Iron deficiency augments bisphenol A-induced oxidative stress in rats

Bisphenol A-induced polycystic ovary syndrome (PCOS) with hormonal and metabolic implications in rats

There is a rising incidence of polycystic ovary syndrome (PCOS) cases worldwide in women of reproductive age due to environmental factors. We evaluated the effect of an environmental estrogen, bisphenol A (BPA) for its reprotoxicity regarding the induction of PCOS in rats and also assessed its hormonal and metabolic implications. There was 66.6 % and 50 % disorder, in the estrus cycle at low (50 µg/kg) and high (500 µg/kg) doses of BPA, respectively. While animals treated with the positive control (dehydroepiandrosterone, DHEA at 6 mg/100 g) caused 100 % disorder. Cystic and atretic follicles along with two corpora lutea were found in the low dose group. However, no corpus luteum was found in the high dose group. Furthermore, hyperplasia and hypertrophy were found in the myometrium, endometrium, and luminal epithelium of the uterus of the low dose and DHEA groups. Additionally, 17β estradiol, progesterone, DHEA, androstenedione, testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone sulphate (DHEAS), antimullerian hormone (AMH), ratio of LH/FSH and testosterone/DHT were increased significantly (P < 0.01) in BPA groups. A significantly higher TSH (P < 0.01) indicates hypothyroidism. Furthermore, hyperglycemia, hyperinsulinemia, HOMA-IR, and HOMAβ indicate insulin resistance in the low-dose group. Thus, the low dose of BPA was found to be more potent as compared to the higher dose in defining the hyperandrogenic state. Our study revealed that BPA may not only be a causative factor in the induction of PCOS but also has metabolic implications bearing on its estrogenic nature.

Cucumeropsis mannii seed oil (CMSO) restores testicular mitochondrial dysfunctions by modulating the activities of dysregulated testicular mitochondrial enzymes in male albino rats exposed to bisphenol A

Bisphenol A, a traditional endocrine disruptor, has been implicated in male infertility. This study investigated the effect of Cucumeropsis mannii seed oil (CMSO) on bisphenol A (BPA)-induced biochemical toxicity in the testicular mitochondria of male albino rats. The rats were assigned randomly to six experimental groups (n = 6), A, B, C, D, E, and F. Group A received 1 mL of olive oil. Groups B and C received 100 mL/kg body weight (BW) of BPA and 7.5 mL/kg BW CMSO, respectively. Rats in groups D, E, and F received preadministered doses of 100 mL/kg BW of BPA, 5 mL/kg BW of BPA, and 2.5 mL/kg BW of CMSO, respectively, followed by 6 weeks of exposure to those doses. Some mitochondrial enzymes, mitochondrial membrane potential (MMP), mitochondria testicular protein, and body weight of rats were determined using standard methods. BPA significantly reduced succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, NADH dehydrogenase, and monoamine oxidase activity. Also, BPA prominently decreased the MMP, mitochondrial testicular protein, and body weight of rats. Interestingly, coadministration of BPA and CMSO restored the dysregulated activities of the enzymes and levels of other biomarkers. We postulated that CMSO may be a promising drug for treating systemic toxicity caused by environmental toxicants such as BPA.

Kaempferol alleviates bisphenol A reproductive toxicity in rats in a dose-dependent manner

BACKGROUND

Endocrine-disrupting chemicals (EDCs), including bisphenol A (BPA), are a major cause of male infertility by disrupting spermatogenesis.

OBJECTIVE

Here, we examined the potential protective benefits of kaempferol (KMF), a flavonol known for its antioxidant properties, on BPA-induced reproductive toxicity in adult male rats.

METHODS

Human skin fibroblast cells (HNFF-P18) underwent cell viability assays. Thirty-five male Wistar rats were assigned to four groups: 1) control, 2) BPA (10 mg/kg), 3,4) BPA, and different dosages of KMF (1 and 10 mg/kg). The study examined the rats' testosterone serum level, antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), oxidative markers malondialdehyde (MDA) and total antioxidant capacity (TAC), body weight, weight ratios of testis and prostate, and histopathological examinations.

RESULTS

The study revealed that using KMF to treat rats exposed to BPA increased cell viability. Moreover, the rats' testosterone levels, which BPA reduced, showed a significant increase after KMF was included in the treatment regimen. Treatment with BPA led to oxidative stress and tissue damage, but simultaneous treatment with KMF restored the damaged tissue to its normal state. Histopathology studies on testis and prostate tissues showed that KMF had an ameliorative impact on BPA-induced tissue damage.

CONCLUSIONS

The research suggests that KMF, a flavonol, could protect male rats from the harmful effects of BPA on reproductive health, highlighting its potential healing properties.

Endocrine-disrupting chemicals: Mainstream recognition of health effects and implications for the practicing internist

Rapidly advancing evidence documents that a broad array of synthetic chemicals found ubiquitously in the environment contribute to disease and disability across the lifespan. Although the early literature focused on early life exposures, endocrine-disrupting chemicals (EDCs) are now understood to contribute substantially to chronic disease in adulthood, especially metabolic, cardiovascular, and reproductive consequences as well as endocrine cancers. The contribution to mortality is substantial, with over 90,000 deaths annually and at least $39 billion/year in lost economic productivity in the United States (US) due to exposure to certain phthalates that are used as plasticizers in food packaging. Importantly, exposures are disproportionately high in low-income and minoritized populations, driving disparities in these conditions. Though non-Hispanic Blacks and Mexican Americans comprise 12.6% and 13.5% of the US population, they bear 16.5% and 14.6% of the disease burden due to EDCs, respectively. Many of these exposures can be modified through safe and simple behavioral changes supported by proactive government action to both limit known hazardous exposures and to proactively screen new industrial chemicals prior to their use. Routine healthcare maintenance should include guidance to reduce EDC exposures, and a recent report by the Institute of Medicine suggests that testing be conducted, particularly in populations heavily exposed to perfluoroalkyl substances-chemicals used in nonstick coatings as well as oil- and water-resistant clothing.

