Evaluation of antioxidant efficacy of different fractions of Tagetes erecta L. Flowers

Abstract

Oxidative stress is an important pathogenesis of numerous chronic diseases. Free radicals and other reactive oxygen species are recognized as agents involved in the pathogenesis of sicknesses. The main characteristic of an antioxidant is its ability to trap free radical. Plants rich in phenolic compounds are generally reported to show good antioxidant activity. Tagetes erecta L (Marigold) belongs to the family Asteraceae. The flowers are especially employed to cure eye diseases, colds, conjunctivitis, coughs, ulcer, bleeding piles and to purify blood. The extractive efficiency of phenolic compounds from plant material is greatly dependent on the choice of solvent. In this study, six solvents of different polarity viz., hexane, toluene, ethyl acetate, acetone, methanol and water have been used for the extraction of Tagetes erecta L. flower by individual cold percolation method. Phenolic and flavonoid content of extracts were determined using Folin- ciocalteu assays and aluminium chloride colorimetric method respectively. Antioxidant activity was carried out by DPPH radical scavenging activity assay, superoxide free radical scavenging (SO) assay, ABTS radical cation scavenging activity, ferric reducing antioxidant power (FRAP), Reducing capacity assessment. Maximum extractive yield was in water extract followed by methanol extract. There was a direct correlation between phenolic content and antioxidant activity. Methanolic extract had maximum phenolic content and maximum FRAP and SO activity. ABTS and DPPH did not show positive correlation with total phenol content in ethyl acetate extract. Ethyl acetate extract had maximum flavonoid content. T. erecta flowers can be used as a natural source of antioxidants to combat the oxidative stress related disorders. Key word: Tagetes erecta, Influence of solvent, Antioxidant activity, positive correlation