The effect of bisphenol A on testicular steroidogenesis and its amelioration by quercetin: an in vivo and in silico approach

Chitosan-TPP encapsulated quercetin nanoparticles: amplified protection mechanisms unveiled against Ethion-induced developmental toxicity through comprehensive in-vivo and in-silico elucidation

Aim

The study investigated Ethion-induced developmental toxicity in Wistar albino rats and the potential ameliorative effects of quercetin and nano-quercetin co-administration. Further, In-silico docking of Ethion and quercetin with MCL-1 was conducted.

Methodology

Quercetin nanoparticles were synthesized by ionic-gelation method. The encapsulated quercetin nanoparticles were characterized for Zeta size, UV-Vis spectroscopy, encapsulation efficiency, and TEM studies. Male rats were administered Ethion (high/low dose), quercetin, and nano-quercetin alone or in combination for 60 days. Female rats were introduced for mating on the 61st day, and pregnant females were observed for 20 gestational days. On GD 20, rats were sacrificed and evaluated for body/organ weight, reproductive indices, fetal morphology, skeletal, and visceral deformities.In silico binding energies of ethion and quercetin with MCL-1 were determined.

Results

Nanoparticle size was 363.2 ± 1.23 nm on day 0 and 385.63 ± 1.53 nm on day 60, with PDI of 0.247 and charge of 22.9 mV. Absorbance maxima were at 374 nm, with encapsulation efficacy of 85.16 ± 0.33%. EHD male crossed females showed decreased body/organ weights, reduced fertility, hematoma, cleft palate, tail curling, and absence of extremity. Nano-quercetin co-administration normalized parameters comparable to controls. Both Ethion and quercetin interacted with MCL-1, with quercetin exhibiting stronger binding energy.

Conclusion

Nano-quercetin demonstrated stronger antioxidant properties than quercetin, counteracting ethion-induced maternal/fetal abnormalities.

Alleviative effect of quercetin against reproductive toxicity induced by chronic exposure to the mixture of phthalates in male rats

Phthalates (PEs) are widely used plasticizers in polymer products, and humans are increasingly exposed to them. This study was designed to investigate the alleviative effect of phytochemicals quercetin (Que) against male reproductive toxicity caused by the mixture of three commonly used PEs (MPEs), and further to explore the underlying mechanism. Forty-eight male SD rats were randomly and evenly divided into control group, Que group, MPEs group and MPEs+Que group (n = 12); The oral exposure doses of MPEs and Que were 450 mg/kg/d and 50 mg/kg/d, respectively. After 91 days of continuous intervention, compared with control group, the testes weight, epididymis weight, serum sex hormones, and anogenital distance were significantly decreased in MPEs group (P < 0.05); Testicular histopathological observation showed that all seminiferous tubules were atrophy, leydig cells were hyperplasia, spermatogenic cells growth were arrested in MPEs group. Ultrastructural observation of testicular germ cells showed that the edges of the nuclear membranes were indistinct, and the mitochondria were severely damaged with the cristae disrupted, decreased or even disappeared in MPEs group. Immunohistochemistry and Western blot analysis showed that testicular CYP11A1, CYP17A1 and 17β-HSD were up-regulated, while StAR, PIWIL1 and PIWIL2 were down-regulated in MPEs group (P < 0.05); However, the alterations of these parameters were restored in MPEs+Que group. The results indicated MPEs disturbed steroid hormone metabolism, and caused male reproductive injuries; whereas, Que could inhibit MPEs' male reproductive toxicity, which might relate to the restored regulation of steroid hormone metabolism.