Oxidative stress increases in liver of lactating rats after BPF-low-dose exposure: perinatal effects in the offspring

Bisphenol F (BPF) is replacing Bisphenol A (BPA) in the manufacture of products due to endocrine-disrupting effects. BPF monomers can also be released into the environment and enter the food chain, resulting in human exposure to low doses. Since bisphenols are primarily metabolized by the liver, this organ is more vulnerable to lower doses of bisphenols than others. Exposure during prenatal development may increase the risk of diseases in adulthood. The aim was to evaluate whether BPF administration could generate oxidative stress in liver of lactating rats, and whether these effects may be also observed in female and male postnatal day 6 (PND6) offspring. Long Evans rats received oral treatment: Control, BPF-low-dose (LBPF) 0.0365 mg/kg b.w./day, and BPF-high-dose (HBPF) 3.65 mg/kg b.w./day. The levels of antioxidant enzymes (CAT, SOD, GR, GPx and GST), glutathione system (GSH, GSSG) and lipid damage markers (MDA, LPO) were measured using colorimetric methods in liver of both lactating dams and in PND6 offspring. Mean values were analyzed using Prism-7. LBPF affected liver defense mechanisms (antioxidant enzymes and glutathione system), increasing ROS levels and producing lipid peroxidation in lactating dams. Similar effects were found in female and male PND6 offspring as a consequence of perinatal exposure.

Mitochondrial oxidative damage by co-exposure to bisphenol A and acetaminophen in rat testes and its amelioration by melatonin

OBJECTIVE

Human exposure to multiple xenobiotics, over various developmental windows, results in adverse health effects arising from these concomitant exposures. Humans are widely exposed to bisphenol A, and acetaminophen is the most commonly used over-the-counter drug worldwide. Bisphenol A is a well-recognized male reproductive toxicant, and increasing evidence suggests that acetaminophen is also detrimental to the male reproductive system. The recent recognition of male reproductive system dysfunction in conditions of suboptimal reproductive outcomes makes it crucial to investigate the contributions of toxicant exposures to infertility and sub-fertility. We aimed to identify toxicity in the male reproductive system at the mitochondrial level in response to co-exposure to bisphenol A and acetaminophen, and we investigated whether melatonin ameliorated this toxicity.

METHODS

Male Wistar rats were divided into six groups (n=10 each): a control group and groups that received melatonin, bisphenol A, acetaminophen, bisphenol A and acetaminophen, and bisphenol A and acetaminophen with melatonin treatment.

RESULTS

Significantly higher lipid peroxidation was observed in the testicular mitochondria and sperm in the treatment groups than in the control group. Levels of glutathione and the activities of catalase, glutathione peroxidase, glutathione reductase, and manganese superoxide dismutase decreased significantly in response to the toxicant treatments. Likewise, the toxicant treatments significantly decreased the sperm count and motility, while significantly increasing sperm mortality. Melatonin mitigated the adverse effects of bisphenol A and acetaminophen.

CONCLUSION

Co-exposure to bisphenol A and acetaminophen elevated oxidative stress in the testicular mitochondria, and this effect was alleviated by melatonin.

Perinatal exposure to environmental endocrine disruptor bisphenol A aggravates the onset of non-alcoholic fatty liver disease (NAFLD) in weanling F1 offspring of obese rats

Bisphenol A (BPA) is a major environmental pollutant and food contaminant with endocrine-disrupting effects on human and animal health. Perinatal and developmental exposure to BPA has been known to cause hepatotoxicity in adulthood. However, its intergenerational effects in a metabolically challenged population have been scarcely investigated. Our study was designed to assess the intergenerational effect of an environmentally relevant dose of BPA and diet-induced parental obesity on the hepatic health outcome of F1 offspring. Wistar rats were given a high-fat diet to induce obesity, followed by chronic low dosages of BPA (10 ppm × 180 days) in drinking water. Post-treatment, rats were crossed within groups to obtain the F1 generation. Weanling pups were observed for weight gain, levels of hepatic antioxidants, liver function enzymes, cholesterol, C-reactive protein, and triglyceride in the serum. Histological changes in the liver tissue were also investigated. mRNA expression of energy homeostasis genes (FTO and MCR-4) in the liver was analyzed alongside blood biomarkers. We observed higher birth weight and rapid weight gain in the test group in comparison with controls, which was consistent with the changes in mRNA and protein expression of FTO and MCR-4. BPA caused a significant, treatment-related change in the inflammatory marker C-reactive protein, lipid peroxidation, antioxidants, and lipid profile. These findings were accompanied by histological changes in the liver tissue characteristic of hepatic steatosis indicating the onset of the non-alcoholic fatty liver disease (NAFLD). Our study offers a link between exposure to BPA in parents and onset of NAFLD in their offspring.

Sex-specific changes in oxidative stress parameters and longevity produced by Bisphenol F and S compared to Bisphenol A in Drosophila melanogaster

Female and male Drosophila melanogaster were exposed separately for seven days to Bisphenol A (BPA), Bisphenol F (BPF), and Bisphenol S (BPS) at concentrations of 0.25, 0.5, and 1 mM. We observed that males exposed to 0.5 and 1 mM BPS showed lower catalase (CAT) activity and higher superoxide dismutase (SOD) and reactive species (RS); CAT activity decreased for BPF 0.5 and 1 mM. Nevertheless, BPA 0.5 and 1 mM decreased CAT activity, increased RS and lipid peroxidation (LPO), and reduced mitochondrial viability. None of the bisphenols altered the cell viability of male flies, although BPA 0.5 and 1 mM reduced longevity. In female flies, BPA and BPS 0.5 and 1 mM increased RS and LPO levels and decreased CAT activity and glutathione-S-transferase (GST), which may have contributed to lower mitochondrial and cell viability. Furthermore, BPS decreased SOD activity at the 1 mM concentration, and BPA reduced the SOD activity at concentrations of 0.5 and 1 mM. In the BPF 1 mM group, there was a reduction in GST activity and an increase in RS and LPO levels. The toxicological effects were different between sexes, and BPA was more harmful than BPF and BPS in male flies. Thus, our findings showed that females were more susceptible to oxidative cell damage when exposed to BPA and BPS than to BPF, and daily exposure to BPA and BPS at all concentrations reduced female longevity, as well as in BPF 1 mM.

