title: Effect of pesticide mixtures on in vitro nervous cells: comparison with single pesticides.
abstract: The toxicity of dimethoate, azinphos-methyl, diazinon, pirimiphos methyl, organophosphorus insecticides, and benomyl (a benzimidazole fungicide) singly and in mixture was studied in a human neuroblastoma cell line, SH-SY5Y. The cells were incubated for 30 min and 4 h with pesticides at concentrations ranging from 0.4 to 100 micrograms/ml, or with the same compounds mixed as follows: (a) dimethoate-diazinon-azinphos; (b) benomyl-pirimiphos; (c) all together. Pesticides in the mixtures were at the same concentration used when tested singly. Diazinon, azinphos-methyl and pirimiphos, but not dimethoate and benomyl, inhibited acetylcholine esterase (AchE) activity, whereas all the compounds inhibited protein synthesis in the following order: benomyl > azinphos > diazinon >> pirimiphos = dimethoate. The mixtures showed a toxicity on AchE activity at a maximum equal to that of the most active compound in the mixture. On the contrary, the mixture were more toxic than the single compounds on protein synthesis, and in certain cases potentiation occurred. Therefore, we can conclude that it is not feasible to predict the toxicity of pesticide mixtures on the basis of the results of the toxicity of single components.
authors.affiliation: Laboratory of Toxicology, University of Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Marinovich
authors.forename: F
authors.initials: F
authors.lastname: Ghilardi
authors.forename: C L
authors.initials: CL
authors.lastname: Galli
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D001542:Benomyl / Q000633:toxicity; D002800:Cholinesterase Inhibitors / Q000633:toxicity; D004338:Drug Combinations; D004347:Drug Interactions; D004357:Drug Synergism; D005506:Food Contamination; D005659:Fungicides, Industrial / Q000633:toxicity*; D006801:Humans; D007306:Insecticides / Q000633:toxicity*; D009447:Neuroblastoma; D009474:Neurons / Q000166:cytology / Q000187:drug effects*; D009946:Organothiophosphorus Compounds; D014176:Protein Biosynthesis; D018675:Toxicity Tests; D014407:Tumor Cells, Cultured; D014873:Water Pollutants / Q000633:toxicity
chemical_list: D002800:Cholinesterase Inhibitors; D004338:Drug Combinations; D005659:Fungicides, Industrial; D007306:Insecticides; D009946:Organothiophosphorus Compounds; D014873:Water Pollutants; D000110:Acetylcholinesterase; D001542:Benomyl