Radical scavenging,proteases activities,and phenolics composition of bark extracts from 21 medicinal plants

Stem barks derived from twenty-one medicinal plants were extracted in methanol (100%) and acetone-water (70: 30 v/v) and at room as well as at reflux temperature conditions. total phenolic contents,determined using fc (folin ciocalteu) reagent,ranged from 528 to 715 mg gae/g of crude extract. 15 out of 21 plants showed dpph activity more than 90% and the rest of plants exhibited the activity in the range of 87-89%. the methanolic extract of p. granatum obtained at room temperature showed the highest antiradical activity (96%). the extracts with similar % radical scavenging of dpph showed significant variation in ec50 value. radical scavenging activity of e. rostrata,m. champaca,a. modesta,p. roxburghii,p. longifolia,e. suberosa,and f. infectoria was evaluated for the first time. a strong correlation between total phenols and antiradical activity was exhibited with r values ranging from 0.7580 to 0.8874 indicating a linear relationship the extracts phenolic composition was studied by hplc. all extracts showed remarkable antioxidant activity (87 to 96%) while moderate activity was exhibited against protease (22 to 56%). gallic acid,tannic acid,quercetin,rutin,catechin,hesperidin,and cinnamic acid were identified as the major phenolic acids in the extracts of selected medicinal plants. © 2015 muhammad asam raza et al.