Effects of Atrazine on Reproductive Health of Nondiabetic and Diabetic Male Rats

Association of Atrazine-Induced Overexpression of Aldo-Keto-Reductase 1C2 (AKR1C2) with Hypoandrogenism and Infertility: An Experimental Study in Male Wistar Rat

Atrazine (ATZ, C8H14ClN5) is a widely used synthetic herbicide that contaminates drinking water. It is a known endocrine disruptor that disrupts various molecular pathways involved in hormone signaling, and DNA damage, and can cause reproductive disorders, including decreased fertility, and abnormal development of reproductive organs, as revealed in animal model studies. However, the effect of ATZ on steroidogenesis in the male reproductive system, especially reduction of ketosteroids to hydroxysteroids, remains unclear. This study investigated the toxicity of ATZ on the male reproductive system in the Wistar rat model, with an emphasis on its adverse effect on aldo-ketoreductase family 1 member C2 (AKR1C2). Male Wistar rats were administered ATZ for 56 days (duration of one spermatogenic cycle) through oral route, at 20, 40 and 60 mg/kg body weight (bw) doses. The results indicate that ATZ exposure affects the body weight, impairs sperm production, and decrease FSH, LH, and testosterone levels. Additionally, the down-regulation of key steroidogenic enzymes by ATZ disrupted the synthesis of testosterone, leading to decreased levels of this essential male hormone. On the other hand, the expression of AKR1C2 (mRNA and protein) in the testis was upregulated. The findings suggest that AKR1C2 plays a role in androgen metabolism. Furthermore, its overexpression may lead to alteration in the expression of genes in the connected pathway, causing an increase in the breakdown or inactivation of androgens, which would result in lower androgen levels and, thereby, lead to hypoandrogenism, as the combined effects of down-regulation of steroidogenic genes and up-regulation of AKR1C2. These findings reveal direct implication of disrupted AKR1C2 in male reproductive health and highlight the need for further research on the impact of environmental toxins on human fertility, ultimately providing for better patient care.

Atrazine: cytotoxicity, oxidative stress, apoptosis, testicular effects and chemopreventive Interventions

Atrazine (ATZ) is an environmental pollutant that interferes with several aspects of mammalian cellular processes including germ cell development, immunological, reproductive and neurological functions. At the level of human exposure, ATZ reduces sperm count and contribute to infertility in men. ATZ also induces morphological changes similar to apoptosis and initiates mitochondria-dependent cell death in several experimental models. When in vitro experimental models are exposed to ATZ, they are faced with increased levels of reactive oxygen species (ROS), cytotoxicity and decreased growth rate at dosages that may vary with cell types. This results in differing cytotoxic responses that are influenced by the nature of target cells, assay types and concentrations of ATZ. However, oxidative stress could play salient role in the observed cellular and genetic toxicity and apoptosis-like effects which could be abrogated by antioxidant vitamins and flavonoids, including vitamin E, quercetin, kolaviron, myricetin and bioactive extractives with antioxidant effects. This review focuses on the differential responses of cell types to ATZ toxicity, testicular effects of ATZ in both in vitro and in vivo models and chemopreventive strategies, so as to highlight the current state of the art on the toxicological outcomes of ATZ exposure in several experimental model systems.

Histopathological, Immunohistochemical, And Molecular Alterations In Brain Tissue And Submandibular Salivary Gland Of Atrazine-Induced Toxicity In Male Rats

Atrazine (ATZ) is herbicide that has been widely used for different crops. This extensive use has resulted in severe deleterious effects in different species. In this work, we investigated the potentially harmful effect of atrazine herbicide on the brain and submandibular salivary gland. Our investigation was carried out on 20 adult male albino rats that were equally divided into two groups. The first group received distilled water as control, while the second group received ATZ at 200 mg/kg body weight/ day via stomach gavage for 30 successive days of the experiment; the oral LD50 for ATZ is 3090 mg/kg. Our findings revealed the ability of ATZ to cause damage to the cerebrum, hippocampus, and submandibular salivary gland. This damage resulted from the induced oxidative stress, which was indicated by a significant elevation in malondialdehyde (MDA) concentration, DNA fragmentation, tumor necrotic factor-alpha (TNF-α) expression, with a significant decrease in reduced glutathione (GSH) level and reduction of B cell lymphoma 2 (BCL2), dopamine receptor D1 (Drd1), cAMP-responsive element-binding protein 1 (Creb1) genes expression after ATZ exposure. Moreover, degeneration of cells, cytoplasmic vacuolation, congestion of blood vessels, a strong immune reaction to caspase 3, and negligible immune expression of a glial fibrillary acidic protein (GFAP) were also noticed in the ATZ-treated group. We concluded that ATZ induces oxidative stress and has a toxic and apoptotic effects on the cerebrum, hippocampus, and salivary gland of adult male albino rats.

