Anxiolytic-like effect of cannabidiol in the rat Vogel conflict test.
Cannabidiol (CBD) is a major constituent of the Cannabis sativa plant. It inhibits the anxiogenic activity of high doses of Delta9-tetrahydrocannabinol and induces anxiolytic-like effects. However, the mechanisms underlying the actions of CBD are unknown. Therefore, the aim of the present study was to test the effects of CBD in the Vogel test, a widely used animal model of anxiety. In addition, it was verified if these effects would depend on benzodiazepine-receptor activation. After 24 h of water deprivation, male Wistar rats were subjected to an initial 3-min non-punished (pre-test) drinking session. This was followed by an additional 24-h period of water deprivation followed by a 3-min punished-licking session (test). Diazepam (3 mg/kg) or CBD (2.5, 5 or 10 mg/kg) were intraperitoneally injected 30 min before the test session. CBD (10 mg/kg) and diazepam had similar anticonflict effects, increasing the number of punished licks. The effect of diazepam, but not of CBD, was prevented by the benzodiazepine-receptor antagonist flumazenil (10 mg/kg). To exclude that the anticonflict effects were reflecting non-specific drug effects, we checked the effects of CBD on water consumption and nociceptive response. The drug did not interfere on the former variable in a non-punished test session. Moreover, contrary to morphine (5 mg/kg), CBD was ineffective in the tail-flick test. In conclusion, CBD induced an anticonflict effect not mediated by benzodiazepine receptors or by non-specific drug interference on nociceptive threshold or water consumption. These results reinforce the hypothesis that this cannabinoid has anxiolytic properties.
Moreira
Fabrício A
FA
Department of Pharmacology, FMRP, University of São Paulo, Av Bandeirantes, 3900, 14049-900, Ribeirão Preto, SP, Brazil. farmoreira@yahoo.com.br
Aguiar
Daniele C
DC
Guimarães
Francisco S
FS
D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001007:Anxiety / Q000523:psychology*; D002185:Cannabidiol / Q000494:pharmacology*; D003220:Conflict, Psychological; D008297:Male; D023421:Models, Animal; D011581:Psychological Tests; D051381:Rats; D017208:Rats, Wistar
D014151:Anti-Anxiety Agents; D002185:Cannabidiol