Effects of red wine intake on human salivary antiradical capacity and total polyphenol content

The protective effects of grape polyphenols have been reported on oral health, though unreasonable alcohol consumption represents a risk factor for developing oral cancer. The possible effects of red wine consumption on salivary antiradical activity were investigated in healthy volunteers for the first time, to the best of our knowledge. Time-course (from 0 min to 240 min) changes of salivary radical-scavenging capacity were measured by the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, in twelve healthy volunteers, after the intake of red wine (125 mL), a capsule of red wine extract (300 mg) or water (125 mL). Furthermore, time-course of salivary total polyphenol levels, detected by the Folin-Ciocalteu colorimetric method, was also determined. Both ABTS and DPPH tests showed that red wine consumption did not increase salivary antiradical activity in volunteers. Conversely, red wine extract administration caused a marked rise in salivary ABTS radical-scavenging capacity within 30 min, followed by a plateau up to 240 min. The same treatment also raised salivary DPPH radical-scavenging activity at any time point, though to a minor extent. The highest salivary polyphenol concentration was reached 30 min after wine drinking, followed by a steady decrease up to 240 min. Wine drinking was not associated to a reduced salivary antiradical capacity. However, wine extract greatly improved the salivary antioxidant status.