Reactivity of Acrylamides Causes Cytotoxicity and Activates Oxidative Stress Response

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.

Species Difference? Bovine, Trout, and Human Plasma Protein Binding of Per- and Polyfluoroalkyl Substances

“…The experimental process of BioSPME conditioning, PFAS extraction from the aqueous solution, and desorption of the PFAS from BioSPME were performed automated by a Hamilton Star Robot (Bonaduz, Switzerland) as described by Huchthausen et al 32 Briefly, the BioSPME 96-Pin Device was conditioned in isopropanol for 20 min and then in Milli-Q water for 10 s. The extraction and desorption processes were performed on a high-speed shaker with a shaking speed of 1000 rpm. The temperature of the shaker was set to 37 °C for The shortest extraction time was 10 min, and the desorption time was always 20 min.…”