Basic and Clinical Neuroscience (Apr 2011)
The Effect of the Flavonoid Quercetin on Pain Sensation in Diabetic Rats
Abstract
Introduction: Hyperalgesia is considered as one of the marked signs of subchronic diabetes mellitus in patients that could affect their lifestyle. This study was designed to investigate the anti-nociceptive effect of chronic administration of quercetin in streptozotocin (STZ)-diabetic rats using formalin and hot tail immersion tests. Methods: Rats were divided into control, control or diabetic groups receiving sodium salicylate, untreated diabetic, and quercetin-treated control and diabetic groups. The treatment groups received i.p. administration of quercetin at a dose of 10 mg/kg for 6 weeks. Finally, hyperalgesia were assessed using standard formalin and hot tail immersion tests. Meanwhile, some markers of oxidative stress were also measured in brain tissue.Results: Quercetin or SS treatment of diabetic rats significantly reduced pain score in chronic phase of formalin test (p<0.05). Regarding hot tail immersion test, diabetic rats showed a significant reduction in tail flick latency as compared to control ones (p<0.05) and quercetin treatment of diabetic rats did significantly increase this latency relative to untreated diabetics (p<0.05). Quercetin treatment of diabetic rats also significantly decreased brain level of malondialdehyde (MDA) (p<0.05) and nitrite (p<0.05) and slightly increased activity of superoxide dismutase (SOD) relative to diabetics. Discussion: Taken together, chronic administration of quercetin could attenuate nociceptive score in chronic phase of formalin test in streptozotocin-diabetic rats and could also increase threshold of thermal nociception.
