Chronic Oral Pelargonidin Alleviates Streptozotocin-Induced Diabetic Neuropathic Hyperalgesia in Rat: Involvement of Oxidative Stress

Diabetes mellitus in some clinical cases is accompanied with hyperalgesia. In this study, weevaluated the possible beneficial effect of chronic pelargonidin (PG) treatment on hyperalgesia instreptozotocin (STZ)-diabetic neuropathic rat. Methods: Male Wistar rats (n = 56) were divided into seven groups, i.e. control, diabetic, PG-treated control, PG (single- and multiple-dose)-treated diabetic, and sodium salicylate-treated control and diabetics. For induction of diabetes, STZ was injected i.p. at a single dose of 60 mg/kg. PG was orally administered at a dose of 10 mg/kg once and/or on alternate days for 8 weeks; 1 week after diabetes induction. After two months, hyperalgesia was assessed using standard formalin and hot tail immersion tests. Meanwhile, markers of oxidative stress in brain were measured. One-way analysis ofvariance was used for statistical analysis of the data. Results: Diabetic rats showed a marked chemical and thermal hyperalgesia, indicating that development of diabetic neuropathy and PG treatment (especiallymultiple-doses) significantly ameliorated the alteration in hyperalgesia (P 0.05-0.01) in diabetic rats ascompared to untreated diabetics. PG (multiple doses) also significantly decreased diabetes-inducedthiobarbituric acid reactive substances formation and non-significantly reversed elevation of nitrite level and reduction of antioxidant defensive enzyme superoxide dismutase. Conclusion: These results clearly suggest that PG prevents diabetic neuropathic hyperalgesia through attenuation of oxidative stress. Iran. Biomed. J. 14 (1 2): 33-39, 2010