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

Products of Bisphenol A Degradation Induce Cytotoxicity in Human Erythrocytes (In Vitro)

The aim of this work has been to study the possible degradation path of BPA under the Fenton reaction, namely to determine the energetically favorable intermediate products and to compare the cytotoxicity of BPA and its intermediate products of degradation. The DFT calculations of the Gibbs free energy at M06-2X/6-311G(d,p) level of theory showed that the formation of hydroquinone was the most energetically favorable path in a water environment. To explore the cytotoxicity the erythrocytes were incubated with BPA and three intermediate products of its degradation, i.e., phenol, hydroquinone and 4-isopropylphenol, in the concentrations 5-200 μg/mL, for 1, 4 and 24 h. BPA induced the strongest hemolytic changes in erythrocytes, followed by hydroquinone, phenol and 4-isopropylphenol. In the presence of hydroquinone, the highest level of RONS was observed, whereas BPA had the weakest effect on RONS generation. In addition, hydroquinone decreased the level of GSH the most. Generally, our results suggest that a preferable BPA degradation path under a Fenton reaction should be controlled in order to avoid the formation of hydroquinone. This is applicable to the degradation of BPA during waste water treatment and during chemical degradation in sea water.

Impact of Bisphenol A on Structure and Function of Mitochondria: A Critical Review

Bisphenol A (BPA) is an industrial chemical used extensively to manufacture polycarbonate plastics and epoxy resins. Because of its estrogen-mimicking properties, BPA acts as an endocrine-disrupting chemical. It has gained attention due to its high chances of daily and constant human exposure, bioaccumulation, and the ability to cause cellular toxicities and diseases at extremely low doses. Several elegant studies have shown that BPA can exert cellular toxicities by interfering with the structure and function of mitochondria, leading to mitochondrial dysfunction. Exposure to BPA results in oxidative stress and alterations in mitochondrial DNA (mtDNA), mitochondrial biogenesis, bioenergetics, mitochondrial membrane potential (MMP) decline, mitophagy, and apoptosis. Accumulation of reactive oxygen species (ROS) in conjunction with oxidative damage may be responsible for causing BPA-mediated cellular toxicity. Thus, several reports have suggested using antioxidant treatment to mitigate the toxicological effects of BPA. The present literature review emphasizes the adverse effects of BPA on mitochondria, with a comprehensive note on the molecular aspects of the structural and functional alterations in mitochondria in response to BPA exposure. The review also confers the possible approaches to alleviate BPA-mediated oxidative damage and the existing knowledge gaps in this emerging area of research.

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.

Boswellic acid protects against Bisphenol-A and gamma radiation induced hepatic steatosis and cardiac remodelling in rats: role of hepatic PPAR-α/P38 and cardiac Calcineurin-A/NFATc1/P38 pathways

Bisphenol-A (BPA) and gamma-radiation are two risky environmental pollutants that human beings are exposed to in everyday life and consequently they threaten human health via inducing oxidative stress, inflammation, and eventually tissue damage. This study aims at appraising the protective effect of Boswellic Acid (BA) (250 mg/kg/day, orally) administration on BPA (150 mg/kg/day, i.p) and γ-irradiation (IR) (3 Gy/week for 4 weeks up to cumulative dose of 12 Gy/experimental course) for 4 weeks-induced damage to liver and heart tissues of rats. The present results indicated a significant improvement against damage induced by BPA and IR revealed in biochemical investigations (hepatic PPAR-α/P38 and cardiac ET-1/Calcineurin-A/NFATc1/P38) and histopathological examination of liver and heart. It could be concluded that BA possesses a protective effect against these two deleterious environmental pollutants which attracted major global concerns due to their serious toxicological impact on human health.

Does ( -)-epigallocatechin-3-gallate protect the neurotoxicity induced by bisphenol A in vivo?

