Chlorpyrifos-induced reproductive toxicity in rats could be partly relieved under high-fat diet

Climate change, microplastics, and male infertility

PURPOSE OF REVIEW

Semen quality is on the decline. While the etiology is unknown, recent literature suggests there may be a relationship between climate change, environmental toxins and male fertility. This review relays new information regarding associations between our environment and male infertility.

RECENT FINDINGS

Several recent studies have documented a negative association between heat stress and spermatogenesis, which suggests that climate change may be a factor in declining in sperm counts. The influence of particle pollution on spermatogenesis has also been recently investigated, with studies demonstrating a negative association. Another possible factor are microplastics, which have been posited to reduce sperm production. Recent animal studies have shown that microplastic exposure alters both adult sperm production and prenatal male genital development. The relationship between endocrine disrupting chemicals and male fertility remains an area of active study, with recent animal and human studies suggesting an association between these chemicals and male fertility.

SUMMARY

The etiology of the decline in male fertility over the past decades is yet unknown. However, changes in our environment as seen with climate change and exposure to pollutants and endocrine disrupting chemicals are proposed mechanisms for this decline. Further studies are needed to investigate this association further.

Exposure to the environmental pollutant chlorpyrifos induces hepatic toxicity through activation of the JAK/STAT and MAPK pathways

Chlorpyrifos (CHP) is an inexpensive highly effective organophosphate insecticide used worldwide. The unguided and excessive use of CHP by farmers has led to its significant accumulation in crops as well as contamination of water sources, causing health problems for humans and animals. Therefore, this study evaluated the toxicological effects of exposure to the environmental pollutant CHP at low, medium, and high (2.5, 5, and 10 mg·kg-1 BW) levels on rat liver by examining antioxidant levels, inflammation, and apoptosis based on the no observed adverse effect levels (NOAEL) (1 mg·kg-1 BW) and the CHP dose that does not cause any visual symptoms (5 mg·kg-1 BW). Furthermore, the involvement of the JAK/STAT and MAPK pathways in CHP-induced toxic effects was identified. The relationship between the expression levels of key proteins (p-JAK/JAK, p-STAT/STAT, p-JNK/JNK, p-P38/P38, and p-ERK/ERK) in the pathways and changes in the expression of markers associated with inflammation [inflammatory factors (IL-1β, IL-6, IL-10, TNF-α), chemokines (GCLC and GCLM), and inflammatory signaling pathways (NF-кB, TLR2, TLR4, NLRP3, ASC, MyD88, IFN-γ, and iNOS)] and apoptosis [Bad, Bax, Bcl-2, Caspase3, Caspase9, and the cleavage substrate of Caspase PARP1] were also determined. The results suggest that CHP exposure disrupts liver function and activates the JAK/STAT and MAPK pathways via oxidative stress, exacerbating inflammation and apoptosis. Meanwhile, the JAK/STAT and MAPK pathways are involved in CHP-induced hepatotoxicity. These findings provide a novel direction for effective prevention and amelioration of health problems caused by CHP abuse in agriculture and households.

The adverse role of endocrine disrupting chemicals in the reproductive system

Reproductive system diseases pose prominent threats to human physical and mental well-being. Besides being influenced by genetic material regulation and changes in lifestyle, the occurrence of these diseases is closely connected to exposure to harmful substances in the environment. Endocrine disrupting chemicals (EDCs), characterized by hormone-like effects, have a wide range of influences on the reproductive system. EDCs are ubiquitous in the natural environment and are present in a wide range of industrial and everyday products. Currently, thousands of chemicals have been reported to exhibit endocrine effects, and this number is likely to increase as the testing for potential EDCs has not been consistently required, and obtaining data has been limited, partly due to the long latency of many diseases. The ability to avoid exposure to EDCs, especially those of artificially synthesized origin, is increasingly challenging. While EDCs can be divided into persistent and non-persistent depending on their degree of degradation, due to the recent uptick in research studies in this area, we have chosen to focus on the research pertaining to the detrimental effects on reproductive health of exposure to several EDCs that are widely encountered in daily life over the past six years, specifically bisphenol A (BPA), phthalates (PAEs), polychlorinated biphenyls (PCBs), parabens, pesticides, heavy metals, and so on. By focusing on the impact of EDCs on the hypothalamic-pituitary-gonadal (HPG) axis, which leads to the occurrence and development of reproductive system diseases, this review aims to provide new insights into the molecular mechanisms of EDCs' damage to human health and to encourage further in-depth research to clarify the potentially harmful effects of EDC exposure through various other mechanisms. Ultimately, it offers a scientific basis to enhance EDCs risk management, an endeavor of significant scientific and societal importance for safeguarding reproductive health.

