Toxicity evaluation of pesticide chlorpyrifos in male Japanese quails (Coturnix japonica)

Environmental safety assessment of cumic acid: A comprehensive study on environmental behaviours and toxicological effects on non-target organisms

Environmental safety assessments are crucial in the research and application of new pesticides. Cuminum cyminum is a widely cultivated crop rich in the antifungal compound cumic acid, which potential can be developed into a new type of botanical fungicide. This study presents an environmental safety assessment of Cuminum cyminum extract and its bioactive component, cumic acid, as prospective agents for botanical fungicides. Evaluation of their toxicity to non-target organisms showed a low impact on silkworms, fish, earthworms, tadpoles, and crops, but moderate toxicity to quails and bees. In addition, adsorption and leaching analyses showed that cumic acid has a strong affinity for soil, resulting in high pesticide concentrations in the topsoil layers and a low leaching tendency. The degradation rate of cumic acid in diverse agricultural soils was rapid, with half-lives ranging from 4.05 to 5.09 days, indicating a low potential for environmental accumulation. Degradation and photolysis studies also showed that cumaric acid did not accumulate readily in the environment. These comprehensive findings highlight the safety and agricultural potential of cumic acid-based products, with implications for the advancement of eco-friendly botanical fungicides derived from cumin extracts.

Toxicological risk assessment of triadimenol for human exposure, broiler health, and food safety

Triadimenol, a widely used triazole fungicide, leaves residues that pose risks to broiler health, food safety, and human health. Current studies focus on lab animals, leaving limited data regarding its impact on non-target organisms in agricultural ecosystems. Moreover, the doses in current studies often exceed typical agricultural pollution levels of triadimenol. Therefore, this study evaluates the toxic effects of triadimenol by exposing broilers to different concentrations (0.05-20 mg/kg) in their feed for 42 days, assessing growth performance, organ index, hematological parameters, histopathology, jejunum morphology, and tissue residues. The results show that triadimenol contamination at 0.05-20 mg/kg in feed does not significantly affect broiler growth performance. However, the significant changes in hematological parameters suggest the potential hematological toxicity of triadimenol in broilers. Triadimenol at 1 mg/kg or higher induces hepatotoxic and nephrotoxic effects, and significantly alters kidney organ index and histopathology in broilers. Additionally, when the triadimenol contamination level in feed exceeds 1 mg/kg, the residues in edible tissues of broilers exceed the limits set by the EU and China. Overall, our study indicates that even low-dose exposure to triadimenol poses potential risks, highlighting the need for strict regulation of its use in agriculture to protect food safety and human health.

Structural gonadal lesions observed in Japanese quail (Coturnix coturnix japonica) following exposure during puberty to the neonicotinoid pesticide, imidacloprid

Exposure to the neonicotinoid insecticide, imidacloprid (IMI), causes reproductive toxicity in mammals and reptiles. However, reports on the effects of IMI on the gonads in birds are grossly lacking. Therefore, this study investigated the effects of pubertal exposure to IMI on the histology, ultrastructure, as well as the cytoskeletal proteins, desmin, smooth muscle actin and vimentin, of the gonads of Japanese quail (Coturnix coturnix japonica). Quails were randomly divided into four groups at 5 weeks of age. The control group was given only distilled water, whereas, the other three experimental groups, IMI was administered by oral gavage at 1.55, 3.1, and 6.2 mg/kg, twice per week for 4 weeks. Exposure to IMI doses of 3.1 and 6.2 mg/kg caused dose-dependent histopathological changes in the ovary and testis. In the ovary, accumulation of lymphocytes, degenerative changes, and necrosis with granulocyte infiltrations were observed, while in the testis, distorted seminiferous tubules, germ cell sloughing, vacuolisations, apoptotic bodies, autophagosomes, and mitochondrial damage were detected. These changes were accompanied by a decreased number of primary follicles (P ≤ 0.05) in the ovary and a decrease (P ≤ 0.05) in the epithelial height, luminal, and tubular diameters of seminiferous tubules at the two higher dosages. In addition, IMI had a negative effect on the immunostaining intensity of desmin, smooth muscle actin, and vimentin in the ovarian and testicular tissue. In conclusion, exposure to IMI during puberty can lead to a range of histopathological alterations in the gonads of Japanese quails, which may ultimately result in infertility.

