficult type of pain to treat and conventional analgesics are well known to be partially effective or ineffective. Synthetic or natural cannabinoids are promising drugs to treat neuropathic pain. It has been reported that the effect of cannabinoid analgesics is not compromised in various experimental neuropathic pain model. The aim of present study was to explore the ameliorative potential of cannabis sativa extract in hyperglycemia-induced neuropathic pain. Streptozotocin (STZ) (20 mg/kg, i.p. x 4 days) was administered to induce experimental diabetes in the rats. The pain threshold in diabetic and non-diabetic rats was measured using paw withdrawal latency test. After 28 days of STZ injection, diabetic rats exhibited a significant thermal hyperalgesia and mechanical allodynia along with increased plasma glucose and decreased body weights as compared with controls rats. Moreover, STZ administration was noted to increased oxidative stress (MDA & nitrite level) and decreased antioxidant enzyme levels (glutathione, catalase and superoxide dismutase) significantly in diabetic rats as compared to the age-matched non diabetic rats. Administration of Cannabis extract (25 50 & 100 mg/kg, p.o.) once daily for 14 days, starting from the 3rd week of STZ-injection, significantly attenuated thermal hyperalgesia and mechanical allodynia. Moreover it reduces oxidative stress and concomitantly increased reduced level of antioxidant enzyme levels observed in diabetic rats. This study suggests that cannabis has a beneficial effect in diabetic neuropathic pain.