Effects of quercetin on gentamicin-induced experimental testicular injury in rats

The purpose of this study was to investigate the effects of gentamicin (GEN) on the testis and whether quercetin (QUE) has any protective effect. Twenty-four adult male Sprague-Dawley rats were divided into equal four groups: control (0.9% saline solution), GEN (80 mg∕kg GEN), QUE (50 mg∕kg QUE) and GEN+QUE (80 mg∕kg GEN + 50 mg∕kg QUE). Histopathological (HP) evaluation of testis was performed, epididymal sperm parameters were analyzed and oxidative status was evaluated. The use of QUE improved the HP findings, such as decrease in the germinal epithelial thickness in the testicular tissue of the GEN group, decrease in the Johnsen's tubular biopsy score (JTBS), increase in the rate of immature cell shedding tubules, and the apoptotic index (AI). In the GEN group, sperm count, and abnormal morphology increased compared to the control group; the viability and motility decreased according to the sperm analysis results. In the GEN+QUE group, QUE was found to improve sperm viability and morphology. In the GEN group, tissue malondialdehyde (MDA) levels increased while superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) levels decreased. Compared with the GEN+QUE group, it was found that the tissue MDA level decreased, while the levels of SOD, CAT and GPx increased. The results demonstrate that GEN impairs testicular structure and function, and QUE treatment can prevent this adverse effect.

In vivo exposure to bisphenol F induces oxidative testicular toxicity: role of Erβ and p53/Bcl-2 signaling pathway

Introduction

Bisphenol F (BPF), an alternative to bisphenol A has been implicated as a gonadotoxic substance. BPF has been shown to induce hormonal imbalance and testicular oxidative damage. However, the mechanism associated with BPF-induced testicular toxicity has not been fully explored. This study was designed to explore the role of tumor protein (p53)/ B-cell lymphoma 2 (BCl-2) signaling and oestrogen receptor beta (Erβ) in BPF-induced testicular toxicity.

Methods

Male Wistar rats were randomized into control (Cntrl), BPF-treated (10, 30, and 50 mg/kg for low dose (BPF-L), medium dose (BPF-M), and high dose (BPF-H) respectively), and BPF-treated recovery (Cntrl-R, BPF-L-R, BPF-M-R, and BPF-H-R). The administration was via gavage and lasted for 28 days and the animals in the recovery groups were allowed 28-days exposure free period for recovery from BPF exposure.

Results

BPF resulted in the distortion of the testicular histoarchitecture, which was accompanied by a significant rise in testicular gamma-lutamyl transferase and lactate dehydrogenase activities but a decline in sorbitol dehydrogenase activities. Also, BPF caused a significant reduction in plasma gonadotropin-releasing hormone, luteinising hormone, follicle-stimulating hormone, and testosterone, which was associated with the downregulation of testicular 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase activities. Furthermore, BPF induced testicular inflammation, redox imbalance, and apoptosis, accompanied by distortion in p53/BCl-2 signaling and overexpression of Erβ. Again, the observed toxic effects of BPF were dose-dependent and not completely reversed by BPF cessation.

Discussion

Bisphenol F induced gonadotoxicity by distorting p53/BCl2 signaling and the expression of Erβ. These observed alterations were not completely reversed after the cessation of BPF exposure.

Pharmacological Activity of Flavonoid Quercetin and Its Therapeutic Potential in Testicular Injury

Quercetin is a natural flavonoid widely found in natural fruits and vegetables. Recent studies have shown that quercetin mediates multiple beneficial effects in a variety of organ damage and diseases, and is considered a healthcare supplement with health-promoting potential. Male infertility is a major health concern, and testicular damage from multiple causes is an important etiology. Previous studies have shown that quercetin has a protective effect on reproductive function. This may be related to the antioxidant, anti-inflammatory, and anti-apoptotic biological activities of quercetin. Therefore, this paper reviews the mechanisms by which quercetin exerts its pharmacological activity and its role in testicular damage induced by various etiologies. In addition, this paper compiles the application of quercetin in clinical trials, demonstrating its practical effects in regulating blood pressure and inhibiting cellular senescence in human patients. However, more in-depth experimental studies and clinical trials are needed to confirm the true value of quercetin for the prevention and protection against testicular injury.

