ASSESSMENT OF ANTIOXIDANT ACTIVITY AND PHYTOCHEMICAL SCREENING OF COLOCASIA ESCULENTA CORM

Colocasia esculenta corm aqueous extract was assessed for its in vitro antioxidant capacity and free radical scavenging potential by seven different assays, viz. total phenolic content, total flavonoid content, total flavonol content, reducing power estimation as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities. Results reveal that the total phenolic, total flavonoid and total flavonol content present in C. esculenta corm extract were found to be 68.25 ± 17.52 mg of GAE (Gallic Acid Equivalent)/g, 26.70 ± 40.18 mg of QE (Quercetin Equivalent)/g and 1.40 ± 53.99 mg of QE/g of dry extract respectively. Reducing power of the extract was found to be concentration dependent as it increase with increase in concentration and it was maximum at the highest evaluated concentration of 200 µg/ml. Significant antioxidant efficacy of C. esculenta corm was further confirmed by IC₅₀ values of DPPH, NO and ABTS radical scavenging assays as they were found to be 74.34 ± 12.17 µg/ml, 65.52 ± 7.76 µg/ml and 132.29 ± 14.13 µg/ml respectively. Results were compared with the reference, ascorbic acid. Phytochemical screening of the aqueous extract of C. esculenta corm also validated its antioxidant potential by showing the presence of certain phytochemicals viz. tannins, saponins, flavonoids, steroids, carbohydrates, proteins and glycosides supposed to be responsible for its antioxidant efficacy. Thus, C. esculenta corm may be explored for developing a novel antioxidant agent.