Phenolic constituents, antioxidant and cytoprotective activities of crude extract and fractions from cultivated artichoke inflorescence

The aim of this study was to investigate the chemical constituents of five phenolic-enriched fractions from artichoke (Cynara scolymus L.) inflorescence, and their antioxidant and cytoprotective effects. A total of 27 phenolic compounds have been tentatively identified and quantified. In addition, the antioxidant capacity (ABTS, DPPH, and FRAP assays) and inhibitory effect on intracellular reactive oxygen species (ROS) production in H2O2-induced HepG2 cells were evaluated. Compared to crude extract, purified extract, n-butanol (n-Bu) and water (H2O) fractions, the ethyl acetate fraction revealed the highest total phenolic and total flavonoid contents, and also showed the strongest antioxidant activity. The crude extract, purified extract, and fractions, in a concentration dependent manner, reduced oxidative stress levels in H2O2-induced HepG-2 cells, especially the ethyl acetate fraction. The inhibitory effects on cell apoptosis might be due to an up-regulation of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity.