Golden mussel (Limnoperna fortunei) as a bioindicator in aquatic environments contaminated with mercury: Cytotoxic and genotoxic aspects.

This study evaluated the Limnoperna fortunei (golden mussel) as a bioindicator of cytotoxicity and genotoxicity in aquatic environments contaminated by heavy metals. Five groups of 50 subjects each were exposed to different concentration of mercuric chloride (HgCl2) (0.001 mg/L, group I; 0.005 mg/L, group II; 0.01 mg/L, group II; 0.02 mg/L, group IV; and 0.1 mg/L, group V). The control group for both chronic and acute treatment did not receive HgCl2. For chronic exposure, the respective groups were placed in aquaria with water contaminated with the above concentrations of HgCl2. For acute exposure, the different concentrations of HgCl2 were injected into the posterior adductor muscle of the individuals belonging to the aforementioned groups. The biological matrix used in the tests was the whole body muscle. Tests (cell viability assay, alkaline comet test; enumeration of micronuclei and necrotic cells, quantification of Hg content in tissues and water, and histopathological analysis of tissues), were carried out on the 7th, 15th, and 30th treatment days or 2 h after injection. Our results demonstrated that L. fortunei showed cell damage in both chronic and acute exposure groups. Significant DNA damage was observed at both the 15th (0.1 mg/L) and 30th (0.01-0.1 mg/L) days of chronic exposure. However, in acute treatment all concentrations induced DNA breaks. The presence of necrosis increased at all concentrations tested for both acute and chronic exposure. Tissue mercury retention on the 15th day was higher than on the 30th day of exposure, while in the same period, there was a decrease in the mercury content of aquarium water. Taking the data together, it is concluded that L. fortunei as a possible bioindicator of the quality of aquatic environments.

Is tartrazine really safe? In silico and ex vivo toxicological studies in human leukocytes: a question of dose.

The use of food colorings has a long-recorded history. Tartrazine (TRZ) is a dye that confers a lemon-yellow color to food and is widely used in the manufacture of numerous food products, as well as in pharmaceuticals and cosmetics. However, few studies have addressed the toxicology of TRZ in human cells or tissues. Considering the frequent consumption of the TRZ dye in food products and the lack of toxicological data, the present study aimed to evaluate the cytotoxicity and genotoxicity of the TRZ dye in human leukocyte cultures and perform theoretical studies to predict its toxicity in silico. Leukocyte cultures were treated with TRZ at concentrations of 5, 17.5, 35, 70, 100, 200, 300, 400, and 500 µg mL-1. All groups were assayed in triplicates. The mutagenicity was evaluated using the micronucleus test, the nuclear division index, and the nuclear division cytotoxicity index, and the chromosomal instability was quantitatively evaluated by band cytogenetics. Genotoxicity was evaluated using the alkaline comet test. Viability was assessed using the Trypan Blue method. Statistical analyses were performed using analysis of variance followed by Tukey's post hoc test, with a p value <0.05 reflecting statistical significance. No mutagenicity or cytotoxicity was found for the dye at the concentrations evaluated. However, DNA damage was induced by TRZ at a concentration of 70 µg mL-1. These results were confirmed by the predictive data from the in silico evaluations. Further studies are required to confirm our data, considering the frequency of the use of TRZ in the diet of the population, including that of children, as well as the exposure to TRZ through drugs, cosmetics, and other non-food products.