Phytochemical Investigation by GCMS Analysis and Antioxidant Activity of Nigella sativa, Curcuma longa, Terminalia chebula, Foeniculum vulgare and Polyherbal Formulation

Abstract

Antioxidants are essential in counteracting free radicals and reducing oxidative stress. Polypharmacy is important traditional therapeutic herbal techniques that make use of the combination of multiple medicinal herbs to obtain additional therapeutic effectiveness. The objective of this study was to perform phytochemical screening by Gas Chromatography-Mass Spectrometry (GC-MS) analysis, and to evaluate the antioxidant activity of Nigella sativa (seeds), Curcuma longa (rhizome), Terminalia chebula (fruits), Foeniculum vulgare (fruits) ethanolic extracts, and an equal mixture of polyherbal formulation of all these four herbal extracts. The ethanolic extract of N. sativa, C. longa, T. chebula, and F. vulgare showed the presence of 31, 32, 33, and 52 chemical components, respectively. Four extracts and their polyherbal formulation were examined for antioxidant activity by DPPH scavenging method. Polyherbal formulation and extracts showed good to moderate antioxidant activities in a dose dependent manner as compared to the standard ascorbic acid. The N. sativa, C. longa, T. chebula, and polyherbal formulation exhibited IC50 value of 16.8, 44.9, 43.3, and 9.45 µg/ml, respectively compared to that of the standard ascorbic acid (IC50= 17.6 µg/ml), while F. vulgare extract did not display IC50 up to the highest selected concentration (50 µg/ml). By examining antioxidant activity, this investigation confirms the understanding of the chemical composition of selected plants and offers evidence to support their ethnomedical use.