Estimation, Characterization of Phenolics Compounds and in Vitro Evaluation of the Antioxidant Activity of Thymus Fontanesii Boiss Et Reut Extracts

Abstract

This study aimed to investigate the hydro methanolic extract and its fractions of aerial parts from Thymus fontanesii Boiss et Reut for their total phenolic and flavonoid contents, characterization of compounds in hydro methanolic extract, and antioxidant activity. The total phenolic and flavonoids were determined by Folin-Ciocalteu and aluminium chloride methods, respectively. The characterization of the crude hydromethanolic extract was done by HPLC UV-DAD, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), andcarotene-linoleic acid tests were used to assess antioxidant activity in vitro. The extracts' total phenolic and flavonoid concentrations ranged from 14.56-237.6 mg gallic acid equivalent (GAE)/g. extract and 1.63-2.27 mg quercetin equivalent (QE)/g extract, respectively where the ethyl acetate fraction has the highest value. The characterization of hydro methanolic extract has revealed the presence of salicylic acid, coumaric acid, rosmarinic acid synergistic acid, naringenin 7-glucoside, and luteolin 7-glucoside. The results of antioxidant tests indicated that for the antiradical test the diethyl ether fraction exhibited stronger antioxidant activity, for the FRAP test methanolic extract was more active than other fractions, at least the chloroform fraction was the stronger protector of β-carotene-linoleic acid system against lipids oxidation. Considering these results T. fontanesii Boiss et Reut aerial part can be used for developing antioxidants, that can act against various oxidative diseases.