Genotoxic effects of the carbamate insecticide, methomyl. II. In vivo studies with pure compound and the technical formulation, “lannate 25”

Abstract

The carbamate insecticide, methomyl, and the methomyl-containing technical formulation, "Lannate 25", were tested for the induction of DNA damage in vivo. Swiss CD1 mice were treated intraperitoneally with test substances and the following tests were performed: alkaline elution of liver and kidney DNA, 8-hydroxyguanosine detection in liver DNA, and 32P-postlabelling analysis of DNA adducts in liver DNA. The clastogenic activity of the two pesticide preparations was also evaluated as micronucleus frequency in bone marrow. No DNA adducts were detected in liver DNA of mice treated with pure methomyl, while a dose-related increase in DNA adducts was found in Lannate 25-treated animals. All other tests were positive with both methomyl and Lannate 25. A summary of genotoxic activity of methomyl is also presented. The hypothesis that the observed genotoxic effects of methomyl are induced indirectly, through formation of active oxygen species, is discussed.

Potential threat of Chlorpyrifos to human liver cells via the caspase-dependent mitochondrial pathways

“…CPF mainly functions as a neurotoxin via inhibition of acetylcholinesterase (AChE), and it is generally considered that CPF has low toxicity for healthy adults because AChE-reactive neurons are restricted to the mammalian central nervous system (Bagley et al, 1989;Moser, 2000). However, more and more examples in recent years have illustrated that chemical substances of anthropogenic origin potentially affect the health of humans through longterm accumulation (Bolognesi et al, 1994). Besides, CPF is a lipophilic molecule and it can easily pass through the cell membrane into the cytoplasm (Ki, Park, Lee, Shin, & Koh, 2013).…”

Assessment of genotoxicity of Lannate-90® and its plant and animal metabolites in human lymphocyte cultures

“…Lannate -20 ® induced a significant increase in the number of sex-linked recessive lethal (55) and CA in mice germ cells including polyploidy and sex univalent (56). Lannate-25 ® had a higher clastogenic activity than pure methomyl in vivo (16) and in vitro (18). With Lannate-90 ® , elevated levels of CA and SCE were found in Vicia faba root tips (22,40).…”

“…Bolognesi et al (16) have observed that in vivo methomyl treatments caused indirect damage of DNA through the formation of active oxygen species. The same authors observed a dose-dependent increase in DNA adducts with Lannate-25 ® commercial formulation, while negative results were obtained with pure methomyl.…”

“…The components of pesticide formulations used as wettable powders usually consist of the carrier, mineral clays, surface active agents, and other ingredients such as stabilisers and dyers. The presence of surface-active agents could increase the genotoxic activity of the active ingredient, favouring the amount of active metabolites at critical cellular targets (16). Metabolic transformation has been shown to have a great impact on pesticide genotoxicity.…”

“…However, positive results have been reported in yeast (15). Additionally, methomyl induced micronuclei formation in mice (16), and elevated levels of sister chromatid exchange (SCE) and chromosomal aberrations (CA) in mice and cultured cells (17)(18)(19)(20). As for plants, Vicia faba root tips also demonstrated elevated levels of CA (21,22).…”