Towards the use of non-psychoactive cannabinoids for prostate cancer.

The palliative effects of Cannabis sativa (marijuana), and its putative main active ingredient, Δ(9) -tetrahydrocannabinol (THC), which include appetite stimulation, attenuation of nausea and emesis associated with chemo- or radiotherapy, pain relief, mood elevation, and relief from insomnia in cancer patients, are well-known. Because of the adverse psychoactive effects of THC, numerous recent preclinical studies have been focused on investigating other non-psychoactive constituents of C. sativa, such as cannabidiol, for potential therapeutic use. In this issue of the British Journal of Pharmacology, De Petrocellis and colleagues present comprehensive evidence that plant-derived cannabinoids, especially cannabidiol, are potent inhibitors of prostate carcinoma viability in vitro. They also showed that the extract was active in vivo, either alone or when administered with drugs commonly used to treat prostate cancer (the anti-mitotic chemotherapeutic drug docetaxel (Taxotere) or the anti-androgen bicalutamide (Casodex)) and explored the potential mechanisms behind these antineoplastic effects.