title: Comparative study of cytotoxic and genotoxic effects induced by herbicide S-metolachlor and its commercial formulation Twin Pack Gold® in human hepatoma (HepG2) cells.
abstract: The in vitro effects of S-metolachlor and its formulation Twin Pack Gold(®) (96% a.i.) were evaluated in human hepatoma (HepG2) cells. Cytokinesis-blocked micronucleus cytome (CBMN-cyt) and MTT assays as well as Neutral Red uptake were employed for genotoxicity and cytotoxicity evaluation. Activities were tested within the concentration range of 0.25-15 μg/ml S-metolachlor for 24h of exposure. Both compounds rendered a minor reduction in the NDI although not reaching statistical significance. Results demonstrated that the S-metolachlor was not able to induce MNs. On the other hand, 0.5-6 μg/ml Twin Pack Gold(®) increased the frequency of MNs. When cytotoxicity was estimated, S-metolachlor was not able to induce either a reduction of lysosomal or mitochondrial activity. Contrarily, whereas 1-15 μg/ml Twin Pack Gold(®) induced a significant reduction of mitochondrial activity, all tested concentrations of the formulated product induced a significant decrease of lysosomal performance as a function of the concentration of the S-metolachlor-based formulation titrated into cultures. Genotoxicity and cytotoxicity differences obtained with pure S-metolachlor and the commercial S-metolachlor-based formulation indicate that the latter may contain additional unsafe xenobiotics and support the concept of the importance of evaluating not only the active principle but also the commercial formulation when estimating the real hazard from agrochemicals.
authors.affiliation: Cátedra de Citología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Calle 64 N° 3, B1904AMA La Plata, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, C1033AAJ, CABA, Argentina.
authors.forename: Noelia
authors.initials: N
authors.lastname: Nikoloff
authors.forename: Luciana
authors.initials: L
authors.lastname: Escobar
authors.forename: Sonia
authors.initials: S
authors.lastname: Soloneski
authors.forename: Marcelo L
authors.initials: ML
authors.lastname: Larramendy
mesh_terms: D000081:Acetamides / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D056945:Hep G2 Cells / Q000187:drug effects; D006801:Humans; D008247:Lysosomes / Q000187:drug effects; D015162:Micronucleus Tests; D008928:Mitochondria / Q000187:drug effects; D018675:Toxicity Tests
chemical_list: D000081:Acetamides; C051786:metolachlor
keywords: 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan; CBMN-cyt; CP; Commercial herbicide formulation; ETOH; HepG2 cells; MN; MN assay; MTT; MTT assay; NDI; NR; Neutral Red; Neutral Red assay; cyclophosphamide; cytokinesis-blocked micronucleus cytome assay; ethanol; micronucleus; nuclear division index