Astaxanthin enhances the longevity of Saccharomyces cerevisiae by decreasing oxidative stress and apoptosis.

The budding yeast, Saccharomyces cerevisiae, is an efficient model for studying oxidative stress, programmed cell death and aging. The present study was carried out to investigate antioxidant, the anti-apoptotic and anti-aging activity of a natural compound, astaxanthin, in S. cerevisiae model. The survivability of yeast antioxidant-deficient strains (sod1Δ, sod2Δ, cta1Δ, ctt1Δ and tsa1Δ) increased by 20%-40% when cells were pre-treated with astaxanthin, compared to hydrogen peroxide alone, as demonstrated in spot and colony forming unit assays. Reduced reactive oxygen species (ROS) levels, increased glutathione, decreased lipid peroxidation and induced superoxide dismutase activity in astaxanthin-treated cells indicate that astaxanthin protected the cells from oxidative-stress-induced cell death. In addition, astaxanthin protected anti-apoptotic-deficient strains (pep4Δ and fis1Δ) against acetic acid and hydrogen peroxide-induced cell death that suggests anti-apoptotic property of astaxanthin, and it was further confirmed by acridine orange/ethidium bromide, annexin V and 4',6-diamidino-2-phenylindole staining. The yeast chronological lifespan assay results showed that astaxanthin extends the lifespan of antioxidant-deficient strains by scavenging ROS, and anti-apoptotic-deficient mutants by protecting from apoptotic cell death compared to their respective untreated cells and wild type. Our results suggest that astaxanthin enhances the longevity of yeast S. cerevisiae by reducing oxidative stress and apoptosis.