Environmental level bisphenol A accelerates alterations of the reno-cardiac axis by the MAPK cascades in male diabetic rats: An analysis based on transcriptomic profiling and bioinformatics

In humans and animal models, the kidneys and cardiovascular systems are negatively affected by BPA from the environment. It is considered that BPA have some potential estrogen-like and non-hormone-like properties. In this study, RNA-sequencing and its-related bioinformatics was used as the basic strategy to clarify the characteristic mechanisms of kidney-heart axis remodeling and dysfunction in diabetic male rats under BPA exposure. We found that continuous BPA exposure in diabetic rats aggravated renal impairment, and caused hemodynamic disorders and dysfunctions. There were 655 and 125 differentially expressed genes in the kidney and heart, respectively. For the kidneys, functional annotation and enrichment, and gene set enrichment analyses identified bile acid secretion related to lipid synthesis and transport, and MAPK cascade pathways. For the heart, these bioinformatics analyses clearly pointed to MAPKs pathways. A total of 12 genes and another total of 6 genes were identified from the kidney tissue and heart tissue, respectively. Western blotting showed that exposure to BPA activated MAPK cascades in both organs. In this study, the exacerbated remodeling of diabetic kidney-heart axis under BPA exposure and diabetes might occur through hemodynamics, metabolism disorders, and the immune-inflammatory response, as well as continuous estrogen-like stimulation, with focus on the MAPK cascades.

Impact of environmental toxin exposure on male fertility potential

Idiopathic infertility is the most common individual diagnosis in male infertility, representing nearly 44% of cases. Research studies dating over the last half-century consistently demonstrate a decline in male fertility that is incompletely explained by obesity, known genetic causes, or diet and lifestyle changes alone. Human exposures have changed dramatically over the same time course as this fertility decline. Synthetic chemicals surround us. Some are benevolent; however, many are known to cause disruption of the hypothalamic-pituitary-gonadal axis and impair spermatogenesis. More than 80,000 chemicals are registered with the United States National Toxicology Program and nearly 2,000 new chemicals are introduced each year. Many of these are known toxins, such as phthalates, polycyclic aromatic hydrocarbons, aromatic amines, and organophosphate esters, and have been banned or significantly restricted by other countries as they carry known carcinogenic effects and are reproductively toxic. In the United States, many of these chemicals are still permissible in exposure levels known to cause reproductive harm. This contrasts to other chemical regulatory legislature, such as the European Union's REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulations which are more comprehensive and restrictive. Quantification of these diverse exposures on an individual level has proven challenging, although forthcoming technologies may soon make this data available to consumers. Establishing causality and the proportion of idiopathic infertility attributable to environmental toxin exposures remains elusive, however, continued investigation, avoidance of exposure, and mitigation of risk is essential to our reproductive health. The aim of this review is to examine the literature linking changes in male fertility to some of the most common environmental exposures. Specifically, pesticides and herbicides such as dichlorodiphenyltrichloroethane (DDT), dibromochloropropane (DBCP), organophosphates and atrazine, endocrine disrupting compounds including plastic compounds phthalates and bisphenol A (BPA), heavy metals, natural gas/oil, non-ionizing radiation, air and noise pollution, lifestyle factors including diet, obesity, caffeine use, smoking, alcohol and drug use, as well as commonly prescribed medications will be discussed.

Bisphenol A in utero exposure induces ovary dysfunction in mice offspring and the ameliorating effects of Cuscuta chinensis flavonoids

To study the alleviating effects of flavonoids from Cuscuta chinensis (CCFs) on ovary injury in female offspring of pregnant mice exposed to BPA, five groups (n = 20) of pregnant mice were intragastrically administrated with BPA (5 mg/kg/day) and CCFs (20 mg/kg/day, 30 mg/kg/day, 40 mg/kg/day) at pregnancy days 1-18. The ovaries and serum of F1 female mice were collected at postnatal day (PND) 21 and PND 56 for the detection of related indicators. The ovarian and testicular histomorphologies were observed with hematoxylin-eosin staining (H&E). The levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and the contents of estradiol (E2), progesterone (P4), and testosterone (T) in serum were detected by radioimmunoassay. The contents of ovarian and testicular estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) were detected by enzyme-linked immunosorbent assay (ELISA). The expression of caspase-7, caspase-9, bcl-2, and bax in ovaries and testes of offspring mice were detected by Western blot, and apoptosis in ovaries and testes was detected by TUNEL. The mRNA relative transcription levels of ERα, progesterone receptor (PgR), DNA methyltransferase1 (Dnmt1), DNA methyltransferase3A (Dnmt3A), and DNA methyltransferase3B (Dnmt3B) were detected by real-time quantitative PCR (RT-qPCR). The ovary of female offspring with PND 56 was treated with bisulfite sequence PCR (BSP). Our results showed that, compared with the BPA group, 40 mg/kg CCFs significantly reduced the ovarian index of F1 females and the ovarian cytoapoptosis (P < 0.01). CCFs also can alleviate the injure of the levels of serum hormone, hormone receptors, and DNMTs induced by BPA in F1 females at PND 21 and PND 56. Forty milligrams per kilogram of CCFs significantly inhibited the hypermethylation of the H19/Igf2 imprinted gene induced by BPA (P < 0.01). It indicated that CCFs adjusted H19/Igf2 methylation by increasing the expression of DNMTs, thereby increasing the levels of reproductive hormones and receptors along with reducing the cytoapoptosis.

