Antiradical and antioxidant activity of flavones from <i>Scutellariae baicalensis radix</i>

<div><p>We evaluated the antioxidant properties of four main flavones from <i>Scutellaria baicalensis</i>: baicalein, wogonin and their glucuronides – baicalin and wogonoside. We used three <i>in vitro</i> assays: free radical scavenging with 2,2′-diphenylpicrylhydrazyl radical, transition metal ions reducing power by phosphomolybdenum assay and inhibition of the hydroxyl radical-induced peroxidation of linoleic acid assay. All flavones have antioxidant capacity, which differs depending on the structure and mechanisms of activity. In all tests, only baicalein – the aglycone with three adjacent hydroxyl groups – exhibited consistent antioxidant effect. Wogonin protected linoleic acid against oxidation. Baicalin displayed less potent antioxidant properties whereas wogonoside did not have significant antioxidant activity.</p></div>