Assessment of total phenolic content and antioxidant potentiality of selected Indian folk medicinal plants by spectrophotometric method

Natural antioxidant capacity of five important folk medicinal plants measured in vitro. Total phenolic content (TPC), flavonoid content (FC) and free radical scavenging capacity of ethanolic, methanolic and aqueous leaf extracts of Lippia alba (LA), Annona squamosa (AS), Hyptis suaveolens (HS), Commiphora wightii (CW) and Milletia pinnata (MP) was assessed using spectrophotometric method. Folin ciocalteu and aluminium chloride method employed to optimise TPC and FC. Free radical scavenging potentiality of leaf extracts was assessed using Ferrous ion chelation (FIC), 2, 2'-diphenyl-1-picrylhydrazyl (DPPH•) scavenging, Hydroxyl (OH•) radical scavenging (HRS) and Superoxide (O- 2) radical scavenging (SRS) methods. Results revealed that the TPC (96.22±5.85 to 519.23±34.90 ?g GAE/gm dry weight) were found significant in aqueous extracts from all the plants except AS (p<0.05). For FC (?g QCE/gm dry weight), ethanol was found optimum for LA (463.94±6.49), CW (289.99±2.70) and MP (347.47±4.50) whereas, aqueous was found more appropriate for rest two plants were found significant instead of ethanol and methanol (all p<0.05). The lowest IC50 (?g/ml) were recorded from A. squamosa (27.72±8.95), H. suaveolens (27.78±0.88), C. wightii (27.18±0.16) and M. pinnata (27.30±0.03). All plants have reflected a high antioxidant capacity; however, the highest antioxidant activity was reported from ethanolic extract of H. suaveolens followed by L. alba, A. squamosa, C. wightii and M. pinnata. Hence, these studies show that all folk medicinal plants contain potential antioxidant bioactive compounds