Abstract

ANTIOXIDANT ASSAY OF CITRUS MEDICA L PEEL METHANOLIC EXTRACT BY USING ABTS*+ DECOLOURISATION METHOD

M. Parvathi Nandan and Dr. Meena Vangalapati*

ABSTRACT

Antioxidants are chemicals that interact with and neutralize free radicals, thus preventing them from causing damage. Antioxidants are also known as “free radical scavengers.” Antioxidants help organisms deal with oxidative stress, caused by free radical damage. Free radicals are chemical species, which contains one or more unpaired electrons due to which they are highly unstable and cause damage to other molecules by extracting electrons from them in order to attain stability. Antioxidant substances block the action of free radicals which have been implicated in the pathogenesis of many diseases including atherosclerosis, ischemic heart disease, cancer, Alzheimer’s disease and in the aging process. Flavonoids and phenolic compounds are the natural antioxidants present mainly in green leafy vegetables and fruits. The total antioxidant capacity of plant extract was determined by using ABTS*+ decolourisation assay. Citrus medica L is a rich source of phenolic compounds and flavonoids. In the present investigation, the total phenolic, flavonoids content and the total antioxidant capacity of Citrus medica L peel which was expressed in terms of trolox equivalents were determined. The results showed that methanolic extract of peel powder contains total phenolic content and flavonoids of concentration 196 μg/ml and 24 μg/ml respectively and the TEAC (Trolox equivalent antioxidant capacity value) for methanolic extract of IC50 value was 8.1μM.

Keywords: Antioxidants, Flavonoids, Citrus medica L, ABTS*+ decolourisation assay, Trolox, TEAC.