Anti-inflammatory Effect of Cannabidiol and Palmitoylethanolamide Containing Topical Formulation on Skin in a 12- O -Tetradecanoylphorbol-13-Acetate-Induced Dermatitis Model in Mice.

Background: Chronic inflammatory skin disorders, such as atopic dermatitis, have significant disease burden worldwide. Although efficacious, the adverse effect profile of topical corticosteroids limits long-term use. As an alternative, cannabinoids have been shown to have anti-inflammatory therapeutic effects.

Objective: The aim of this study was to assess the effects of a topical cannabinoid product using dermatitis mouse model.

Methods: Thirty-five mice were randomized into treatment groups. 12- O -tetradecanoylphorbol-13-acetate was used as an irritant on 1 ear with the contralateral ear serving as a control. Ear edema was calipered. The test product containing 0.9% cannabidiol and palmitoylethanolamide was compared with a potent topical corticosteroid.

Results: Treatment with topical cannabinoid formulation reduced ear edema by 51.27% at 24 hours' and 65.69% at 48 hours' postapplication. Alternatively, mometasone reduced ear edema by 89.82% at 24 hours and 98.25% at 48 hours. Natural reduction (control) in ear edema was 26.32% at 24 hours and 44.21% at 48 hours. Both test groups resulted in significantly decreased edema when compared with baseline ( P < 0.05), as well as compared with the negative control group ( P < 0.05).

Conclusions: Significant reduction in ear edema, a marker for localized cutaneous inflammation, could be attributed to anti-inflammatory properties of cannabinoids. Although effects were less robust than topical corticosteroid use, cannabinoid formulations have therapeutic promise for dermatitis.