Resveratrol inhibits periodontal pathogens in vitro

Abstract

AIM: Oral hygiene maintenance is an essential requirement for successful orthodontic treatment in all patients, particularly ‘high-risk’ candidates with a history of periodontal disease. The gram-negative anaerobic bacteria, A. actinomycetemcomitans (Aa) and P. gingivalis (Pg), are key components in the aetiology of periodontal disease, and associated hard tissue destruction. Resveratrol is a phytoalexin, produced naturally by several plants when under attack by bacterial or fungal pathogens. It is found in many foods including mulberries, peanuts, and the skin of labrusca and muscadine grapes. The objective of this study was to evaluate the effect of resveratrol on growth of periodontal pathogens Aa and Pg in vitro. For comparison, resveratrol’s effect on a variety of other oral microorganisms was also evaluated. MATERIALS AND METHOD: As resveratrol demonstrates a poor solubility in water, different concentrations of resveratrol in the solvent dimethyl sulphoxide (DMSO) were added to calibrated suspensions of the microorganisms. As a control, a parallel series of dilutions containing the vehicle DMSO alone were used to measure the effect of the solvent. Minimum inhibitory concentrations of the periodontal pathogens were calculated. All suspensions were incubated for 1, 3, 6, and 24 hours in an anaerobic chamber at 37°C. At each time interval, selected dilutions from each culture broth were plated on blood agar plates. Colonies appearing on blood agar plates were visually counted at at day 3 for Aa, and day 5 for Pg. RESULTS: The periodontal bacteria, Aa and Pg, showed a significant decrease (P < 0.05) in viable counts after 1 hour, whilst no colony forming units were observed after 24 hours. There was no effect on the other microorganisms tested. CONCLUSION: Resveratrol possesses significant antimicrobial properties on periodontal pathogens in vitro.