Susceptibility of male reproductive system to bisphenol A, an endocrine disruptor: Updates from epidemiological and experimental evidence

Bisphenol A (BPA) is an omnipresent environmental pollutant. Despite being restrictions in-force for its utilization, it is widely being used in the production of polycarbonate plastics and epoxy resins. Direct, low-dose, and long-term exposure to BPA is expected when they are used in the packaging of food products and are used as containers for food consumption. Occupationally, workers are typically exposed to BPA at higher levels and for longer periods during the manufacturing process. BPA is a known endocrine disruptor chemical (EDC), that causes male infertility, which has a negative impact on human life from emotional, physical, and societal standpoints. To minimize the use of BPA in numerous consumer products, efforts and regulations are being made. Despite legislative limits in numerous nations, BPA is still found in consumer products. This paper examines BPA's overall male reproductive toxicity, including its impact on the hypothalamic-pituitary-testicular (HPT) axis, hormonal homeostasis, testicular steroidogenesis, sperm parameters, reproductive organs, and antioxidant defense system. Furthermore, this paper highlighted the role of non-monotonic dose-response (NMDR) in BPA exposure, which will help to improve the overall understanding of the harmful effects of BPA on the male reproductive system.

Effect of bromelain on sperm quality, testicular oxidative stress and expression of oestrogen receptors in bisphenol-A treated male mice

Bisphenol A (BPA) as an endocrine-disrupting chemical (EDC) with low estrogenic activity increases oxidative stress and testicular damage. Bromelain is a mixture of different thiol endopeptidases and other components with many uses as a natural anti-inflammatory enzyme. The present study aimed to evaluate the effect of bromelain on male reproductive failure induced by BPA. A total of 60 healthy adult male mice were randomly divided into six groups (n = 6), including control, bromelain (70 mg/kg), BPA (5 and 600 mg/kg), and BPA (5 and 600 mg/kg) + bromelain. BPA and bromelain were administrated orally for 35 days. Then, the epididymis and testes were removed to evaluate sperm parameters, oxidative stress markers, serum levels of testosterone concentrations, and oestrogen receptors expression. The BPA significantly (P < 0.05) decreased sperm count, motility, viability, and normal sperm morphology, as well as testosterone levels, oestrogen receptors alpha (ERα) and beta (ERβ), GPx, CAT, and SOD activity than control. Also, BPA significantly (P < 0.05) increased the sperm anomalies, and MDA concentration. Co-administration of bromelain + BPA caused a significantly (P < 0.05) increase sperm count, normal sperm morphology, testosterone levels, expression of ERα and ERβ, and GPx, CAT, and SOD activity than the BPA group (P < 0.05). Also, Bromelain significantly (P < 0.05) decreased sperm anomalies and MDA concentration than control. Based on the results of this study, it appears that BPA causes side effects on male reproduction. While, bromelain has the potential to reduce the side effects of BPA on the male reproductive system.

Dietary zinc deficient condition increases the Bisphenol A toxicity in diabetic rat testes

Bisphenol A (BPA) is a widely used endocrine disrupter that causes male reproductive dysfunction in humans and rodents. Diabetes-induced hyperglycemia alters spermatogenesis and antioxidant status, which negatively impacts male fertility in adults. Zinc (Zn) deficiency is a global health concern maintaining the testicular structure and functions in developing gonads. The present experiment was designed to investigate the role of Zn deficiency on BPA-induced germ cell and male gonadal toxicity in diabetic conditions. Rats were randomly divided into eight different groups - control (normal feed and water), BPA (10 mg/kg/day), ZDD (fed with a Zn-deficient diet), DIA (diabetic), BPA+ZDD, BPA+DIA, ZDD+DIA and BPA+ZDD+DIA for four weeks. Animals' body and organ weight, sperm count, motility and sperm morphology were examined; testes and epididymis histopathology were investigated. Testicular DNA damage and sperm apoptosis were evaluated by halo and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays respectively. Testicular catalase and octamer-binding transcription factor 4 (OCT4) expressions were evaluated by western blot analysis. The present results demonstrated that dietary Zn-deficient condition significantly increased the BPA-induced testicular, epididymal and sperm toxicity in diabetic rats due to hypogonadism, increased sperm abnormalities, epididymis, testicular structure and DNA damages, sperm apoptosis as well as decreased testicular catalase and OCT4 expressions. The present results revealed that dietary Zn-deficient condition exacerbated the BPA-induced testicular and epididymal toxicity as well as perturbed the general male reproductive health in diabetic rats.