Chlorpyrifos induces placental oxidative stress and barrier dysfunction by inducing mitochondrial apoptosis through the ERK/MAPK signaling pathway: In vitro and in vivo studies

Chlorpyrifos (CPF) is an organophosphorus pesticide that is widely used in agricultural production and residential environments worldwide. In this study, we determined the harmful effects and toxicological mechanism of CPF in porcine trophectoderm (pTr) cells and the placenta of female mice during pregnancy. The findings revealed that CPF significantly decreased cell viability and increased intracellular lactate dehydrogenase (LDH) release in pTr cells. Similarly, CPF induced reproductive toxicity in pregnant maternal mice, including decreased maternal, fetal, and placental weights. Moreover, following CPF treatment, pTr cells and the placenta of female mice showed significant apoptosis. JC-1 staining and flow cytometry analysis also revealed that the mitochondrial membrane potential (MMP) of pTr cells treated with CPF was significantly depolarized. Additionally, CPF can induce an increase in reactive oxygen species (ROS) and barrier dysfunction in pTr cells and the placenta of female mice. We further verified that CPF-induced mitochondrial apoptosis is mediated by the MAPK signaling pathway, as shown by using of small molecular inhibitors of related proteins. Also, CPF-induced oxidative stress, barrier dysfunction, and mitochondrial apoptosis in pTr cells were alleviated by U0126, an inhibitor of the ERK/MAPK signaling pathway. These findings suggested that exposure to CPF in early pregnancy might be a potential risk fator affecting placental formation and function in humans and animals.

Endocrine disrupting chemicals and male fertility: from physiological to molecular effects

The deleterious effects of chemical or non-chemical endocrine disruptors (EDs) on male fertility potential is well documented but still not fully elucidated. For example, the detection of industrial chemicals' metabolites in seminal plasma and follicular fluid can affect efficiency of the gametogenesis, the maturation and competency of gametes and has guided scientists to hypothesize that endocrine disrupting chemicals (EDCs) may disrupt hormonal homoeostasis by leading to a wide range of hormonal control impairments. The effects of EDCs exposure on reproductive health are highly dependent on factors including the type of EDCs, the duration of exposure, individual susceptibility, and the presence of other co-factors. Research and scientists continue to study these complex interactions. The aim of this review is to summarize the literature to better understand the potential reproductive health risks of EDCs in France.

Contaminants of Emerging Concern (CECs) and Male Reproductive Health: Challenging the Future with a Double-Edged Sword

Approximately 9% of couples are infertile, with half of these cases relating to male factors. While many cases of male infertility are associated with genetic and lifestyle factors, approximately 30% of cases are still idiopathic. Contaminants of emerging concern (CECs) denote substances identified in the environment for the first time or detected at low concentrations during water quality analysis. Since CEC production and use have increased in recent decades, CECs are now ubiquitous in surface and groundwater. CECs are increasingly observed in human tissues, and parallel reports indicate that semen quality is continuously declining, supporting the notion that CECs may play a role in infertility. This narrative review focuses on several CECs (including pesticides and pharmaceuticals) detected in the nearshore marine environment of False Bay, Cape Town, South Africa, and deliberates their potential effects on male fertility and the offspring of exposed parents, as well as the use of spermatozoa in toxicological studies. Collective findings report that chronic in vivo exposure to pesticides, including atrazine, simazine, and chlorpyrifos, is likely to be detrimental to the reproduction of many organisms, as well as to sperm performance in vitro. Similarly, exposure to pharmaceuticals such as diclofenac and naproxen impairs sperm motility both in vivo and in vitro. These contaminants are also likely to play a key role in health and disease in offspring sired by parents exposed to CECs. On the other side of the double-edged sword, we propose that due to its sensitivity to environmental conditions, spermatozoa could be used as a bioindicator in eco- and repro-toxicology studies.

Chitosan oligosaccharide alleviates and removes the toxicological effects of organophosphorus pesticide chlorpyrifos residues

The abuse of chlorpyrifos (CHP), a commonly used organophosphorus pesticide, has caused many environmental pollution problems, especially its toxicological effects on non-target organisms. First, CHP enriched on the surface of plants enters ecosystem circulation along the food chain. Second, direct inflow of CHP into the water environment under the action of rainwater runoff inevitably causes toxicity to non-target organisms. Therefore, we used rats as a model to establish a CHP exposure toxicity model and studied the effects of CHP in rats. In addition, to alleviate and remove the injuries caused by residual chlorpyrifos in vivo, we explored the alleviation effect of chitosan oligosaccharide (COS) on CHP toxicity in rats by exploiting its high water solubility and natural biological activity. The results showed that CHP can induce the toxicological effects of intestinal antioxidant changes, inflammation, apoptosis, intestinal barrier damage, and metabolic dysfunction in rats, and COS has excellent removal and mitigation effects on the toxic damage caused by residual CHP in the environment. In summary, COS showed significant biological effects in removing and mitigating blood biochemistry, antioxidants, inflammation, apoptosis, gut barrier structure, and metabolic function changes induced by residual CHP in the environment.

