The effects of bisphenol A on some plasma cytokine levels and distribution of CD8+ and CD4+ T lymphocytes in spleen, ileal Peyer's patch and bronchus associated lymphoid tissue in rats

Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs

In 2015, EFSA established a temporary tolerable daily intake (t-TDI) for BPA of 4 μg/kg body weight (bw) per day. In 2016, the European Commission mandated EFSA to re-evaluate the risks to public health from the presence of BPA in foodstuffs and to establish a tolerable daily intake (TDI). For this re-evaluation, a pre-established protocol was used that had undergone public consultation. The CEP Panel concluded that it is Unlikely to Very Unlikely that BPA presents a genotoxic hazard through a direct mechanism. Taking into consideration the evidence from animal data and support from human observational studies, the immune system was identified as most sensitive to BPA exposure. An effect on Th17 cells in mice was identified as the critical effect; these cells are pivotal in cellular immune mechanisms and involved in the development of inflammatory conditions, including autoimmunity and lung inflammation. A reference point (RP) of 8.2 ng/kg bw per day, expressed as human equivalent dose, was identified for the critical effect. Uncertainty analysis assessed a probability of 57-73% that the lowest estimated Benchmark Dose (BMD) for other health effects was below the RP based on Th17 cells. In view of this, the CEP Panel judged that an additional uncertainty factor (UF) of 2 was needed for establishing the TDI. Applying an overall UF of 50 to the RP, a TDI of 0.2 ng BPA/kg bw per day was established. Comparison of this TDI with the dietary exposure estimates from the 2015 EFSA opinion showed that both the mean and the 95th percentile dietary exposures in all age groups exceeded the TDI by two to three orders of magnitude. Even considering the uncertainty in the exposure assessment, the exceedance being so large, the CEP Panel concluded that there is a health concern from dietary BPA exposure.

Therapeutic potential of vitamin D against bisphenol A-induced spleen injury in Swiss albino mice

Bisphenol A (BPA), a ubiquitous plasticizer, is capable of producing oxidative splenic injury, and ultimately led to spleen pathology. Further, a link between VitD levels and oxidative stress was reported. Hence the role of VitD in BPA-induced oxidative splenic injury was investigated in this study. Sixty male and female Swiss albino mice (3.5 weeks old) were randomly divided into control and treated groups 12 mice in each (six males and six females). The control groups were further divided into sham (no treatment) and vehicle (sterile corn oil), whereas the treatment group was divided into VitD (2,195 IU/kg), BPA (50 μg/kg), and BPA+VitD (50 μg/kg + 2,195 IU/kg) groups. For six weeks, the animals were dosed intraperitoneally (i.p). One week later, at 10.5 weeks old, mice were sacrificed for biochemical and histological analyses. Findings showed BPA triggered neurobehavioral abnormalities and spleen injury with increased apoptotic indices (e.g. DNA fragmentation) in both sexes. A significant increase was found in lipid peroxidation marker, MDA in splenic tissue, and leukocytosis. Conversely, VitD treatment altered this scenario into motor performance preservation, reducing oxidative splenic injury with a decrease in the percent apoptotic index. This protection was significantly correlated with preserving leukocyte counts and reduced MDA levels in both genders. It can be concluded from the above findings that VitD treatment has an ameliorative effect on oxidative splenic injury induced by BPA, highlighting the continuous crosstalk between oxidative stress and the VitD signaling pathway.

The determination of the effect of in ovo administered monosodium glutamate on the embryonic development of thymus and bursa of Fabricius and percentages of alpha-naphthyl acetate esterase positive lymphocyte in chicken

