In vitro Methods for Estimation of the Antioxidant Activity of Natural Compounds

Abstract

The role of free radicals in pathogenesis of many dysfunctions such as carcinogenesis, cardiovascular diseases and aging is intensively studied. Attention is focused on the contribution of natural antioxidants to protection against the processes. During the last decade, many analytical methods have been developed to determine the antioxidant activity of natural compounds and their mixtures in vitro. This paper reviews the assays used most frequently for this purpose. The procedures are divided into two groups. The first group involves the methods based on the generation of various radical species and their elimination by treatment with potential antioxidant compounds. The tests used for the evaluation of total antioxidant activity (e.g., Trolox equivalent antioxidant capacity, diphenylpicrylhydrazyl, oxygen radical absorbance capacity) and the methods testing the ability to prevent lipid peroxidation are included. The other group includes the procedures that are based on measurement of redox properties of compounds (ferric reducing antioxidant potential assay, cyclic voltammetry, HPLC with coulochemical detection).