Bisphenol A (BPA) is one of the chemicals that is firmly accompanied by hippocampal neuronal injury. As oxidative stress appears to be a major contributor to neurotoxicity induced by BPA, antioxidants with remarkable neuroprotective effects can play a valuable protective role. Around the world, ( -)-epigallocatechin-3-gallate (EGCG) was one of the most popular antioxidants that could exert a beneficial neuroprotective role. Here, we examined the potential efficiency of EGCG against neurotoxicity induced by BPA in the hippocampal CA3 region of the rat model. This study revealed that EGCG was unable to abrogate the significant decrease in circulating adiponectin level and hippocampal superoxide dismutase activity as well as an increase in hippocampal levels of nitric oxide and malondialdehyde. Notably, EGCG failed to antagonize the oxidative inhibitory effect of BPA on hippocampal neurotransmission and its associated cognitive deficits. In addition, the histopathological examination with immunohistochemical detection of caspase-3 and NF-kB/p65 emphasized that EGCG failed to protect hippocampal CA3 neurons from apoptotic and necrotic effects induced by BPA. Our study revealed that EGCG showed no protective role against the neurotoxic effect caused by BPA, which may be attributed to its failure to counteract the BPA-induced oxidative stress in vivo. The controversial effect is probably related to EGCG's ability to impede BPA glucuronidation and thus, its detoxification. That inference requires further additional experimental and clinical studies.

Role of dietary selenium in alleviating bisphenol A toxicity of liver albino rats: Histological, ultrastructural, and biomarker assessments

Bisphenol A (BPA) is used as a plasticizer in polycarbonate plastics. It has been used in consumer products and epoxy resins for decades as protective coatings and linings for food and beverage bottles. This can trigger human reactions to BPA which interferes with estrogen receptors. Our study explored the ameliorative effects of selenium (Se) in male rats on liver damage caused by BPA. Rats were divided into four groups at random: The first one obtained olive oil and acted as a control. Se (0.5 mg/kg diet) was given for the second group. The third one was treated with BPA (10 mg/kg body weight/day) orally. Concomitantly Se (0.5 mg/kg diet) and BPA (10 mg/kg body weight/day) were given orally in the fourth one. Liver specimens were prepared for light, electron microscopes and the serum samples were screened for biochemical markers. In the BPA received group, histological findings indicated apoptotic hepatic histological changes such as sinusoidal congestion, cytoplasmic vacuolation and leukocyte infiltration. Ultrastructurally, the same group had mitochondrial degeneration, rough endoplasmic reticulum swelling, and nuclear pyknosis, as well as fat droplet deposition and lysosome enhancement. Liver enzymes: In the BPA group, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) have been substantially increased. Moreover, histological and ultrastructural improvements were seen in the rat population treated with BPA and Se, whereas ALT and AST levels were lowered and malondialdehyde (MDA), glutathione peroxidase (GPx), human C reactive protein (hCRP), and the serum levels of interleukin-6 (IL-6) were significantly modulated. PRACTICAL APPLICATIONS: Bisphenol A (BPA) is used in the manufacturing of polycarbonate plastic (e.g., water bottles, baby bottles) and epoxy resins (e.g., inner coating in metallic food cans). It is a non-polymer preservative for other plastics, one of the contaminants of the atmosphere and a common endocrine estrogenic disruptor. Our study explored the ameliorative effects of selenium (Se) in male rats on liver damage caused by BPA. Rats were divided into four groups at random: The first one obtained olive oil and acted as a control. Se (0.5 mg/kg diet) was given for the second group. The third one was treated with BPA (10 mg/kg body weight/day) orally. Concomitant Se (0.5 mg/kg diet) and BPA (10 mg/kg body weight/day) were given in the fourth one. Liver specimens were prepared for light, electron microscopes and the serum samples were screened for biochemical markers.

