Anti-neuropathic Pain Effects of Ethyl Acetate Extract of Ferula asafoetida Oleo-Gum-Resin in Streptozotocin-induced Diabetic Rats

Objective: Diabetic Neuropathic Pain (DNP) is a common complication in both types of diabetes, which does not respond well to common pain medications. Asafoetida, an oleo-gum-resin extracted from Ferula asafoetida, is used as an analgesic, sedative, and antispasmodic in Iranian traditional medicine. Hence, the present study aimed to investigate the anti-neuropathic pain effects of asafoetida in streptozotocin-induced diabetic rats. Methods: Forty male Wistar rats were randomly divided into five groups. In four groups, diabetes was induced by intraperitoneal injection of a single-dose of streptozotocin (60 mg/kg). Three diabetic groups were treated once daily with asafoetida extract at doses 25, 50, and 100 mg/kg for 25 days. In all groups, the neuropathic pain was evaluated using behavioral tail-flick and von-Frey tests on days 0, 7, 14, 21, and 28. In addition, fasting blood glucose was also measured at the mentioned days. Key Findings: According to the results obtained from the behavioral tests, neuropathic pain was established in the diabetic rats on day 21. However, in comparison to untreated animals, the intensity of the pain (thermal hyperalgesia and mechanical allodynia) was significantly lower in groups receiving asafoetida extract (50 mg/kg, P<0.05 and 100 mg/kg, P<0.01). In addition, the extract could decrease fasting blood glucose in a dose-dependent manner (P<0.05). Conclusion: Ethyl acetate extract of asafoetida can prevent the development of neuropathic pain in diabetic rats. This effect may be, in part, due to the glucose lowering effect of asafoetida. However, further studies are needed to determine the possible mechanisms of action in relieving DNP.