Reproductive effects of subchronic exposure to acetamiprid in male rats

Acetamiprid induces cardiotoxicity in rats by dysregulating α7 nAChR and its downstream targets: The ameliorative role of resveratrol

Acetamiprid (ACP) is a novel neonicotinoid insecticide used for controlling insect pests. Resveratrol (RSV) is a natural polyphenol that possesses anti-oxidant, anti-inflammatory and anti-apoptotic actions. The current research explores the mechanism of ACP-induced cardiotoxicity and the alleviative effects of RSV. Male rats were allocated to four groups of ten each. Rats were treated daily for 90 days via oral route. Control rats received distilled water, ACP rats received 25 mg acetamiprid/kg, RSV rats received 20 mg resveratrol/kg and ACP + RSV rats received both ACP and RSV. ACP exposure increased serum creatine phosphokinase activity and cardiac troponin level. It also induced oxidative stress, as evidenced by the glutathione reduction, and malondialdehyde elevation, as well as the detrimental histopathological and immunohistochemical changes in the myocardium. Gene expression analysis revealed down-regulation in the mRNA expression of the survival-related genes α7 nAChR, Erk and Bcl-2, and up-regulation in the apoptosis-related genes Jnk, Bax and Caspase-3. Conversely, the concomitant administration of ACP with RSV alleviated most of the aforementioned toxic impacts. It can be concluded that ACP induces cardiotoxicity by dysregulating the mRNA expression of α7 nAChR and its downstream targets. Additionally, RSV is proved to be a promising ameliorative agent against ACP-induced cardiotoxicity.

Comparison of prenatal and postnatal exposure to neonicotinoids and their temporal trends in breast milk

Although the potential effects of neonicotinoids (NEOs) in early life have received considerable attention, data on the exposure of mothers and infants to NEOs are scarce. In this study, four parent NEOs and one metabolite were widely detected in paired maternal serum (MS), umbilical cord serum (UCS) and breast milk (BM) samples, with median total NEO concentrations (ΣNEOs) of 113, 160 and 69 ng/L, respectively. Decreasing trends were observed for N-desmethyl-acetamiprid (30 %/year), acetamiprid (22 %/year) and ΣNEOs (15 %/year) in breast milk between 2014 and 2022, whereas increasing trends were seen for clothianidin (17 %/year) and thiamethoxam (30 %/year). N-desmethyl-acetamiprid was the predominant compound in all matrices. However, the contributions of N-desmethyl-acetamiprid (35 %) and thiamethoxam (36 %) in breast milk were similar in 2022. Moreover, thiamethoxam has become the predominant contributor to the estimated daily intake of ΣNEOs since 2018, with the highest contribution of 71 % in 2022, suggesting the effects of NEOs continue to evolve and more attention should be paid to the new NEOs. Notably, the correlations and ratios of NEOs between paired UCS and MS were more significant and higher than those between paired BM and MS, respectively, indicating that NEO exposure was largely affected by the prenatal period.

Mechanistic insights into acetamiprid-induced genotoxicity on the myocardium and potential ameliorative role of resveratrol

The current study aimed to explore the genotoxic impacts of the insecticide acetamiprid (ACP) on the myocardium and assess the ameliorative role of resveratrol (RSV). Male rats (10/group) were treated via oral route for 90 days: control; ACP (25 mg/kg); RSV (20 mg/kg); ACP+RSV. Peripheral blood micronucleus test, oxidative stress analysis, comet assay, 8-hydroxydeoxyguanosine and gene expression assessment were performed. The findings revealed that ACP has myocardial genotoxic effects, as demonstrated by increased micronucleus and 8-hydroxydeoxyguanosine formation and increased all comet parameters. Oxidative stress analysis demonstrated that ACP elevated H2O2 and NO levels while decreasing catalase and GST activities. Acetamiprid dysregulated the expression of genes related to oxidative stress and DNA damage response. However, RSV co-treatment resulted in significant protection against these genotoxic impacts. Resveratrol reduced DNA damage and restored the oxidative balance in the myocardium. Moreover, RSV modulated the Nrf2/HO-1 and Atm/P53 pathways, potentiating antioxidant defense and DNA repair.

