Thiamethoxam inhibits blastocyst expansion and hatching via reactive-oxygen species–induced G2 checkpoint activation in pigs

Smartphone-based molecularly imprinted sensors for rapid detection of thiamethoxam residues and applications

In order to achieve rapid detection of thiamethoxam residues in mango, cowpea and water, this study modified the screen printed carbon electrode (SPCE) to make a specific molecular imprinting sensor (Thiamethoxam-MIP/Au/rGO/SPCE) for thiamethoxam. An integrated smartphone platform was also built for thiamethoxam residue analysis. The performance of the complete system was analyzed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The system was then applied for the rapid determination of thiamethoxam residues in water, mango and cowpea samples. The results showed that the molecular sensor showed good linearity in the range 0.5–3.0 μmol/L of thiamethoxam. The detection limit of thiamethoxam was 0.5 μmol/L. Moreover, the sensor had good reproducibility and anti-interference performance. The average recovery rates of the pesticide residues in water, mango and cowpea samples were in the range of 90–110% with relative standard deviations < 5%. The rapid detection system for thiamethoxam residue constructed in this study was simple, reliable, reproducible and had strong anti-interference. It has broad application prospects in the field detection of thiamethoxam residue, and serves as a valuable reference for the further development of rapid detection technology of pesticide residues in the field of environment and food safety.

Mechanisms of deleterious effects of some pesticide exposure on pigs

The increase in the size of the global population increases the food and energy demand, making the use of pesticides in agricultural and livestock industries unavoidable. Exposure to pesticides can be toxic to the non-target species, such as humans, wildlife, and livestock, in addition to the target organisms. Various chemicals are used in the livestock industry to control harmful organisms, such as insects, weeds, and parasites. Pigs are one of the most important food sources for humans. In addition, pigs can be used as promising models for assessing the risk of absorption of environmental pollutants through the skin and oral exposure since they are physiologically similar to humans. Exposure to numerous environmental pollutants, such as mycotoxins, persistent organic pollutants, and heavy metals, has been reported to adversely affect growth, fertility, and endocrine homeostasis in pigs. Various pesticides have been observed in porcine tissues, blood, urine, and processed foods; however, there is a lack of comprehensive understanding of their effects on porcine health. This review provides a comprehensive description of the characteristics of pesticides that pigs can be exposed to and how their exposure affects porcine reproductive function, intestinal health, and endocrine homeostasis in vivo and in vitro.

Thiamethoxam Exposure Induces Endoplasmic Reticulum Stress and Affects Ovarian Function and Oocyte Development in Mice

Neonicotinoids are the most widely used insecticides in modern agriculture, and their residues have been found in the environment and food. Previous studies reported that neonicotinoids exert toxic effects in various tissues, but whether they interfered with the female reproductive process remains unknown. In our present research, thiamethoxam was selected as a representative neonicotinoid to establish a mouse toxicity model with gavage. We found that thiamethoxam decreased the ovarian coefficient and disrupted the expression of female hormone receptors, subsequently affecting follicle development. Ovarian granulosa cells from the thiamethoxam exposure group underwent a high level of apoptosis. Using transcriptome analysis, we showed that thiamethoxam exposure altered the expression of multiple oocyte genes related to inflammation, apoptosis, and endoplasmic reticulum stress. Thiamethoxam also adversely affected oocyte and embryo development. Western blotting and fluorescence staining results confirmed that thiamethoxam affected the integrity of DNA, triggered apoptosis, promoted oxidative stress and endoplasmic reticulum stress, and impaired mitochondrial function. Collectively, our results indicated that thiamethoxam exposure disrupts ovarian homeostasis and decreases oocyte quality via endoplasmic reticulum stress and apoptosis induction.

N-(2-mercaptopropionyl)-glycine enhances in vitro pig embryo production and reduces oxidative stress

This study evaluated the effects of different concentrations (1, 10, 25, 50, and 100 µM) of the antioxidant N-(2-mercaptopropionyl)-glycine (NMPG), during the culture of in vitro-fertilized porcine oocytes. While the highest concentrations of NMPG (50 and 100 µM) were toxic to the developing embryos during the first two days of culture, 25 µM NMPG achieved cleavage rates that were similar to those achieved by the control but did not sustain blastocyst production by Day 7 of culture. Compared to the control culture medium, the culture medium supplemented with 10 µM NMPG increased (P < 0.05) the rates of blastocyst formation, decreased (P < 0.05) the intracellular levels of reactive oxygen substances, and downregulated (P < 0.05) the expression of the oxidative stress related gene GPX1. In conclusion, these results demonstrated that supplementation of porcine embryo culture medium with 10 µM NMPG can attenuate oxidative stress and increase the yield of in vitro production of blastocysts.

In vitro exposure to thiacloprid-based insecticide formulation promotes oxidative stress, apoptosis and genetic instability in bovine lymphocytes

A proprietary thiacloprid-based neonicotinoid insecticide formulation is widely used in agriculture to protect vegetables and fruit against various pests. However, its effect on animal cells has not been fully elucidated. In this study, bovine peripheral lymphocytes were incubated with different concentrations of this formulation (10; 30; 60; 120 and 240 μg.mL^-1) for 4 h to address the potential cytotoxic and genotoxic effects of the insecticide. Insecticide formulation treatment resulted in decreased cell viability and proliferation, p53-mediated cell cycle arrest at the G₀/G₁ phase, and apoptosis induction accompanied by elevated levels of mitochondrial superoxide and protein carbonylation. Oxidant-based DNA damage and DNA damage response (DDR) were also observed, namely the formation of micronuclei, DNA double-strand breaks and slightly elevated recruitment of p53 binding protein (53BP1) foci. Our results contribute to the elucidation of insecticide effects on animal lymphocyte cultures after short-term exposure. Due to increased application of neonicotinoids worldwide, resulting in both higher yields and adverse effects on non-target animals and humans, further in vivo and in vitro experiments should be performed to confirm their cytotoxic and genotoxic activities during short-term exposure.