High-Fat Diet Aggravates the Disorder of Glucose Metabolism Caused by Chlorpyrifos Exposure in Experimental Rats

Epidemiological research has demonstrated that the increase in high fat consumption has promoted the morbidity of diabetes. Exposure to organophosphorus pesticides (such as chlorpyrifos) may also increase the risk of diabetes. Although chlorpyrifos is a frequently detected organophosphorus pesticide, the interaction effect between chlorpyrifos exposure and a high-fat diet on glucose metabolism is still unclear. Thus, the effects of chlorpyrifos exposure on glucose metabolism in rats eating a normal-fat diet or a high-fat diet were investigated. The results demonstrated that the glycogen content in the liver decreased and that the glucose content increased in chlorpyrifos-treated groups. Remarkably, the ATP consumption in the chlorpyrifos-treatment group was promoted in the rats eating a high-fat diet. However, chlorpyrifos treatment did not change the serum levels of insulin and glucagon. Notably, the contents of liver ALT and AST changed more significantly in the high-fat chlorpyrifos-exposed group than in the normal-fat chlorpyrifos-exposed group. Chlorpyrifos exposure caused an increase in the liver MDA level and a decrease in the enzyme activities of GSH-Px, CAT, and SOD, and the changes were more significant in the high-fat chlorpyrifos-treatment group. The results indicated that chlorpyrifos exposure led to disordered glucose metabolism in all dietary patterns as a result of antioxidant damage in the liver, in which a high-fat diet may have aggravated its toxicity.

A Cross-Species Analysis Reveals Dysthyroidism of the Ovaries as a Common Trait of Premature Ovarian Aging

Although the imbalance of circulating levels of Thyroid Hormones (THs) affects female fertility in vertebrates, its involvement in the promotion of Premature Ovarian Aging (POA) is debated. Therefore, altered synthesis of THs in both thyroid and ovary can be a trait of POA. We investigated the relationship between abnormal TH signaling, dysthyroidism, and POA in evolutionary distant vertebrates: from zebrafish to humans. Ovarian T3 signaling/metabolism was evaluated by measuring T3 levels, T3 responsive transcript, and protein levels along with transcripts governing T3 availability (deiodinases) and signaling (TH receptors) in distinct models of POA depending on genetic background and environmental exposures (e.g., diets, pesticides). Expression levels of well-known (Amh, Gdf9, and Inhibins) and novel (miR143/145 and Gas5) biomarkers of POA were assessed. Ovarian dysthyroidism was slightly influenced by genetics since very few differences were found between C57BL/6J and FVB/NJ females. However, diets exacerbated it in a strain-dependent manner. Similar findings were observed in zebrafish and mouse models of POA induced by developmental and long-life exposure to low-dose chlorpyrifos (CPF). Lastly, the T3 decrease in follicular fluids from women affected by diminished ovarian reserve, as well as of the transcripts modulating T3 signaling/availability in the cumulus cells, confirmed ovarian dysthyroidism as a common and evolutionary conserved trait of POA.

Bioinspired engineered nickel nanoparticles with multifunctional attributes for reproductive toxicity

Nickel nanoparticles (Ni-NPs) have potential applications in high-tech sectors such as battery manufacturing, catalysis, nanotube printing and textile. Apart from their increasing utilisation in daily life, there are concerns about their hazardous nature as they are highly penetrable in biological systems. The carcinogenic and mutagenic ability of Ni-NPs is evident but the research gaps are still there concerning the safety evaluation of Ni-NPs regarding male reproductive ability. This controlled randomized research was planned to assess the male reproductive toxicity of Ni-NPs in Sprague Dawley rats. Ni-NPs of spherical shape and mean particle size of 56 nm were used in the study, characterized by SEM, EDS and XRD. The twenty-five healthy rats (200-220 g) were used for toxicity investigation of Ni-NPs and divided into five groups; negative control (0 Ni-NPs), placebo group (0.9% saline) and three Ni-NPs treated groups (@ 15, 30 and 45 mg/kg BW). The results of 14 days of intraperitoneal exposure to Ni-NPs revealed that a higher dose (45 mg/kg BW) of Ni-NPs caused a significant reduction in body weight, serum testosterone, daily sperm production while the testis index and Ni accumulation and histological changes (necrosis in basement membrane and seminiferous tubules, vacuole formation) in testicular tissues increased with increasing dose of Ni-NPs. It can be concluded from the study that Ni-NPs have potential reproductive toxicity. This study provided the baseline data of Ni-NPs toxicity for the male reproductive system and can be applied for risk assessment in Ni-NPs based products.

Chlorpyrifos induces apoptosis and necroptosis via the activation of CYP450s pathway mediated by nuclear receptors in LMH cells

Chlorpyrifos (CPF), an organophosphorus pesticide, is detected commonly in environments, where it is thought to be highly toxic to non-target organisms. However, the mechanism of CYP450s pathway mediated by nuclear receptors on CPF-induced apoptosis and necroptosis at the cellular level and the effect of CPF on the cytotoxicity of the chicken hepatocarcinoma cell line (LMH) has also not been reported in detail. Therefore, this experiment aims to explore whether CPF can improve apoptosis and necroptosis in LMH cells by activating the nuclear receptors/CYP450s axis. LMH cells, the subject of this study, were exposed to 5 μg/mL, 10 μg/mL, and 15 μg/mL doses of CPF. With the increase of CPF concentration, the increase of nuclear receptor level led to the up-regulation of CYP450s activity. With the massive production of ROS, the expression of apoptotic pathway genes (Bax, Caspase9, and Caspase3) enhanced, while Bcl-2 expression dropped sharply. The expression of programmed necroptosis genes (RIPK1, RIPK3, and MLKL) heightened, and Caspase8 reduced considerably. In short, our data suggests that excessive activation of nuclear receptors and CYP450s induced by CPF promotes ROS production, which directs apoptosis and programmed necroptosis in LMH cells.