Monosodium glutamate (MSG) is a flavor enhancer commonly used in modern nutrition. In this study, it was aimed to determine the effect of in ovo administered MSG on the embryonic development of thymus, bursa of Fabricius, and percentages of alpha-naphthyl acetate esterase (ANAE) positive lymphocyte by using histological, histometrical, and enzyme histochemical methods in chickens. For this purpose, 410 fertile eggs were used. The eggs were then divided into five groups: group 1 (control group, n = 40 eggs), group 2 (distilled water-injected group, n = 62 eggs), group 3 (0.12 mg/g egg MSG-injected group, n = 80 eggs), group 4 (0.6 mg/g egg MSG-injected group, n = 90 eggs), and group 5 (1.2 mg/g egg MSG-injected group, n = 138 eggs), and injections were performed via the egg yolk. On the 18th and 21st days of the incubation, the eggs were randomly opened from each group until six live embryos were obtained. The embryos of each group were sacrificed by decapitation, and blood, thymus, and bursa of Fabricius tissue samples were taken from the obtained embryos. The MSG-treated groups were found to be retarded embryonic development of thymus and bursa of Fabricius tissue compared to the control and distilled water groups. MSG treatment also resulted in reduced lymphoid follicles count and follicle diameters in bursa of Fabricius (P < 0.05). The percentage of peripheral blood ANAE positive lymphocytes was significantly lower in the MSG-treated groups than in the control and distilled water groups (P < 0.05). In conclusion, it has been found that in ovo administered MSG can adversely affect the embryonic development of thymus and bursa of Fabricius and decrease percentage of ANAE positive lymphocyte.

1,8-cineole alleviates bisphenol A-induced apoptosis and necroptosis in bursa of Fabricius in chicken through regulating oxidative stress and PI3K/AKT pathway

Bisphenol A (BPA), an important chemical raw material, is now a ubiquitous environmental contaminant. As an endocrine disruptor similar to estrogen, BPA increases the risk of various metabolic and chronic diseases. BPA has immunotoxicity to humans and animals. 1,8-cineole (CIN) is a plant-derived monoterpene with antioxidant and antiapoptosis actions. However, there are no reports about whether CIN could antagonize the BPA-induced apoptosis and necroptosis in bursa of Fabricius (BF) of chicken. This study was to elucidate the ameliorative mechanism of CIN on the apoptosis and necroptosis in BF induced by BPA. 120 broilers (1-day-old) were randomly divided into four groups: control group, CIN group, CIN and BPA co-treatment group, and BPA group. TUNEL analysis results, histopathological variations, and the overexpression of proapoptosis biomakers (Caspase 3, Bax, Cyt-c, and p53) and necroptosis pathway-related factors (RIPK1, RIPK3, MLKL, and FADD) indicated that BPA exposure induced the apoptosis and necroptosis in chicken BF. Moreover, BPA treatment elevated the levels of oxidative stress indexes (MDA, iNOS, and NO) and weaken antioxidases activity (SOD, GPx, and CAT) and total antioxidant capacity in chicken BF. BPA administration also lessened the expression of PI3K and AKT and promoted HSPs (HSP27, HSP40, HSP60, and HSP70) activation. whereas CIN supplementation prominently mitigated BPA-caused these changes and the apoptosis and necroptosis damages. In brief, this study illuminated that CIN could protect the chicken BF against BPA-induced apoptosis and necroptosis through restraining oxidative stress and activating PI3K/AKT pathway.

The effects of bisphenol A given in ovo on bursa of Fabricius development and percentage of acid phosphatase positive lymphocyte in chicken

Bisphenol A (BPA), one of the endocrine disrupting chemicals, is the object of great concern because of its widespread use throughout the world. In this study, it was aimed to determine the effects of in ovo administrated BPA on the bursa of Fabricius and percentage of acid phosphatase positive lymphocyte in peripheral blood by means of histological and enzyme histochemical methods. For this purpose, 310 fertile eggs of Isa Brown laying parent stock were used. The eggs were divided into 5 groups as control, vehicle control, 50, 100, and 250μg/egg BPA. At days 13, 18, and 21 of incubation, eggs were opened until 10 living embryos were obtained from each group. Tissue samples were taken from the obtained embryos and processed for enzyme histochemical methods in addition to routine histological techniques. It was observed that, in BPA-treated groups, embryonic development of bursa of Fabricius was retarded. It was also indicated that the percentage of peripheral blood ACP-ase positive lymphocytes was significantly decreased. These results suggested that a limited maternal transfer of BPA into the eggs might be lead to immunosuppression in chicks.

Vitamin D mitigates adult onset diseases in male and female mice induced by early-life exposure to endocrine disruptor BPA

Background

During early development, environmental compounds can induce adult onset diseases and disrupt the circulating vitamin D (VitD) levels.

Aim

This study aimed to examine the protective role of VitD against the adverse effects of BPA on male and female mice.

