Antimicrobial effect of resveratrol on dermatophytes and bacterial pathogens of the skin

The phytoalexin resveratrol is commonly found in food and drinks, including red wine, grapes, and peanuts. Many studies have shown that this compound has anti-inflammatory properties, and it has been ascribed as having health benefits that help to prevent cancer and coronary heart disease. A treatment that combines antimicrobial and anti-inflammatory actions may be desirable for alleviating many skin conditions that range in severity. Therefore, we evaluated the antimicrobial activity of resveratrol against bacteria and dermatophytes that are major etiologic agents of human skin infections. Using the broth microdilution protocol of the National Committee for Clinical Laboratory Standards (NCCLS) M7-A5, growth of the bacterial species Staphylococcus aureus, Enterococcus faecalis, and Pseudomonas aeruginosa was inhibited at 171-342 microg/mL of resveratrol in the solvent dimethyl sulfoxide. Using the NCCLS protocol M38-P, activity against the fungal species Trichophyton mentagrophytes, Trichophyton tonsurans, Trichophyton rubrum, Epidermophyton floccosum, and Microsporum gypseum was also tested. The growth of dermatophytes was inhibited at 25-50 microg/mL of resveratrol. Thus, this study indicates a novel application for resveratrol, a molecule of plant defense, to combat human fungal pathogens. Resveratrol and its analogs may have wide application to skin conditions that afflict a significant portion of our population, and may also have promising clinical potentials in diabetic wounds.