Reactivity of Acrylamides Causes Cytotoxicity and Activates Oxidative Stress Response

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

Acrylamides are widely used industrial chemicals that cause adverse effects in humans or animals, such as carcinogenicity or neurotoxicity. The excess toxicity of these reactive electrophilic chemicals is especially interesting, as it is mostly triggered by covalent reactions with biological nucleophiles, such as DNA bases, proteins, or peptides. The cytotoxicity and activation of oxidative stress response of 10 (meth)acrylamides measured in three reporter gene cell lines occurred at similar concentrations. Most acrylamides exhibited high excess toxicity, while methacrylamides acted as baseline toxicants. The (meth)acrylamides showed no reactivity toward the hard biological nucleophile 2-deoxyguanosine (2DG) within 24 h, and only acrylamides reacted with the soft nucleophile glutathione (GSH). Second-order degradation rate constants ( k GSH) were measured for all acrylamides with N, N'-methylenebis(acrylamide) (NMBA) showing the highest k GSH (134.800 M -1 h -1) and N, N-diethylacrylamide (NDA) the lowest k GSH (2.574 M -1 h -1). Liquid chromatography coupled to high-resolution mass spectrometry was used to confirm the GSH conjugates of the acrylamides with a double conjugate formed for NMBA. The differences in reactivity between acrylamides and methacrylamides could be explained by the charge density of the carbon atoms because the electron-donating inductive effect of the methyl group of the methacrylamides lowered their electrophilicity and thus their reactivity. The differences in reactivity within the group of acrylamides could be explained by the energy of the lowest unoccupied molecular orbital and steric hindrance. Cytotoxicity and activation of oxidative stress response were linearly correlated with the second-order reaction rate constants of the acrylamides with GSH. The reaction of the acrylamides with GSH is hence not only a detoxification mechanism but also leads to disturbances of the redox balance, making the cells more vulnerable to reactive oxygen species. The reactivity of acrylamides explained the oxidative stress response and cytotoxicity in the cells, and the lack of reactivity of the methacrylamides led to baseline toxicity.

Details

Original languageEnglish
Pages (from-to)1374–1385
Number of pages12
JournalChemical Research in Toxicology
Volume36
Issue number8
Publication statusPublished - 2 Aug 2023
Peer-reviewedYes

External IDs

WOS 001039842700001
PubMed 37531411
Mendeley 3889cea5-6fcd-372b-9a01-7318e5645996
Scopus 85168427658

Keywords

Keywords

  • Bases hsab theory, In-vitro, Electrophilic reactivity, Environmental-pollutants, Conceptual-framework, Acute toxicity, Dna, Glutathione, Mechanisms, Water, Oxidative Stress, Oxidation-Reduction, Humans, Glutathione/metabolism, Animals, Acrylamides/toxicity, Acrylamide/toxicity