Cannabinoids, a group of compounds that encompasses some major components of cannabis such as THC and CBD, are long known to inhibit abnormal proliferation of cancerous cell lines. More recently, the cannabinoid receptors which these compounds directly bind to and act on to induce downstream effects were found to be widely expressed in keratinocyte, a type of skin cells.
For these reasons, medical researchers hypothesized that cannabinoids can have therapeutic benefits for psoriasis, a skin disorder in which skin cells multiply up to 10 times faster than normal, clumping up into dry, bumpy patches. A research study therefore was conducted on 4 cannabis-derived cannabinoids, THC, CBD, cannabinol, and cannabigerol for their ability to inhibit the proliferation of a hyper-proliferating human keratinocyte cell line. Indeed, the scientists found that all tested compounds inhibited excessively growing keratinocytes in a concentration-dependent manner, with higher cannabinoid concentration halting proliferation of more skin cells more quickly. Researchers then hypothesized that the mechanism of this action may involve the activation of cannabinoid receptors in skin cells. This, however, did not seem to be the case because when the cannabinoid receptors were blocked, the anti-proliferating activity of the cannabis-derived cannabinoids remained.
In other words, although cannabinoids indeed inhibit keratinocyte proliferation, and therefore can be potential drug candidates for psoriasis, their mechanism of action is not through the activation of cannabinoid receptors, their main biological targets. That mechanism, until now, remains to be explored.
Dr. Caplan and his team treat patients with psoriasis often and would be happy to discuss your interest in medical cannabis and how it may help treat your psoriasis.