Glyphosate Interference in Follicular Organization in the Wall Lizard Podarcis siculus.

Glyphosate (Gly) is a broad-spectrum herbicide widely used thanks to its high efficiency and low toxicity. However, evidence exists of its toxic effects on non-target organisms. Among these, the animals inhabiting agricultural fields are particularly threatened. Recent studies demonstrated that exposure to Gly markedly affected the morphophysiology of the liver and testis of the Italian field lizard Podarcis siculus. The present study aimed to investigate the effects of the herbicide on the female reproductive system of this lizard in order to have a full picture of Gly-induced reproductive impairment. The animals were exposed to 0.05 and 0.5 µg/kg of pure Gly by gavage for 3 weeks. The results demonstrated that Gly, at both doses tested, profoundly interfered with ovarian function. It induced germ cells' recruitment and altered follicular anatomy by anticipating apoptotic regression of the pyriform cells. It also induced thecal fibrosis and affected oocyte cytoplasm and zona pellucida organizations. At the functional levels, Gly stimulated the synthesis of estrogen receptors, suggesting a serious endocrine-disrupting effect. Overall, the follicular alterations, combined with those found at the level of the seminiferous tubules in males, suggest serious damage to the reproductive fitness of these non-target organisms, which over time could lead to a decline in survival.

Behavioral alterations and gills damage in Mytilus galloprovincialis exposed to an environmental concentration of delorazepam.

Psychoactive compounds, and benzodiazepines (BZPs) in particular, represent an important class of emerging pollutants due to their large (ab)use and high resistance to degradation. Nowadays it is known that sewage treatment does not completely eliminate these substances and, therefore, BZPs and their metabolites reach concern levels in most aquatic environments all over Europe, ranging from µg/L to ng/L. In this study, we investigated the effects of delorazepam on Mytilus galloprovincialis, a model organism in toxicity testing and a key species in coastal marine ecosystems. Given its psychoactive activity, the study primarily addressed discovering the effects on behavior, by conventional valve opening and closure tests. Possible cytotoxic activity was also investigated by analyzing valve abductor muscles, gills histology, and correlated oxygen consumption. Results demonstrate negative effects on mussel behavior, interference with metabolism, and alteration of gill morphology and protein content. In conclusion, delorazepam confirms its toxicity to aquatic environments, highlighting the possibility that BZDs can ultimately affect the structure of the food web and the functions of the coastal ecosystems.

Effects of Cadmium Exposure on Gut Villi in Danio rerio.

In aquatic organisms, cadmium exposure occurs from ovum to death and the route of absorption is particularly wide, being represented by skin, gills and gastrointestinal tract, through which contaminated water and/or preys are ingested. It is known that cadmium interferes with the gut; however, less information is available on cadmium effects on an important component of the gut, namely goblet cells, specialized in mucus synthesis. In the present work, we studied the effects of two sublethal cadmium concentrations on the gut mucosa of Danio rerio. Particular attention was paid to changes in the distribution of glycan residues, and in metallothionein expression in intestinal cells. The results show that cadmium interferes with gut mucosa and goblet cells features. The effects are dose- and site-dependent, the anterior gut being more markedly affected than the midgut. Cadmium modifies the presence and/or distribution of glycans in the brush border and cytoplasm of enterocytes and in the goblet cells' cytoplasm and alters the metallothionein expression and localization. The results suggest a significant interference of cadmium with mucosal efficiency, representing a health risk for the organism in direct contact with contamination and indirectly for the trophic chain.