140 contaminants belonging to various classes (organochlorine and organophosphorus pesticides, pyrethroid insecticides, carbamates, fungicides, acaricides, herbicides, synergists, insect growth regulators, polychlorobiphenyls, polycyclic aromatic hydrocarbons) were simultaneously analysed by GC-MS/MS in marine sediments, aquatic plant leaves and fish tissues samples. A total of 260 samples from five stations along the coast of Tunisia were evaluated. The results highlight that only 28 residues (12 polychlorobiphenyls, 8 organochlorine pesticides, 7 polycyclic aromatic hydrocarbons and triphenyl phosphate) were detected at levels higher than relative LOQ values. The amounts in sediment samples were compared with Sediment Quality Guidelines (SQGs) showing that the values are acceptable and no toxic effect is expected on aquatic organisms. A little variation of contaminant residues in sediment samples among coastal stations was recorded. Namely, with respect to almost all polychlorobiphenyls and organochlorine pesticides, higher values were recorder in summer. With respect to almost all polycyclic aromatic hydrocarbons, higher values were recorder in autumn. Aquatic plant leaves showed a residue accumulation higher than that of other compartments of marine system. The data about fish samples (Sparus aurata and Sarpa salpa, the two most frequently caught fish species at five sites on the central coast of Tunisia) do not pose direct hazard to human health because values were lower than protection limits.

Bifenazate is a novel acaricide for selective foliar spraying and is widely used to control mites in agricultural production. However, its toxicity to aquatic organisms is unknown. Here, a zebrafish model was used to study bifenazate toxicity to aquatic organisms. Exposure to bifenazate was found to cause severe cardiotoxicity in zebrafish embryos, along with disorders in the gene expression related to heart development. Bifenazate also caused oxidative stress. Cardiotoxicity caused by bifenazate was partially rescued by astaxanthin (an antioxidant), accompanied by cardiac genes and oxidative stress-related indicators becoming normalized. Our results showed that exposure to bifenazate can significantly change the ATPase activity and gene expression levels of the calcium signaling pathway. These led to heart failure, in which the blood accumulated outside the heart without entering it, eventually leading to death. The results indicated that bifenazate exposure caused cardiotoxicity in zebrafish embryos through the induction of oxidative stress and inhibition of the calcium signaling pathway.

Spirotetramat, a member of tetronic and tetramic acid derivatives, is a unique insecticide and acaricide. Although the effect on zebrafish embryos lipid biosynthesis of spirotetramat has been characterized, the energy metabolism and toxic effect mechanism warrant further investigation. To investigate the toxic mechanism of spirotetramat on energy metabolism, zebrafish embryos were exposed to 100, 500 and 1000 µg/L of spirotetramat for 4 days. Untargeted metabolomics showed the synthesis and degradation of ketone pathway metabolites (R)-3-Hydroxybutyric acid and Acetoacetate significantly decreased, as well as increasing the abundance of Anti-Acetyl Coenzyme A Carboxylase protein (ACC1). Down-regulation of the genes related to ß-oxidation and the tricarboxylic acid cycle in the embryos show decreased energy metabolism. Carnitine palmitoyltransferase 1 (CPT- I) significantly decreased while citrate synthase (CS) significantly increased. Additionally, mitochondrial lesions in embryos were found using electron microscopy. Our study provides novel and robust perspectives, which show that spirotetramat treatment in embryos leads to metabolic disturbances that adversely affect cellular energy homeostasis.

