RESUMO
Acid Black 10B (AB10B) is widely used for the production of textiles, leather and prints. It is a representative of azo dyes and it is well documented that some of these compounds are mutagenic per se, and that cleavage products (in particular aromatic amines) may cause damage of the genetic material and cancer. Since no toxicological data on AB10B have been published, we evaluated its mutagenic activity in Salmonella/microsome assays and studied its acute toxic and genotoxic properties in a human derived liver cell line (HepG2) which retained the activities of drug metabolizing enzymes. The compound did not cause cytotoxicity (MTT assay), but clear genotoxic effects were detected in pro- and eukaryotic indicator cells. Dose dependent induction of his+ revertants was seen in strain TA98 which detects frameshift mutations without metabolic activation; a more pronounced effect was seen in its derivative YG1024 which overexpresses N-acetyltransferase. Induction of single/double strand breaks by Comet assay was detected with concentrations > 0.125â¯mg/mL in liver derived cells; as well as increased rates for micronucleus (reflecting structural and numeric chromosomal aberrations) and nuclear buds which are a consequence of gene amplifications were seen with a higher dose (2.0â¯mg/mL) (pâ¯<â¯0.05; Tukey's test). The mutational pattern which was observed in the bacterial tests indicates that the cleavage product p-nitroaniline may cause the genotoxic effects of the dye. Our findings indicate that exposure of humans and the release of the compound into the environment may lead to adverse effects due to its DNA damaging activity.
Assuntos
Negro de Amido/toxicidade , Compostos Azo/toxicidade , Testes Imunológicos de Citotoxicidade/métodos , Dano ao DNA/efeitos dos fármacos , Mutagênicos/toxicidade , HumanosRESUMO
The leaves of coca (Erythroxylum coca var. coca), a South American shrub which contains cocaine, other alkaloids and phenolics are widely used by indigenous populations of the Andes. It is currently not known if coca consumption causes genotoxic effects in humans. This information is important to predict potential long-term toxic effects such as cancer induction. Therefore, the buccal cytome assay was used to analyze oral cells from 45 uni- and bilateral chewers and 23 controls living in the Altiplano of the Peruvian Andes. In total, 123,471 cells were evaluated from chewers and 57,916 from controls. Information concerning the consumption levels and habits and also use of lime were collected with questionnaires. Chewing of the leaves did not induce nuclear anomalies reflecting genetic damage such as micronuclei (MNi) and nuclear buds; in the highest exposure group (but not in the overall group) even a significant decrease in the frequencies of cells with MNi (by 64 %) was observed. However, we found significantly elevated levels of other nuclear anomalies (karyorrhexis and karyolysis) which reflect cytotoxic effects in the coca users. The frequencies of these anomalies increased with the daily consumption and when lime was used to improve the release of the alkaloids. In contrast to other chewing habits (betel, tobacco and khat), consumption of coca leaves does not induce genetic instability in cells from the oral cavity and our findings indicate that no adverse health effects take place in chewers which are associated with DNA damage. However, the significant increase in certain anomalies shows that acute toxic effects are caused by coca consumption.