The antioxidant activity of ethanolic and aqueous extracts of dandelion (Taraxacum officinale L.)

Abstract Introduction : Dandelion ( Taraxacum officinale L.) has been commonly used in traditional and contemporary medicine due to its diuretic and hepatoprotective properties. It contains polyphenols, vitamins and terpenes – i.e. compounds with antioxidant potential. Natural antioxidants protect organisms against oxidative stress, an important factor in the ageing process and in the pathogenesis of neoplastic, cardiovascular, neurodegenerative and some other diseases. Materials and methods : Raw dandelion plant material consisted of fresh and dried leaves, flowers and roots, harvested from a natural site. The extracts for analysis were prepared using an ultrasonic bath (extraction time 15, 30 and 60 min) in water, and 40% (v/v), 70% (v/v) and 96% (v/v) ethanol mixtures used as solvents. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing anti-oxidant power (FRAP) methods. Results : The antioxidant activity of dandelion depended on the type of raw material used, as well as the type of solvent and extraction time. The highest DPPH activity was found for dried flower extracts prepared in 70% ethanol for 30 min. With FRAP method, the highest reduction capacity was observed for dried leaf extracts in 40% ethanol for 30 min. Conclusions : The antioxidant potential of ethanolic and aqueous dandelion extracts was observed. This finding suggests the usefulness of this plant as a source of antioxidants to be used in pharmaceutical and cosmetic industries.