Triazole pesticides exposure impaired steroidogenesis associated to an increase in AHR and CAR expression in testis and altered sperm parameters in chicken

Understanding the impact of triazoles on female fertility and embryo development: Mechanisms and implications

Triazoles are among the most widely used fungicides that were launched in 1980s and are one of the most important pesticide groups used in agriculture as plant growth regulators and stress protectors. Triazoles are also frequently used in the pharmaceutical industry to treat fungal and bacterial infections as well as to treat and prevent some forms of pneumonia. Humans are normally exposed to triazoles through food, water, and medications, which raises concerns about their potential adverse effects on health. Therefore, this review was planned to examine the impact of triazole fungicides on female fertility, as well as their teratogenic and embryotoxic effects. Various search engines such as PubMed, Google Scholar, Elsevier, IEEE were used to search the relevant articles published between 2006 and 2024 using the following keywords: "azoles," "female infertility," "reproductive toxicity," "teratogenicity," "triazoles," and "embryo toxicity." The findings suggest that triazoles might negatively affect female fertility and embryonic development through multiple mechanisms including inhibition or interference with key enzymes such as CYP17A1 and CYP19A1 (aromatase) involved in steroid hormone synthesis, endocrine disruption, oxidative stress, disruption of signaling pathways, and apoptosis. This review consolidates current knowledge on the teratogenic and embryotoxic properties of triazole fungicides, providing a comprehensive understanding of their health implications and addressing critical research gaps.

Consequences of in vitro exposure of chicken spermatozoa to the fungicide tebuconazole

Tebuconazole (TEB), a fungicide that inhibits 14α-demethylase (CYP51) and disrupts ergosterol synthesis, poses environmental and health risks due to its persistence and low biodegradability. This study examined TEB in vitro effects on rooster spermatozoa. In Experiment 1, semen from 10 Green-legged Partridge roosters was incubated with TEB (0, 0.1, 1, 10, 100 µM) at 36°C for 3 hours. Sperm motility was analyzed with Computer-Aided Sperm Analysis (CASA) system, while flow cytometry assessed membrane integrity, mitochondrial function, acrosome status, chromatin structure, intracellular calcium, apoptosis, caspase activity, and lipid peroxidation after 1 and 3 hours of exposure. Malondialdehyde (MDA) concentration and total antioxidant capacity (T-OAC) were measured by spectrophotometer. In Experiment 2, calcium channel blockers (SNX 325, MRS-1845, Nifedipine, HC-056456) were tested under the same conditions, focusing on motility, membrane integrity, calcium levels, apoptosis, caspase activity, and lipid peroxidation. Results in experiment 1 have shown that TEB (0.1, 1, 10 µM) reduced sperm velocity (VAP) after 3 hours (P < 0.01) without altering other motility parameters. Acrosome status, intracellular calcium level, and lipid peroxidation decreased significantly at all TEB concentrations (P < 0.01). Early apoptosis declined at 1 µM TEB (P < 0.01), while mitochondrial activity and membrane integrity remained stable. MDA levels were reduced (P < 0.01), with no effect on T-OAC. In Experiment 2, calcium channel blockers decreased motility parameters (VAP, VCL, VSL, MOT, PROG) and intracellular calcium levels (P < 0.01), but did not affect membrane integrity. Lipid peroxidation and caspase activity declined (P < 0.01), with no impact on early apoptosis. These findings underscore TEB's role in inhibiting calcium channels, reducing ion influx, blocking calcium-driven pore formation, thereby preserving membrane integrity. This mechanism mitigates early apoptosis and lipid peroxidation in chicken sperm, shedding light on TEB's impact on motility, calcium balance, and cell function.

Oxidative and Molecular-Structural Alterations of Spermatozoa in Swine and Ram Exposed to the Triazole Ipconazole

Triazole pesticides are widely used throughout the world, but their abuse causes toxic effects in non-targeted organisms. In the present study, the cytotoxic effect of the triazole ipconazole was evaluated in porcine and ram spermatozoa. Ipconazole significantly reduced sperm viability, increased ROS levels, altered catalase and SOD enzyme activity, and caused alterations in the molecular mRNA expression of structural biomarkers (PRM1, ODF2, AKAP4, THEG, SPACA3 and CLGN) related to fertility in males, as well as the overexpression of BAX (cell death) and ROMO1 (oxidative stress) mRNA. Our results indicate that the fungicide triazole is involved in cellular, enzymatic and molecular alteration of porcine and ram spermatozoa, and is possibly a factor in the development of infertility in male mammals.

