Comparative antioxidant analysis of extracts prepared from Indigofera longiracemosa aerial parts identifies leaf methanolic extract as a promising antioxidant

Abstract

Extraction of phytochemicals from the leaves and stems of Indigofera longiracemosa, a previously underexplored dye-yielding plant, was done using four solvents of increasing polarity followed by in vitro assessment of their antioxidant potential. Of the four solvent extracts, methanol extract yielded the highest percentage of phytochemicals. Methanol extracts of leaves and stems also showed the best antioxidant potential in in vitro antioxidant assays. Further, comparison with known standard antioxidant molecules showed lower IC50 values for the extracts tested. Our study thereby validates for the first time the antioxidant potential of I. longiracemosa aerial parts, and identifies an extract enriched in phytochemicals capable of quenching free radicals in vitro at concentrations lower than or comparable to pure antioxidant molecules.