Prenatal BPA exposure disrupts male reproductive functions by interfering with DNA methylation and GDNF expression in the testes of male offspring rats

BPA is a ubiquitous environmental endocrine-disrupting chemical, and maternal exposure to BPA is associated with impaired male reproductive functions; however, the mechanisms remain to be elucidated. Glial cell line-derived neurotrophic factor (GDNF) plays an important role in maintaining normal spermatogenesis and fertility. However, the effect of prenatal BPA exposure on GDNF expression and its mechanism in the testis has not been reported. In this study, pregnant Sprague-Dawley rats were respectively exposed to 0, 0.05, 0.5, 5, and 50 mg/kg/day BPA via oral gavage from gestational day (GD) 5 to GD 19, with 6 pregnant rats in each group. ELISA, histochemistry, real-time PCR, western blot, and methylation-specific PCR (MSP) were used to detect the sex hormone levels, testicular histopathology, mRNA and protein expression of DNA methyltransferases (DNMTs) and GDNF, and the promoter methylation of Gdnf in the testes of male offspring at postnatal day (PND) 21 and PND 56. Prenatal BPA exposure increased body weight; decreased sperm counts and serum levels of testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH); and induced testicular histological damage, which indicated the damage of male reproductive function. Prenatal BPA exposure also upregulated Dnmt1 in 5 mg/kg group and Dnmt3b in 0.5 mg/kg group, but down-regulated Dnmt1 in 50 mg/kg group at PND 21. At PND 56, Dnmt1 was significantly increased in 0.05 mg/kg group but decreased in 0.5, 5, and 50 mg/kg groups, Dnmt3a was decreased, and Dnmt3b was markedly increased in 0.05 and 0.5 mg/kg groups but decreased in 5 and 50 mg/kg groups. The mRNA and protein expression levels of Gdnf were decreased markedly in 0.5 and 50 mg/kg groups at PND 21. And the methylation level of Gdnf promoter was significantly increased in 0.5 mg/kg group, but decreased in 5 and 50 mg/kg groups at PND 21. In conclusion, our study indicates that prenatal BPA exposure disrupts male reproductive functions, interferes with the expression of DNMTs, and decreases Gdnf expression in the testes of male offspring. Gdnf expression may be regulated by DNA methylation; however, the detailed mechanism needs to be further investigated.

Natural Products in Mitigation of Bisphenol A Toxicity: Future Therapeutic Use

Bisphenol A (BPA) is a ubiquitous environmental toxin with deleterious endocrine-disrupting effects. It is widely used in producing epoxy resins, polycarbonate plastics, and polyvinyl chloride plastics. Human beings are regularly exposed to BPA through inhalation, ingestion, and topical absorption routes. The prevalence of BPA exposure has considerably increased over the past decades. Previous research studies have found a plethora of evidence of BPA’s harmful effects. Interestingly, even at a lower concentration, this industrial product was found to be harmful at cellular and tissue levels, affecting various body functions. A noble and possible treatment could be made plausible by using natural products (NPs). In this review, we highlight existing experimental evidence of NPs against BPA exposure-induced adverse effects, which involve the body’s reproductive, neurological, hepatic, renal, cardiovascular, and endocrine systems. The review also focuses on the targeted signaling pathways of NPs involved in BPA-induced toxicity. Although potential molecular mechanisms underlying BPA-induced toxicity have been investigated, there is currently no specific targeted treatment for BPA-induced toxicity. Hence, natural products could be considered for future therapeutic use against adverse and harmful effects of BPA exposure.

Inflammatory and proapoptotic effects of inhaling gasoline fumes on the lung and ameliorative effects of fenugreek seeds

Impacts of inhaling gasoline fumes on the lungs of adult male rats and the alleviating role of fenugreek seeds were evaluated. Twenty-four rats were divided into four groups, unexposed control and fenugreek groups, gasoline exposed groups for 6 h/6 day/week for 10 weeks with and without supplementation of fenugreek seed powder in food (5% w/w). Rats exposed to gasoline fumes showed significant elevation in lung tumor necrosis factor-α, as an inflammatory marker, and the proapoptotic marker Bax with a reduction in the antiapoptotic marker Bcl2. Moreover, remarkable elevations in transforming growth factor-β1, collagen and hydroxyproline were observed as fibrotic markers. Lung oxidative stress markers (hydrogen peroxides, malondialdehyde, and protein carbonyl) increased significantly along with marked decrease in total antioxidant capacity, superoxide dismutase, and catalase levels. Additionally, marked decreases in white and red blood cell counts, hemoglobin content, platelet count, accompanied by elevated red cell distribution width percentage were observed, supporting the inflammatory status. Histopathological changes represented by hematoxylin&eosin, immunohistochemistry staining for Bax&Bcl2, and transmission electron microscopy supported the negative impacts of gasoline fumes compared to the control group. Fenugreek seeds supplementation with gasoline exposure showed pronounced alleviation of lung biochemical and histopathological changes compared to the gasoline-exposed group.

