Genotoxicity of the herbicide 2,4-dichlorophenoxyacetic and a commercial formulation, 2,4-dichlorophenoxyacetic acid dimethylamine salt. I. Evaluation of DNA damage and cytogenetic endpoints in Chinese Hamster ovary (CHO) cells.
Genotoxicity of the 2,4-dichlorophenoxyacetic acid (2,4-D) and a commercially-used derivative, 2,4-D dimethylamine salt (2,4-D DMA), was evaluated in CHO cells using SCE and single cell gel electrophoresis (SCGE) assays. Log-phase cells were treated with 2.0-10.0 microg/ml of herbicides and harvested 24 and 36 h later for SCE analysis. Both agents induced significant dose-dependent increases in SCE, regardless of the harvesting time (2,4-D: r=0.98 and r=0.88, P<0.01, for 24 and 36 h harvesting times; 2,4-D DMA: r=0.97 and r=0.88, P<0.01, for 24 and 36 h harvesting times). Neither test compound altered cell-cycle progression or proliferative replication index (P>0.05), but the higher doses of both compounds reduced the mitotic index of cultures harvested at 24 and 36 h (P<0.05). A 90-min treatment with 2.0-10.0 microg/ml 2,4-D and 2,4-D DMA produced dose-dependent increases in the frequency of DNA-strand breaks detected in the SCGE assay, both in cultures harvested immediately after treatment and in cultures harvested 36 h later. The doses of 2,4-D and 2,4-D DMA were equally genotoxic in all of the assays. The results indicate that 2,4-D induces SCE and DNA damage in mammalian cells, and should be considered as potentially hazardous to humans.
González
M
M
Cátedra de Citología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata 1900, Argentina.
Soloneski
S
S
Reigosa
M A
MA
Larramendy
M L
ML
D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity*; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004249:DNA Damage; D004123:Dimethylamines / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D006540:Herbicides / Q000633:toxicity*; D008940:Mitotic Index; D009153:Mutagens / Q000633:toxicity*; D012854:Sister Chromatid Exchange / Q000187:drug effects*
D004123:Dimethylamines; D006540:Herbicides; D009153:Mutagens; C037991:2,4-D amine; D015084:2,4-Dichlorophenoxyacetic Acid