Testicular toxicity of bisphenol compounds: Homeostasis disruption of cholesterol/testosterone via PPARα activation

The widespread application of bisphenols (BPs) has made them ubiquitous in the environment. Although the side effects of bisphenol A (BPA) substitutes have received increasing attention, studies on their reproductive toxicity remain lacking. In this research, the effects of BPA and its substitutes, including bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF), on the male reproductive system were evaluated. Results proved that these BPs disturbed germ cell proliferation, induced germ cell apoptosis, and perturbed sperm physiologies and spermatogenesis, which resulted from the disruption of testosterone (T) biosynthesis in Leydig cells (LCs). Importantly, in vitro and in vivo studies indicated that the exhausted cholesterol in LCs accounted for the reduced T production. Furthermore, the knockdown of peroxisome proliferator-activated receptor alpha (PPARα) remarkably ameliorated the downregulation of cholesterogenesis-related genes (i.e., Hmgcs1, Hmgcr, and Srebf2), indicating that PPARα played a critical role in BPs-induced testicular dysfunction. Overall, our studies indicated that BPS, BPF, and BPAF could induce testicular toxic effects similar to that of BPA, which were associated with the PPARα pathway.

The consequence and mechanism of dietary flavonoids on androgen profiles and disorders amelioration

Androgen is a kind of steroid hormone that plays a vital role in reproductive system and homeostasis of the body. Disrupted androgen balance serves as the causal contributor to a series of physiological disorders and even diseases. Flavonoids, as an extremely frequent family of natural polyphenols, exist widely in plants and foods and have received great attention when considering their inevitable consumption and estrogen-like effects. Mounting evidence illustrates that flavonoids have a propensity to interfere with androgen synthesis and metabolism, and also have a designated improvement effect on androgen disorders. Therefore, flavonoids were divided into six subclasses based on the structural feature in this paper, and the literature about their effects on androgens published in the past ten years was summarized. It could be concluded that flavonoids have the potential to regulate androgen levels and biological effects, mainly by interfering with the hypothalamic-pituitary-gonadal axis, androgen synthesis and metabolism, androgen binding with its receptors and membrane receptors, and antioxidant effects. The faced challenges about androgen regulation by flavonoids masterly include target mechanism exploration, individual heterogeneity, food matrixes interaction, and lack of clinical study. This review also provides a scientific basis for nutritional intervention using flavonoids to improve androgen disorder symptoms.

In vivo and in vitro short-term bisphenol A exposures disrupt testicular energy metabolism and negatively impact spermatogenesis in zebrafish

This study investigated the in vitro and short-term in vivo effects of Bisphenol A (BPA) on testicular energy metabolism and morphology in the zebrafish (Danio rerio). Testes were incubated in vitro for 1 h or fish were exposed in vivo to BPA in the tank water for 12 h. Testicular lactate, glycogen and cholesterol were measured and ¹⁴C-deoxy-d-glucose uptake and activity of lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. In addition, testis samples from the in vivo exposures were subject to digital analysis of testicular cells using Ilastik software and the Pixel Classification module and estimation of apoptosis by Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) immunohistochemical analysis. Our results from in vitro studies showed that BPA at 10 pM and 10 μM decreased testicular lactate content, glycogen content and LDH activity, but increased testicular AST activity. In addition, only BPA at 10 pM significantly decreased testicular ALT activity and cholesterol content. However, ¹⁴C-deoxy-d-glucose uptake was not changed. Furthermore, our results from in vivo studies showed that 10 pM BPA but not 10 μM BPA reduced testicular content of lactate and glycogen. In addition, both BPA concentrations decreased AST activity, whereas only BPA at 10 μM reduced ALT activity. However, LDH activity was not changed. Additionally, both concentrations of BPA induced spermatocyte apoptosis and a decrease in the proportion of the surface area of spermatids and spermatozoa. Collectively these data suggest that short-term BPA exposure affects energy metabolism and spermatogenesis in male zebrafish.

