Genotoxic mode of action and threshold exploration of 2-methyl furan under 120-day sub-chronic exposure in male Sprague-Dawley rats

Ecotoxicol Environ Saf. 2024 Mar 15:273:116125. doi: 10.1016/j.ecoenv.2024.116125. Epub 2024 Feb 23.

Abstract

2-Methylfuran (2-MF) is an important member of the furan family generated during food thermal processing. An in-vivo multiple endpoint genotoxicity assessment system was applied to explore the genotoxic mode of action and threshold of 2-MF. Male Sprague-Dawley rats received 2-MF by oral gavage at doses of 0.16, 0.625, 2.5, and 10 mg/kg.bw/day for 120 days. An additional 15 days were granted for recovery. The Pig-a gene mutation frequency of RET and RBC showed significant increases among the 2-MF groups on day 120. After a 15-day recovery period, the Pig-a gene mutation frequency returned to levels similar to those in the vehicle control. The tail intensity (TI) values of peripheral blood cells at a dose of 10 mg/kg.bw/day significantly increased from day 4 and remained at a high level after the recovery period. No statistical difference was found in the micronucleus frequency of peripheral blood between any 2-MF dose group and the corn oil group at any timepoint. 2-MF may not induce the production of micronuclei, but it could cause DNA breakage. It could not be ruled out that 2-MF may accumulate in vivo and cause gene mutations. Hence, DNA, other than the spindle, may be directly targeted. The mode of action of 2-MF may be that it was metabolized by EPHX1 to more DNA-active metabolites, thus leading to oxidative and direct DNA damage. The point of departure (PoD) of 2-MF-induced genotoxicity was derived as 0.506 mg/kg bw/day.

Keywords: 2-methylfuran; Benchmark dose; DNA damage; Genotoxicity; Mode of action; Pig-a assay.

MeSH terms

  • Animals
  • DNA / metabolism
  • DNA Damage*
  • Furans / metabolism
  • Furans / toxicity
  • Male
  • Micronucleus Tests
  • Mutagenicity Tests
  • Rats
  • Rats, Sprague-Dawley
  • Reticulocytes* / metabolism

Substances

  • 2-methylfuran
  • Furans
  • DNA