Evaluation of Antioxidant Activity, Phenol and Flavonoid Contents of Some Selected Indian Medicinal Plants

Phenolic compounds from plants are a class of antioxidant agents which act as free radical terminators. Flavonoids show antioxidant activity and their mechanism of action are through scavenging or chelating process. Our present study, we carried out a systematic record of the relative antioxidant activity is selected Indian medicinal plant species extracts. The total phenol varied from 24.0 +/- 1 to 288.5 +/- 5 mg/g in the methanol extracts. Flavonoid contents were between 25.05 +/- 0.18 and 78.2 +/- 4.5 mg/g. 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging effect of the extract was determined spectrophotometrically. The highest radical scavenging effect was observed in Camellia sinensis with IC50 = 0.017 mg/ml. The potency of radical scavenging effect of Camellia sinensis extract was about 4 times greater than synthetic antioxidant butylated hydroxyl toluene (BHT). The greater amount of phenolic compounds leads to more potent radical scavenging effect as shown by Camellia sinensis extract.