Thiacloprid impairs reproductive functions of male Wistar rats

Global male infertility correlated to the rise of endocrine-disrupting chemicals, including insecticides, has grown into a pressing problem. Thiacloprid is one of the most commonly used neonicotinoids that accounts for more than 25% of the global pesticide industry. However, its impact on the reproductive system and male fertility has not been fully elucidated. The object of this study was to explore the adverse effects of thiacloprid on male Wistar rats' reproductive system. Thirty healthy male rats were separated into one of three groups: control group, and two groups that were orally administered with low (22.5 mg/kg) and high dose (62.1 mg/kg) of thiacloprid for 56 days. Thiacloprid significantly (p<0.05) reduced body weight and relative testicular weight, as well as sperm quality (count, motility, viability, and morphology), in a dose-dependent manner. THIA-treated groups revealed a large effect (d > 0.8) on semen quality with Cohen's d of (6.57, 8.82), (20.14, 23.54), and (2.81, 9.10) for count, motility, and viability respectively. Meanwhile, the serum testosterone level dropped while the levels of luteinizing and follicle-stimulating hormones increased. 17ꞵ-hydroxy steroid dehydrogenase and 3ꞵ-hydroxy steroid dehydrogenase levels were significantly decreased in a dose-dependent manner. The activity of the tested antioxidant enzymes catalase (CAT), glutathione reduced (GSH), and superoxide dismutase (SOD) exhibited a considerable decrease compared to the control group with a significant elevation in the lipid peroxidation activity as indicated by malondialdehyde (MDA) level. The testicular histology revealed degenerative changes in spermatogenic cells and interstitial tissue. Comet assay revealed DNA fragmentation in treated groups' testicular tissue. Thiacloprid exposure interferes with reproductive function and impairs male Wistar rat fertility. Such harmful consequences may also develop in humans frequently exposed to thiacloprid.

Genotoxic effects of sub-lethal doses of nicotine and acetamiprid in neuroblasts of Drosophila melanogaster and Drosophila suzukii

Neonicotinoids form a class of insecticides that are chemically related to nicotine and are widely used in crop protection. They have adverse effects on the neuronal nicotinic acetylcholine receptors (nAChRs). One of the neonicotinoids approved for control of the invasive pest Drosophila suzukii is acetamiprid. Despite concerns regarding its genotoxicity and data indicating the presence of small amounts of this substance in fruits intended for consumption, effects of its low doses on nerve cells are yet to be investigated. To determine whether the neurotoxic effects are species-specific and vary depending on the insecticide present in diet, multigenerational cultures of Drosophila melanogaster and D. suzukii were prepared, in this study, in media supplemented with different concentrations (below the LC50) of acetamiprid and nicotine. Acetamiprid, analogous to nicotine, caused damage to the DNA of neuroblasts in both species, at sublethal concentrations, along with a decrease in mobility, which remained at a similar level over subsequent generations. D. suzukii was found to be more sensitive to nicotine and acetamiprid, due to which the genotoxic effects were stronger even at lower doses of toxins. The results collectively indicated that even low concentrations of acetamiprid affect the stem cells of developing fly brain, and that long-term response to the tested insecticides is species-specific.

Cinnamon nanoemulsion mitigates acetamiprid-induced hepatic and renal toxicity in rats: biochemical, histopathological, immunohistochemical, and molecular docking analysis

Acetamiprid (ACDP) is a widely used neonicotinoid insecticide that is popular for its efficacy in controlling fleas in domestic settings and for pets. Our study aims to offer a comprehensive examination of the toxicological impacts of ACDP and the prophylactic effects of cinnamon nanoemulsions (CMNEs) on the pathological, immunohistochemical, and hematological analyses induced by taking ACDP twice a ‎week for 28 days. Forty healthy rats were divided into four groups (n = 10) at random; the first group served as control rats; the second received CMNEs (2 mg/Kg body weight); the third group received acetamiprid (ACDP group; 21.7 mg/Kg body weight), and the fourth group was given both ACDP and CMNEs by oral gavage. Following the study period, tissue and blood samples were extracted and prepared for analysis. According to a GC-MS analysis, CMNEs had several bioactive ingredients that protected the liver from oxidative stress by upregulating antioxidant and anti-inflammatory agents. Our findings demonstrated that whereas ACDP treatment considerably boosted white blood cells (WBCs) and lymphocytes, it significantly lowered body weight gain (BWG), red blood cells (RBCs), hemoglobin (Hb), hematocrit (HCT), and platelets (PLT). ACDP notably reduced antioxidant enzyme activities: superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) and elevated hydrogen peroxide and malondialdehyde levels compared with other groups. ACDP remarkably raised alanine aminotransferase (ALT), aspartate amino transaminase (AST), and alkaline phosphatase (ALP) levels.Moreover, the histopathological and immunohistochemistry assays discovered a severe toxic effect on the liver and kidney following ACDP delivery. Furthermore, cyclooxygenase 2 (COX-2) + immunoexpression was enhanced after treatment with CMNEs. All of the parameters above were returned to nearly normal levels by the coadministration of CMNEs. The molecular docking of cinnamaldehyde with COX-2 also confirmed the protective potential of CMNEs against ACDP toxicity. Our findings highlighted that the coadministration of CMNEs along with ACDP diminished its toxicity by cutting down oxidative stress and enhancing antioxidant capacity, demonstrating the effectiveness of CMNEs in lessening ACDP toxicity.