As a widely used organotin acaricide nowadays, azocyclotin (ACT) could induce thyroidal endocrine disruption in fishes and amphibians, but its dominant disrupting mode remains unknown. In this study, zebrafish were firstly exposed to ACT (0.18–0.36 ng/mL) from 2 hpf (hours post fertilization) to 30 dpf (days post fertilization), and a series of developmental toxicological endpoints and thyroid hormones were measured. Result showed that no developmental toxicity to zebrafish was found in 0.18 and 0.24 ng/mL groups except decreased body weight (30 dpf, 0.24 ng/mL). However, exposed to 0.36 ng/mL ACT led to reductions in heartbeat (48 hpf), hatching rate (72 hpf) and bodyweight (30 dpf). General tendencies of decreases in free T3 but increases in free T4 and reductions in ratio of free T3/T4 were also found, inferring that type II deiodinase (Dio2) was repressed. This inference was confirmed by Western analysis that Dio2 expression reduced by 42.7% after 0.36 ng/mL ACT treatment. Moreover, RNA-Seq analysis implied that exposed to 0.36 ng/mL ACT altered the genome-wide gene expression profiles of zebrafish. Totally 5660 genes (involving 3154 down-regulated and 2596 up-regulated genes) were differentially expressed, and 13 deferentially expressed genes including down-regulated dio2 were significantly enriched in thyroid hormone signaling pathway. Subsequently, an in vitro thyroid receptor-reporter gene assay using GH3 cells was performed to further explore the potential disrupting mechanism. Result showed that luciferase activity slightly increased after exposure to ACT alone or ACT combined with low level T3, but was suppressed when combined with high level T3. It indicted there probably existed a competitive relationship in some extent between ACT and T3 in vivo. Overall, the present study provided preliminary evidences that long-term exposure to trace ACT repressed Dio2 expression, declined T3 and then activated thyroid receptor-mediated signaling, thereby leading to integrated thyroid endocrine disruption in zebrafish larvae.

Chlorpyrifos (O, O-diethyl-O-(3,5,6-trichloro-2-pyridyl) phosphorothioate) is a broad-spectrum organophosphate insecticide and acaricide, widely used in our country. Nowadays, it is the principal insecticide in the market employed for agricultural purposes. A number of studies tending to study the affinity of different pesticides with soil have been performed, but only a few refer to chlorpyrifos. Because of its intensive use, a wide range of terrestrial ecosystems may be contaminated with chlorpyrifos, and there is a need to evaluate its environmental behavior and effects. The aim of our work is to study the interaction and persistence of a commercial formulation of chlorpyrifos on an agricultural soil from Provincia de Buenos Aires, Argentina. In this case, recovery percentages increased with the increase of initial concentration of the pesticide until a concentration of about 25 ppm is reached, and then a decrease was observed. The half-time life was not affected by an increase in chlorpyrifos concentration.

Dimethoate ([O,O-dimethyl S-(N-methylcarbamoylmethyl) phosphorodithioate]) is an organophosphate insecticide and acaricide widely used for agricultural purposes. Genotoxicity refers to the ability of a chemical agent interact directly to DNA or act indirectly leading to DNA damage by affecting spindle apparatus or enzymes involved in DNA replication, thereby causing mutations. Taking into consideration the importance of genotoxicity induced by dimethoate, the purpose of this manuscript was to provide a mini review regarding genotoxicity induced by dimethoate as a result of oxidative stress. The present study was conducted on studies available in MEDLINE, PUBMED, EMBASE, and Google scholar for all kind of articles (all publications published until May, 2020) using the following key words: dimethoate, omethoate, DNA damage, genetic damage, oxidative stress, genotoxicity, mutation, and mutagenicity. The results showed that many studies were published in the scientific literature; the approach was clearly demonstrated in multiple tissues and organs, but few papers were designed in humans. In summary, new studies within the field are important for better understanding the pathobiological events of genotoxicity on human cells, particularly to explain what cells and/or tissues are more sensitive to genotoxic insult induced by dimethoate.