Investigation of the effect of hesperidin on some reproductive parameters in testicular toxicity induced by Bisphenol A

Bisphenol A (BPA) is one of the chemicals that cause dysfunction and infertility in testicles. Therefore, it is crucial to develop effective treatments against this damage. In this study, the effects of Hesperidin (HESP), a flavonoid in testicular toxicity induced by BPA in rats, on oxidative stress, inflammation, apoptosis, histological damage, spermatogenesis, steroidogenic enzymes and reproductive hormones were investigated. Our study used 52 Sprague Dawley male rats weighing 250-300 g, and four experimental groups were formed. From the experimental groups, 1 ml of olive oil was administered to the control group, HESP at a dose of 50 mg/kg to the HESP group, BPA at a dose of 100 mg/kg to the BPA group, HESP at a dose of 50 mg/kg to the BPA + HESP group and 100 mg/kg BPA was administered intragastrically (ig) for 14 days. We determined that BPA administration causes apoptosis, histological damage, inflammation, oxidative stress and toxic effects on spermatogenesis and steroidogenic enzymes in testicles. We observed that the administration of HESP with BPA attenuated oxidative stress, inflammation and apoptosis resulting in therapeutic effects on both steroidogenic enzymes and spermatogenesis and reproductive hormones (FSH, LH and testosterone). Our findings from this study clearly showed that while HESP treatment alleviates oxidative damage, inflammation and apoptosis in testicles of rats treated with BPA, it has regulatory effects on steroidogenic enzymes, spermatogenesis and serum reproductive hormones.

Oxidative Stress and Male Infertility: Role of Herbal Drugs

Infertility is a universal health problem affecting 15% of couples, out of which 20-30% cases are due to male infertility. The leading causes of male infertility include hormonal defects, physical reasons, sexual problems, hazardous environment, stressful lifestyle, genetic factors, epigenetic factors, and oxidative stress. Various physiological functions involve reactive oxygen species (ROS) and nitrogen species at appropriate levels for proper smooth functioning. ROS control critical reproductive processes such as capacitation, acrosomal reaction, hyperactivation, egg penetration, and sperm head decondensation. The excessive free radicals or imbalance between ROS and endogenous antioxidant enzymes damages sperm membrane by inducing lipid peroxidation causing mitochondrial dysfunction and DNA damage that eventually lead to male infertility. Numerous synthetic products are available in the market to treat infertility problems, largely ending in side effects and repressing symptoms. Ayurveda contains a particular group of Rasayana herbs, called vajikarana, that deals with nourishment and stimulation of sexual tissues, improves male reproductive vitality, and deals with oxidative stress via antioxidant mechanism. The present study aims to describe oxidative stress and the role of herbal drugs in treating male infertility.

Antioxidant effect of Vitamin E on the male rat reproductive system by a high oral dose of Bisphenol-A

Among researchers, environmental pollutants and their contribution to male fertility are still being discussed. The use of antioxidants manages to boost the reproductive system with the scavenging of free radicals. This study aimed to investigate the inhibiting function of Vitamin E (VE) on Bisphenol-A (BPA) toxicity in the male rats’ reproductive system. Male rats were divided into 4 groups: control (negative control) group, BPA group treated by 250 mg/kg/day (positive control), VE group treated by 150 mg/kg/day (comparative control) and BPA + VE group that received both doses at the same time (Oral treatment by gavage; 56 days). Sperm parameters, testicular tissue morphometric and biochemical tests were evaluated. Sperm count, motility, viability, normal morphology, sperm tail length, spermatogenesis index and serum testosterone levels significantly decreased in the BPA group compared to the control group. Versus a significant enhancement in the positive-TUNEL germinal cells and serum malondialdehyde (MDA) levels were observed. Moreover, BPA exhibited no effect on sperm maturity and DNA integrity. In the simultaneous treatment group (BPA + EV), VE could improve and regulate all the mentioned parameters within the control group range. As mentioned, there was a significant difference in the results in the positive control group compared to the negative control group. But these data improved significantly in the BPA + VE. It can be concluded that in this group, VE was able to overcome the toxicity caused by positive control in their simultaneous treatment and maintain the data at the negative control group range. Therefore, no significant change was observed in the BPA + VE group compared to the negative control group.