Impact of Sex and Age on the Mevalonate Pathway in the Brain: A Focus on Effects Induced by Maternal Exposure to Exogenous Compounds

The mevalonate pathway produces cholesterol and other compounds crucial for numerous cellular processes. It is well known that age and sex modulate this pathway in the liver. Recently, similar effects were also noted in different brain areas, suggesting that alterations of the mevalonate pathway are at the root of marked sex-specific disparities in some neurodevelopmental disorders related to disturbed cholesterol homeostasis. Here, we show how the mevalonate pathway is modulated in a sex-, age- and region-specific manner, and how maternal exposure to exogenous compounds can disturb the regulation of this pathway in the brain, possibly inducing functional alterations.

Zinc deficient diet increases the toxicity of bisphenol A in rat testis

Zinc (Zn) plays an important role in maintaining the process of spermatogenesis and reproductive health. Bisphenol A (BPA), an endocrine disrupting chemical is known to be a reproductive toxicant in different animal models. The present study was designed to study the effect of two of the utmost determinative factors (Zn deficient condition and influence of toxicant BPA) on germ cell growth and overall male reproductive health in the testis, epididymis, and sperm using (a) biochemical, (b) antioxidant, (c) cellular damage, (d) apoptosis, and (e) protein expression measurements. Rats were divided into Control (normal feed and water), BPA (100 mg/kg/d), zinc deficient diet (ZDD; fed with ZDD), and BPA + ZDD for 8 weeks. Body and organ weights, sperm motility and counts, and sperm head morphology were evaluated. The histology of testes, epididymides, and prostate was investigated. Testicular deoxyribonucleic acid (DNA) damage was evaluated by Halo and Comet assay, apoptosis of sperm and testes were quantified by TUNEL assay. Serum protein electrophoretic patterns and testicular protein expressions such as Nrf-2, catalase, PCNA, and Keap1 were analyzed by Western blot analysis. The results showed that BPA significantly increased the testicular, epididymal, and prostrate toxicity in dietary Zn deficient condition due to testicular hypozincemia, hypogonadism, increased cellular and DNA damage, apoptosis, as well as perturbations in protein expression.

Improvement of Testicular Steroidogenesis Using Flavonoids and Isoflavonoids for Prevention of Late-Onset Male Hypogonadism

Androgen production, being important for male fertility, is mainly accomplished by the Leydig cells from the interstitial compartment of the testis. Testosterone plays a critical role in testis development, normal masculinization, and the maintenance of spermatogenesis. Within seminiferous tubules, appropriate Sertoli cell function is highly dependent on testicular androgen levels and is essential to initiate and maintain spermatogenesis. During aging, testosterone production by the testicular Leydig cells declines from the 30s in humans at a rate of 1% per year. This review outlines the recent findings regarding the use of flavonoids and isoflavonoids to improve testosterone production, contributing to normal spermatogenesis and preventing age-related degenerative diseases associated with testosterone deficiency. With the cumulation of information on the actions of different flavonoids and isoflavonoids on steroidogenesis in Leydig cells, we can now draw conclusions regarding the structure-activity relationship on androgen production. Indeed, flavonoids having a 5,7-dihydroxychromen-4-one backbone tend to increase the expression of the steroidogenic acute regulatory protein (StAR), being critical for the entry of cholesterol into the mitochondria, leading to increased testosterone production from testis Leydig cells. Therefore, flavonoids and isoflavonoids such as chrysin, apigenin, luteolin, quercetin, and daidzein may be effective in delaying the initiation of late-onset hypogonadism associated with aging in males.

