In vitro antioxidant evaluation of dandelion (Taraxacum officinale Web.) water extracts

Dandelion is a quite widespread medicinal plant, which is widely used as so up, salad, coffee substitute, wine and natural source of flavouring. Its ch oleretic, diuretic, anti-inflammatory, appetite-stimulating and laxative pr operties are well known. The aim of this study was to verify the antioxidan t properties of lyophilized extracts derived from dandelion root and leaves . The total polyphenol, flavonoid and free SH-group contents of root and le af extracts were determined spectrophotometrically as well as the hydrogen donating ability and reducing power property. Radical scavenging capacity o f extracts was measured in H2O2/(OH)-O-.-luminol-microperoxidase system by chemiluminometric method. The folium extract with approximately 3 times hig her polyphenol (9.9 g%) and 6 times higher flavonoid content (0.086 g%) pro ved to be more effective as hydrogen-donor (I-50 = 160 mu g), reducing agen t (740 ASE mg(-1)) and H2O2 scavenger (I-50 = 155 mu g) compared to radix e xtract with lower polyphenol and flavonoid content.