Researchers at the University of California have reported that resveratrol inhibits acne growth and boosts the antibacterial effect when combined with benzoyl peroxide.
The study, published on Sept. 17, 2014, in Dermatology and Therapy, sought to dermine whether resveratrol may be a potential treatment for acne vulgaris. The researchers conduced colony-forming unit (CFU) assays with transmission electron microscopy using Propionibacterium acnes (P. acnes) treated with different concentration of resveratrol, benzoyl peroxide or a combination of both. The cultures were monitored for 10 days. Blood was drawn from healthy human volunteers, and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays were used to assess cytotoxicity in monocytes and keratinocytes.
The researchers found that all concentrations of benozyl peroxide killed the bacteria, but that these effects were not sustained past 24 hours. Conversely, resveratrol inhibited bacterials growth for a longer period of time rather than killing the bacteria. Therefore, together these two ingredients killed the bacteria initially and prevented development of future bacteria.
Electron microscopy of P. acnes treated with resveratrol revealed altered bacterial morphology, with loss of membrane definition and loss of well-defined extracellular fimbrial structures. Resveratrol was less cytotoxic than benzoyl peroxide.
The researchers concluded that the combination of these two compounds may be a future treatment for acne. Not only would the two have better antibacterial efficacy agains P. acnes, but their combination reduces the concentration of benzoyl peroxide needed, thereby reducing cytotoxicity.
Further in vivo human studies and clinical trials are needed to validate these findings. The study was funded by the Women’s Dermatologic Society and National Institutes of Health. A patent application has been filed for the combination treatment of benzoyl peroxide and resveratrol, which is owned by University of California Regents.