Pro- and antioxidant effects and cytoprotective potentials of nine edible vegetables in southwest Nigeria.

Antioxidant and cytoprotective activities of boiled, cold, and methanolic extracts of nine edible vegetables in Southwest Nigeria were evaluated in the 1,1-diphenyl-2-picrylhydrazyl free radical assay and hemagglutination assay in bovine erythrocytes, respectively. Crassocephalum rubens showed the highest antioxidant activity (56.5%), Solanum americanum and Vernonia amygdalina exhibited moderate antioxidant activity (26.0-37.5% and 14.8-36.2%, respectively), Solanum macrocarpon, Telfaria occidentalis, Amaranthus hybridus, and Jatropha tanjorensis produced weak activity (1.6-15.8%, 1.6-7.7%, 2.8-6.62%, and 10.7-12.1%, respectively), while Celosia argentea and Talinum triangulare were pro-oxidants. It was also shown that extracts from all the vegetables are pro-oxidants at high concentrations of either 1 or 5 mg/mL or both. On the other hand, the studies on the cytoprotective effect showed that all the plant extracts demonstrated a very low hemagglutination titer value between 0.32 and 5.56 except S. americanum methanolic extract, which had a titer of 50.0. These results indicated correlation between the antioxidant properties and the hemagglutination values of these plant extracts; however, the membrane stabilizing capacity of the extracts supports the plants' antioxidant activity.