Ion-Trap Mass Spectrometric Analysis of Bisphenol A Interactions With Titanium Dioxide Nanoparticles and Milk Proteins

Quantitative analysis of endocrine-disrupting molecules such as bisphenol A (BPA) in freshwater to determine their widespread occurrence in environmental resources has been challenged by various adsorption and desorption processes. In this work, ion trap mass spectrometry (ITMS) analysis of BPA was aimed at studying its molecular interactions with titanium dioxide (TiO2) nanoparticles and milk whey proteins. Addition of sodium formate prevented TiO2 nanoparticles from sedimentation while enhancing the electrospray ionization (ESI) efficiency to produce an abundance of [BPA + Na]+ ions at m/z 251.0. More importantly, the ESI-ITMS instrument could operate properly during a direct infusion of nanoparticles up to 500 μg/mL without clogging the intake capillary. Milk protein adsorption of BPA could decrease the [BPA + Na]+ peak intensity significantly unless the proteins were partially removed by curdling to produce whey, which allowed BPA desorption during ESI for quantitative analysis by ITMS.

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.

Hydrothermal synthesis of NiFe2O4 nanoparticles as an efficient electrocatalyst for the electrochemical detection of bisphenol A

In this study, the sensitive and selective detection of bisphenol A (BPA) was achieved using a screen-printed carbon electrode (NFO/SPCE) modified with hydrothermally synthesized NiFe₂O₄ nanoparticles.

Bisphenol A-induced oxidative damage in the hepatic and cardiac tissues of rats: The modulatory role of sesame lignans

Bisphenol A (BPA) is an environmental pollutant that is widely produced throughout the world. It is primarily used in the manufacture of polycarbonate plastics, epoxy resins, paints and dental materials. BPA has been reported to promote hepatotoxicity and cardiotoxicity. The antioxidant activity of sesame lignans is well established. The current study assessed the protective efficiency of sesame lignans against BPA-induced hepatotoxicity and cardiotoxicity. Rats were divided into 4 groups: A control group, a BPA-treated group, a sesame lignans-treated group and a sesame lignans and BPA-treated group. Rats were orally administered their respective doses daily [30 mg/kg body weight (BW) BPA and/or 20 mg/kg BW sesame lignans] for 6 weeks. Liver function tests were performed using serum of all groups. Lipid profile and antioxidant status were also measured in liver tissue of the studied groups. The results were confirmed by histopathological examination of liver and heart tissues. The oral administration of BPA was revealed to elicit significant decreases in the activities of hepatic glutathione peroxidase, glutathione reductase, superoxide dismutase and glutathione. It also significantly increased levels of malondialdehyde. Furthermore, BPA-treatment resulted in lipid accumulation, elevated activities of alanine aminotransferase, creatine kinase MB and lactate dehydrogenase, and histological changes of liver and heart tissues. However, the co-administration of sesame lignans and BPA attenuated hepatotoxicity, cardiotoxicity and BPA-induced histological changes. The results of the current study indicated that sesame lignans may be helpful in the development of novel natural drugs to treat hepatic and cardiovascular disorders.

Comparative analysis of BPA and HQ toxic impacts on human erythrocytes, protective effect mechanism of tannins (Rhus typhina)

Several studies reported that bisphenol A (BPA) and its metabolite hydroquinone (HQ) have adverse effects on human and animal health. In this work, a comparative study of influence of the BPA and HQ, environment pollutants, on human erythrocytes was carried out. It was shown that BPA and HQ to varying extents caused oxidative damage in human erythrocytes: hemolysis, decreased GSH level, and methemoglobin formation. It was demonstrated that hydrolysable tannins 3,6-bis-O-di-O-galloyl-1,2,4-tri-O-galloyl-β-D-glucose (C₅₅H₄₀O₃₄) and 1,2,3,4,6-penta-O-galloyl-β-D-glucose (C₄₁H₃₂O₂₆) (PGG) isolated from the Rhus typhina L. leaves in the range of 1-50 μM concentrations inhibited hemolysis and methemoglobin formation and also increased intracellular reduced glutathione in erythrocytes treated with BPA or HQ. It was revealed by electron paramagnetic resonance (EPR) using 5-doxyl-stearic acid (5-DS) that C₅₅H₄₀O₃₄ and C₄₁H₃₂O₂₆ increased the rigidity of erythrocyte membranes at the depth of 5th carbon atom of the fatty acid hydrocarbon chain. Taken together, these results allow to conclude that tannins from the Rhus typhina L. leaves protect erythrocytes from oxidative stress caused by BPA or HQ both due to their antioxidant activity as well as their interaction with the erythrocyte membrane components.

