Pharmacologyonline 2: 450459 (2009) Shukla et al. 450 IVITRO ATIOXIDAT ACTIVITY OF AERIAL PARTS OF LIPPIA ODIFLORA RICH. Sangita Shukla* 1 , Saluja A K 2 , Pandya S S 3 1 Department of Pharmacognosy, Indukaka Ipcowala College of Pharmacy, New Vallabh Vidyanagar,P.O. Box 53, Po. Vitthal Udyognagar, Dist. Anand, Gujarat+ 388121. Phone: +91 9898047135 2 Department of Pharmacognosy, A.R.College of Pharmacy, Vallabh Vidyanagar, Gujarat+388120 3 Department of Pharm.Chemistry, Babaria Institute of Pharmacy, Varnama, Gujarat+391240 Summary As per Ayurveda, Rich. [ (Linn.) Greene.] is used in various diseases, some of which occur due to generation of free radicals. In the present study, antioxidant and free radical scavenging activity of defatted and fractionated methanolic extract of aerial parts of (MELN) was evaluated using methods like 1, 1+diphenyl, 2+picryl hydrazine (DPPH) radical scavenging activity, H 2 O 2 scavenging activity, Nitric Oxide (NO) radical scavenging activity, Nitro Blue Tetrazolium (NBT) reduction assay, β+carotene+ lineolate bleaching assay and Total reduction ability by Fe 3+ +Fe 2+ transformation (Reducing power assay). Ascorbic acid was used as a reference antioxidant compound. In DPPH radical scavenging activity, H 2 O 2 scavenging activity, NO scavenging activity and NBT reduction assay the IC 50 values obtained for MELN were found to be 799.74 @g/ml, 53.15 @g /ml, 61.51 @g/ml and 45.60 @g/ml respectively and for Ascorbic acid the IC 50 values were found to be 511.36 @g/ml, 33.06 @g/ml, 42.40 @g/ml and 94.82 @g/ml respectively. In the reduction power assay increase in absorbance was observed in a dose dependant manner. Total phenolic content was measured using Folin+Ciocalteu phenol reagent which showed that 1 mg of the extract contained 114.89 @g/ml total phenolics equivalent to gallic acid. The results obtained in the present study indicate that the antioxidant activity of MELN may be due to the presence of flavonoids. Key Words: ,antioxidant, flavonoids, total phenolic content.