Medium-term effects of Ag supplied directly or via sewage sludge to an agricultural soil on Eisenia fetida earthworm and soil microbial communities.

The widespread use of silver nanoparticles (AgNPs) in consumer products that release Ag throughout their life cycle has raised potential environmental concerns. AgNPs primarily accumulate in soil through the spreading of sewage sludge (SS). In this study, the effects of direct exposure to AgNPs or indirect exposure via SS contaminated with AgNPs on the earthworm Eisenia fetida and soil microbial communities were compared, through 3 scenarios offering increasing exposure concentrations.

Accumulation, speciation and localization of silver nanoparticles in the earthworm Eisenia fetida.

The use of silver nanoparticles (AgNPs) in agriculture and many consumer products has led to a significant release of Ag in the environment. Although Ag toxicity in terrestrial organisms has been studied extensively, very little is known about the accumulation capacity and coping mechanisms of organisms in Ag-contaminated soil. In this context, we exposed Eisenia fetida earthworms to artificial OECD soil spiked with a range of concentrations of Ag (AgNPs or AgNO).

Ecotoxicology of silver nanoparticles and their derivatives introduced in soil with or without sewage sludge: A review of effects on microorganisms, plants and animals.

Silver nanoparticles (AgNPs) are widely incorporated in many products, partly due to their antimicrobial properties. The subsequent discharge of this form of silver into wastewater leads to an accumulation of silver species (AgNPs and derivatives resulting from their chemical transformation), in sewage sludge. As a result of the land application of sewage sludge for agricultural or remediation purposes, soils are the primary receiver media of silver contamination.

Adverse effects of fly ashes used as immobilizing agents for highly metal-contaminated soils on Xenopus laevis oocytes survival and maturation-a study performed in the north of France with field soil extracts.

Amphibians are now recognized as the most endangered group. One of this decline causes is the degradation of their habitat through direct contamination of water, soil leaching, or runoff from surrounding contaminated soils and environments. In the North of France, the extensive industrial activities resulted in massive soil contamination by metal compounds.

Effects of glyphosate and a commercial formulation Roundup® exposures on maturation of Xenopus laevis oocytes.

Pesticides are often found at high concentrations in small ponds near agricultural field where amphibians are used to live and reproduce. Even if there are many studies on the impacts of phytopharmaceutical active ingredients in amphibian toxicology, only a few are interested in the earlier steps of their life cycle. While their populations are highly threatened with extinction.

Exposures to chemical contaminants: What can we learn from reproduction and development endpoints in the amphibian toxicology literature?

Environmental contamination is one of the major factors or cofactors affecting amphibian populations. Since 2000, the number of studies conducted in laboratory conditions to understand impacts of chemical exposures increased. They aimed to characterize biological effects on amphibians.

Impact of cadmium on forage kale (Brassica oleracea var. viridis cv "Prover") after 3-,10- and 56-day exposure to a Cd-spiked field soil.

Cadmium (Cd) is a highly toxic element for living organisms and is widespread in metal-contaminated soils. As organisms which can grow up on these polluted areas, plants have some protection mechanisms against Cd issues. Among the plant kingdom, the Brassicaceae family includes species which are known to be able to tolerate and accumulate Cd in their tissues.

Ferroquine, the next generation antimalarial drug, has antitumor activity.

Despite the tremendous progress in medicine, cancer remains one of the most serious global health problems awaiting new effective therapies. Here we present ferroquine (FQ), the next generation antimalarial drug, as a promising candidate for repositioning as cancer therapeutics. We report that FQ potently inhibits autophagy, perturbs lysosomal function and impairs prostate tumor growth in vivo.

Maturation of Xenopus laevis oocytes under cadmium and lead exposures: Cell biology investigations.

Since amphibians are recognised as good models to assess the quality of environments, only few studies have dealt with the impacts of chemical contaminants on their gametes, while toxic effects at this stage will alter all the next steps of their life cycle. Therefore, we propose to investigate the oocyte maturation of Xenopus laevis in cadmium- and lead-contaminated conditions. The impacts of cadmium and lead ions were explored on events involved in the hormone-dependent process of maturation.

Cadmium but not lead exposure affects Xenopus laevis fertilization and embryo cleavage.

Among the toxicological and ecotoxicological studies, few have investigated the effects on germ cells, gametes or embryos, while an impact at these stages will result in serious damage at a population level. Thus, it appeared essential to characterize consequences of environmental contaminant exposures at these stages. Therefore, we proposed to assess the effects of exposure to cadmium and lead ions, alone or in a binary mixture, on early stages of Xenopus laevis life cycle.

Comparative avoidance behaviour of the earthworm Eisenia fetida towards chloride, nitrate and sulphate salts of Cd, Cu and Zn using filter paper and extruded water agar gels as exposure media.

We studied the avoidance behaviour of the earthworm Eisenia fetida towards Cd, Cu, and Zn, trace elements (TEs) tested as chloride, nitrate and sulphate salts. Sub adults were exposed individually using dual-cell chambers at 20+2°C in the dark. Recordings were realised at different dates from 2h to 32h.

Xenopus laevis oocyte maturation is affected by metal chlorides.

