Przybylak, KP, Schultz, TW, Richarz, AN, Mellor, CL, Escher, SE and Cronin, MTD (2016) Read-Across of 90-Day Rat Oral Repeated-Dose Toxicity: A Case Study for Selected β-olefinic Alcohols. Computational Toxicology. ISSN 2468-1113

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Abstract

There are no in vivo repeated-dose data for the vast majority of β-olefinic alcohols. However, there are robust and consistent ex vivo data suggesting many of these chemicals are metabolically transformed, especially in the liver, to reactive electrophilic toxicants which react in a mechanistically similar manner to acrolein, the reactive metabolite of 2-propen-1-ol. Hence, an evaluation was conducted to determine suitability of 2-propen-1-ol as a read-across analogue for other β-olefinic alcohols. The pivotal issue to applying read-across to the proposed category is the confirmation of the biotransformation to metabolites having the same mechanism of electrophilic reactivity, via the same metabolic pathway, with a rate of transformation sufficient to induce the same in vivo outcome. The applicability domain for this case study was limited to small (C3 to C6) primary and secondary -olefinic alcohols. Mechanistically, these -
unsaturated alcohols are considered to be readily metabolised by alcohol dehydrogenase to polarised α, -unsaturated aldehydes and ketones. These metabolites are able to react via the Michael addition reaction mechanism with thiol groups in proteins resulting in cellular apoptosis and/or necrosis. The addition of the non-animal in chemico reactivity data (50% depletion of free glutathione) reduced the uncertainty so the read-across prediction for the straight-chain olefinic-unsaturated alcohols is deemed equivalent to a standard test. Specifically, the rat oral 90-day repeated-dose No Observed Adverse Effect Level (NOAEL) for 2-propen-1-ol of 6 mg/kg body weight bw/d in males based on increase in relative weight of liver and 25 mg/kg bw/d in females based on bile duct hyperplasia and periportal hepatocyte hypertrophy in the liver, is read across to fill data gaps for the straight-chained analogues.

Item Type:	Article
Subjects:	Q Science > QD Chemistry R Medicine > RM Therapeutics. Pharmacology
Divisions:	Pharmacy & Biomolecular Sciences
Publisher:	Elsevier
Date Deposited:	08 Mar 2017 09:09
Last Modified:	04 Sep 2021 12:10
DOI or ID number:	10.1016/j.comtox.2016.11.001
URI:	https://researchonline.ljmu.ac.uk/id/eprint/5140

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