Assessment of free radicals scavenging activity of seven natural pigments and protective effects in AAPH-challenged chicken erythrocytes

The purpose of this study was to compare the antioxidant capacities of seven natural pigments including the fat-soluble pigments curcumin, lycopene, lutein and β-carotene and water-soluble pigments - betalain, capsanthin and cyanidin-3-rutinoside relative to a commonly-used synthetic food antioxidant BHA. The antioxidant capacities of seven pigments and BHA were evaluated based on their ability to quench several free radicals, including DPPH, ABTS, O2·-, H2O2 as well as using FRAP assay. Specifically, curcumin and cyanidin-3-rutinoside, which showed the highest antioxidant capacities, were further investigated using a chicken erythrocyte model. After separating pretreatments of the two pigments, AAPH was added to the erythrocyte-pigment medium to induce oxidative stress. Then the attenuation effects of the two pigments on AAPH-induced oxidative damage in chicken erythrocytes were assessed. It was found that both curcumin and cyanidin-3-rutinoside significantly attenuated apoptosis and hemolysis, decreased MDA content, and increased T-SOD activity in a time- and dose- dependent manner.