Effects of Se-phenyl thiazolidine-4-carboselenoate on mechanical and thermal hyperalgesia in brachial plexus avulsion in mice: Mediation by cannabinoid CB1 and CB2 receptors

In this study, we investigated the therapeutic effects of treatment with (R)-Se-phenyl thiazolidine-4-carboselenoate (Se-PTC), an organic selenium compound with antinociceptive properties, against mechanical and thermal hyperalgesia induced by brachial plexus avulsion (BPA), a neuropathic model in mice. The involvement of cannabinoid CB1 and CB2 receptors in the Se-PTC anti-hyperalgesic effect was also investigated. Se-PTC treatment at (25 and 50 mg/kg, per oral, p.o.) lowered (BPA model) induced mechanical and thermal hyperalgesia in mice. Pretreatment with cannabinoid CB1 (AM251; 1 mg/kg, intraperitoneally, i.p.), or CB2 (AM630; 3 mg/kg, i.p.) receptor antagonists reverted the mechanical and thermal anti-hyperalgesic effect of Se-PTC (25 mg/kg) in the BPA model. Selective CB1 (ACEA, 10 mg/kg, i.p.) and CB2 (JWH-133, 10 mg/kg, i.p.) receptor agonists lowered mechanical and thermal hyperalgesia in the BPA model, and this effect was prevented by selective CB1 and CB2 receptor antagonists. Gabapentin (70 mg/kg, p.o.), positive control administration also lowered mechanical and thermal hyperalgesia in the BPA model. The results suggest that the mechanical and thermal hyperalgesia observed following BPA in mice is dependent on cannabinoid receptors. The results indicate that modulating cannabinoid receptors represent a valuable approach for the treatment of neuropathic pain. In conclusion, the results suggested that Se-PTC produces pronounced mechanical and thermal anti-hyperalgesic effects in neuropathic models in mice by modulating CB1 and CB2 receptors. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.