Non-acute exposure of neonicotinoids, health risk assessment, and evidence integration: a systematic review

Neonicotinoid pesticides are utilized against an extensive range of insects. A growing body of evidence supports that these neuro-active insecticides are classified as toxicants in invertebrates. However, there is limited published data regarding their toxicity in vertebrates and mammals. the current systematic review is focused on the up-to-date knowledge available for several neonicotinoid pesticides and their non-acute toxicity on rodents and human physiology. Oral lethal dose 50 (LD50) of seven neonicotinoids (i.e. imidacloprid, acetamiprid, clothianidin, dinotefuran, thiamethoxam, thiacloprid, and nitenpyram) was initially identified. Subsequently, a screening of the literature was conducted to collect information about non-acute exposure to these insecticides. 99 studies were included and assessed for their risk of bias and level of evidence according to the Office of Health and Translation (OHAT) framework. All the 99 included papers indicate evidence of reproductive toxicity, hepatotoxicity, nephrotoxicity, neurotoxicity, immunotoxicity, and oxidative stress induction with a high level of evidence in the health effect of rodents and a moderate level of evidence for human health. The most studied type of these insecticides among 99 papers was imidacloprid (55 papers), followed by acetamiprid (22 papers), clothianidin (21 papers), and thiacloprid (11 papers). While 10 of 99 papers assessed the relationship between clothianidin, thiamethoxam, dinotefuran, and nitenpyram, showing evidence of liver injury, dysfunctions of oxidative stress markers in the reproductive system, and intestinal toxicity. This systematic review provides a comprehensive overview of the potential risks caused by neonicotinoid insecticides to humans and rodents with salient health effects. However, further research is needed to better emphasize and understand the patho-physiological mechanisms of these insecticides, taking into account various factors that can influence their toxicity.

The impact of the insecticide acetamiprid on the embryogenesis of the aquatic model organism Xenopus laevis

Acetamiprid (ACT) is used extensively in agriculture worldwide, although data on ACT concentrations in natural water bodies and its impact on aquatic organisms are limited. To study whether ACT influences the embryogenesis of the South African clawed frog Xenopus laevis, embryos were incubated in ACT solutions from 0.01 to 100 mg/L. The low concentrations were chosen on the basis of concentrations already found in nature. ACT treatment leads to shorter embryo lengths, intestine malformation and reduced eye areas. It also affects the cranial cartilage and cardiac development as well as the embryo's mobility. The expression of tissue-specific marker genes is affected as well. Thus, our study suggests that pesticides may lead to an increased mortality of non-target organisms and emphasizes the importance of regular testing for ACT concentrations in nature. Our study provides an overview of ACT effects and can therefore be used as a basis for an ACT risk assessment.

Reproductive effects of pubertal exposure to neonicotinoid thiacloprid in immature male mice

Thiacloprid (THIA) is a kind of neonicotinoid, a widely used insecticide class. Animal studies of adult and prenatal exposure to THIA have revealed deleterious effects on mammalian sperm fertility and embryonic development. A recent cross-sectional study linked higher THIA concentrations to delayed genitalia development stages in adolescent boys, suggesting that pubertal exposure to THIA may adversely affect reproductive development in immature males. Hence, this study aimed to investigate the effects of daily oral administration of THIA during puberty on the reproductive system of developing male mice. Young male C57 BL/6 J mice aged 21 days were administrated with THIA at concentrations of 10 (THIA-10), 50 (THIA-50) and 100 mg/kg (THIA-100) for 4 weeks by oral gavage. It is found that exposure to 100 mg/kg THIA diminished sexual behavior in immature male mice, caused a decrease in the spermatogenic cell layers and irregular arrangement of the seminiferous epithelium, and down-regulated the mRNA levels of spermatogenesis-related genes Ddx4, Scp3, Atg5, Crem, and Ki67, leading to an increase of sperm abnormality rate. In addition, THIA exposure at 50 and 100 mg/kg reduced the serum levels of testosterone and FSH, and decreased the expression levels of Star and Cyp11a1 related to testosterone biosynthesis. THIA exposure at 10 mg/kg did not produce any of the above significant changes. In conclusion, the high dose of THIA exposure impaired reproductive function in immature mice. It seems that THIA has no detrimental effects on the reproductive system of mice at low dose of 10 mg/kg.

