Journal of Xenobiotics

Detection of polystyrene nanoplastics in biological tissues with a fluorescent molecular rotor probe

2020-11-16T21:11:29+00:00

The release of nanoplastics (NPs) from the weathering and degradation of plastics is an important environmental concern. Given their small sizes and their invasiveness in cells, methods for the detection of NPs in biological tissues are urgently needed. A simple fluorescence-based methodology for the detection of polystyrene NPs in biological tissues is proposed. The commercially available molecular rotor probe 9- (dicyanovinyl)-julolidine (DCVJ) has the properties to detect changes in hydrophobicity and microviscosity and was used to detect NPs. Increasing concentrations of 50 and 100 nm NPs in water and in tissue extracts were mixed with the DCVJ probe and the emission spectra determined between 480-800 nm at 450 nm excitation. The data revealed that NPs induces a second emission peak at 620 nm that differed from the normal spectra of the biological extract at 500 nm. A significant linear relationship was obtained for NPs of both sizes (r=0.98; P<0.001) with a theoretical limit of detection of 65 ng/mL. A simple and rapid microplate spectrofluorometric method for the semi-quantitative detection of polystyrene NPs in biological tissues is thus presented.

An amplicon-based sequencing approach for the study of aeromycology

2020-11-16T21:11:55+00:00

Not available.

Effects of copper on the early development of Xenopus laevis: the case of CuSO4 and Bordeaux mixture solutions

2020-11-16T21:12:46+00:00

Not available.

Behavioral effects of the neurotoxin ß-N-methylamino-L-alanine on the mangrove rivulus (Kryptolebias marmoratus) larvae

2020-11-16T21:12:21+00:00

Mangrove rivulus, Kryptolebias marmoratus, is a hermaphrodite fish capable of self-fertilization. This particularity allows to naturally produce highly homozygous and isogenic individuals. Despite the low genetic diversity, rivulus can live in extremely variable environments and adjust its phenotype accordingly. This species represents a unique opportunity to clearly distinguish the genetic and non-genetic factors implicated in adaptation and evolution, such as epigenetic mechanisms. It is thus a great model in aquatic ecotoxicology to investigate the effects of xenobiotics on the epigenome, and their potential long-term impacts. In the present study, we used the mangrove rivulus to investigate the effects of the neurotoxin ß-N-methylamino-L-alanine (BMAA) on larvae behaviors after 7 days exposure to two sub-lethal concentrations. Results show that BMAA can affect the maximal speed and prey capture (trials and failures), suggesting potential impacts on the organism’s fitness.

Effects of chronic exposure to benzophenone and diclofenac on DNA methylation levels and reproductive success in a marine copepod

2020-11-16T21:13:12+00:00

The UV-filter benzophenone and the anti-inflammatory diclofenac are commonly detected in the environment. The aim of this study was to assess the multigenerational effects of chronic exposure to low concentrations of these chemicals on toxicity and DNA methylation levels in the copepod Gladioferens pectinatus. Acute toxicity tests were conducted to determine the sensitivity of G. pectinatus to the chemicals. All chemicals impacted breeding, hatching and egg viability. Diclofenac (1 mg.L^-1) reduced the number of eggs per gravid female. Benzophenone (0.5 mg.L^-1) decreased egg hatching success. Exposure to the reference toxicant copper (0.02 mg.L^-1) led to unsuccessful hatching. Effects on DNA methylation was estimated by the percentage of 5- methylcytosine. The treatments resulted in strong differences in DNA methylation with increased methylation in the exposed animals. The two chemicals impacted both egg viability and the induction of differential DNA methylation, suggesting potential intra- and trans-generational evolutionary effects.

Thiamethoxam Actara® induced alterations in kidney liver cerebellum and hippocampus of male rats

2018-10-29T11:14:45+00:00

Thiamethoxam (TMX), a second-generation neonicotinoid insecticide, is one of the most widely used insecticides in Algeria. The present study assessed the effects of repeated subchronic exposure to the commercial formulation of thiamethoxam (Actara®, 25% WG) in albino male rats. The toxic effects of thiamethoxam (TMX) were studied biochemically and histopathologically. Twenty-eight male albino rats weighing between 226 and 243 g were randomly assigned to four groups. One group served as control, and the other three were served as experimental groups administered a neonicotinoid thiamethoxam (TMX; 26, 39 and 78 mg/kg/day) for 6 weeks. The effects of the insecticide on various biochemical parameters were evaluated at 2, 4 and 6 weeks. Histopathological studies were carried out in the liver, kidney, cerebellum and hippocampus at the end of the experiment. Changes in biochemical parameters glucose, ALT (alanine aminotransferase), AST (aspartate aminotransferase), γGT (gamma-glutamyltransferase) ALP (alkaline phosphatase) urea and creatinine were observed in treated-groups in a dose dependent manner when compared to the control. Histopathological alterations were more intense in male rats from the TMX high dose group than those from group 2 and 3. Based on these results, subchronic oral administration of thiamethoxam altered the biochemical parameters, which correlated with histopathological changes in the liver kidney and brain.