Melatonin Ameliorates BPA Induced Oxidative Stress in Human Red Blood Cells: An In vitro Study

BACKGROUND

Bisphenol A (BPA) is a xenobiotic that causes oxidative stress in various organs in living organisms. Blood cells are also an endpoint where BPA is known to cause oxidative stress. Blood cells, especially red blood cells (RBCs), are crucial for maintaining homeostasis and overall wellbeing of the organism. They are highly susceptible to oxidative stress induced by xenobiotics. However, there is limited data about the oxidative stress induced by BPA in blood, especially in red blood cells. This study was carried out to evaluate BPA induced oxidative stress in human RBCs in vitro and its amelioration by melatonin.

OBJECTIVE

To find if melatonin exerts a protective effect on the oxidative stress induced by the BPA in human red blood cells in vitro.

METHODS

The erythrocyte suspensions (2 ml) were divided into six groups and treated with 0, 50, 100, 150, 200, and 250 μg/ml of BPA. Another set of erythrocyte suspension with similar BPA treatment and 50 μM Melatonin per group was also set. Incubations lasted for 12 hrs in the dark. Lipid peroxidation, glutathione, glutathione reductase, catalase, and superoxide dismutase were measured as indicators of oxidative stress.

RESULTS

BPA caused a significant increase in lipid peroxidation. A decrease in GSH levels was also observed. The activities of all the studied antioxidants also decreased with BPA treatment. Melatonin was seen to mitigate the oxidative stress induced by BPA.

CONCLUSION

Treatment of red blood cells with BPA caused an increase in oxidative stress, while melatonin decreased the induced oxidative stress.

Bisphenols and Male Reproductive Health: From Toxicological Models to Therapeutic Hypotheses

Bisphenols, and in particular bisphenol A (BPA), have been widely used for the production of plastic manufacts in the last 50 years. Currently, BPA is present in a variety of daily use polycarbonate plastics and epoxy resins, and dietary ingestion is considered the main route of human exposure. Accordingly, BPA is the chemical pollutant with the widest exposure in humans, involving nearly 90% of general population, according to recent studies. Concerns about BPA effects on human health date back to 1930s, when severe impact on male sexual development was suggested. Now, the acknowledged biological effects of BPA are various. In regard to human fertility, BPA has been shown to disrupt hormone signaling even at low concentrations. Results from human epidemiological studies have reported BPA interference with follicle stimulating hormone, inhibin B, estradiol, testosterone levels, and sexual function in male subjects. Moreover, recent studies have reported an association between BPA levels and reduced sperm concentration, motility, normal morphology, sperm DNA damage, and altered epigenetic pattern, resulting in trans-generational legacy of BPA effects. In this review, the recognized effects of BPA on male reproductive health are described, from the most recent issues on experimental models to epidemiological data. In addition, the very recent interest about the use of nutraceutical remedies to counteract BPA effects are discussed.

In Vivo Evaluation of Histopathological Alterations and Trace Metals Estimation of the Small Intestine in Bisphenol A-Intoxicated Rats

BPA, a ubiquitously used plasticizer, has become one of the contaminants of emerging concern and causes many serious health implications in humans due to multiple exposure pathways. The current study was aimed at investigating the deformities of structures that arise by exposure of the small intestine to BPA through trace elements estimation of tissues as well as the study of serum profile. Two major groups of Wistar rats were established: one control group and the other experimental group, which was further divided into four groups based on dose (10 mg/kg/bodyweight and 25 mg/kg/bodyweight, respectively) and duration of exposure (6 and 12 weeks, respectively). Histological study of the small intestine showed the distorted structures in the experimental groups. The special staining performed illustrated the accumulation of calcium deposits in the small intestinal tissue in treated groups. Trace metals estimation showed a significant increase in the metallic content of sodium and iron and a decrease in the calcium content in the experimental groups (p=0.05). Serum profiling illustrated an increase in total iron-binding capacity and glucose levels and a decrease in the serum total iron level (p=0.05). An increased expression of a proinflammatory cytokine (IFN-α) was observed in the liver. From all these findings, it was inferred that BPA caused many structural alterations in the small intestinal tissue, which further affected its functioning. The calcium deposits seen through special staining affected the motility of the small intestine and caused its dysfunction. It was also induced from serum profiling that BPA affected the homeostasis of iron and glucose and caused its imbalance. Also, as BPA got absorbed from the small intestine and reached the liver via the blood stream, it caused hepatoxicity in the liver and led to increased inflammatory response by IFN-α against the toxicant.

Dichotomy of bisphenol A-induced expression of peroxisome proliferator-activated receptors in hepatic and testicular tissues in mice

Environmental and dietary exposure to bisphenol A (BPA) and its toxicological consequences are extensively reported. BPA has multiple cellular targets. One of the mechanisms of action of BPA involves interaction with and activation of nuclear receptors (NRs) including peroxisome proliferator activated-receptors (PPARs). PPARs regulate genes involved in adipogenesis, and metabolism of glucose, lipid and cholesterol. Study of tissue and dose specific PPAR expression may decipher the toxicity outcome of BPA exposure. We studied expression of three forms of PPARs in mouse liver and testes exposed to BPA for 14 days. mRNA and protein expression of all forms of PPAR increased linearly (monotonic) with the dose in the liver while non-monotonic but dose specific effects were observed in the testes showing a differential pattern of expression. However, histopathological study showed a dose-dependent pattern of changes in liver as well as testes demonstrating a monotonic effect. These findings imply that other PPAR-independent mechanisms may play a role in BPA-induced pathological changes. The present study warrants exploration of the role of PPARs in BPA-induced effects on male reproductive functions and offers an insight into the peculiar response of BPA at low subchronic levels which may be helpful in designing appropriate risk assessment framework.