Berberine mitigates acetamiprid-induced hepatotoxicity and inflammation via regulating endogenous antioxidants and NF-κB/TNF-α signaling in rats

Acetamiprid is a neonicotinoid insecticide used on a large scale and has been reported for oxidative stress-mediated toxicity and physiological alterations in mammals. The plant-derived natural antioxidant berberine (BBR) possesses protective potential against inflammation, structural changes, and cellular toxicity. The current study aimed to investigate the toxic effects of acetamiprid exposure and the antioxidative and anti-inflammatory efficacy of BBR in rat liver tissue. The results showed that intragastric exposure of acetamiprid (21.7 mg/kg b.wt, i.e., 1/10 of LD50) for 21 days significantly elicited oxidative stress as evidenced by lipid peroxidation, protein oxidation, and depletion of endogenous antioxidants. Furthermore, acetamiprid exposure elevated NF-κB, TNF-α, IL-1β, IL-6, and IL-12 expression and caused structural alterations in liver tissue. Biochemical results showed that 2-h pre-treatment of BBR (150 mg/kg b.wt; 21 days) reduced damage to lipids and proteins, replenished GSH, enhanced SOD and catalase activities, and offered antioxidative effects against acetamiprid toxicity. Also, BBR suppressed inflammation by regulating NF-κB/TNF-α signaling in hepatic tissue of acetamiprid-intoxicated rats. Histopathological examination confirmed the hepatoprotective effects of BBR. Our findings indicate that BBR might be a potential ameliorative agent against oxidative stress-mediated hepatotoxicity.

Screening of Toxic Effects of Neonicotinoid Insecticides with a Focus on Acetamiprid: A Review

Recently, neonicotinoids have become the fastest-growing class of insecticides in conventional crop protection, with extensive usage against a wide range of sucking and chewing pests. Neonicotinoids are widely used due to their high toxicity to invertebrates, simplicity, flexibility with which they may be applied, and lengthy persistence, and their systemic nature ensures that they spread to all sections of the target crop. However, these properties raise the risk of environmental contaminations and potential toxicity to non-target organisms. Acetamiprid is a new generation insecticide, which is a safer alternative for controlling insect pests because of its low toxicity to honeybees. Acetamiprid is intended to target nicotinic acetylcholine receptors in insects, but its widespread usage has resulted in negative impacts on non-target animals such as mammals. This review summarizes in vivo and in vitro animal studies that investigated the toxicity of specific neonicotinoids. With summarized data, it can be presumed that certain concentrations of neonicotinoids in the reproductive system cause oxidative stress in the testis; spermatogenesis disruption; spermatozoa degradation; interruptions to endocrine function and Sertoli and Leydig cell function. In the female reproductive system, acetamiprid evokes pathomorphological alterations in follicles, along with metabolic changes in the ovaries.

A combination of the frequent fungicides boscalid and dimoxystrobin with the neonicotinoid acetamiprid in field-realistic concentrations does not affect sucrose responsiveness and learning behavior of honeybees

The increasing loss of pollinators over the last decades has become more and more evident. Intensive use of plant protection products is one key factor contributing to this decline. Especially the mixture of different plant protection products can pose an increased risk for pollinators as synergistic effects may occur. In this study we investigated the effect of the fungicide Cantus® Gold (boscalid/dimoxystrobin), the neonicotinoid insecticide Mospilan® (acetamiprid) and their mixture on honeybees. Since both plant protection products are frequently applied sequentially to the same plants (e.g. oilseed rape), their combination is a realistic scenario for honeybees. We investigated the mortality, the sucrose responsiveness and the differential olfactory learning performance of honeybees under controlled conditions in the laboratory to reduce environmental noise. Intact sucrose responsiveness and learning performance are of pivotal importance for the survival of individual honeybees as well as for the functioning of the entire colony. Treatment with two sublethal and field relevant concentrations of each plant protection product did not lead to any significant effects on these behaviors but affected the mortality rate. However, our study cannot exclude possible negative sublethal effects of these substances in higher concentrations. In addition, the honeybee seems to be quite robust when it comes to effects of plant protection products, while wild bees might be more sensitive.

