Evaluation of antioxidant capacity of the aqueous extract of Cynara scolymus L. (Asteraceae) in vitro and in Saccharomyces cerevisiae

Abstract

The present study evaluated the antioxidant capacity of the aqueous extract of the leaves of Cynara scolymus on Saccharomyces cerevisiae strains, proficient and deficient in antioxidant defenses, and by in vitro methods with 1,1-diphenyl-2-picrylhydrazyl (DPPH.), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS.+), inhibition of hydrogen peroxide, lipid peroxidation, formation of nitric oxide, and removal of the hydroxyl radical. A simultaneous quantitative analysis to total phenolics, flavonoids and hydrolysable tannin was also performed, and according to the results obtained, phenolic compounds (661.15±20.11 mg GAE/g of E), flavonoids (123.96±11.47 mg R/g of E) and hydrolysable tannin (14.25±3.18 mg GAE/g of E) were detected in the aqueous extract of C. scolymus. The aqueous extract at study showed high antioxidant capacity in all antioxidant methods in vitro and exhibited significant antioxidant capacity to protect strains of S. cerevisiae from oxidative damage induced by hydrogen peroxide. The analysis of the correlation made between the content of phenolic compounds and the different antioxidants in vitro methods, indicated that these compounds are mainly responsible for the antioxidant capacity of the aqueous extract of C. scolymus. Therefore, this study suggests that the aqueous extract of leaves of C. scolymus is a great natural source of compounds with antioxidant capacity.