Transgenerational effect of parental obesity and chronic parental bisphenol A exposure on hormonal profile and reproductive organs of preadolescent Wistar rats of F1 generation: A one-generation study

There is a global concern about adverse health effects of endocrine-disrupting chemicals (EDCs). Bisphenol A (BPA), an estrogenic and obesogenic compound, used in the plastic and medical industry has a dominant position among EDCs as far as human health and regulatory scenario are concerned. Due to its omnipresence across the biosphere, population of all age groups and health status is unavoidably exposed to BPA. Transgenerational exposure to BPA and its effects have also been recognized. However, there is no report on the transgenerational effect of BPA on metabolically disordered parents, such as obese ones. We studied effect of BPA exposure in F0 generation and its impact on F1 generation and factored parental obesity in transgenerational effect of concurrent exposure to low dose BPA (10 ppm × 180 days) in Wistar rats in a one-generation study protocol. The exposed F0 generation animals were crossed and F1 generation was analyzed 35 days after birth for indications of reproductive toxicity. We observed changes in hormone levels and disturbance in glucose and lipid homeostasis. Animals showed increased serum cholesterol and triglycerides along with higher birth weight and rapid weight gain. Histopathological evidence confirmed the presence of regressive and inflammatory changes in the ovary and testis. The test group showed metabolic disturbances in comparison to control group. Our study showed the additive effect of parental obesity in transgenerational reproductive toxicity of BPA. Female animals of F1 generation of BPA-treated obese parents showed more insulin resistance than males with similar exposure scenario. Our study highlights the confounding role of metabolic disorders such as obesity in the transgenerational toxicity of BPA, which otherwise itself is implicated in the aetiology of such metabolic disorders, directly or indirectly.

Water and soil pollution as determinant of water and food quality/contamination and its impact on male fertility

Over the past two decades, public health has focused on the identification of environmental chemical factors that are able to adversely affect hormonal function, known as endocrine disruptors (EDs). EDs mimic naturally occurring hormones like estrogens and androgens which can in turn interfere with the endocrine system. As a consequence, EDs affect human reproduction as well as post and pre-natal development. In fact, infants can be affected already at prenatal level due to maternal exposure to EDs. In particular, great attention has been given to those chemicals, or their metabolites, that have estrogenic properties or antagonistic effects on the activity of androgen or even inhibiting their production. These compounds have therefore the potential of interfering with important physiological processes, such as masculinization, morphological development of the urogenital system and secondary sexual traits. Animal and in vitro studies have supported the conclusion that endocrine-disrupting chemicals affect the hormone-dependent pathways responsible for male gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, epidemiological studies have reported an overall decline of male fertility and an increased incidence of diseases or congenital malformations of the male reproductive system. The majority of studies point towards an association between exposure to EDs and male and/or female reproductive system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants has yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Despite the lack of consistency in the results of so many studies investigating endocrine-disrupting properties of many different classes of chemicals, the overall conclusion points toward a positive association between exposure to EDs and reproductive system. Future studies should focus on a uniform systems to examine human populations with regard to the exposure to specific EDs and the direct effect on the reproductive system.

Protective effect of Lespedeza cuneata ethanol extract on Bisphenol A-induced testicular dysfunction in vivo and in vitro

PURPOSE

Bisphenol A (BPA) has been regarded as a possible risk factor for reproductive health. We examined potential reproductive health benefits of Lespedeza cuneata ethanol extract (LCE). Previously, Lespedeza cuneata showed many therapeutic effects. However, the protective effect of LCE on BPA-induced testicular dysfunction and its mechanisms have not been precisely studied.

METHODS

Mice were randomly divided into six groups (n = 7). Sperm counts and motility were measured by light microscope. Testosterone, total cholesterol, triglycerides, HDL, LDL-cholesterol, glucose, free fatty acids, hs-CRP, Angiotensinogen, Angiotensin II, GOT, GPT, TBARS, GSH, CAT, and SOD1 were measured in mouse serum. The potential protective effects of the LCE on mouse sertoli cells were evaluated.

RESULTS

Oral administration of LCE in BPA-exposed male mice restored testis weight, sperm count, motility, and testosterone levels by inhibiting markers in serum. In addition, treatment with LCE in BPA-treated TM4 sertoli cells recovered cell viability by attenuating Bax expression and activating caspase 3 and PARP.

CONCLUSIONS

These results indicate that LCE prevented BPA-induced testicular dysfunction and cell viability in BPA-treated TM4 sertoli cells. Our study also suggests that LCE has the potential to protect male reproductive health.

Anatomical specificity of the brain in the modulation of Neuroglobin and Cytoglobin genes after chronic bisphenol a exposure

The aim of this study was to investigate the influence of Bisphenol A (BPA) exposure on Neuroglobin (Ngb) and Cytoglobin (Cygb) as well as oxidative stress gene expression in the cerebellum, hippocampus, hypothalamus and cortex. Male Wistar rats were randomly divided into 3 groups: Control and two groups receiving 2 different daily BPA dosages, 5 or 25 mg/kg from postnatal day 50 (PND50) through PND90 and they were euthanized at PND105. In the cortex, we found an increase in Ngb gene expression and also in superoxide dismutase 1 and Catalase (Cat). In the cerebellum, we found an increase in Ngb and Cat, in the hypothalamus, there was a decrease in Cygb and an increase in glutathione peroxidase and Cat and in hypoxia-inducible factor 1 alpha (Hif1α) at the low dosage and a decrease in Hif1α at the high BPA dosage. Finally, in the hippocampus, we observed a decrease in Ngb and Cygb and an increase in Hif1α. In summary, BPA promotes the modulation of both Ngb and Cygb, but such changes occur by different mechanisms depending on the exposure dose and anatomical area.

Melatonin protects oocyte quality from Bisphenol A-induced deterioration in the mouse

Bisphenol A (BPA) has been reported to adversely affect the mammalian reproductive system in both sexes. However, the underlying mechanisms regarding how BPA disrupts the mammalian oocyte quality and how to prevent it have not been fully defined. Here, we document that BPA weakens oocyte quality by impairing both oocyte meiotic maturation and fertilization ability. We find that oral administration of BPA (100 μg/kg body weight per day for 7 days) compromises the first polar body extrusion (78.0% vs 57.0%, P<.05) by disrupting normal spindle assembly, chromosome alignment, and kinetochore-microtubule attachment. This defect could be remarkably ameliorated (76.7%, P<.05) by concurrent oral administration of melatonin (30 mg/kg body weight per day for 7 days). In addition, BPA administration significantly decreases the fertilization rate of oocytes (87.2% vs 41.1%, P<.05) by reducing the number of sperm binding to the zona pellucida, which is consistent with the premature cleavage of ZP2 as well as the mis-localization and decreased protein level of ovastacin. Also, the localization and protein level of Juno, the sperm receptor on the egg membrane, are strikingly impaired in BPA-administered oocytes. Finally, we show that melatonin administration substantially elevates the in vitro fertilization rate (63.0%, P<.05) by restoring above defects of fertilization proteins and events, which might be mediated by the improvement of oocyte quality via reduction of ROS levels and inhibition of apoptosis. Collectively, our data reveal that melatonin has a protective action against BPA-induced deterioration of oocyte quality in mice.