Widespread use of toxic agrochemicals and pesticides for agricultural products storage in Africa and developing countries: Possible panacea for ecotoxicology and health implications

Chemicals used for storage majorly possess insecticidal activities - deterring destructive insect pests and microorganisms from stored agricultural produce. Despite the controversy about their safety, local farmers and agro-wholesalers still predominantly use these chemicals in developing countries, especially Africa, to ensure an all-year supply of agriproducts. These chemicals could have short- or long-term effects. Despite the state-of-the-art knowledge, factors such as poor education and awareness, limited agricultural subventions, quests for cheap chemicals, over-dosage, and many more are the possible reasons for these toxic chemicals' setback and persistent use in developing countries. This paper provides an up-to-date review of the environmental and ecological effects, as well as the health impacts arising from the indiscriminate use of toxic chemicals in agriproducts. Existing data link pesticides to endocrine disruption, genetic mutations, neurological dysfunction, and other metabolic disorders, apart from the myriad of acute effects. Finally, this study recommended several naturally sourced preservatives as viable alternatives to chemical counterparts and emphasized the invaluable role of education and awareness programs in mitigating the use in developing nations for a sustainable society.

Reproductive Effects of S. boulardii on Sub-Chronic Acetamiprid and Imidacloprid Toxicity in Male Rats

The potential health-promoting effects of probiotics against intoxication by pesticides is a topic of increasing commercial interest with limited scientific evidence. In this study, we aimed to investigate the positive effects of probiotic Saccharomyces boulardii on the male reproductive system under low dose neonicotinoid pesticide exposure conditions. We observed that acetamiprid and imidacloprid caused a degeneration and necrosis of the spermatocytes in the tubular wall, a severe edema of the intertubular region and a hyperemia. This was concomittant to increased levels of 8-hydroxy-2'-deoxyguanosine reflecting oxidative stress, and an increase in caspase 3 expression, reflecting apoptosis. According to our results, Saccharomyces boulardii supplementation mitigates these toxic effects. Further in vivo and clinical studies are needed to clarify the molecular mechanisms of protection. Altogether, our study reinforces the burden of evidence from emerging studies linking the composition of the gut microbiome to the function of the reproductive system.

The Effect of Increasing the Dose of Acetamiprid and Dichlorvos Pesticides on the Reproductive Performance of Laboratory Mice

Background

Pesticides are widely used around the world. However, these chemicals are being used more frequently and at increased doses in underdeveloped and developing countries. Although the hazard of pesticides has been studied in ecological fields, the effect of residual amounts of these compounds on the physiological processes of the body has always been debated.

Materials and Methods

In this experimental study, 45 greenhouse cucumber plants were sprayed with dichlorvos and acetamiprid pesticides in concentrations of twofold (acetamiprid 500 g/1000 L and dichlorvos 4 L/1000 L) and threefold of the recommended dose. After 24 h, the residual amount was obtained. To evaluate the residual effect of the mentioned pesticides, an equivalent of this residue was added to the drinking water of 105 mice.

Results

Pesticide residues were obtained for twofold and threefold concentrations of the recommended dose, 1.5 and 2.5 (mg/kg cucumber) for acetamiprid and 0.5 and 1 (mg/kg cucumber) for dichlorvos, respectively. Application of these chemicals at higher doses not only significantly reduced the body weight, food consumption, testosterone production, testicular germ cells and embryo numbers, but also increased the levels of follicle-stimulating hormone and luteinizing hormone in mice.

Conclusions

The emergence of biological disorders and reducing reproductive potential in male mice can be attributed to the addition of pesticides to their drinking water. Therefore, to reduce the hazards caused by insecticides, it is recommended to familiarize farmers with the harmful effects of overdose of pesticides and monitoring the residuals in agricultural products.

Ameliorative effect of avocado oil against lufenuron induced testicular damage and infertility in male rats

Lufenuron is a benzoylurea pesticide that causes significant histological and histochemical damage in mammals. Avocado is a common food in the human diet that contains antioxidant and antitumor properties. In male rats, avocado oil's protection against lufenuron-induced reproductive deterioration, oxidative stress, and DNA damages was investigated. Twenty-eight mature male rats were selected and distributed into four groups: Group 1, control group were administered distilled water orally; Group 2 received 4 ml/kg avocado; Group 3 was given lufenuron (1.6 mg/kg), and Group 4 was given avocado oil/lufenuron. The findings show that lufenuron treatment reduces reproductive hormone levels, sperm count, motility, viability and causes negative histopathological changes in testicular tissue, such as decreased epithelial height and increased luminal diameter degenerated spermatogenesis. Furthermore, lufenuron reduced the content of antioxidant enzymes while increasing the level of malondialdehyde, nitric oxide and corresponding DNA damage. Results showed that lufenuron is associated with testicular function impairment, which leads to infertility. Treatment with avocado oil improved reproductive hormone secretions, enzymatic activity, histological and DNA damage parameters in testis tissues, reducing the negative effects of lufenuron, proving that it may have a therapeutic role against lufenuron-mediated testicular toxicity.

