Figure 3.

The effect of antioxidants on photogeneration of superoxide anion in suspension of melanolipofuscin (MLF) granules isolated from younger (18–29 y. o.) and older (50–59 y. o.) detected by EPR spin trapping using DMPO as a spin trap. (a) Representative EPR spectra of DMPO-OOH spin adducts recorded in irradiated MLF_50-59 samples (upper signal) and simulated EPR spectrum for MLF_50-59 sample (lower signal); simulation parameters: a_N = 1.2995 mT, a_H1 = 1.0458 mT, a_H2 = 0.1335 mT, and R² = 0.935. (b) Kinetics of the DMPO-OOH spin adduct formation during blue light illumination of MLF samples isolated from donors: 18–29 y. o. (solid, green circle) or 50–59 y. o. (solid, red triangle) and in suspension of granules from younger donors (open, green circle) and from older donors (open, red triangle), enriched with combination of antioxidants. (c) Calculated rates of light induced accumulation of DMPO-OOH spin adduct in suspensions of MLF with no antioxidants (no ZEA/TOC) (brown bar) and samples supplemented with mixture of zeaxanthin and α-tocopherol (+ ZEA/TOC) (white bar). Values are means of three replicate samples (error bars indicate SD (n = 3)). Outcomes differed significantly between irradiated MLF samples from each donors group (18–29 y. o. and 50–59 y. o.) and between light treated MLF_18-29 and MLF_50-59 without and with antioxidants, as indicated by asterisks (t-test analyses, p < 0.05).