A low-Δ9tetrahydrocannabinol cannabis extract induces hyperphagia in rats

Appetite stimulation via partial agonism of cannabinoid type 1 receptors by Delta(9)tetrahydrocannabinol (Delta(THC)-T-9) is well documented and can be modulated by non-Delta(THC)-T-9 phytocannabinoids. Delta(THC)-T-9 concentrations sufficient to elicit hyperphagia induce changes to both appetitive (reduced latency to feed) and consummatory (increased meal one size and duration) behaviours. Here, we show that a cannabis extract containing too little Delta(THC)-T-9 to stimulate appetite can induce hyperphagia solely by increasing appetitive behaviours. Twelve, male Lister hooded rats were presatiated before treatment with a low-Delta(THC)-T-9 cannabis extract (0.5, 1.0, 2.0 and 4.0 mg/kg). Hourly intake and meal pattern data were recorded and analyzed using one-way analyses of variance followed by Bonferroni post-hoc tests. The cannabis extract significantly increased food intake during the first hour of testing (at 4.0 mg/kg) and significantly reduced the latency to feed versus vehicle treatments (at doses >= 1.0 mg/kg). Meal size and duration were unaffected. These results show only the increase in appetitive behaviours, which could be attributed to non-Delta(THC)-T-9 phytocannabinoids in the extract rather than Delta(THC)-T-9. Although further study is required to determine the constituents responsible for these effects, these results support the presence of non-Delta(THC)-T-9 cannabis constituent(s) that exert a stimulatory effect on appetite and likely lack the detrimental psychoactive effects of Delta(THC)-T-9. Behavioural Pharmacology 21:769-772 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.