Olive Leaf Extract Attenuates Chlorpyrifos-Induced Neuro- and Reproductive Toxicity in Male Albino Rats

Chlorpyrifos (CPF) is a common organophosphorus insecticide. It is associated with negative consequences such as neurotoxicity and reproductive injury. This study aimed to observe the ability of olive leaf extract to attenuate chlorpyrifos toxicity, which induced neuro- and reproductive toxicity in male albino rats. Olive leaf extract (OLE) exhibits potent antioxidant and antiapoptotic properties. Twenty-two mature male rats were divided into four groups: control (saline), CPF (9 mg/kg), OLE (150 mg/kg), and CPF + OLE. Treatment was administered orally for 80 days. The CPF significantly reduced serum sex hormones, sperm counts and motility, high oxidants (MDA), and depleted antioxidants (GSH, SOD, TAC) in the brain and testes homogenate; additionally, it decreased serum AChE and brain neurotransmitters, increased Bax, decreased Bcl-2, and boosted caspase-3 immune expression in neural and testicular cells. Immunological expression of Ki 67 in the cerebrum, cerebellum, choroid plexus, and hippocampus was reduced, and α-SMA in testicular tissue also decreased. Histopathological findings were consistent with the above impacts. OLE co-administration significantly normalized all these abnormalities. OLE showed significant protection against neural and reproductive damage caused by CPF.

Hormonal profile changes induced by pesticide mixture exposure in female rats revealed by hair analysis

Pesticide exposure has been associated with hormonal disruption in both animals and humans. However, there is limited knowledge of the combined effects of complex mixtures of pesticides on endogenous hormone levels. Here, we used hair analysis to assess the impact of a pesticide mixture comprising 19 components from multiple chemical classes at eight doses of 0-400 μg/kg body weight (bw) three times per week per component on concentrations of 36 steroid and thyroid hormones in female rats over a 90-day exposure period. We detected 13 hormones in rat hair, namely estradiol (E2), androstenedione (AD), testosterone (T), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), pregnenolone (P5), progesterone (P4), 11-deoxycorticosterone (11-DOC), corticosterone (CORT), 3,3'-l-diiodothyronine (T2), 3,5,3'-l-triiodothyronine (T3), 3,3',5'-l-triiodothyronine (rT3), and 3,5,3',5'-l-tetraiodothyronine (T4). In comparison to the control group, hair E2 concentration was significantly lower in the two highest (200 and 400 μg/kg bw) exposure groups, whereas hair DHEAS and CORT concentrations were significantly higher in the 40 μg/kg bw and the highest exposure groups, respectively. Results from generalized additive models suggest that pesticide exposure resulted in monotonic dose responses in hair E2 concentration, CORT concentration and DHEA/CORT molar ratio but nonmonotonic dose responses in hair T concentration, DHEAS concentration, P4/P5 and DHEA/DHEAS molar ratios. The associations of E2, CORT and DHEA/CORT ratio with exposure intensity were confirmed by their significant linear relationships with hair concentrations of at least 23 of the 25 exposure biomarkers analyzed. Our results demonstrate that exposure to low levels of the pesticide mixture evaluated here can alter hair reproductive and adrenal hormones levels.

Combined exposures to bisphenols, polychlorinated dioxins, paracetamol, and phthalates as drivers of deteriorating semen quality

BACKGROUND

Semen quality in men continues to decline in Western countries, but the contours of the issue remain obscure, in relation to contributing chemicals.

OBJECTIVES

To obtain more clarity about the chemicals that drive the deterioration of semen quality, we conducted a mixture risk assessment based on European exposures.

METHODS

We included chemicals capable of affecting semen quality after prenatal exposures, among them androgen receptor antagonists, substances that disrupt prostaglandin signalling, suppress testosterone synthesis, inhibit steroidogenic enzymes or activate the aryl hydrocarbon receptor. We employed the Hazard Index approach (HI), based on risk quotients of exposures in Europe and reference doses for reductions in semen quality. By summing up the risk quotients of the 29 chemicals included in the assessment we examined fold-exceedances of "acceptable" mixture exposures relative to an index value of 1. For bisphenols A, F, S, phthalates DEHP, DnBP, BBzP, DiNP, n-butyl paraben and paracetamol we relied on biomonitoring studies in which these 9 chemicals were measured together in the same subjects. This allowed us to construct personalised Hazard Indices.