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

Bisphenol A (BPA), a phenyl ring containing synthetic xenoestrogen, is widely used in the manufacture of polycarbonate plastics, epoxy resins and as a non-polymer additive to other plastics. Food is considered as the main source of exposure to BPA as it leaches out from food containers as well as surface coatings. It causes toxicity in the liver, kidney, brain, and other organs by initiating the process of lipid peroxidation. The present investigation was an attempt to evaluate the effect of BPA on steroidogenesis and its amelioration by quercetin. Inbred Swiss strain male albino mice were orally administered with 80, 120 and 240 mg per kg body weight per day of BPA for 45 days. The results revealed that BPA causes significant (p < 0.05) and dose-dependent changes in the body weight and biochemical parameters like protein, cholesterol and lipid contents as well as activities of 3β-and 17β-hydroxysteroid dehydrogenases in the testis of mice. It was also found to significantly reduce the testosterone level in serum. Oral administration of quercetin (30, 60 and 90 mg per kg body weight per day) along with a high dose of BPA (240 mg per kg body weight per day) for 45 days caused significant amelioration in the body weight and steroidogenesis as compared to the BPA alone treated group. The effect was dose-dependent. This amelioration in BPA-induced toxicity might be due to the antioxidative properties of quercetin. The reduction in the function of enzymes was confirmed by in silico bindings. BPA and quercetin show competitive binding with steroidogenic enzymes as well as binding with each other. This could be a possible mechanism to reduce the toxic effect of BPA which has been supported by molecular dynamics simulations for molecular level recognition with structural insights.

Protective effects of silymarin against bisphenol A-induced hepatotoxicity in mouse liver

Bisphenol A (BPA) is an endocrine-disrupting chemical released into the environment, with severe consequences for human health, including metabolic syndrome and associated pathological conditions. Due to limited information on BPA-induced hepatotoxicity, the present study focused on investigating the association between BPA-induced toxicity and inflammatory markers in the liver, and how these injuries may be alleviated using the natural agent silymarin, a flavonoid with antioxidant properties obtained from Silybum marianum. Administration of BPA to male CD-1 mice for 10 days caused a significant increase in the number of cells immunopositive for interleukin 6 and tumor necrosis factor-α, pro-inflammatory cytokines that mediate the hepatic inflammatory response. Treatment with 200 mg/kg of silymarin concurrently with BPA for 10 days resulted in a diminished level of pro-inflammatory cytokines and in significantly reduced ultrastructural injuries. Additionally, silymarin was able to restore the significantly decreased glycogen deposits observed following BPA exposure to normal levels, thus favoring hepatic glycogenesis. This study represents the first report of silymarin ability to reduce hepatic lesions and to counteract inflammation caused by BPA in mice. A dose of 200 mg/kg silymarin was sufficient to induce a protective effect against structural and ultrastructural injuries induced by BPA and to lower the levels of pro-inflammatory cytokines observed in murine liver tissue following exposure to BPA.

Eryptosis-inducing activity of bisphenol A and its analogs in human red blood cells (in vitro study)

Bisphenols are important chemicals that are widely used in the manufacturing of polycarbonates, epoxy resin and thermal paper, and thus the exposure of humans to these substances has been noted. The purpose of this study was to assess eryptotic changes in human erythrocytes exposed (in vitro) to bisphenol A (BPA) and its selected analogs, i.e.,bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF). The erythrocytes were incubated with compounds studied at concentrations ranging from 1 to 250μg/mL for 4, 12 or 24h. The results showed that BPA and its analogs increased cytosolic calcium ions level with the strongest effect noted for BPAF. It has also been revealed that all bisphenols analyzed, and BPAF and BPF in particular increased phosphatidylserine translocation in red blood cells, which confirmed that they exhibited eryptotic potential in this cell type. Furthermore, it was shown that BPA and its analogs caused significant increase in calpain and caspase-3 activities, while the strongest effect was noted for BPAF. BPS, which is the main substituent of bisphenol A in polymers and thermal paper production exhibited similar eryptotic potential to BPA. Eryptotic changes in human erythrocytes were provoked by bisphenols at concentrations, which may influence the human body during occupational exposure or subacute poisoning with these compounds.

