Resveratrol inhibition of Propionibacterium acnes.

OBJECTIVES To evaluate the effects of the anti-inflammatory hydroxystilbene, resveratrol, on Propionibacterium acnes growth. METHODS Three different strains of P. acnes were tested against resveratrol at concentrations between 0 and 200 mg/L. Piceatannol was included as a second hydroxystilbene to compare with resveratrol, and erythromycin and benzoyl peroxide were used as positive controls. RESULTS After 24 h of treatment with resveratrol, the average 50% inhibitory concentration (IC(50)) was 73 mg/L and the average 100% inhibitory concentration (IC(100)) was 187 mg/L for the three strains of P. acnes tested. The IC(50) and IC(100) of piceatannol were 123 and 234 mg/L, respectively. The highest concentration of resveratrol tested (200 mg/L) was bactericidal, whereas lower concentrations were bacteriostatic. CONCLUSIONS Resveratrol, an anti-inflammatory hydroxystilbene, is capable of inhibiting P. acnes growth.