Vanilloid TRPV1 receptor mediates the antihyperalgesic effect of the nonpsychoactive cannabinoid, cannabidiol, in a rat model of acute inflammation

Publisher Website
Google Scholar
Abstract
Cannabidiol (CBD), a nonpsychoactive marijuana constituent, was recently shown as an oral antihyperalgesic compound in a rat model of acute inflammation. We examined whether the CBD antihyperalgesic effect could be mediated by cannabinoid receptor type 1 (CB1) or cannabinoid receptor type 2 (CB2) and/or by transient receptor potential vanilloid type 1 (TRPV1). Rats received CBD (10 mg kg−1) and the selective antagonists: SR141716 (N‐(piperidin‐1‐yl)‐5‐(4‐chlorophenyl)‐1‐(2,4‐dichlorophenyl)‐4‐methyl‐1H‐pyrazole‐3‐carboxamide) for CB1, SR144528 (N‐[(1S)‐endo‐1,3,3‐trimethylbicyclo[2.2.1]heptan‐2‐yl]‐5‐(4‐chloro‐3‐methylphenyl)‐1‐(4‐methylbenzyl)pyrazole‐3 carboxamide) for CB2 and capsazepine (CPZ) for TRPV1 receptors. The intraplantar injection of carrageenan in rats induced a time‐dependent thermal hyperalgesia, which peaked at 3 h and decreased at the following times. CBD, administered 2 h after carrageenan, abolished the hyperalgesia to the thermal stimulus evaluated by plantar test. Neither SR141716 (0.5 mg kg−1) nor SR144528 (3 and 10 mg kg−1) modified the CBD‐induced antihyperalgesia; CPZ partially at the lowest dose (2 mg kg−1) and fully at the highest dose (10 mg kg−1) reversed this effect. These results demonstrate that TRPV1 receptor could be a molecular target of the CBD antihyperalgesic action.British Journal of Pharmacology (2004) 143, 247–250. doi:10.1038/sj.bjp.0705920