Taxifolin Potently Diminishes Levels of Reactive Oxygen Species in Living Cells Possibly by Scavenging Peroxyl Radicals

Taxifolin, a naturally occurring dihydroflavonol, has been reported to possess antioxidant activity, whereas there is little information regarding its antioxidant potency as a flavonoid. In the present study, the antioxidant efficacy of taxifolin in living cells was compared to that of catechin, a potent radical scavenger, by using flow cytometry with the redox-sensitive fluorescent dye, 2′,7′-dichlorodihydrofluorescein diacetate. Further, diminishing efficacy of taxifolin on peroxyl radicals was assessed by using an electron spin resonance spin-trapping technique. Taxifolin significantly reduced tert-butyl hydroperoxide-induced increases in Reactive Oxygen Species (ROS) levels in Caco-2 cells; the effect of taxifolin was stronger than that of catechin. Taxifolin also scavenged peroxyl (ROO^•) radicals with statistically significance compared to that of catechin. This study showed that taxifolin has the potential to diminish ROS levels in living cells, possibly by scavenging ROO^•.