Methods

A total of 60 male and female Swiss Albino mice (3 weeks old) were randomly divided into 5 groups; each consisted of 12 mice (6 males and 6 females) and was treated as follows: Group I received no treatment (sham control); Group II, sterile corn oil only (vehicle control); Group III, BPA (400 μg/kg); Group IV, VitD (2,195 IU/kg); and Group V, BPA + VitD. At 10.5 weeks, the animals were sacrificed to conduct histological examinations.

Results

BPA-exposed mice were found to have neurobehavioral abnormalities, heart, kidney, and lung diseases with increased apoptotic indices in both sexes. On the other hand, the treatment of BPA mice with VitD altered this scenario with modulated motor activity, enhanced body and organ weights, and preserved the heart, kidney, and lung architecture, alongside a decreased percent apoptotic index.

Conclusion

Our findings illustrate that VitD protects mice against BPA-induced heart, kidney, and lung abnormalities.

The effects of in ovo administered bisphenol A on tibial growth plate histology in chicken

OBJECTIVES

The aim of this study was to determine of the effects of in ovo administered BPA on embryonic development of the tibial growth plate using histological methods in chickens.

METHODS

Three hundred and ten fertile eggs of Isa Brown laying parent stock were divided into five groups as untreated control, vehicle-injected control, 50, 100, and 250 μg/egg BPA. At the 13th, 18th, and 21st days of incubation, eggs were randomly opened from each group until 10 live embryos were obtained. Embryos were weighed and crown-rump length was measured. Tibial tissue samples were taken from embryos. Tibia weight, relative tibia weight and tibia length were determined. Tissue samples were fixed in 10% buffered formalin solution. Sections were stained with Safranin O staining methods and zones in the growth plate were measured. Also, proliferating cell nuclear antigen (PCNA) was stained immunohistochemically.

RESULTS

The mortality in the BPA treated groups was higher than untreated control group. The results have revealed that mean relative embryo weights, crown-rump length, mean tibia weight, relative tibia weight, and tibia length of BPA treated groups were significantly lower when compared to the untreated control and vehicle-injected control groups. Also, proliferative zone get significantly narrowed, whereas the transitional and hypertrophic zone thickened and PCNA positive chondrocytes increased in growth plate of BPA treated groups.

CONCLUSION

These results have suggested that developmental exposure to BPA adversely affected development of the tibial growth plate.

Physiological and metabolic approach of plastic additive effects: Immune cells responses

Human and wildlife are continually exposed to a wide range of compounds and substances, which reach the body through the air, water, food, or personal care products. Plasticizers are compounds added to plastics and can be released to the environment under certain conditions. Toxicological studies have concluded that plasticizers, phthalates, and bisphenols are endocrine disruptors, alter the endocrine system and functioning of the immune system and metabolic process. A functional immune response indicates favourable living conditions for an organism; conversely, a weak immune response could reveal a degraded environment that requires organisms to adapt. There is growing concern about the presence of plastic debris in the environment. In this review, the current knowledge of the action of plasticizers on leukocyte cells will be itemized. We also point out critically the role of some nuclear and membrane receptors as key players in the action of plasticizers on cells possess immune function. We discuss the role of erythrocytes within the immune responses and the alteration caused by plasticizers. Finally, we highlight data evidencing mitochondrial dysfunctions triggered by plasticizing toxic action, which can lead to immunosuppression.

Pre-activation with TLR7 in combination with thioridazine and loratadine promotes tumoricidal T-cell activity in colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy worldwide. Our previous studies have shown that combinatorial treatment with thioridazine and loratadine may effectively inhibit CRC. However, the translation of these research findings to clinical practice was impaired by issues related to a lack of therapeutic specificity and to immune evasion. Toll-like receptor (TLR) agonists have been used as adjuvants to enhance the effectiveness of cancer vaccines. The aim of this study was to evaluate the therapeutic efficiency of immunotherapy with thioridazine and loratadine in combination with resiqumiod (R848), a small-molecule TLR7 agonist, in suppressing CRC growth in a mouse model. Twenty-four BALB/c mice were randomly assigned to treatment with PBS, R848, thioridazine + loratadine, or thioridazine + loratadine + R848. Cytokine levels were measured with ELISA. Overall survival, as well as tumor volume and tumor weight, was recorded. Cytotoxicity was measured by counting the numbers of CD8 and CD3-positive (CD8CD3) or CD4 and CD3-positive (CD3CD4) T-cells. The immune response induced by cytokines (as interferon-γ, interleukin-6, and tumor necrosis factor-α) was significantly stronger in mice treated with thioridazine + loratadine + R848. Moreover, thioridazine + loratadine + R848 significantly delayed tumor development and prolonged survival, which was associated with enhanced immune response and dendritic cell maturation. This study suggested that thioridazine + loratadine + R848 combinatorial treatment may be effective in overcoming immune evasion by tumor cells, with promising therapeutic potential in CRC.

