Protective Effect of Astaxanthin on Yeast Cells with Defects in Mitochondrial Function under Oxidative Stress and Aging.

Mitochondria are involved in electron transport for energy production, generating cellular ATP through oxidative phosphorylation, which in turn generates reactive oxygen species (ROS). When mitochondrial ROS exceeds the ability of antioxidant enzymes to scavenge free radicals, it leads to mitochondrial dysfunction. In this study, we used astaxanthin, a well-known natural anti-aging compound, but its unique role in protecting yeast cells with mitochondrial dysfunction is poorly understood. Pre-treatment of astaxanthin significantly increased the viability of these mutant strains (bcs1∆, cox10∆, sdh2∆, sdh4∆, and sco1∆) when compared to H2O2-treated cells and growth in non-fermentable media, as demonstrated in colony-forming unit and spot assays. Astaxanthin pre-treated cells show a decrease in the levels of intracellular ROS, catalase activity, apoptosis, and an increase in mitochondrial membrane potential compared to H2O2-treated cells. This demonstrates that astaxanthin protects cells from oxidative stress-induced cell death. Similarly, pre-treatment with astaxanthin modulates the expression of nuclear-encoded mitochondrial genes (mitonuclear genes) and DNA repair genes (APN1 and OGG1) under oxidative stress. These results indicate that astaxanthin scavenges ROS and mitigates oxidative DNA damage. Astaxanthin also extends the lifespan of short-lived mutant strains as evaluated by the chronological lifespan assay. Overall, this study indicates that astaxanthin, a powerful antioxidant, supports cells with mitochondrial dysfunction and can be used as an anti-aging compound to encourage healthy aging.