screening of thirteen medicinal plant extracts for antioxidant activity

antioxidants are vital substances which possess the ability to protect the body from damage caused by free radical induced oxidative stress. a variety of free radical scavenging antioxidants exist within the body which many of them are derived from dietary sources like fruits, vegetables and teas. in this study the antioxidant activity and radical scavenging activity of methanolic extracts of selected plant materials, traditionally used by iranian population as folk remedies was evaluated against linoleic acid peroxidation and 2,2-diphenyl-1-picrylhydrazyl radical. the antioxidant activity expressed as ic50 ranged from1.28 ng/ml in biebresteinia multifida to 63.48 ng/ml in polypodium vulgare. radical scavenging activities expressed as ic50 varied from 1.83 µg/ml in salix sp. to 187.88 µg/ml in allium hirtifolium.