title: Nicotinamide exerts antioxidative effects on senescent cells.
abstract: Nicotinamide (NAM) has been shown to suppress reactive oxygen species (ROS) production in primary human fibroblasts, thereby extending their replicative lifespan when added to the medium during long-term cultivation. Based on this finding, NAM is hypothesized to affect cellular senescence progression by keeping ROS accumulation low. In the current study, we asked whether NAM is indeed able to reduce ROS levels and senescence phenotypes in cells undergoing senescence progression and those already in senescence. We employed two different cellular models: MCF-7 cells undergoing senescence progression and human fibroblasts in a state of replicative senescence. In both models, NAM treatment substantially decreased ROS levels. In addition, NAM attenuated the expression of the assessed senescence phenotypes, excluding irreversible growth arrest. N-acetyl cysteine, a potent ROS scavenger, did not have comparable effects in the tested cell types. These data show that NAM has potent antioxidative as well as anti-senescent effects. Moreover, these findings suggest that NAM can reduce cellular deterioration caused by oxidative damage in postmitotic cells in vivo.
authors.affiliation: Department of Life Science, University of Seoul, Seoul 130-743, Korea.
authors.forename: Ju Yeon
authors.initials: JY
authors.lastname: Kwak
authors.affiliation: Department of Life Science, University of Seoul, Seoul 130-743, Korea.
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Ham
authors.affiliation: Biochemistry, Pusan National University Medical College, Busan 602-739, Korea.
authors.forename: Cheol Min
authors.initials: CM
authors.lastname: Kim
authors.affiliation: Department of Life Science, University of Seoul, Seoul 130-743, Korea.
authors.forename: Eun Seong
authors.initials: ES
authors.lastname: Hwang
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D059447:Cell Cycle Checkpoints; D016922:Cellular Senescence / Q000187:drug effects*; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D061986:MCF-7 Cells; D008297:Male; D009536:Niacinamide / Q000494:pharmacology*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D009536:Niacinamide
keywords: ROS; aging; antioxidant; nicotinamide; senescence