title: Promutagen activation of triazine herbicides metribuzin and ametryn through Vicia faba metabolism inducing sister chromatid exchanges in human lymphocytes in vitro and in V. faba root tip meristems.
abstract: The aim of our study was the induction of sister chromatid exchanges (SCE) in human lymphocytes in vitro and in root tip meristems of Vicia faba to evaluate the genotoxic effects of metribuzin and ametryn. Direct treatments of these herbicides on human lymphocytes in vitro applied 24 h after the beginning of culture did not induce SCE; however, they showed a cytotoxic effect in the cultures expressed as cellular death. On the contrary, when extracts of V. faba roots, treated for 4 h with metribuzin and ametryn (in vivo activation), were added to the lymphocyte cultures, SCEs were significantly induced with an asymptotic response. Negative responses appeared with the in vitro assays, in which metribuzin and ametryn were added directly to the 48 h lymphocyte cultures for 4 h. Nevertheless, in treatments in which the S10 metabolic mix was added, the SCE frequencies were significantly different to the control, although a concentration-response relationship was only observed with metribuzin. The results showed that both herbicides needed the V. faba metabolism to produce SCE in human lymphocyte cultures. Metribuzin and ametryn applied to V. faba root tip meristems for 4 h increased SCE frequency significantly, and a concentration-response relationship was observed with both herbicides.
authors.affiliation: Facultad de Estudios Superiores-Iztacala, Universidad Nacional Autónoma de México (UNAM). Av. de los Barrios s/n, Los Reyes Iztacala, Tlalnepantla, 54090 Edo. de México, México.
authors.forename: Saúl
authors.initials: S
authors.lastname: Flores-Maya
authors.forename: Sandra
authors.initials: S
authors.lastname: Gómez-Arroyo
authors.forename: María Elena
authors.initials: ME
authors.lastname: Calderón-Segura
authors.forename: Rafael
authors.initials: R
authors.lastname: Villalobos-Pietrini
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Waliszewski
authors.forename: Leticia Gómez
authors.initials: LG
authors.lastname: de la Cruz
mesh_terms: D001711:Biotransformation; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006540:Herbicides / Q000378:metabolism / Q000633:toxicity*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000473:pathology; D018519:Meristem / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D009153:Mutagens / Q000378:metabolism / Q000633:toxicity*; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D014227:Triazines / Q000378:metabolism / Q000633:toxicity*; D031307:Vicia faba / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: D006540:Herbicides; D009153:Mutagens; D014227:Triazines; C100057:ametryne; C009235:metribuzin