title: Ability of Allium cepa L. root tips and Tradescantia pallida var. purpurea in N-nitrosodiethylamine genotoxicity and mutagenicity evaluation.
abstract: N-nitroso compounds, such as N-nitrosodiethylamine (NDEA), can be formed by the reaction of secondary amines with nitrosating agents, and are suspected to be involved in tumors in humans. NDEA has been considered a weak carcinogen in genotoxic assays probably due to the inefficient nitrosamine activation system that is used and/or to the efficient repair system. In this work, we evaluated the sensibility of Allium cepa L. root tips and Tradescantia stamen hair mutation assay (Trad-SH) using Tradescantia pallida var. purpurea for NDEA (0.1; 0.5; 5 and 25 mM) genotoxicity and mutagenicity induction. Allium cepa L. was treated with different NDEA concentrations for 3h, for 3 consecutive days, including negative control (distilled water) and positive control maleic hydrazide (MH 30 mg/mL). After treatment, the roots were hydrolyzed, squashed, and the mitotic index (MI) and cytological abnormalities were scored. The results revealed a cytostatic effect of NDEA (0.5 and 5mM), showing a significant reduction in the MI. Chromosome stickiness suggests a NDEA toxic effect. T. pallida purpurea did not respond to mutagens with a dose-dependent pattern. In conclusion, our study indicates that the root tips of Allium cepa L. have sensibility to detect NDEA genotoxicity, but not for Trad-SH test.
authors.affiliation: Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Claudia R
authors.initials: CR
authors.lastname: de Rainho
authors.forename: Andréa
authors.initials: A
authors.lastname: Kaezer
authors.forename: Claudia A F
authors.initials: CA
authors.lastname: Aiub
authors.forename: Israel
authors.initials: I
authors.lastname: Felzenszwalb
mesh_terms: D002869:Chromosome Aberrations / Q000139:chemically induced*; D032461:Chromosomes, Plant / Q000187:drug effects / Q000235:genetics; D004052:Diethylnitrosamine / Q000633:toxicity*; D009152:Mutagenicity Tests; D019697:Onions / Q000187:drug effects* / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects* / Q000235:genetics; D034823:Tradescantia / Q000187:drug effects* / Q000235:genetics
chemical_list: D004052:Diethylnitrosamine