Metabolic activation of three arylamines and two organophosphorus insecticides by coriander (Coriandrum sativum) a common edible vegetable.

Organophosphorus insecticides and arylamines, widely distributed in the environment, can be activated into mutagens by plants. Plant activation of three aromatic amines, 4-nitro-o-phenylenediamine (NOP), m-phenylenediamine (m-PDA) and 2-aminofluorene (2AF), and two organophosphorus insecticides, dimethoate and methyl parathion has been the focus of this study. The plant cell/microbe coincubation assay was used employing coriander (Coriandrum sativum) suspended cell cultures as the activating system. Interestingly, this vegetable is included in the Mexican diet and ingested generally uncooked and could have epidemiological consequences. As a genetic end point, the Salmonella typhimurium tester strain TA98 was used. Protein contents, as well as peroxidase activity and peroxidase activity inhibited by diethyldithiocarbamate (DEDTC) of coriander cultures were determined after the coculture. Coriander cells highly activated three aromatic amines, NOP, m-PDA and 2-AF to mutagenic products detected in Salmonella. On the other hand, insecticides were only lightly activated, probably because peroxidase activity of coriander cells was inhibited, corroborated by DEDTC peroxidase inhibition. In all the assays, NOP was the more potent mutagenic compound. The results demonstrated that coriander cells were metabolically competent and suitable for a plant cell microbe coincubation assay, developed to analyze the promutagen activation by plant systems and can be used as a indicator of potential genetic effects.

Sister chromatid exchanges in Vicia faba induced by arsenic-contaminated drinking water from Zimapan, Hidalgo, Mexico.

Sister chromatid exchanges (SCE) in Vicia faba root tips were used to examine well water containing high levels of arsenic. The increased amount of arsenic was contained in well water from different towns of Zimapan, Hidalgo, Mexico. Treatments of 3 h were applied followed by the differential staining technique of Tempelaar et al. (Mutation Res. 103 (1982) 321-326). Concentrations of arsenic from 0.267 up to 1.070 mg/l were determined by colorimetry in the polluted samples used for this study. These values were above the permissible limit of 0.05 mg/l in drinking water. In all cases, except one in which the As concentration was 0.021, the arsenic-contaminated water produced significant increases of SCE compared with the control (p < 0.001) and a concentration-response relationship was observed. The SCE potency factor of 33 per mg/l of arsenic was calculated as the slope of a common regression line, pooling data previously obtained in the Comarca Lagunera and the results observed in Zimapan.