Antioxidant and Free Radical Scavenging Activities of Different Fractions of Anethum Graveolens Leaves Using in Vitro Models

Summary The protective effects of fruits and vegetables against chronic diseases have been in part attributed to the presence of antioxidants in these foods. Anethum graveolens L. (dill) [Umbelliferae] is used in Iranian folk medicine as an anti-hypercholesterolaemic plant. To clarify the mode of action, primarily the antioxidant potency of the leaf crude extract and its different fractions (diethyl ether, ethyl acetate and water) were investigated, employing various established in vitro systems such as the ferric reducing antioxidant power (FRAP) and 2, 2′-azinobis 3-ethylbenzothiazoline-6sulfonate (ABTS) assays, 1,1-diphenyl-2-picrylhydrazyl (DPPH) /nitric oxide radical scavenging, iron ion chelating activity and inhibitory effect on Fe 2+ /ascorbate induced lipid peroxidation in rat liver homogenate. In the above assays, crude extract and all the fractions showed antioxidant potential to varying degrees. Among these fractions, ethyl acetate fraction exhibited higher antioxidant potency compared to the other fractions. The ethyl acetate fraction also exhibited the highest anti-hyperlipidaemic effects in animal models. These data clearly indicate that A. graveolens especially its ethyl acetate fraction possess potent antioxidant property, and this might account for its anti-hyperlipidaemic and anti-hypercholesterolaemic effects. Kew words: Anethum graveolens, Antioxidant potency, Ferric reducing antioxidant power, Lipid peroxidation, Nitric oxide radical scavenging.