Protective effects of ascorbic acid against the genetic and epigenetic alterations induced by 3,5-dimethylaminophenol in AA8 cells

J Appl Toxicol. 2015 May;35(5):466-77. doi: 10.1002/jat.3046. Epub 2014 Sep 1.


Exposure to monocyclic aromatic alkylanilines (MAAs), namely 2,6-dimethylaniline (2,6-DMA), 3,5-dimethylaniline (3,5-DMA) and 3-ethylaniline (3-EA), was significantly and independently associated with bladder cancer incidence. 3,5-DMAP (3,5-dimethylaminophenol), a metabolite of 3,5-DMA, was shown to induce an imbalance in cytotoxicity cellular antioxidant/oxidant status, and DNA damage in mammalian cell lines. This study was designed to evaluate the protective effect of ascorbic acid (Asc) against the cytotoxicity, reactive oxygen species (ROS) production, genotoxicity and epigenetic changes induced by 3,5-DMAP in AA8 Chinese Hamster Ovary (CHO) cells. In different cellular fractions, 3,5-DMAP caused alterations in the enzyme activities orchestrating a cellular antioxidant balance, decreases in reduced glutathione levels and a cellular redox ratio as well as increases in lipid peroxidation and protein oxidation. We also suggest that the cellular stress caused by this particular alkylaniline leads to both genetic (Aprt mutagenesis) and epigenetic changes in histones 3 and 4 (H3 and H4). This may further cause molecular events triggering different pathological conditions and eventually cancer. In both cytoplasm and nucleus, Asc provided increases in 3,5-DMAP-reduced glutathione levels and cellular redox ratio and decreases in the lipid peroxidation and protein oxidation. Asc was also found to be protective against the genotoxic and epigenetic effects initiated by 3,5-DMAP. In addition, Asc supplied protection against the cell cycle (G1 phase) arrest induced by this particular alkylaniline metabolite.

Keywords: 3,5-dimethylaminophenol; alkylaniline; ascorbic acid; cytotoxicity; genotoxicity; monocyclic aromatic amine; reactive oxygen species.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aminophenols / toxicity*
  • Aniline Compounds / toxicity
  • Animals
  • Antioxidants / metabolism
  • Ascorbic Acid / pharmacology*
  • CHO Cells
  • Cell Cycle Checkpoints / drug effects
  • Cricetinae
  • Cricetulus
  • DNA Damage / drug effects
  • Epigenesis, Genetic / drug effects*
  • Glutathione / metabolism
  • Histone Acetyltransferases / metabolism
  • Histone Deacetylases / metabolism
  • Histones / metabolism
  • Lipid Peroxidation / drug effects
  • Oxidative Stress / drug effects
  • Reactive Oxygen Species / metabolism


  • 3,5-dimethylaminophenol
  • Aminophenols
  • Aniline Compounds
  • Antioxidants
  • Histones
  • Reactive Oxygen Species
  • 3,5-dimethylaniline
  • 2,6-xylidine
  • Histone Acetyltransferases
  • Histone Deacetylases
  • Glutathione
  • Ascorbic Acid
  • 3-ethylaniline