Extracts from the Mediterranean Food Plants Carthamus lanatus, Cichorium intybus, and Cichorium spinosum Enhanced GSH Levels and Increased Nrf2 Expression in Human Endothelial Cells

The Mediterranean diet is considered to prevent several diseases. In the present study, the antioxidant properties of six extracts from Mediterranean plant foods were assessed. The extracts' chemical composition analysis showed that the total polyphenolic content ranged from 56 to 408 GAE mg/g dw of extract. The major polyphenols identified in the extracts were quercetin, luteolin, caftaric acid, caffeoylquinic acid isomers, and cichoric acid. The extracts showed in vitro high scavenging potency against ABTS(•+) and O(2) (•−) radicals and reducing power activity. Also, the extracts inhibited peroxyl radical-induced cleavage of DNA plasmids. The three most potent extracts, Cichorium intybus, Carthamus lanatus, and Cichorium spinosum, inhibited OH(•)-induced mutations in Salmonella typhimurium TA102 cells. Moreover, C. intybus, C. lanatus, and C. spinosum extracts increased the antioxidant molecule glutathione (GSH) by 33.4, 21.5, and 10.5% at 50 μg/ml, respectively, in human endothelial EA.hy926 cells. C. intybus extract was also shown to induce in endothelial cells the transcriptional expression of Nrf2 (the major transcription factor of antioxidant genes), as well as of antioxidant genes GCLC, GSR, NQO1, and HMOX1. In conclusion, the results suggested that extracts from edible plants may prevent diseases associated especially with endothelium damage.