Anti-hypernociceptive effects of methanol extract of Boswellia dalzielii on STZ-induced diabetic neuropathic pain

Painful neuropathy that can cause hyperalgesia and allodynia is the most common and debilitating complication of diabetes. Both hyperglycemia and oxidative stress clearly play a key role in the progression of diabetic neuropathy. The search for new natural products with combined anti-inflammatory, antioxidant, hypoglycemic and antinociceptive properties is important in the treatment of this disease. The purpose of this study was to evaluate the anti-hypernoceptive effect of the methanolic extract of Boswellia dalzielii in streptozotocin-induced diabetic mice. Thus, the mice were injected with 200 mg/kg of streptozotocin to produce hyperglycemia. Von Frey filaments, hotplate, acetone and formalin tests were used to evaluate anti-nociceptive activity. Assays of catalase, SOD, MDA and NO determined the antioxidant properties. When administered, methanolic extract of Boswellia dalzielii (250 and 500 mg/kg, p.o.) significantly reduced licking/biting behavior during the first and second phase of the formalin test in a dose-dependent manner. Moreover, this extract significantly improved the glycemia of diabetic mice, it also significantly decreased the levels of TNF alpha, IL-1 beta in the serum and the sciatic nerve, decreased the levels of MDA and NO, and then increased the activity of SOD and catalase enzymes. Our results suggest that methanolic extract of Boswellia dalzielii can be a useful therapeutic agent, presumably for both prevention and reversal of pathophysiologic pain. This effect seems to imply hyperglycemic and antioxidant properties of this plant.