Antioxidant Effect of Caffeic Acid Derivatives on Sod and Glutathione Defective Yeasts

Hydroxycinnamic acids have received particular attention because they are the most abundant phenolic class in our diet and because of the increasing interest in reducing oxidative damages. These damages are related to diseases such as cancer and atherosclerosis, as well as neurodegenerative disorders. The objective of this study was to evaluate the antioxidant protection of chlorogenic and caffeic acids and caffeic acid phenethyl ester (CAPE) against oxidative stress in vivo. Antioxidant activity was evaluated using BY4741 strain and superoxide dismutase- and glutathione-deficient (sod1 and gsh1) mutants of Saccharomyces cerevisiae through cell viability assays, lipid peroxidation levels and glutathione quantification. In the cell viability tests, caffeic acid promoted higher stress tolerance, with a 106% increase in S. cerevisiae BY4741. However, in the sod1 mutant, the effect of chlorogenic acid was more prominent, showing a 3.3-fold increase and in the gsh1 mutant all treatments provided a similar level of protection. The phenolic acids protected cell membranes in control and mutant cells at thesamelevel. CAPE maintained the GSH concentration at levels similar to the non-stressed control (48.6 +/- 10.9 nmol/mg of cells). The maintenance of cytoplasmic levels of GSH that was promoted by CAPE, despite the induction of stress, indicates its superior antioxidant protection to its precursor, caffeic acid.