Mitochondrial dysfunction induced by Bisphenol A is a factor of its hepatotoxicity in rats

Bisphenol A (BPA), an estrogenic and endocrine disrupting agent, is widely used in manufacturing of polycarbonate plastics and epoxy resins. BPA and other endocrine disrupting chemicals (EDCs) act via multiple mechanisms including interference with mitochondrial functions. Mitochondria are the hub of cellular energy pool and hence are the target of many EDCs. We studied perturbation of activities of mitochondrial enzymes by BPA and its possible role in hepatotoxicity in Wistar rats. Rats were exposed to BPA (150 mg/kg, 250 mg/kg, 500 mg/kg per os, for 14 days) and activities of enzymes of mitochondrial electron transport chain (ETC) were measured. Besides, other biochemical parameters such as superoxide generation, protein oxidation, and lipid peroxidation (LPO) were also measured. Our results indicated a significant decrease in the activities of enzymes of mitochondrial ETC complexes, i.e., complex I, II, III, IV, and V along with significant increase in LPO and protein oxidation. Additionally, a significant increase in mitochondrial superoxide generation was also observed. All these findings could be attributed to enhanced oxidative stress, decrease in reduced glutathione level, and decrease in the activity of superoxide dismutase in rat liver mitochondria isolated from BPA-treated rats. BPA treatment also caused a significant increase in serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase indicating its potential hepatotoxicity. Furthermore, histopathological findings revealed marked edema formation, hepatocellular degeneration, and necrosis of liver tissue in BPA-exposed rats. In conclusion, this study provides an evidence of impaired mitochondrial bioenergetics and liver toxicity after high-dose BPA exposure in rats. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1922-1934, 2016.

Effects of bisphenol A on male and couple reproductive health: a review

Bisphenol A (BPA) is a ubiquitous environmental toxicant with endocrine-disrupting properties and is suspected to affect human reproduction. The objective of this review was to summarize the potential effects of male exposure to BPA on markers of testicular function and couple reproductive outcomes. Five epidemiologic studies on BPA and reproductive hormones all found significant associations with at least one reproductive hormone; however, no consistent relationships were observed across studies. Six epidemiologic studies evaluated the relation between BPA and semen parameters, and although the majority reported negative associations with various parameters, there were few consistent trends across studies. Finally, three epidemiologic studies examined BPA and couple reproductive outcomes, and only one found an association. Overall, the evidence supporting an association between BPA exposure and adverse male reproductive health outcomes in humans remains limited and inconclusive. Reasons for the discrepancies in results could include, but are not limited to, differences in study populations (e.g., fertile vs. subfertile men), BPA urinary concentrations (occupationally vs. nonoccupationally exposed), misclassification of BPA exposure (e.g., using one urine sample to characterize exposure vs. multiple samples), sample sizes, study design (e.g., cross-sectional vs. prospective), and residual confounding (e.g., due to diet and lifestyle factors). It is also possible that some of the statistically significant findings were due to chance alone. Clearly, further studies are needed to further clarify the role of this ubiquitous endocrine-disrupting chemical on male reproductive health.

Melatonin controlled apoptosis and protected the testes and sperm quality against bisphenol A-induced oxidative toxicity

Epidemiological reports have indicated a correlation between the increasing bisphenol A (BPA) levels in the environment and the incidence of male infertility. In this study, the protective effects of melatonin on BPA-induced oxidative stress and apoptosis were investigated in the rat testes and epididymal sperm. Melatonin (10 mg/kg body weight (bw)) was injected concurrently with BPA (50 mg/kg bw) for 3 and 6 weeks. The administration of BPA significantly increased oxidative stress in the testes and epididymal sperm. This was associated with a decrease in the serum testosterone level as well as sperm quality, chromatin condensation/de-condensation level, and the percentage of haploid germ cells in the semen. BPA administration caused a significant increase in apoptosis accompanied by a decrease in the expression of the antiapoptotic proteins Bcl-2 in the testes and epididymal sperm. The concurrent administration of melatonin decreased oxidative stress by modulating the levels of glutathione, superoxide dismutase, and catalase as well as the malondialdehyde and hydrogen peroxide concentrations in the testes and sperm. Melatonin sustained Bcl-2 expression and controlled apoptosis. Furthermore, melatonin maintained the testosterone levels, ameliorated histopathological changes, increased the percentages of seminal haploid germ cells, and protected sperm chromatin condensation process, indicating appropriate spermatogenesis with production of functional sperm. In conclusion, melatonin protected against BPA-induced apoptosis by controlling Bcl-2 expression and ameliorating oxidative stress in the testes and sperm. Thus, melatonin is a promising pharmacological agent for preventing the potential reproductive toxicity of BPA following occupational or environmental exposures.

