Brimonidine is a highly specific α2 adrenergic receptor agonist and acts on vascular smooth muscle to constrict blood vessels. Currently, it is used for the treatment of rosacea as a gel formulation under the brand name of Mirvaso. We experienced that Mirvaso treatment of patients with acne and rosacea resulted in alleviation of flushing as well as improvement of acne. Since it is well recognized that inflammatory reaction induced by Propionibacterium acnes (P.acnes) is critically important in the pathogenesis of acne, we speculate that brimonidine has anti-inflammatory activity in addition to its vasoconstrictive effect. In this study, we investigated the effects of brimonidine tartrate on P.acnes-induced inflammation in monocytes and keratinocytes that are importantly involved in acne pathogenesis. We examined the expression of α2 adrenergic receptor in both monocytes and keratinocytes. When applied to both cells, brimonidine tartrate suppressed the P.acnes-induced pro-inflammatory cytokine such as IL-1β, IL-6, and IL-8 in monocytes and keratinocytes. Also, brimonidine tartrate reduced pro-inflammatory cytokine secretion by P.acnes. These results demonstrate that brimonidine has additional anti-inflammatory property besides its vasoconstrictive potential, suggesting that brimonidine is beneficial in the treatment of patients with acne and rosacea via dual action mechanisms.

Effects of brimonidine tartrate on P. acnes-induced inflammatory reaction