RESULTS

Highly exposed subjects experienced combined exposures to the 9 chemicals that exceeded the index value of 1 by more than 100-fold; the median was a 17-fold exceedance. Accounting for median background exposures to the remaining 20 chemicals added a Hazard Index of 1.39. Bisphenol A made the largest contribution to the HI, followed by polychlorinated dioxins, bisphenols S and F and DEHP. Eliminating bisphenol A alone would still leave unacceptably high mixture risks. Paracetamol is also a driver of mixture risks among subjects using the drug.

CONCLUSIONS

Tolerable exposures to substances associated with deteriorations of semen quality are exceeded by a large margin. Bisphenols, polychlorinated dioxins, phthalates and analgesics drive these risks. Dedicated efforts towards lowering exposures to these substances are necessary to mitigate risks.

Advances in organophosphorus pesticides pollution: Current status and challenges in ecotoxicological, sustainable agriculture, and degradation strategies

Organophosphorus pesticides (OPPs) are one of the most widely used types of pesticide that play an important role in the production process due to their effects on preventing pathogen infection and increasing yield. However, in the early development and application of OPPs, their toxicological effects and the issue of environmental pollution were not considered. With the long-term overuse of OPPs, their hazards to the ecological environment (including soil and water) and animal health have attracted increasing attention. Therefore, this review first clarified the classification, characteristics, applications of various OPPs, and the government's restriction requirements on various OPPs. Second, the toxicological effects and metabolic mechanisms of OPPs and their metabolites were introduced in organisms. Finally, the existing methods of degrading OPPs were summarized, and the challenges and further addressing strategy of OPPs in the sustainable development of agriculture, the environment, and ecology were prospected. However, methods to solve the environmental and ecological problems caused by OPPs from the three aspects of use source, use process, and degradation methods were proposed, which provided a theoretical basis for addressing the stability of the ecological environment and improving the structure of the pesticide industry in the future.

Effects on Puberty of Nutrition-Mediated Endocrine Disruptors Employed in Agriculture

Pesticide residues are largely found in daily consumed food because of their extensive use in farming and their long half-life, which prolongs their presence in the environment. Many of these pesticides act as endocrine-disrupting chemicals after pre- or postnatal exposure, significantly affecting, among other things, the time of puberty onset, progression, and completion. In humans, precocious or delayed puberty, and early or delayed sexual maturation, may entail several negative long-term health implications. In this review, we summarize the current evidence on the impact of endocrine-disrupting pesticides upon the timing of the landmarks of female and male puberty in both animals (vaginal opening, first estrus, and balanopreputial separation) and humans (thelarche, menarche, gonadarche). Moreover, we explore the possible mechanisms of action of the reviewed endocrine-disrupting pesticides on the human reproductive system. Access to safe, healthy, and nutritious food is fundamental for the maintenance of health and wellbeing. Eliminating the presence of hazardous chemicals in largely consumed food products may increase their nutritional value and be proven beneficial for overall health. Consequently, understanding the effects of human exposure to hazardous endocrine-disrupting pesticides, and legislating against their circulation, are of major importance for the protection of health in vulnerable populations, such as children and adolescents.

Promising effects of gingerol against toxins: A review article

Ginger is a medicinal and valuable culinary plant. Gingerols, as an active constituent in the fresh ginger rhizomes of Zingiber officinale, exhibit several promising pharmacological properties. This comprehensive literature review was performed to assess gingerol's protective and therapeutic efficacy against the various chemical, natural, and radiational stimuli. Another objective of this study was to investigate the mechanism of anti-inflammatory, antioxidant, and antiapoptotic properties of gingerol. It should be noted that the data were gathered from in vivo and in vitro experimental studies. Gingerols can exert their protective activity through different mechanisms and cell signaling pathways. For example, these are mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-kB), Wnt/β-catenin, nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE), transforming growth factor beta1/Smad3 (TGF-β1/Smad3), and extracellular signal-related kinase/cAMP-response element-binding protein (ERK/CREB). We hope that more researchers can benefit from this review to conduct preclinical and clinical studies, treat cancer, inflammation, and attenuate the side effects of drugs and industrial pollutants.

3-Indolepropionic acid upturned male reproductive function by reducing oxido-inflammatory responses and apoptosis along the hypothalamic-pituitary-gonadal axis of adult rats exposed to chlorpyrifos