The neonicotinoid, imidacloprid, disrupt the chicken sperm quality through calcium efflux

Imidacloprid (IMI), an insecticide from the neonicotinoid group widely used in agriculture, has drawn attention due to its potential harmful effects on non-target species, including bird populations. In the present work, we investigated the effect of IMI on avian semen by in vitro exposure of rooster spermatozoa to this pesticide. The semen was collected twice a week. Samples collected on one day were pooled and incubated with the following IMI concentrations: 0 mM, 0.5 mM, 5 mM, 10 mM, and 50 mM at 36°C for 3 h. Comprehensive semen analysis was carried out after 1 h and 3 h of incubation, evaluating sperm motility parameters with the CASA system and using flow cytometry to assess membrane integrity, mitochondrial activity, acrosome integrity, chromatin structure, intracellular calcium level and apoptosis markers such as: early apoptosis and caspase activation and lipid peroxidation. The results of the first experiment suggest that low concentrations of IMI have a different effect on sperm motility compared to higher concentrations. In IMI samples, we also observed a lower percentage of cells with a high level of calcium ions compared to the control, and a lower level of lipid peroxidation. We concluded that IMI may act as a blocker of calcium channels, preventing the influx of these ions into the cell. To confirm this mechanism, we conducted a second experiment with calcium channel blockers: SNX 325, MRS-1845, and Nifedipine. The results of this experiment confirmed that the mechanism of action of IMI largely relies on the blockade of calcium channels in rooster sperm. Blocking the influx of calcium ions into the cell prevents the formation of Ca²⁺-dependent pores, thereby preventing an increase in cell membrane permeability, ultimately blocking early apoptosis and lipid peroxidation in chicken spermatozoa.

Chemometrics-driven prediction and prioritization of diverse pesticides on chickens for addressing hazardous effects on public health

The extensive use of various pesticides in the agriculture field badly affects both chickens and humans, primarily through residues in food products and environmental exposure. This study offers the first quantitative structure-toxicity relationship (QSTR) and quantitative read-across-structure toxicity relationship (q-RASTR) models encompassing the LOEL and NOEL endpoints for acute toxicity in chicken, a widely consumed protein. The study's significance lies in the direct link between chemical toxicity in chicken, human intake, and environmental damage. Both the QSTR and the similarity-based read-across algorithms are applied concurrently to improve the predictability of the models. The q-RASTR models were generated by combining read-across derived similarity and error-based parameters, alongside structural and physicochemical descriptors. Machine Learning approaches (SVM and RR) were also employed with the optimization of relevant hyperparameters based on the cross-validation approach, and the final test set prediction results were compared. The PLS-based q-RASTR models for NOEL and LOEL endpoints showed good statistical performance, as traced from the external validation metrics Q2F1: 0.762-0.844; Q2F2: 0.759-0.831 and MAEtest: 0.195-0.214. The developed models were further used to screen the Pesticide Properties DataBase (PPDB) for potential toxicants in chickens. Thus, established models can address eco-toxicological data gaps and development of novel and safe eco-friendly pesticides.

In vitro exposure to triazoles used as fungicides impairs human granulosa cells steroidogenesis

Triazoles are the main components of fungicides used in conventional agriculture. Some data suggests that they may be endocrine disruptors. Here, we found five triazoles, prothioconazole, metconazole, difenoconazole, tetraconazole, and cyproconazole, in soil or water from the Centre-Val de Loire region of France. We then studied their effects from 0.001 µM to 1000 µM for 48 h on the steroidogenesis and cytotoxicity of ovarian cells from patients in this region and the human granulosa line KGN. In addition, the expression of the aryl hydrocarbon receptor (AHR) nuclear receptor in KGN cells was studied. Overall, all triazoles reduced the secretion of progesterone, estradiol, or both at doses that were non-cytotoxic but higher than those found in the environment. This was mainly associated, depending on the triazole, with a decrease in the expression of CYP51, STAR, CYP11A1, CYP19A1, or HSD3B proteins, or a combination thereof, in hGCs and KGN cells and an increase in AHR in KGN cells.