Pesticides are used to protect crops and to eliminate pests, though non-target organisms such as mammals are also affected from their usage. Etoxazole (organoflourine pesticide) is an acaricide used to combat spider mites which are the parasites of various crops. The present study aims to investigate the effects of etoxazole on the level of MDA (malondialdehyde) and activities of CAT (catalase), GPx (glutathione peroxidase), and AChE (acetylcholinesterase) in liver and kidney tissues of Wistar rats (Rattus norvegicus var. albinos). Rats received etoxazole intraperitoneally with doses of 2.2, 11, and 22 mg/kg b.w./day for 21 days. Control rats received the same volume of the serum physiologic. Following etoxazole exposures, activities of CAT, GPx, and AChE in the liver and kidney of rats significantly decreased at all doses compared to control group. Oppositely, MDA levels in these tissues increased significantly at all doses following etoxazole exposures. The present study demonstrated that etoxazole, at all doses, had toxic effects in the liver and kidney parameters, suggesting their possible use as effective biomarkers in determining the toxic effects of etoxazole. This may suggest that these biomarkers could also be used as a tool to monitor pesticide-affected areas before severe toxic effects begin in non-target animals and humans.

The stereoselective cytotoxicity of new chiral acaricide etoxazole and its dissipation in citrus and soil were investigated for the first time. Enantioselective toxicity and oxidative stress of etoxazole toward MCF-7 cells was conducted. The phenomenon of dose- and form-dependent cytotoxicity was demonstrated by MTT and LDH assays, ROS generation, and SOD and CAT activity alternation. Cytotoxicity ranks were found to be consistent with oxidative damage as (R)- > Rac- > (S)-etoxazole. Moreover, the results of enantioselective degradation showed that (S)-etoxazole degraded faster than its antipode (R)-etoxazole. The gradual raise of EF values indicated the achievement of enantioselective degradation in citrus and soil, leaving the enrichment of (R)-etoxazole isomer. Significant differences of environmental behavior and cytotoxicity of etoxazole enantiomers were found in this study which provided valuable insight into the mechanism of potential toxicity and warranted more careful assessment of this pesticide before its agricultural application.

Deltamethrine (DLM) is a synthetic pyrethroid with broad spectrum activities against acaricides and insects. Widely used for agricultural and veterinary purposes, its human and animal exposure occurs by ingestion of contaminated water and food and leads to serious health problems. Kefir is fermented milk with numerous health favors counting restorative properties of bacterial flora, immune system stimulation, cholesterol reduction, as well as anti-mutagenic and anti-tumor properties. The present study was undertaken to examine the hepatoprotective and antioxidant potential of kefir against DLM toxicity in male Wistar albino rats. DLM-treated animals revealed a significant increase in serum biochemical parameters as well as hepatic protein and lipid oxidations but caused an inhibition in antioxidant enzymes. Additionally, we have observed an increase in hepatocyte DNA damages. This toxic effect was confirmed by histological study. Kefir administration normalized the elevated serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (T bilirubin), and cholesterol. It also reduced DLM-induced protein carbonyl (PC) and malondialdehyde (MDA) formations. Furthermore, Kefir treatment restored catalase (CAT) and superoxide dismutase (SOD) activities. The co-treatment as well as the pre-treatment by kefir showed an improvement of oxidative status as well as suppressed inflammation and DNA damages. However, the pre-treatment seems to be the most efficient. Therefore, it could be concluded that kefir is a natural product able to protect against the hepatotoxic effects of DLM by its free radical-scavenging and potent antioxidant activity.

Carbofuran is an anticholinesterase carbamate commonly used as an insecticide, nematicide and acaricide in agricultural practice throughout the world. However, data on its sorption in temperate soils from Europe is limited. Laboratory studies were conducted to determine the adsorption of carbofuran on three distinct Austrian soils using batch experiments and radiometric techniques. Carbofuran adsorption capacity of the soils was found to be low in the three soils tested and showed to be related to the soils clay and organic carbon contents. The pesticide presented linear adsorption isotherms in all of the three soils. Due to the low sorption of carbofuran in the soils tested and to its high water solubility, there is a risk of migration to water bodies through run off and consequent negative effects on aquatic organisms and soil biota.