Investigation of the effects of bisphenol-A exposure on lymphoid system in prenatal stage

Bisphenol-A (BPA) used in the production of plastic materials is a temperature-soluble agent. It also has a steroid hormone-like activity; therefore, it poses a danger to human health. In our study, we aimed to investigate the effects of BPA on lymph node and spleen in male rats exposed to this agent during prenatal stage. The pregnant female rats were divided into four groups: control, sham, low dose (300 µg/kg BPA), and high dose (900 µg/kg BPA). BPA was dissolved in 1 mL of corn oil and administered to the pregnant rats every day during pregnancy. On the 21st and 45th day after the birth, male rats' lymph node and spleen samples were taken and histopathological examination was performed. Samples were stained with hematoxylin and eosin to determine the general histological appearance, and with CD3 and CD20 immunohistochemically. The results of staining were evaluated by H-score, and statistical analysis was performed. In the samples, BPA applications were not found to cause significant tissue damage. But there was a significant decrease in the immunoreactivities of CD3 and CD20 after BPA applications in both 21st and 45th day samples. After high dose BPA administration, decreased CD3 immunoreactivity was statistically significant. It is thought that BPA does not cause histologically significant tissue damage, but it may impair organ function at cellular level. The investigation of molecules involved in organ function will be useful in revealing the mechanisms that will cause dysfunction.

Lung inflammation induced by exposure to Bisphenol-A is associated with mTOR-mediated autophagy in adolescent mice

Epidemiologic studies show that there is a link between Bisphenol A (BPA) exposure and lung inflammation. Despite this, the molecular mechanisms are not entirely known. This study sought to determine whether exposure to BPA affected the development of ovalbumin (OVA) induced lung inflammation in adolescent female mice and whether the mechanism was related to mTOR-mediated autophagy pathway. Female 4-week-old C57BL/6 mice after one week of domestication were randomly divided into five groups (8/group): control group, OVA group, 0.1 μg mL^-1 BPA + OVA group, 0.2 μg mL^-1 BPA + OVA group and 0.4 μg mL^-1 BPA + OVA group. BPA exacerbated airway hyperresponsiveness (AHR), induced the pathological changes in the lung, which also enhanced inflammatory cells and cytokine levels. In addition, BPA exposure affected expression of autophagy associated proteins and genes. This research results indicated that BPA aggravated OVA-induced lung inflammation and induced abnormal immune function in mice, and its mechanism was related to the activation of autophagy pathway by down-regulation expression of mTOR. These findings suggest that therapeutic strategies to target autophagy may offer a new approach for severe asthma therapy.

Immunomodulatory effects of synthetic endocrine disrupting chemicals on the development and functions of human immune cells

Endocrine disrupting chemicals (EDCs) are added to food, cosmetics, plastic packages, and children's toys and have thus become an integral part of the human environment. In the last decade, there has been increasing interest in the effect of EDCs on human health, including their impact on the immune system. So far, researchers have proved that EDCs (e.g. bisphenols, phthalates, triclosan, phenols, propanil, tetrachlorodibenzo-p-dioxin, diethylstilbestrol, tributyltin (TBT), and parabens) affect the development, functions, and lifespan of immune cells (e.g., monocytes, neutrophils, mast cells, eosinophils, lymphocytes, dendritic cells, and natural killers). In this review, we have summarized the current knowledge of the multivariable influence of EDCs on immune cells and underlined the novel approach to EDC studies, including dose-dependent effects and low-dose effects. We discuss critically the possible relationship between exposure to EDCs and immunity related diseases (e.g. allergy, asthma, diabetes, and lupus). Moreover, based on the literature, we construct a model of possible mechanisms of EDC action on immune cells at cellular, molecular, and epigenetic levels.