Green tea potentially ameliorates bisphenol a-induced oxidative stress: an in vitro and in silico study

The present investigation was an attempt to elucidate oxidative stress induced by bisphenol A on erythrocytes and its amelioration by green tea extract. For this, venous blood samples from healthy human adults were collected in EDTA vials and used for preparation of erythrocytes suspension. When erythrocyte suspensions were treated with different concentrations of BPA/H2O2, a dose-dependent increase in hemolysis occurred. Similarly, when erythrocytes suspensions were treated with either different concentrations of H2O2 (0.05-0.25 mM) along with BPA (50 μg/mL) or 0.05 mM H2O2 along with different concentrations of BPA (50-250 μg/mL), dose-dependent significant increase in hemolysis occurred. The effect of BPA and H2O2 was found to be additive. For the confirmation, binding capacity of bisphenol A with erythrocyte proteins (hemoglobin, catalase, and glutathione peroxidase) was inspected using molecular docking tool, which showed presence of various hydrogen bonds of BPA with the proteins. The present data clearly indicates that BPA causes oxidative stress in a similar way as H2O2 . Concurrent addition of different concentrations (10-50 μg/mL) of green tea extract to reaction mixture containing high dose of bisphenol A (250 μg/mL) caused concentration-dependent amelioration in bisphenol A-induced hemolysis. The effect was significant (P < 0.05). It is concluded that BPA-induced oxidative stress could be significantly mitigated by green tea extract.

Green tea potentially ameliorates bisphenol a-induced oxidative stress: an in vitro and in silico study

The present investigation was an attempt to elucidate oxidative stress induced by bisphenol A on erythrocytes and its amelioration by green tea extract. For this, venous blood samples from healthy human adults were collected in EDTA vials and used for preparation of erythrocytes suspension. When erythrocyte suspensions were treated with different concentrations of BPA/H₂O₂, a dose-dependent increase in hemolysis occurred. Similarly, when erythrocytes suspensions were treated with either different concentrations of H₂O₂ (0.05–0.25 mM) along with BPA (50 μg/mL) or 0.05 mM H₂O₂ along with different concentrations of BPA (50–250 μg/mL), dose-dependent significant increase in hemolysis occurred. The effect of BPA and H₂O₂ was found to be additive. For the confirmation, binding capacity of bisphenol A with erythrocyte proteins (hemoglobin, catalase, and glutathione peroxidase) was inspected using molecular docking tool, which showed presence of various hydrogen bonds of BPA with the proteins. The present data clearly indicates that BPA causes oxidative stress in a similar way as H₂O₂ . Concurrent addition of different concentrations (10–50 μg/mL) of green tea extract to reaction mixture containing high dose of bisphenol A (250 μg/mL) caused concentration-dependent amelioration in bisphenol A-induced hemolysis. The effect was significant (P < 0.05). It is concluded that BPA-induced oxidative stress could be significantly mitigated by green tea extract.

Bisphenol a and reproductive health: update of experimental and human evidence, 2007-2013

BACKGROUND

In 2007, an expert panel reviewed associations between bisphenol A (BPA) exposure and reproductive health outcomes. Since then, new studies have been conducted on the impact of BPA on reproduction.

OBJECTIVE

In this review, we summarize data obtained since 2007, focusing on a) findings from human and animal studies, b) the effects of BPA on a variety of reproductive end points, and c) mechanisms of BPA action.

METHODS

We reviewed the literature published from 2007 to 2013 using a PubMed search based on keywords related to BPA and male and female reproduction.

DISCUSSION

Because BPA has been reported to affect the onset of meiosis in both animal and in vitro models, interfere with germ cell nest breakdown in animal models, accelerate follicle transition in several animal species, alter steroidogenesis in multiple animal models and women, and reduce oocyte quality in animal models and women undergoing in vitro fertilization (IVF), we consider it an ovarian toxicant. In addition, strong evidence suggests that BPA is a uterine toxicant because it impaired uterine endometrial proliferation, decreased uterine receptivity, and increased implantation failure in animal models. BPA exposure may be associated with adverse birth outcomes, hyperandrogenism, sexual dysfunction, and impaired implantation in humans, but additional studies are required to confirm these associations. Studies also suggest that BPA may be a testicular toxicant in animal models, but the data in humans are equivocal. Finally, insufficient evidence exists regarding effects of BPA on the oviduct, the placenta, and pubertal development.

CONCLUSION

Based on reports that BPA impacts female reproduction and has the potential to affect male reproductive systems in humans and animals, we conclude that BPA is a reproductive toxicant.

Bisphenol A exposure is associated with low-grade urinary albumin excretion in children of the United States

Urinary bisphenol A (BPA), a widely used biomarker of exposure to BPA, has been associated with cardiometabolic derangements in laboratory studies and with low-grade albuminuria in Chinese adults. Despite the known unique vulnerability of children to environmental chemicals, no studies have examined associations of urinary BPA with albuminuria in children. As exposure to BPA is widespread in the United States population, we examined data from 710 children in the 2009-10 National Health and Nutrition Examination Survey with urinary BPA measurements and first morning urine samples with creatinine values. Controlled for a broad array of sociodemographic and environmental risk factors as well as insulin resistance and elevated cholesterol, children with the highest compared with the lowest quartile of urinary BPA had a significant 0.91 mg/g higher albumin-to-creatinine ratio, adjusted for the urinary BPA concentration. When the multivariable model was reprised substituting continuous measures of BPA, a significant 0.28 mg/g albumin-to-creatinine ratio increase was identified for each log unit increase in urinary BPA. Thus, an association of BPA exposure with low-grade albuminuria is consistent with previous results found in Chinese adults and documents this in children in the United States. Our findings broaden the array of adverse effects of BPA to include endothelial dysfunction as evidenced by the low-grade albuminuria and support proactive efforts to prevent harmful exposures.

Alfa-lipoic acid protects testosterone secretion pathway and sperm quality against 4-tert-octylphenol induced reproductive toxicity

The protective effect of α-lipoic acid (LA) (50 mg/kg bw) against 4-tert-octylphenol (OP) (50 mg/kg bw) induced reproductive toxicity in male rats was studied. LA was injected 1h prior to OP administration three times a week. OP caused significant increase in oxidative stress in hypothalamus and epididymal sperm, disturbed hormonal levels in serum, decreased sperm quality, increased DNA fragmentation and loss of 35 and 95 kDa proteins in sperm, as well as elevated proliferating index in testis. LA protected against oxidative stress through promoting the levels of glutathione and glutathione-S-transferase in hypothalamus and sperm. In addition, LA prevented the decrease in testosterone, dehydroepiandrosterone sulfate, 3β-hydroxysteroid dehydrogenase, and inhibited the elevations in sex-hormone-binding globulin levels and showed normal sperm quality. LA modulated proliferation of germ cell, protected against DNA fragmentation and maintained membrane protein organization in the sperm. In conclusion, LA normalized oxidative stress and protected testosterone synthesis pathway across hypothalamus-testicular axis and sperm quality indicating its defensive influence against OP-induced oxidative reproductive dysfunction in male rats.