The influence of polyphenols on metabolic disorders caused by compounds released from plastics - Review

Persistent organic pollutants (POPs) released from plastics into water, soil and air are significant environmental and health problem. Continuous exposure of humans to these substances results not only from the slow biodegradation of plastics but also from their ubiquitous use as industrial materials and everyday products. Exposure to POPs may lead to neurodegenerative disorders, induce inflammation, hepatotoxicity, nephrotoxicity, insulin resistance, allergies, metabolic diseases, and carcinogenesis. This has spurred an increasing intense search for natural compounds with protective effects against the harmful components of plastics. In this paper, we discuss the current state of knowledge concerning the protective functions of polyphenols against the toxic effects of POPs: acrylonitrile, polychlorinated biphenyls, dioxins, phthalates and bisphenol A. We review in detail papers from the last two decades, analyzing POPs in terms of their sources of exposure and demonstrate how polyphenols may be used to counteract the harmful environmental effects of POPs. The protective effect of polyphenols results from their impact on the level and activity of the components of the antioxidant system, enzymes involved in the elimination of xenobiotics, and as a consequence - on the level of reactive oxygen species (ROS). Polyphenols present in daily diet may play a protective role against the harmful effects of POPs derived from plastics, and this interaction is related, among others, to the antioxidant properties of these compounds. To our knowledge, this is the first extensive review of in vitro and in vivo studies concerning the molecular mechanisms of interactions between selected environmental toxins and polyphenols.

In silico and in vitro studies to elucidate the role of 1HYN and 1QKI activity in BPA induced toxicity and its amelioration by Gallic acid

Bisphenol A (BPA) is well known as an artificial environmental endocrine disrupting (ED) chemical. BPA also leads to many deleterious impacts on human blood through the production of reactive oxygen species and by some unknown mechanism. Up to now, very few studies have been conducted to assess the impact of BPA on Red Blood Corpuscle (RBC), Complete Blood Count (CBC), and no study on 1HYN (Erythrocyte Band 3 membrane protein) and 1QKI (Human Glucose 6 Phosphate Dehydrogenase) have been so far carried out. Besides, no study has been conducted to assess the ameliorating impact of the most commonly available antioxidant like Gallic Acid (GA). The present investigation revealed that BPA exposure (50-200  μg ml^-1) causes significant increase in percent hemolysis and morphological alteration of RBC, as well as significant reduction in CBC except White Blood Cell (WBC), Platelet, and Red blood density width (RDW). BPA exposure also caused a significant reduction in G6PD activity. In silico docking study revealed that BPA effectively binds with 1HYN and 1QKI protein to alter its activity. Concurrent addition of GA (10-50  μg ml^-1) with highest dose of BPA (200  μg ml^-1) ameliorates all parameters significantly as compared to BPA (200  μg ml^-1) treatment. Ameliorating effect of GA is mainly due to its antioxidant property and interaction with BPA, was confirmed using UV-VIS-NIR Spectrophotometric, molecular dynamic simulation and docking approach by YASARA software.

Effects of Bisphenols on Testicular Steroidogenesis

Over the last decades, the adverse effects of human exposure to the so-called "endocrine disruptors" have been a matter of scientific debate and public attention. Bisphenols are synthetic chemicals, widely used in the manufacture of hard plastic products. Bisphenol A (BPA) is one of the best-known environmental toxicants proven to alter the reproductive function in men and to cause other health problems. Consumer concern resulted in "BPA free" products and in the development of bisphenol analogs (BPA-A) to replace BPA in many applications. However, these other bisphenol derivatives seem to have effects similar to those of BPA. Although a number of reviews have summarized the effects of BPA on human reproduction, the purpose of this article is to review the effects of bisphenols on testicular steroidogenesis and to explore their mechanisms of action. Testicular steroidogenesis is a fine-regulated process, and its main product, testosterone (T), has a crucial role in fetal development and maturation and in adulthood for the maintenance of secondary sexual function and spermatogenesis. Contradictory outcomes of both human and animal studies on the effects of BPA on steroid hormone levels may be related to various factors that include study design, dosage of BPA used in in vitro studies, timing and route of exposure, and other confounding factors. We described the main possible molecular target of bisphenols on this complex pathway. We report that Leydig cells (LCs), the steroidogenic testicular component, are highly sensitive to BPA and several mechanisms concur to the functional impairment of these cells.