Effects of bioflavonoid quercetin on delayed luminescence of hydrogen peroxide-treated yeast cells

Quercetin is a natural antioxidant. Due to its quenchingeffect on free radicals, we expect that quercetin hasconsistent effects on delayed luminescence (DL) of cells.Quantification of these effects can help answer thequestion on the origin of DL, which at the moment is stilla matter of debate. We determined clonogenic survivaland DL emission spectra of Saccharomyces cerevisiaeyeast cells following treatment with various doses of theoxidant agent hydrogen peroxide (H2O2), in the presenceor absence of the bioflavonoid at different concentrations.We obtained that H2O2 treated cells emit more photons inthe red-region of the visible domain. A consistentdecrease in DL intensity is observed in quercetin-treatedcells, suggesting that free radicals substantially contributeto DL emission in this cell type.