Baicalein inhibits oxidative stress-induced cellular damage via antioxidant effects

Baicalein (5,6,7-trihydroxyflavone) is a phenolic flavonoid compound derived mainly from the root of Scutellaria baicalensis Georgi, a medicinal plant traditionally used in oriental medicine. In our previous study, baicalein attenuated mitochondrial oxidative stress by scavenging reactive oxygen species (ROS) and by induction of nuclear factor erythroid 2-related factor 2 transcription factor-mediated manganese superoxide dismutase. In the present study, the protective effects of baicalein against oxidative stress-induced damage, especially cellular components including DNA, lipid, and protein, were studied. The results of this study showed that baicalein scavenged intracellular ROS. Baicalein inhibited the H2O2-induced DNA damage that was demonstrated by decreased phospho-H2A.X expression and DNA tail formation. In addition, it prevented the lipid peroxidation shown by the fluorescence intensity of diphenyl-1-pyrenylphosphine and the formation of thiobarbituric acid reactive substances. Moreover, baicalein inhibited protein oxidation demonstrated by protein carbonyl formation. Furthermore, baicalein protected cells via the inhibition of apoptosis induced by H2O2. The findings of this study suggest that baicalein provides protection for cellular components against oxidative damage via scavenging ROS and inhibiting apoptosis.