title: Carbamate insecticide methomyl confers cytotoxicity through DNA damage induction.
abstract: Carbamate insecticide methomyl could induce genotoxic effects, including micronuclei, chromosome aberrations and sister-chromatid exchanges. However, methomyl induction of cytotoxicity through DNA damage is largely unknown. Here we identify cytotoxicity and potential genotoxicity of methomyl in vitro. We have employed alkaline comet assay, γH2AX foci formation and DNA ladder assay to detected DNA damage and apoptosis of Drosophila S2, HeLa and HEK293 cells. The alkaline comet assay was used to evaluate total DNA single strand breaks (SSBs) in the target cells exposed in vitro to sublethal concentrations of methomyl. As expected, methomyl induced significant concentration-dependent increases in DNA damage of target cells compared with the negative control, as measured by increases in tail length (μm), tail DNA (percentage of the comet tail) and tail moment (arbitrary units). In agreement with the comet assay data, the percentage of γH2AX positive reaction in HeLa cells also revealed methomyl caused DNA double strand breaks (DSBs) in a time-dependent manner. Moreover, methomyl induced a significant increase of apoptosis in Drosophila S2, HeLa and HEK293 cells in a concentration- and time-dependent manner, as determined by Urea PAGE DNA fragmentation analysis. In conclusion, methomyl is a strongly genotoxic agent that induces cell DNA damage and apoptosis in vitro at these sublethal concentrations.
authors.affiliation: Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Guanggang
authors.forename: Li
authors.initials: L
authors.lastname: Diqiu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Jianzhong
authors.forename: Guan
authors.initials: G
authors.lastname: Jingmin
authors.forename: Zhai
authors.initials: Z
authors.lastname: Huifeng
authors.forename: Shi
authors.initials: S
authors.lastname: Mingan
authors.forename: Tao
authors.initials: T
authors.lastname: Liming
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002219:Carbamates / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival; D020552:Comet Assay; D053904:DNA Breaks, Single-Stranded; D004249:DNA Damage / Q000187:drug effects*; D053938:DNA Fragmentation; D004330:Drosophila; D057809:HEK293 Cells; D006367:HeLa Cells; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007306:Insecticides / Q000633:toxicity*; D008724:Methomyl / Q000633:toxicity*
chemical_list: D002219:Carbamates; C468783:H2AX protein, human; D006657:Histones; D007306:Insecticides; D008724:Methomyl