Meta-analysis and experimental validation identified atrazine as a toxicant in the male reproductive system

Atrazine (ATZ), as a widely used triazine herbicide, is an environmental endocrine disruptor (EDC) that can cause many health problems. Therefore, we conducted this study based on the evidence of rats and mice to figure out the characteristics of ATZ damage to the reproductive system and further evaluate its health effects on the human. PRISMA's guidelines were followed according to the principles recommended by the Cochrane Handbook for Systematic Review. Health assessment was performed using the OHAT approach. Our new data were obtained from randomized controlled trials in rats designed in accordance with toxicological guidelines. Exposure to ATZ was significantly associated with decreased testosterone production (SMD = - 0.90, 95% CI - 1.27 to - 0.53), and reduced absolute weights of testis (SMD = - 0.41, 95% CI - 0.61 to - 0.22) and other reproductive organs. The damaging effect of sperm quality was also observed clearly, which included reduction of sperm count both in epididymis (SMD = - 2.32, 95% CI - 2.83 to - 1.81) and testis (SMD = - 1.01, 95% CI - 1.37 to - 0.64), decrease in sperm motility (SMD = - 8.86, 95% CI - 10.88 to - 6.83), and increase in sperm abnormality. Subgroup analysis revealed consistency across different species, life stage, and dosage. In addition, we found that ATZ exposure at a daily dose of 120 mg/kg during adolescence could cause decrease in weight gain and histological damage to the testis. The gene expression levels of Nrf2/HO-1 and Bcl-2/caspase signaling pathways in testis tissues were changed significantly. The results of this SR indicated that exposure to ATZ was associated with impairment of male reproductive system in rodents regardless of species, exposure life stage, and dosage. It is believed that ATZ exposure may have similar effects on male reproductive system of human beings. Pathways related to oxidative stress and apoptosis may be the mechanism leading to testicular damage in rats treated with ATZ.

Atrazine exposure in gestation and breastfeeding affects Calomys laucha sperm cells

The present study evaluated the effects of low doses of atrazine administered during gestation and breastfeeding on sperm characteristics of the wild rodent Calomys laucha. Adult females were divided into groups of 10 and administered different doses of atrazine through gavage, during gestational or breastfeeding period. At 3 months of age, the F1 adult male progeny of these females was evaluated. We observed a drastic reduction in the total and progressive motility of male sperm cells at all doses and during both the exposure periods. Moreover, the plasma membrane integrity of adult male sperm cells decreased at all doses of atrazine administered during the breastfeeding, whereas the membrane fluidity of these cells increased at all tested doses. Atrazine led to a decrease in the sperm mitochondrial functionality at all doses and during both exposure periods. The damage to the sperm DNA was higher in males exposed to the highest dose (1.0 mg/kg) during the gestation period, and in animals exposed to the lowest dose of atrazine (0.1 mg/kg) during breastfeeding period. Furthermore, the highest dose (1.0 mg/kg) of atrazine reduced the sperm concentration. Furthermore, the reduced levels of reactive oxygen species (ROS) were observed at all evaluated doses in males exposed during the gestation period. These results suggest that the administration of low doses of atrazine at critical periods of development may permanently reduce the sperm quality in C. laucha.

Oxidative stress in triazine pesticide toxicity: a review of the main biomarker findings

This review article provides a summary of the studies relying on oxidative stress biomarkers (lipid peroxidation and antioxidant enzymes in particular) to investigate the effects of atrazine and terbuthylazine exposure in experimental animals and humans published since 2010. In general, experimental animals showed that atrazine and terbuthylazine exposure mostly affected their antioxidant defences and, to a lesser extent, lipid peroxidation, but the effects varied by the species, sex, age, herbicide concentration, and duration of exposure. Most of the studies involved aquatic organisms as useful and sensitive bio-indicators of environmental pollution and important part of the food chain. In laboratory mice and rats changes in oxidative stress markers were visible only with exposure to high doses of atrazine. Recently, our group reported that low-dose terbuthylazine could also induce oxidative stress in Wistar rats. It is evident that any experimental assessment of pesticide toxic effects should take into account a combination of several oxidative stress and antioxidant defence biomarkers in various tissues and cell compartments. The identified effects in experimental models should then be complemented and validated by epidemiological studies. This is important if we wish to understand the impact of pesticides on human health and to establish safe limits.