Effect of Neonicotinoid Pesticides on Japanese Water Systems: Review with Focus on Reproductive Toxicity

Neonicotinoid pesticides (NPs) are neurotoxic substances. They are highly effective as insecticides owing to their water solubility, permeability, and long-lasting activity. These molecules are structurally similar to nicotine and act as nicotinic acetylcholine receptor agonists. The administration of NPs to experimental animals reportedly causes neuromuscular and reproductive disorders. Moreover, recently reported problems caused by NPs include damage to land-dwelling creatures (such as mammals and birds), hydrobiology, and ecosystems. This review summarizes the recent reports on NP concentrations detected in river systems in several Japanese regions. These values were lower than the environmental standard values; however, seasonal variations were observed. Furthermore, reports on NP-induced testicular and ovarian toxicity were examined, revealing that the mechanism of injury is mainly driven by oxidative stress. The use of NPs is declining worldwide, except in Japan; therefore, continuous monitoring remains necessary.

Carbamate Pesticides: Shedding Light on Their Impact on the Male Reproductive System

Carbamates are widely used and known around the world as pesticides in spite of also having medical applications. This class of chemicals is classified as acetylcholinesterase inhibitors, blocking acetylcholine hydrolyzation in a reversible manner. Their lack of species selectivity and their reported high toxicity can induce, upon exposure, adverse outcomes in male fertility that may lead to infertility. In addition, they are also considered endocrine-disrupting chemicals and can interfere with the hypothalamic–pituitary–testicular axis, essential for the normal function of the male reproductive system, thus being able to provoke male reproductive dysfunctions. Although the molecular mechanisms are not fully understood, various signaling pathways, such as those mediated by acetylcholine or kisspeptin, are affected by exposure to carbamates, thus compromising steroidogenesis and spermatogenesis. Over the last decades, several studies, both in vitro and in vivo, have reported a myriad of negative effects of carbamates on the male reproductive system. In this review, an up-to-date overview of the impact of carbamates on the male reproductive system is discussed, with an emphasis on the role of these compounds on acetylcholine regulation and the male endocrine system.

Biochemical and histopathological investigation of the protective effects of melatonin and vitamin E against the damage caused by acetamiprid in Balb-c mouse testicles at light and electron microscopic level

The protective effects of melatonin (Mel) and vitamin E (Vit E) against the negative effects of acetamiprid (Acmp) on testicles, reproductive hormones, and oxidative stress parameters were investigated in the present study. A total of 50 Balb-c male mice were used in 7 groups; 6 mice in the control groups (distilled water, corn oil, ethanol), and 8 in other groups (Acmp, Acmp + Mel, Acmp + Vit E, Acmp + Vit E + Mel). After the experiment, which lasted 21 days, hematoxylin eosin (H&E), periodic acid Schiff (PAS), and caspase-3 immunohistochemical (IHC) staining was performed on the testicular tissues. Also, the tissues were examined ultrastructurally with the transmission electron microscopy (TEM). In the Acmp group, there were decreased seminiferous tubule diameter and epithelial thickness, epithelial degeneration, decreased spermatozoa in the lumen, decreased PAS-positive staining in the seminiferous epithelial basement membrane, edema in the interstitial area, and hydropic degeneration in Leydig cells. Caspase-3 immunoreactivity was higher than in the other groups. TEM examination showed degeneration in tubule cells, lysosomal accumulation in cells of the spermatogenic line, vacuolizations with myelin figures, and necrosis. Hydropic degeneration, electron-dense lipid vacuoles, and chromatolysis were evident in the Leydig cell cytoplasm. In Sertoli cells, electron-dense lysosomal deposits were noted. In biochemical terms, there were decreased tissue glutathione (GSH) and total antioxidant status (TAS), and increased malondialdehyde (MDA) and total oxidant status (TOS). Plasma luteinizing hormone (LH), follicular stimulating hormone (FSH), and testosterone levels were decreased. In the groups with melatonin, vitamin E, and both were applied together, tissue damage, and apoptotic cell death were reduced at both light microscopic and ultrastructural levels. In biochemical terms, there were decreased oxidative parameters and increased hormonal parameters. It was found that vitamin E was more effective in decreasing oxidative parameters and increasing antioxidative parameters when compared to melatonin, and hormonal parameters increased at a higher level in the Acmp + Vit E group than in all groups. As a result, it was found that exposure to Acmp caused damage to testicular tissue, induced oxidative stress in testicles, and decreased plasma LH, FSH, and testosterone levels, and although vitamin E is more effective than melatonin in preventing this damage, both are effective.