We examined the effect of 3-Indolepropionic acid (3-IPA), an antioxidant on the organophosphorus pesticide chlorpyrifos (CPF)-induced reproductive toxicity in rats. The five experimental rat cohorts were treated per os for 14 consecutive days as follows: Control (Corn oil 2 mL/kg body weight), CPF alone (5 mg/kg), 3-IPA alone (40 mg/kg) and the co-treated rat cohorts (CPF:5 mg/kg + 3-IPA: 20 or 40 mg/kg). Biomarkers of testicular and epididymal function, oxidative stress, myeloperoxidase (MPO) activity and the levels of nitric oxide (NO), reactive oxygen and nitrogen (RONS) species and lipid peroxidation (LPO) were assessed. Also, tumour necrosis factor-alpha (TNF-α), Bcl-2-associated X (Bax) and B cell lymphoma 2 (Bcl-2) proteins were estimated, and tissue histology was microscopically examined. CPF alone significantly (p < 0.05) increased biomarkers of reproductive toxicities were averted in rats co-treated 3-IPA. Decreases in antioxidants and increases in lipid peroxidation and reactive oxygen and nitrogen species were lessened (p < 0.05) in CPF and 3-IPA co-treated rats. CPF mediated increases in TNF-α, NO, Bax, and MPO activity was reduced (p < 0.05) in the epididymis, testes, and hypothalamus of rats co-treated with 3-IPA. In addition, Bcl-2 expression was increased in rats co-treated with 3-IPA dose-dependently. Histopathological examination revealed severe lesions induced by CPF were prevented in rats co-treated with 3-IPA. Our findings demonstrate that exogenous 3-IPA reduced CPF-induced oxidative stress, inflammation, and apoptosis in the epididymis and testes of male rats.

Chronic chlorpyrifos exposure induces oxidative stress, apoptosis and immune dysfunction in largemouth bass (Micropterus salmoides)

This study was undertaken to (a) evaluate the destructive effects of chronic exposure to low-dose of chlorpyrifos (CPF) on antioxidant system and immune function in largemouth bass (Micropterus salmoides), and (b) to examine whether dietary supplementation of curcumin can mitigate the adverse effects induced by CPF contamination. The experiment consisted of three groups (with three replicates, 30 fish per replicate) which lasted for 60 days: A control group (without CPF exposure or CU application), CP group (exposed to 0.004 mg/L of CPF), and CU group (exposed to 0.004 mg/L of CPF and fed a diet containing 100 mg curcumin per kg feed). The results showed that CPF contamination leads to reduced weight gain, severe histopathological lesions, decreased activity of antioxidant enzymes and down-regulated expression of antioxidant-related genes. Moreover, CPF upregulated the expression of pro-inflammatory genes such as TNF-α, IL-8, IL-15, downregulated anti-inflammatory genes TGF-β1, IL-10, and promoted apoptosis through overexpression of Caspase-3, Caspase-8, caspase-9 and Bax. In addition, curcumin supplementation showed significant improvement in oxidative stress, apoptosis and immune dysfunction, but the improved effect gradually weakened during the exposure last. Gas chromatography-mass spectrometry (GC-MS) analysis for accumulation of CPF in muscle supported the changes of general physiological structure, excessive apoptotic responses, abnormal antioxidant and immune system functions and posed potential human health risks to children based on target hazard quotient. These results suggested that chronic exposure to CPF can cause oxidative stress, apoptosis and immune dysfunction, and that curcumin have the potential to reduce pesticides residues in fish. This also highlights the importance of monitoring pesticides residues in aquatic products and aquaculture aquatic environments.

Environmental pollution and diabetes mellitus

Diabetes mellitus (DM) is a chromic metabolic disease that affects a large segment of the population worldwide. Physical inactivity, poor nutrition, and genetic predisposition are main risk factors for disease development. In the last decade, it was clear to the scientific community that DM development is linked to a novel disease inducer that was later defined as diabetogenic factors of pollution and endocrine disrupting agents. Environmental pollution is exponentially increasing in uncontrolled manner in several countries. Environmental pollutants are of diverse nature and toxicities, including polyaromatic hydrocarbons (PAHs), pesticides, and heavy metals. In the current review, we shed light on the impact of each class of these pollutants and the underlined molecular mechanism of diabetes induction and biological toxicities. Finally, a brief overview about the connection between coronavirus disease 2019 and diabetes pandemics is presented.

Programming of intestinal homeostasis in male rat offspring after maternal exposure to chlorpyrifos and/or to a high fat diet

Alteration of programming of the intestinal wall maturation may be responsible for non-communicable chronic diseases in adulthood. It may originate from prenatal exposure of mothers to deleterious environmental factors such as pesticides or western diet. This work was undertaken to determine whether disturbances of the digestive tract function and of innate immunity of offspring at adulthood could be due to maternal exposure to a pesticide, chlorpyrifos (CPF) and a High Fat Diet (HFD) starting 4 months before gestation and lasting until weaning of offspring. Fifty-one male Wistar rats coming from 4 groups of dams exposed to CPF, HFD, both and control were followed from birth to 8 weeks of age. They were fed standard chow and received no treatment. The maternal pesticide exposure slows down fetal and postnatal weight gain without histological injuries of the gut mucosa. CPF or HFD both induced modifications of tight junctions and mucins genes expressions without inducing an increase in epithelial permeability or an inflammatory state. Co-exposure to both CPF and HFD did not exacerbate the effects observed with each factor separately. Despite the lack of direct contact except through breast milk until weaning, CPF or HFD maternal exposure have demonstrated preliminary gut barrier impacts on offspring.