Few studies have been conducted using Xenopus laevis germ cells as oocytes, though these cells offer many advantages allowing both electrophysiological studies and morphological examination. Our aim was to investigate the effects of metal (cadmium, lead, cobalt and zinc) exposures using cell biology approaches. First, cell survival was evaluated with both phenotypical and electrophysiological approaches.

Mycosubtilin and surfactin are efficient, low ecotoxicity molecules for the biocontrol of lettuce downy mildew.

The use of surfactin and mycosubtilin as an eco-friendly alternative to control lettuce downy mildew caused by the obligate pathogen Bremia lactucae was investigated. Preliminary ecotoxicity evaluations obtained from three different tests revealed the rather low toxicity of these lipopeptides separately or in combination. The EC50 (concentration estimated to cause a 50 % response by the exposed test organisms) was about 100 mg L(-1) in Microtox assays and 6 mg L(-1) in Daphnia magna immobilization tests for mycosubtilin and 125 mg L(-1) and 25 mg L(-1) for surfactin, respectively.

Gene expression analysis of 4 biomarker candidates in Eisenia fetida exposed to an environmental metallic trace elements gradient: a microcosm study.

Past activities of 2 smelters (Metaleurop Nord and Nyrstar) led to the accumulation of high amounts of Metal Trace Elements (TEs) in top soils of the Noyelles-Godault/Auby area, Northern France. Earthworms were exposed to polluted soils collected in this area to study and better understand the physiological changes, the mechanisms of acclimation, and detoxification resulting from TE exposure. Previously we have cloned and transcriptionally characterized potential biomarkers from immune cells of the ecotoxicologically important earthworm species Eisenia fetida exposed in vivo to TE-spiked standard soils.

Growth and metal accumulation in Porcellio scaber exposed to poplar litter from Cd-, Pb-, and Zn-contaminated sites.

This study aimed at determining, in the laboratory, the effects of poplar litter collected in woody habitats contaminated by heavy metals on growth and metal accumulation in the terrestrial isopod Porcellio scaber. Cd, Pb, and Zn pseudototal and CaCl(2)-extractable concentrations in litter types were determined using AAS. Juveniles were fed ad libitum, individually, for 28 days with four litter types presenting an increasing gradient of metal contamination.

Metallic trace element body burdens and gene expression analysis of biomarker candidates in Eisenia fetida, using an "exposure/depuration" experimental scheme with field soils.

Smelting plant activities lead to the accumulation of Metal Trace Elements (MTEs) in soils. The presence of high concentrations of MTEs can generate an environmental stress likely to affect macroinvertebrates living in close soil contact such as the Annelida Oligochaeta. Eisenia fetida, an ecotoxicologically important test species, was successively exposed to two field soils: (1) a highly contaminated agricultural topsoil collected near the former smelter Metaleurop Nord (Noyelles-Godault, France) which contaminated surrounding soils by its atmospheric emissions [exposure phase], and then (2) a slightly contaminated topsoil from an urban garden located in the conurbation of Lille (Wambrechies) [depuration phase].

Assessing the effects of FBC ash treatments of metal-contaminated soils using life history traits and metal bioaccumulation analysis of the earthworm Eisenia andrei.

Earthworms (Eisenia andrei) were exposed, in controlled conditions, to metal-contaminated soils previously treated in situ with two types of fluidized bed combustion ashes. Effects on this species were determined by life history traits analysis. Metal immobilizing efficiency of ashes was indicated by metal bioaccumulation.

Metallothionein response following cadmium exposure in the oligochaete Eisenia fetida.

We studied the metallothionein (MT) response in cadmium-exposed worms (Eisenia fetida) both at the protein level by Dot Immunobinding Assay (DIA) with a polyclonal antibody raised against the most immunogenic part of this protein and at the expression level by Northern blotting using a specific probe. MT appeared as two close isoforms. DIA results clearly demonstrated significant differences in MT level of whole worm heat-treated supernatants between E.

Improved single-cell gel electrophoresis assay for detecting DNA damage in Eisenia foetida.

The earthworm (Eisenia foetida) is an attractive sentinel species for detecting genotoxicity in soil. In this study, an improved single-cell gel electrophoresis (SCGE) assay was developed for detecting DNA damage in the coelomocytes (lymphocytes) of earthworms. Coelomocytes were obtained from the coelomic fluid using a modified extrusion medium that did not include the mucolytic agent guaiacol.

DNA damage measured by the single-cell gel electrophoresis (Comet) assay in mammals fed with mussels contaminated by the 'Erika' oil-spill.

This research aimed to estimate potential genotoxicity for consumers resulting from the ingestion of seafood contaminated with polycyclic aromatic hydrocarbons (PAHs) released into the marine environment after the 'Erika' shipwreck along the coasts of south Brittany, in France. Mussels (Mytilus sp.) collected from sites on the Atlantic coast that were affected by the oil slick in various degrees, were used to feed rats daily for 2 and 4 weeks.

Genotoxicity related to transfer of oil spill pollutants from mussels to mammals via food.

Heavy fuel oils containing high levels of polycyclic aromatic hydrocarbons (PAHs) were released into the marine environment after the Erika oil spill on the Atlantic coast. As highly condensed PAH pollutants can bioaccumulate in invertebrates, their transfer to vertebrates through the food chain was of concern. This study aimed to estimate potential genotoxic effects in rats fed for 2 or 4 weeks with the marine mussel Mytilus edulis contaminated by oil pollutants.