title: The lipophilic antioxidants alpha-tocopherol and coenzyme Q10 reduce the replicative lifespan of Saccharomyces cerevisiae.
abstract: Reactive oxygen species contribute to cellular ageing and an increased level of oxidative stress is often associated with ageing in many organisms. Supplementation of antioxidants has been advocated to decrease cellular oxidative stress and potentially extend lifespan. A genetically modified K6001 strain of Saccharomyces cerevisiae was employed to determine the effect of several antioxidants, including D-erythroascorbic acid, alpha-tocopherol and coenzyme Q(10) on yeast cell replicative ageing. The replicative lifespan of the K6001 strain was assessed by absorbance change as cells exhibited a linear growth in glucose medium. In this study, water-soluble D-erythroascorbic acid had little effect on cell replicative lifespan. However, supplementation of the growth medium with the lipophilic antioxidants alpha-tocopherol increased oxidative stress and decreased cell lifespan. The use of alpha-tocopherol analogues revealed that the antioxidant activity and the membrane retention ability of alpha-tocopherol were involved in the lifespan reduction effect. Supplementation with either coenzyme Q(10) alone, or in combination with alpha-tocopherol also led to a reduction in yeast replicative lifespan. This study highlights a potential pro-oxidant action of antioxidants.
authors.affiliation: Ramaciotti Centre for Gene Function Analysis and Department of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Yuen Ting
authors.initials: YT
authors.lastname: Lam
authors.forename: Roland
authors.initials: R
authors.lastname: Stocker
authors.forename: Ian W
authors.initials: IW
authors.lastname: Dawes
mesh_terms: D000375:Aging / Q000187:drug effects; D000975:Antioxidants / Q000494:pharmacology*; D002478:Cells, Cultured; D004261:DNA Replication / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D030781:Organisms, Genetically Modified; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000502:physiology*; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000494:pharmacology; D024502:alpha-Tocopherol / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D014451:Ubiquinone; C024989:coenzyme Q10; D024502:alpha-Tocopherol