Perinatal exposure to chlorpyrifos and/or a high-fat diet is associated with liver damage in male rat offspring

Metabolic impairments in childhood are known to promote the development of type 2 diabetes and/or obesity in adulthood. These impairments may result from perinatal exposure to harmful environmental factors, such as pesticide residues or the consumption of a "western" diet. In the present study, we sought to determine whether an obesogenic profile, metabolic disorders and liver damage in offspring (observed during young adulthood) were related to maternal exposure to the pesticide chlorpyrifos (CPF) and/or a high-fat diet (HFD) starting 4 months before conception and ending at weaning. After the end of exposure, 51 male rat pups were left to develop under normal conditions and were studied in young adulthood. Despite the absence of direct exposure to harmful factors (other than through the dam's milk), maternal exposure to CPF or an HFD was associated with changes in the offspring's metabolic activity in the liver in the offspring. This indirect exposure to CPF was associated with a relative reduction in the expression of genes coding for enzymes involved in lipid or glucose metabolism but did induce histopathological changes in the offspring at adulthood. Maternal exposure to an HFD alone or to CPF alone gave similar results in offspring, changes in the same direction. Exposure of the mother to HFD did not exacerbate CPF effects. Co-exposure to both CPF and HFD did not increase the observed effects compared to each factor taken separately.

Endocrine disrupting chemicals: Impacts on human fertility and fecundity during the peri-conception period

It is becoming increasingly difficult to avoid exposure to man-made endocrine disrupting chemicals (EDCs) and environmental toxicants. This escalating yet constant exposure is postulated to partially explain the concurrent decline in human fertility that has occurred over the last 50 years. Controversy however remains as to whether associations exist, with conflicting findings commonly reported for all major EDC classes. The primary aim of this extensive work was to identify and review strong peer-reviewed evidence regarding the effects of environmentally-relevant EDC concentrations on adult male and female fertility during the critical periconception period on reproductive hormone concentrations, gamete and embryo characteristics, as well as the time to pregnancy in the general population. Secondly, to ascertain whether individuals or couples diagnosed as sub-fertile exhibit higher EDC or toxicant concentrations. Lastly, to highlight where little or no data exists that prevents strong associations being identified. From the greater than 1480 known EDCs, substantial evidence supports a negative association between exposure to phthalates, PCBs, PBDEs, pyrethroids, organochloride pesticides and male fertility and fecundity. Only moderate evidence exists for a negative association between BPA, PCBs, organochloride pesticides and female fertility and fecundity. Overall fewer studies were reported in women than men, with knowledge gaps generally evident for both sexes for all the major EDC classes, as well as a paucity of female fertility studies following exposure to parabens, triclosans, dioxins, PFAS, organophosphates and pyrethroids. Generally, sub-fertile individuals or couples exhibit higher EDC concentrations, endorsing a positive association between EDC exposure and sub-fertility. This review also discusses confounding and limiting factors that hamper our understanding of EDC exposures on fertility and fecundity. Finally, it highlights future research areas, as well as government, industry and social awareness strategies required to mitigate the negative effects of EDC and environmental toxicant exposure on human fertility and fecundity.

A comprehensive review on chlorpyrifos toxicity with special reference to endocrine disruption: Evidence of mechanisms, exposures and mitigation strategies

Chlorpyrifos (CPF) is a broad-spectrum chlorinated organophosphate (OP) pesticide used for the control of a variety of insects and pathogens in crops, fruits, vegetables, as well as households, and various other locations. The toxicity of CPF has been associated with neurological dysfunctions, endocrine disruption, and cardiovascular diseases (CVDs). It can also induce developmental and behavioral anomalies, hematological malignancies, genotoxicity, histopathological aberrations, immunotoxicity, and oxidative stress as evidenced by animal modeling. Moreover, eye irritation and dermatological defects are also reported due to CPF toxicity. The mechanism of action of CPF involves blocking the active sites of the enzyme, acetylcholinesterase (AChE), thereby producing adverse nervous system effects. Although CPF has low persistence in the body, its active metabolites, 3,5,6-trichloro-2-pyridinol (TCP), and chlorpyrifos-oxon (CPO) are comparatively more persistent, albeit equally toxic, and thus produce serious health complications. The present review has been compiled taking into account the work related to CPF toxicity and provides a brief compilation of CPF-induced defects in animals and humans, emphasizing the abnormalities leading to endocrine disruption, neurotoxicity, reproductive carcinogenesis, and disruptive mammary gland functionality. Moreover, the clinical signs and symptoms associated with the CPF exposure along with the possible pharmacological treatment are reported in this treatise. Additionally, the effect of food processing methods in reducing CPF residues from different agricultural commodities and dietary interventions to curtail the toxicity of CPF has also been discussed.

Chlorpyrifos inhibits sperm maturation and induces a decrease in mouse male fertility

BACKGROUND

Pesticides, especially organophosphorus pesticides such as chlorpyrifos (CPF), play an important role in modern agriculture. Studies have shown that pesticide residues are an important cause of male reproductive injury in mammal.

AIM

The aim of this study was to evaluate the reproductive damage caused by CPF in male mice and investigate the underlying mechanisms.

