Genotoxic effects of anthropogenic environments in the leaf litter-dwelling scorpion Tityus pusillus Pocock, 1893 (Scorpiones; Buthidae).

Invertebrates are harmed by pollution of their habitats. Litter-dwelling sedentary scorpions, such as Tityus pusillus, studied here, may be good models for examining the genotoxic effects of xenobiotics in soil. Thirty specimens were collected from five sites in Northeast Brazil with different levels of human disturbance, as well as a laboratory group. The comet assay was performed on hemolymph cell samples. Damage Index (DI) and Damage Frequency (DF%) were measured. Much higher genotoxicity was observed in animals collected in an area with human interference and solid waste, compared to those obtained in more pristine areas or the laboratory. T. pusillus may be a useful model for environmental genotoxicity assays.

Canavalia ensiformis lectin induced oxidative stress mediate both toxicity and genotoxicity in Drosophila melanogaster.

Mannose/glucose-binding lectin from Canavalia ensiformis seeds (Concanavalin A - ConA) has several biological applications, such as mitogenic and antitumor activity. However, most of the mechanisms involved in the in vivo toxicity of ConA are not well known. In this study, the Drosophila melanogaster model was used to assess the toxicity and genotoxicity of different concentrations of native ConA (4.4, 17.5 and 70 µg/mL) in inhibited and denatured forms of ConA. The data show that native ConA affected: the survival, in the order of 30.6 %, and the locomotor performance of the flies; reduced cell viability to levels below 50 % (4.4 and 17.5 µg/mL); reduced nitric oxide levels; caused lipid peroxidation and increased protein and non-protein thiol content. In the Comet assay, native ConA (17.5 e 70 µg/mL) caused DNA damage higher than 50 %. In contrast, treatments with inhibited and denatured ConA did not affect oxidative stress markers and did not cause DNA damage. We believe that protein-carbohydrate interactions between ConA and carbohydrates of the plasma membrane are probably the major events involved in these activities, suggesting that native ConA activates mechanisms that induce oxidative stress and consequently DNA damage.