10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 4 2012(October - December) Free radicals and reactive oxygen species are generated in the body due to various physiological and biochemical processes. They are responsible for various chronic diseases like cancer, diabetes and oxidative damage of DNA and proteins. There is a huge demand of herbal antioxidant compounds in the market. lessThan i greaterThan Padaeria foetida,Tribulus terrestris and Oxalis corniculata lessThan /i greaterThan are used in traditional healthcare system to cure various diseases. During the present investigation the biochemical profiling and lessThan i greaterThan In vitro lessThan /i greaterThan free radical scavenging activity of methanolic extract of the selected plants have been studied. Total polyphenol content was found highest in lessThan i greaterThan Paederia foetida lessThan /i greaterThan ( 35.67mg of gallic acid equivalent per gram of the extract) followed by lessThan i greaterThan Tribulus terrestris lessThan /i greaterThan (25.67 mg of gallic acid/gram of the extract) and lessThan i greaterThan Oxalis corniculata lessThan /i greaterThan extracts .(16.87 mg of gallic acid/gram of the extract). The IC lessThan sub greaterThan 50 lessThan /sub greaterThan value of the lessThan i greaterThan Padaeria foetida,Tribulus terrestris and Oxalis corniculata lessThan /i greaterThan 21.32 µg/ml,22.87 µg/ml and 32.78 µg/ml respectively. ROJITA MISHRA AND SATPAL SINGH BISHT Free radicals, reactive oxygen species, Polyphenol content,IC50 669-675