METHODS

In vivo, C57BL/6 mice (6-8 weeks old) were treated with CPF for 14, 70, and 80 days by intraperitoneal injection, intragastric administration, and dietary supplementation, respectively. Then, sperm from the cauda epididymidis was cultured in vitro to confirm the deleterious effects of CPF.

RESULTS

The in vivo results indicated that, after treatment with CPF by dietary supplementation and intraperitoneal injection, the expression of reproduction-related genes in the mouse testes was altered, although the mice were fertile and the testes presented no morphological abnormalities. Notably, mating experiments revealed that the fertility of male mice was decreased following CPF administration by gavage. Sperm motility within the cauda epididymidis declined significantly after CPF treatment, which was accompanied by a decrease in sperm density, upregulation of relative reactive oxygen species (ROS) levels, and downregulation of glutathione reductase activity. In vitro incubation experiments showed that sperm rapidly lost their capacity for linear movement; the relative ROS levels also increased significantly, while the mitochondrial membrane potential (MMP) showed a significant decrease. However, the integrity of the plasma membrane was not affected by CPF administration.

CONCLUSIONS

The above data indicated that exposure to CPF reduces sperm motility by disrupting mitochondrial function and increasing the level of oxidative stress during sperm maturation, thereby reducing the fecundity of male mice.

Pesticides-induced energy metabolic disorders

Metabolic disorders have become a heavy burden on society. Recently, through excessive use, pesticides have been found to be present in environmental matrixes and sometimes even accumulate in humans or other mammals through the food chain, which then causes health concerns. Evidence has indicated that pesticides have the potential to induce energy metabolic disorders by disturbing the physical process of energy absorption in the intestine and energy storage in the liver, adipose tissue and skeletal muscle in humans or other mammals. In addition, the homeostasis of energy regulation by the pancreas and immune cells is also affected by pesticides. These pesticide-induced disruptions ultimately cause abnormal levels of blood glucose and lipids, which in turn induce the development of related metabolic diseases, including overweight, underweight, insulin resistance and even diabetes. In this review, the results of previous studies focused on the induction of metabolic disorders by pesticides are summarized. We hope that this work will facilitate the discovery of a potential strategy for the treatment of diseases caused by pesticides.

Synergic effects of aerobic exercise and eugenol supplement on germ cell development and testicular tissue structure in chlorpyrifos-treated animal model

Insecticide chlorpyrifos (CPF) with increased oxidative stress, structural destruction, and hemostasis of testicular tissue leads to male infertility. The present study investigated the protective effect of exercise (Exe) and eugenol supplementation (Sup) on CPF-induced testicular spermatogenic disorders in male rats. In this experimental study, 21 adult male albino rats were divided into seven groups, control (Co: 6 weeks), CPF (6 weeks), Co + Oil (2 weeks healthy food and 4 weeks oil), Co + Dimethylsulfoxide (DMSO: 6 weeks), CPF + Sup (2 weeks CPF and 4 weeks CPF + Sup), CPF + Exe (2 weeks CPF and 4 weeks CPF + Exe), and CPF + Exe + Sup (2 weeks CPF and 4 weeks CPF + Exe + Sup) group. All treatments were done intraperitoneally (5 days a week). Exe groups were subjected to run at moderate exercise intensity for 5 days per week over 6 weeks. DMSO groups were administered to the equal volume of vehicle for 6 consecutive weeks. Finally, the animals were sacrificed with Co2 gas and then alterations in testicular histology and sperm parameters were evaluated. Protein expression of PLZF and IGFα in the CPF group showed a significant decrease compared with the control group (p ˂ 0.001 for both). It was shown that CPF + Exe + Sup (p ˂ 0.001) and CPF + Sup (p ˂ 0.01) groups had a significant increase in protein expression of PLZF, but the protein expression of IGFα showed a significant increase just in the CPF + Exe + Sup group (p ˂ 0.001). Also, CPF caused a significant decrease in Leydig counts, Sertoli cell count, spermatogonium counts, spermatocyte cell count, spermatid cell count, and tunica thickness as well as a significant increase in testicle diameter (p ˂ 0.01) and ducts diameter compared with the control group. It seems that aerobic exercise with eugenol supplementation suppresses the disruption effects of CPF on testicular tissue (cellular and structural) by increasing the antioxidant capacity and improving the secretion of sex hormones. Therefore, the aerobic exercise with supplement of the eugenol has potential therapeutic targets for male infertility that need further study.

Chlorpyrifos Induces Metabolic Disruption by Altering Levels of Reproductive Hormones

Chlorpyrifos (CPF) is a widely used organophosphorus pesticide and detected frequently in fruits, vegetables, as well as in urine and blood in humans. Studies have suggested that CPF can induce metabolic disruption, such as type-2 diabetes mellitus and changed body weight. The main mechanisms are based on oxidative damage, fatty-acid synthesis, and lipid peroxidation. Studies have also shown that CPF can change reproductive hormone (RH) levels. CPF might result in metabolic disorders through altered RH levels. Here, we review the studies showing that CFP causes metabolic disruption. Then, we present the studies showing that CFP changes RH levels. Finally, we discuss a potential pathway of how CPF elicits metabolic disruption.