Fighting Bisphenol A-Induced Male Infertility: The Power of Antioxidants

Bisphenol A (BPA), a well-known endocrine disruptor present in epoxy resins and polycarbonate plastics, negatively disturbs the male reproductive system affecting male fertility. In vivo studies showed that BPA exposure has deleterious effects on spermatogenesis by disturbing the hypothalamic–pituitary–gonadal axis and inducing oxidative stress in testis. This compound seems to disrupt hormone signalling even at low concentrations, modifying the levels of inhibin B, oestradiol, and testosterone. The adverse effects on seminal parameters are mainly supported by studies based on urinary BPA concentration, showing a negative association between BPA levels and sperm concentration, motility, and sperm DNA damage. Recent studies explored potential approaches to treat or prevent BPA-induced testicular toxicity and male infertility. Since the effect of BPA on testicular cells and spermatozoa is associated with an increased production of reactive oxygen species, most of the pharmacological approaches are based on the use of natural or synthetic antioxidants. In this review, we briefly describe the effects of BPA on male reproductive health and discuss the use of antioxidants to prevent or revert the BPA-induced toxicity and infertility in men.

Herbal foodstuffs in Avicenna's recommended diet to improve sperm quality and increase male fertility; an evidence-based approach

Attention to diet was considered important issues in improvement of men infertility in Persian Medicine (PM). The purpose of this study was to extract herbal foodstuffs introduced by Avicenna, one of the greatest PM physicians to improve the semen production and to provide evidence of their impact on the basis of current studies."Canon of Medicine", the most important Avecinna's book, was searched with keywords equivalent to semen, fertility and infertility, main herbal foodstuffs were extracted and was searched with keywords sperm, semen, infertility, and fertility in Google scholar, PubMed and Scopus databases. Manuscripts from 1950 up to December 2019 were selected and reviewed. Almond, Onion, Chickpea, Garlic, Coconut, Palm date, Sesame, Fenugreek, Carrot, Fig, Grapes, Pistachio, Hazelnut and Walnut are among main foodstuffs which recommended by Avicenna and there is also evidence that they have positive effects on testosterone production and improvement of various sperm parameters, including count, motility and morphology. Containing large amount of different macro and micronutrients such as vitamins including vit B, C, A and E, minerals such as Mg, Se, Zn, Cu and Fe, important unsaturated fatty acids such as linoleic and oleic acids, amino acids such as lysine and arginine and phytochemicals such as polyphenols, flavonoids, triterpenes and steroids can be considered as a main factor in the effectiveness of these foodstuffs. Designing a diet based on the fruits, vegetables, nuts and seeds that Avicenna has recommended, may be effective in treating male infertility but further studies are needed to clarify this issue. Research on the effectiveness of his other recommended foodsuffs may also offer new treatments and supplements for this purpose.

Selenium attenuates bisphenol A incurred damage and apoptosis in mice testes by regulating mitogen-activated protein kinase signalling

Being a vital micronutrient, along with a trace element, selenium (Se) protects the cells from oxidative stress (OS) in the form of selenoproteins. Bisphenol A (BPA) is a xeno-oestrogenic compound that adversely affects the spermatogenesis process by inducing oxidative stress, which ultimately leads to male infertility. Therefore, it is hypothesised that Se could protect against BPA-induced OS, and further germ cell death by modifying mitogen-activated protein kinase (MAPK) signalling. Male Balb/c mice were divided into four groups: Group I (C) (0.2 ppm Se), Group II (Se) (0.5 ppm Se), Group III (BPA) (0.2 ppm Se, and BPA = 1 mg/kg orally) and Group IV (Se + BPA) (0.5 ppm Se, and BPA = 1 mg/kg bodyweight orally). Results indicated that BPA-treated animals demonstrated a marked decrease in antioxidant enzyme activities (superoxide dismutase, catalase, redox ratio), a marked elevation in the expressions of stress-activated kinases (c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38) and the expressions of pro-apoptotic markers (caspase-9, caspase-8 and caspase-3). However, Se supplementation considerably restored the antioxidant enzyme activities and lowered the expressions of stress-activated kinases, which further down-regulated the apoptosis. Thus, Se supplementation demonstrated to be effective against BPA provoked testicular damage.