Vitamin C coadministration augments bisphenol A, nonylphenol, and octylphenol induced oxidative damage on kidney of rats

The aim of this study was to investigate whether bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) induce oxidative stress on the kidney tissue of male rats and whether coadministration of vitamin C, an antioxidant, can prevent any possible oxidative stress. The Wistar male rats were divided into seven groups, including control, BPA, NP, OP, BPA+C, NP + C, OP +C. BPA, NP, and OP (25 mg/kg/day) was administered alone; vitamin C (60 mg/kg/day) was administered along with BPA, OP, and NP to the rats for 50 days. There was a decrease in serum concentration of blood urea nitrogen (BUN) in NP and OP groups compared with control group. Vitamin C coadministration with BPA, NP, and OP did not produce significant increase in BUN concentration in BPA +C, NP+ C, and OP + C group as compared with BPA, NP, and OP groups, respectively. The lowest serum creatinine activity and the highest lactate dehydrogenase (LDH) activity was present in kidney of BPA+C, NP+C and OP+C groups compared with BPA, NP, and OP groups. The malondialdehyde (MDA) levels were significantly higher while glutathione (GSH) levels were lower in treatment groups than controls. Furthermore, an increase was observed in MDA levels whereas a decrease was observed in GSH levels in BPA+ C, NP + C, and OP+ C groups compared with BPA, NP, and OP groups, respectively. These finding are in accordance with immunohistochemical staining of MDA and GSH. Histopathological examination of the kidneys of rats in BPA, OP, NP, BPA+ C, NP + C, and OP+ C groups revealed necrotic lesions, congestion, and mononuclear cell infiltration. In conclusion BPA, NP, and OP might induce oxidative damage in kidney of rats. In addition, coadministration of vitamin C with BPA, NP, and OP to male rats augments this damage in the kidney of male rats.

Bisphenol a exposure in Mexico City and risk of prematurity: a pilot nested case control study

BACKGROUND

Presence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely.

METHODS

A nested case-control subset of 60 participants in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) study in Mexico City, Mexico were selected based on delivering less than or equal to 37 weeks of gestation and greater than 37 weeks of gestation. Third trimester archived spot urine samples were analyzed by online solid phase extraction coupled with high performance liquid chromatography isotope dilution tandem mass spectrometry.

RESULTS

BPA was detected in 80.0% (N = 48) of the urine samples; total concentrations ranged from < 0.4 μg/L to 6.7 μg/L; uncorrected geometric mean was 1.52 μg/L. The adjusted odds ratio of delivering less than or equal to 37 weeks in relation to specific gravity adjusted third trimester BPA concentration was 1.91 (95%CI 0.93, 3.91, p-value = 0.08). When cases were further restricted to births occurring prior to the 37th week (n = 12), the odds ratio for specific-gravity adjusted BPA was larger and statistically significant (p < 0.05).

CONCLUSIONS

This is the first study to document measurable levels of BPA in the urine of a population of Mexican women. This study also provides preliminary evidence, based on a single spot urine sample collected during the third trimester, that pregnant women who delivered less than or equal to 37 weeks of gestation and prematurely (< 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks.

Effect of imidacloprid on antioxidant enzymes and lipid peroxidation in female rats to derive its No Observed Effect Level (NOEL)

Technical imidacloprid was evaluated for its effect on oxidative stress and Lipid peroxidation (LPO) in female rats for No Observed Effect Level (NOEL). Activities of Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx), and level of Glutathione (GSH) and LPO were estimated in liver, kidney and brain of rats after oral administration of imidacloprid (5, 10, 20 mg/kg/day) for 90 days. Imidacloprid at 5 and 10 mg/kg/day has not produced changes in SOD, CAT, GPx and level of GSH and LPO in liver, brain and kidney. However 20 mg/kg/day has produced significant changes in SOD, CAT, GPx, GSH, LPO in liver; SOD, CAT and GPx in brain and LPO in kidney. Therefore, it is concluded that imidacloprid has not generated oxidative stress at 5 and 10mg/kg/day but induced changes at 20 mg/kg/day. Hence 10 mg/kg/day may be considered as NOEL through antioxidant enzymes and LPO in female rats.

How safe is bisphenol A? Fundamentals of toxicity: metabolism, electron transfer and oxidative stress

The FDA recently announced concern about the safety of bisphenol A (BPA) and the need for more research. In the current controversy, scant attention is being paid to toxicity at the fundamental, molecular level, which is the topic of this report. Important information is provided by extensive studies on metabolism. The principal pathway is detoxification, mainly by conjugation leading to a glucuronide. A minor route entails oxidation by hydroxylation to a catechol followed by further transformation to an o-quinone. The catechol-o-quinone couple is capable of redox cycling with generation of reactive oxygen species (ROS) and oxidative stress (OS). o-Quinones are highly electron affinic with very favorable reduction potentials that permit electron transfer (ET) under physiological conditions. Only small amounts are sufficient to generate large quantities of ROS catalytically. There is extensive evidence for production of ROS, which buttresses ET by o-quinone as a plausible source. In addition, there are numerous reports on toxicity to body constituents by BPA. Those adversely affected include the liver, DNA, genes, CNS, reproductive system and kidney. Since a plethora of prior studies links ROS-OS with toxicity, it is reasonable to propose a similar connection for BPA. Cell signaling also plays a role. There are various other factors involved with toxic responses, including age, with the fetus and infants being the most vulnerable. A report concludes that human exposure to BPA is not negligible. The present overview represents a novel, integrated approach to BPA toxicity. A similar article was recently published in this journal which deals with toxicity of prevalent phthalate plasticizers.