Comparative study of the effect of BPA and its selected analogues on hemoglobin oxidation, morphological alterations and hemolytic changes in human erythrocytes

Bisphenol A (BPA) has been shown to provoke many deleterious impacts on human health, and thus it is now successively substituted by BPA analogues, whose effects have been poorly investigated. Up to now, only one study has been realized to assess the effect of BPA on human erythrocytes, which showed its significant hemolytic and oxidative potential. Moreover, no study has been conducted to evaluate the effect of BPA analogues on red blood cells. The purpose of the present study was to compare the impact of BPA and its selected analogues such as bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF) on hemolytic and morphological changes and hemoglobin oxidation (methemoglobin formation) of human erythrocytes. The erythrocytes were incubated with different bisphenols concentrations ranging from 0.5 to 500μg/ml for 1, 4 and 24h. The compounds examined caused hemolysis in human erythrocytes with BPAF exhibiting the strongest effect. All bisphenols examined caused methemoglobin formation with BPA inducing the strongest oxidative potential. Flow cytometry analysis showed that all bisphenols (excluding BPS) induced significant changes in erythrocytes size. Changes in red blood cells shape were conducted using phase contrast microscopy. It was noticed that BPA and BPAF induced echinocytosis, BPF caused stomatocytosis, while BPS did not provoke significant changes in shape of red blood cells. Generally, the results showed that BPS, which is the main substituent of bisphenol A in polymers and thermal paper production, exhibited significantly lower disturbance of erythrocyte functions than BPA.

Activation of Autophagic Flux against Xenoestrogen Bisphenol-A-induced Hippocampal Neurodegeneration via AMP kinase (AMPK)/Mammalian Target of Rapamycin (mTOR) Pathways

The human health hazards related to persisting use of bisphenol-A (BPA) are well documented. BPA-induced neurotoxicity occurs with the generation of oxidative stress, neurodegeneration, and cognitive dysfunctions. However, the cellular and molecular mechanism(s) of the effects of BPA on autophagy and association with oxidative stress and apoptosis are still elusive. We observed that BPA exposure during the early postnatal period enhanced the expression and the levels of autophagy genes/proteins. BPA treatment in the presence of bafilomycin A1 increased the levels of LC3-II and SQSTM1 and also potentiated GFP-LC3 puncta index in GFP-LC3-transfected hippocampal neural stem cell-derived neurons. BPA-induced generation of reactive oxygen species and apoptosis were mitigated by a pharmacological activator of autophagy (rapamycin). Pharmacological (wortmannin and bafilomycin A1) and genetic (beclin siRNA) inhibition of autophagy aggravated BPA neurotoxicity. Activation of autophagy against BPA resulted in intracellular energy sensor AMP kinase (AMPK) activation, increased phosphorylation of raptor and acetyl-CoA carboxylase, and decreased phosphorylation of ULK1 (Ser-757), and silencing of AMPK exacerbated BPA neurotoxicity. Conversely, BPA exposure down-regulated the mammalian target of rapamycin (mTOR) pathway by phosphorylation of raptor as a transient cell's compensatory mechanism to preserve cellular energy pool. Moreover, silencing of mTOR enhanced autophagy, which further alleviated BPA-induced reactive oxygen species generation and apoptosis. BPA-mediated neurotoxicity also resulted in mitochondrial loss, bioenergetic deficits, and increased PARKIN mitochondrial translocation, suggesting enhanced mitophagy. These results suggest implication of autophagy against BPA-mediated neurodegeneration through involvement of AMPK and mTOR pathways. Hence, autophagy, which arbitrates cell survival and demise during stress conditions, requires further assessment to be established as a biomarker of xenoestrogen exposure.