Joint toxic effects of the type-2 alkene electrophiles.
Human populations are exposed to complex environmental mixtures of acrolein, methylvinyl ketone (MVK) and other type-2 alkenes. Many members of this chemical class are electrophiles that possess a common molecular mechanism of toxicity; i.e., protein inactivation via formation of stable cysteine adducts. Therefore, acute or chronic exposure to type-2 alkene mixtures could represent a health risk due to additive or synergistic interactions among component chemicals. Despite this risk, there is little experimental information regarding the joint effects of type-2 alkenes. In the present study we used sum of toxic units (TUsum = ∑TUi) to assess the relative toxicity of different type-2 alkene mixtures. These studies involved well characterized environmental type-2 alkene toxicants and included amide (acrylamide; ACR), ketone (methyl vinyl ketone; MVK), aldehyde (2-ethylacrolein; EA) and ester (methyl acrylate; MA) derivatives. In chemico analyses revealed that both binary and ternary mixtures could deplete thiol groups according to an additive joint effect at equitoxic and non-equitoxic ratios; i.e., TUsum = 1.0 ± 0.20. In contrast, analyses of joint effects in SNB19 cell cultures indicated that different permutations of type-2 alkene mixtures produced mostly synergistic joint effects with respect to cell lethality; i.e., TUsum < 0.80. A mixture of ACR and MA was shown to produce joint toxicity in a rat model. This mixture accelerated the onset and development of neurotoxicity relative to the effects of the individual toxicants. Synergistic effects in biological models might occur when different cellular proteomes are targeted, whereas additive effects develop when the mixtures encompasses a similar proteome.
Department of Anesthesiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, United States.
Lihai
L
Zhang
Department of Anesthesiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, United States.
Brian C
BC
Geohagen
Department of Chemistry, Iona College, New Rochelle, NY, United States.
Terrence
T
Gavin
Department of Anesthesiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, United States. Electronic address: lopachin@einstein.yu.edu.
Richard M
RM
LoPachin
D020106:Acrylamide / Q000633:toxicity; D000447:Aldehydes / Q000737:chemistry / Q000633:toxicity; D000475:Alkenes / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D007659:Ketones / Q000737:chemistry / Q000633:toxicity; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D000447:Aldehydes; D000475:Alkenes; D007659:Ketones; D020106:Acrylamide
Acrylamide; Additive; Concentration addition; Environmental toxicology; Synergistic; Toxicant mixture