Exposure to neonicotinoids and serum testosterone in men, women, and children

Neonicotinoids are the most used pesticides in the world and, despite being harmful to honeybees, they are considered safe for mammals. However, they have been associated with decreasing testosterone levels in several experimental animal models. In the present study, we aimed to determine the association of urinary neonicotinoids with serum testosterone in humans. We analyzed data on 2014 male and female participants to the National Health and Nutrition Examination Survey conducted between 2015 and 2016 aged 6 or older. In linear regression adjusted for age and potential confounders, serum total testosterone was 37.78% lower with 10-fold increase in urinary total neonicotinoids (95% CI: -58.82, -6.00), 20.81% lower with 10-fold increase in urinary 5-hydroxy-imidacloprid (95% CI: -34.94, -3.62) and 25.01% lower with 10-fold increase in urinary n-desmethyl-acetamiprid (95% CI: -39.80, -6.58) among males. Serum free androgen index (FAI) was also decreased with higher urinary n-desmethyl-acetamiprid. In females, serum total testosterone was 32.91% lower with 10-fold increase in urinary total neonicotinoids (95% CI: -54.93, -0.13), 21.32% lower with 10-fold increase in urinary 5-hydroxy-imidacloprid (95% CI: -29.31, -12.42) and 15.42% lower with urinary detection of 5-hydroxy-imidacloprid (95% CI: -22.80, -7.34). FAI was likewise reduced with higher urinary levels of 5-hydroxy-imidacloprid and N-desmethyl-acetamiprid. In conclusion, this study using a sample representative of the US population is the first to report that exposure to neonicotinoids is associated with decreased serum testosterone levels in humans. However, future prospective studies are warranted to confirm these findings.

Mechanisms and histopathological impacts of acetamiprid and azoxystrobin in male rats

Acetamiprid (neonicotinoid insecticide) and azoxystrobin (fungicide) are widespread pesticides used for pest management, but they have the potential for toxicity to mammals. The goal of this study was to look for oxidative stress, metabolic alterations, and reproductive problems in male rats' serum after 2 months of exposure to sub-lethal dosages of acetamiprid and azoxystrobin. Seven classes of male rats were formed: control, 3 groups of acetamiprid (1/10, 1/20, 1/40 LD₅₀), and 3 groups of azoxystrobin (1/10, 1/20, 1/40 LD₅₀) and were orally daily treated (n = 8/group). Our findings revealed that acetamiprid and azoxystrobin disrupted oxidative and metabolic processes in the examined rats throughout 30 and 60 days of testing. The levels of nitric oxide increased significantly, while catalase, a superoxide dismutase enzyme, and glutathione reductase activity were reduced. Serum levels of sex hormones, calcium, and total protein have all dropped substantially in rats. In comparison to the control group, the testis and liver structure, as well as spermatozoa parameters, had distinct histological characteristics. In conclusion, acetamiprid and azoxystrobin exhibit dose- and time-dependent effects on oxidative parameters that cause testis damage.

Urinary neonicotinoid concentrations and pubertal development in Chinese adolescents: A cross-sectional study

BACKGROUND

Animal studies suggest that exposure to certain neonicotinoids may interfere with the normal function of endocrine system in mammals. However, evidence from human studies is limited.

OBJECTIVES

This study conducted a cross-sectional analysis to examine urinary neonicotinoids concentrations in Chinese adolescents and its association with pubertal development.

METHODS

774 urine samples from 439 boys (median age: 13.7 years; 25th-75th percentile: 12.7-14.5 years) and 335 girls (median age: 13.7 years; 25th-75th percentile: 12.7-14.5 years) were collected for determination of ten neonicotinoids (imidacloprid, nitenpyram, acetamiprid, thiacloprid, imidaclothiz, thiamethoxam, clothianidin, dinotefuran, flonicamid, sulfoxaflor) and one metabolite (N-desmethyl-acetamiprid). Urinary creatinine was detected for concentration adjustment. Pubertal development including pubic hair, axillary hair, genitalia (boys), testicular volume (boys) and breast (girls) assessed by Tanner stages and others (spermarche, facial hair for boys and menarche for girls) were obtained by physical examination and questionnaire. Logistic and bayesian kernel machine regression were used to investigate the association between neonicotinoids concentrations and pubertal developments.

RESULTS

High detection rates ranged from 72.0% to 100.0% for all neonicotinoids. Boys and girls with thiacloprid concentration at the >75th percentile had lower stage of genitalia development (OR: 0.83, 95% CI: 0.33-0.93) and higher stage of axillary hair development (OR: 1.46, 95% CI: 1.12-3.41), respectively, compared with those at the <25th percentile. The estimate change in genitalia stage was significantly different at or above the 75th percentile concentration of neonicotinoids mixture compared to the 50th percentile concentration. No associations were found between other urinary neonicotinoids and other indicators of puberty.

