Ameliorative potential of rosiglitazone in tibial and sural nerve transection-induced painful neuropathy in rats

The present study was designed to investigate the ameliorative potential of rosiglitazone, a peroxisome proliferator-activated receptor gamma (PPAR gamma) agonist, in tibial and sural nerve transection-induced neuropathic pain in rats. The pinprick, cold immersion, hot plate and hot immersion tests were performed to assess the degree of mechanical and cold hyperalgesia; heat hyperalgesia and allodynia, respectively. The tissue thio-barbituric acid reactive species and reduced glutathione were measured as the markers of oxidative stress. Furthermore, the myeloperoxidase activity (a specific marker of inflammation) was also measured along with the determination of the calcium levels. Rosiglitazone (2.5,5 and 10 mg/kg p.o.), was administered for 28 days after tibial and sural nerve transection. Administration of rosiglitazone (5 and 10 mg/kg p.o.) attenuated tibial and sural nerve transection-induced mechanical and cold hyperalgesia without modulating heat hyperalgesia. Rosiglitazone also attenuated tibial and sural nerve transection-induced increase in oxidative stress, myeloperoxidase activity and calcium levels. It may be concluded that rosiglitazone has ameliorative potential in attenuating the painful state associated with tibial and sural nerve transection, which may further be attributed to anti-inflammatory actions with subsequent decrease in oxidative stress and calcium levels. (C) 2009 Elsevier Ltd. All rights reserved.