Effect of atrazine on testicular toxicity involves accommodative disorder of xenobiotic metabolizing enzymes system and testosterone synthesis in European quail (Coturnix coturnix)

Due to the wide use of atrazine (ATR), the concern has increased regarding the negative impact of ATR on reproduction. Nevertheless, the reproductive effects caused by different exposure concentrations and the severity of toxic damage are poorly understood. In organisms, ATR is metabolized and degraded through phase II enzyme systems, and changes in cytochrome P450 (CYP) enzymes may have a regulatory role in the harm of ATR. However, less information is available on the induction of CYPs by ATR in avian organisms, and even less on its effects on the testis. Birds are exposed to ATR mainly through food residues and contaminated water, the purpose of this study was to examine reproductive toxicity by different exposure concentrations and elaborate metabolic disorders caused by ATR in European quail (Coturnix coturnix). In this study, the quail were given ATR at 50 mg/kg, 250 mg/kg and 500 mg/kg by oral gavage for 45 days, and the testicular weight coefficients, histopathology and ultrastructure of testes, primary biochemical functions, sex steroid hormones, critical protein levels in the testosterone synthesis pathway, the expression of genes involved CYPs, gonad axis and nuclear receptors expression were investigated. Altogether, testicular coefficient decreased significantly in the high-dose group (1.22%) compared with the control group (3.03%) after 45 days of ATR exposure, and ATR is a potent CYP disruptor that acts through the NXRs and steroid receptor subfamily (APND, CAR, ERND and ERα) without a dose-dependent manner. Notably, ATR interfered with the homeostasis of hormones by triggering the expression of hormones on the gonad axis (LH and E2). These results suggest that exposure to ATR can cause testicular toxicity involving accommodative disorder of phase II enzyme and testosterone synthesis in European quail.

What can we learn from commercial insecticides? Efficacy, toxicity, environmental impacts, and future developments

Worldwide pesticide usage was estimated in up to 3.5 million tons in 2020. The number of approved products varies among different countries, however, in Brazil, there are nearly 5000 of such products available. Among them, insecticides correspond to a group of mounting importance for controlling crop pests and disease-associated vectors in public health. Unfortunately, resistance to commercially approved insecticides is commonly observed, limiting the use of these products. Thus, the search for more effective and environmentally friendly products is both a challenge and a necessity since several insecticides are no longer allowed in many countries. In this review, we discuss the historical strategies used in the development of modern insecticides, including chemical structure alterations, mechanism of action and their impact on insecticidal activity. The environmental impact of each pesticide class is also discussed, with persistence data and activity on non-target organisms, along with the human toxicological effect. By tracing the historical route of discovery and development of blockbuster pesticides like DDT, pyrethroids and organophosphates, we also aim to categorize and relate the successful chemical alterations and novel pesticide development strategies that resulted in safer alternatives. A brief discussion on the Brazilian registration procedure and a perspective of insecticides currently approved in the country was also included.

Assessment of DNA damage induced by endosulfan in grass carp (Ctenopharyngodon idella Valenciennes, 1844)

Endosulfan is an organochlorine pesticide, which is commonly used throughout the world. It accumulates in the environment and may cause significant damage to the ecosystems, particularly to the aquatic environments. The present study was conducted to evaluate the genotoxic effect of endosulfan on the grass carp (Ctenopharyngodon idella) blood. The fish were exposed to three different concentrations, 0.75 ppb/day, 1.0 ppb/day, and 1.5ppb/day of endosulfan for 7, 14, 21, and 28 days. The study was a randomized control trial and the control group was not exposed to endosulfan. The results showed that after 7 days, the level of DNA damage in all the concentrations was significant (P < 0.05), while after 14, 21, and 28 days' trials, highly significant (P < 0.000) level of DNA damage was observed. Hence, time- and dose-dependent DNA damage was observed in fish DNA by comet assay. It is concluded from our results that with the increase in endosulfan concentration and exposure duration, the level of DNA damage also increased. As the current study showed the severe genotoxic effect of endosulfan in Ctenopharyngodon idella, therefore, the imprudent and indiscriminate use of endosulfan should be controlled and monitored by the concerned government authorities.