CONCLUSIONS

Higher thiacloprid concentration was associated with delayed genitalia development in boys and early axillary hair development in girls. Neonicotinoids mixture was negatively associated with genitalia stage in the joint effect. Given the characteristic of the cross-sectional study, our results need further confirmation of the causal relationship.

Single injection of very mild dose botulinum toxin in the vastus lateralis improves testicular spermatogenesis and sperm motility in ageing experimental mice

Background

Botulinum toxin (BoNT) is a widely used therapeutic agent that blocks the excessive release of acetylcholine at the neuromuscular junction. Previously, repeated intracremasteric injections and slight overdose of BoNT have been reported to induce adverse effects in the testicular parameter of experimental rodents. However, a mild dose of BoNT is highly beneficial against skin ageing, neuromuscular deficits, overactive urinary bladder problems, testicular pain and erectile dysfunctions. Considering the facts, the possible therapeutic benefits of BoNT on the testis might be achieved at a very minimal dosage and via a distal route of action. Therefore, we revisited the effect of BoNT, but with a trace amount injected into the vastus lateralis of the thigh muscle, and analyzed histological parameters of the testis, levels of key antioxidants and sperm parameters in ageing experimental mice.

Results

Experimental animals injected with 1 U/kg bodyweight of BoNT showed enhanced spermatogenesis in association with increased activities of key antioxidants in the testis, leading to enhanced amount of the total sperm count and progressive motility.

Conclusions

This study signifies that a mild intramuscular dose of BoNT can be considered as a potent treatment strategy to manage and prevent male infertility.

Thymol alleviates imidacloprid-induced testicular toxicity by modulating oxidative stress and expression of steroidogenesis and apoptosis-related genes in adult male rats

The present work was designed to assess the potential ameliorative effect of thymol on the testicular toxicity caused by imidacloprid (IMI) in adult male rats. Forty adult male rats were allocated into four groups; control group was given corn oil, thymol-treated group (30 mg/kg b.wt), IMI-treated group (22.5 mg/kg b.wt), and IMI + thymol-treated group. All administrations were done by gavage every day for duration of 56 days. As a result, the IMI exposure caused a significant decline in the body weight change, reproductive organ weights, sperm functional parameters, and serum level of testosterone, widespread histological alterations, and apoptosis in the testis. Additionally, the IMI-treated rats exhibited a remarkable increment in the serum levels of follicle stimulating hormone and luteinizing hormone. Also, IMI induced testicular oxidative stress, as indicated by elevated malondialdehyde (MDA) levels and a marked decline in the activity of antioxidant enzymes and reduced glutathione (GSH), and total antioxidant capacity (TAC) levels. Moreover, IMI treatment significantly downregulated the mRNA expression of steroidogenic genes and proliferating cell nuclear antigen (PCNA) immunoexpression in the testicular tissue. However, thymol co-administration significantly mitigated the IMI-induced toxic effects. Our findings suggested that IMI acts as a male reproductive toxicant in rats and thymol could be a potential therapeutic option for IMI reprotoxic impacts.

Occupational use of agrochemicals results in inhibited cholinesterase activity and altered reproductive hormone levels in male farmers from Buea, Cameroon

The efficiency of agro pesticides and fertilizers in eliminating pests and scaling up crop yield has motivated farmers to increase their use. Unfortunately, health hazards caused on farmers by these agrochemicals are of growing concern, though not well elucidated. In order to evaluate the effects of occupational exposure to agrochemicals on some key parameters of male farmers' health in Buea Subdivision, Cameroon, a total of 101 men, including 62 farmers using the agrochemicals and a reference population of 39 men not involved in occupational utilization of the agrochemicals, were interviewed on use of protective equipment, exposure symptoms and reproductive health status. Thereafter, serum cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] activities, total antioxidant capacity and reproductive hormones [follicle-stimulating hormone (FSH), luteinizing hormone and testosterone] were assessed. Results revealed that farmers mainly used insecticides followed by fungicides, herbicides and fertilizers, but with inadequate protective measures. The use of agrochemicals resulted in several exposure symptoms including weakness, itches, burning sensation, headache, sneezing, coughing and vomiting, as well as decrease in serum AChE activity when compared to the reference population. The agrochemicals impacted negatively on the farmers' reproductive health as evidenced by increased FSH levels. Taken altogether, these results suggested that exposure to agrochemicals adversely affects farmers' health. Therefore, there is a need to further sensitize the farmers on the use of protective equipment to mitigate the exposure and resulting health hazards.