Phytochemical analysis and comprehensive evaluation of antimicrobial and antioxidant properties of 61 medicinal plant species

AbstractPlants are rich source of therapeutic compounds that have tremendous applications in pharmaceutical industry. To find new sources of antimicrobial and antioxidant agents, methanol/chloroform and aqueous extracts of 61 medicinal plants were evaluated systematically. Antimicrobial activity was assessed against six bacterial and five fungal strains, while natural antioxidants were studied using reducing power (RP), total antioxidant capacity (TAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Six plants exhibited broad spectrum antibacterial activity while two exerted significant antifungal activity. Total phenolic content (TPC) of the samples varied from 20.2 to 85.6mg/g dry weight (DW) in M/C extracts and 5.5 to 62.1mg/g DW in aq. extracts, expressed as gallic acid equivalents (GAE). Total flavonoid content (TFC) varied from 2.9 to 44.5mg quercitin equivalent (QE)/g DW of sample for M/C extracts and 2.4 to 37.1mg QE/g DW for aq. extracts. The results showed that antioxidant activities of plant species varied to a great extent not only among extracts (M/C and aq.) but also between the assays used for antioxidant evaluation. Significant linear correlation (p