Cytotoxicity, redox and immune status in African catfish, Clarias gariepinus (Burchell, 1822) exposed to bisphenol A (BPA) and its analogues

Effects of 2,4-dichlorophenol on non-specific immunity, histopathological lesions, and redox balance in African Catfish, clarias gariepinus (Burchell, 1822)

The toxic effects of 2, 4-dichlorophenol (2, 4-DCP) on aquatic organisms are well-established; however, the details regarding the mechanisms underlying the toxicity, especially immunotoxicity are poorly understood. Consequently, the aim of this study was to investigate the histopathologic, oxidative stress and immunotoxic effects attributed to exposure to sublethal concentrations of 2,4-DCP in the African catfish, Clarias gariepinus. Juvenile C. gariepinus were exposed to 0.4, 0.8, or 1.6 mg/L 2, 4-DCP for 28 days after which blood and head kidney were extracted for the determination of various nonspecific innate immune parameters while the liver was excised for histopathology examination and measurement of oxidative stress biomarkers. Control fish were maintained in water spiked 10 µL/L ethanol, representing the solvent control. A significant increase was noted in the activities of lactate dehydrogenase and superoxide dismutase as well as in levels of lipid peroxidation and DNA fragmentation in a dose-dependent manner, with higher adverse effects observed at the highest concentration tested (1.6 mg/L). The total white blood cells (WBC) count was significantly elevated in fish exposed to 2,4-DCP compared to control. Myeloperoxidase content was decreased significantly in fish exposed to 2,4-DCP especially at the highest concentration (1.6 mg/L) compared to controls. The respiratory burst activity did not differ markedly amongst groups. Histopathological lesions noted included edema, leucocyte infiltration, and depletion of hemopoietic tissue in the head kidney of exposed fish. There was significant upregulation in the mRNA expression of tumor necrosis factor (TNF-α) and heat shock protein 70 (HSP 70) but downregulation of major histocompatibility complex 2 (MHC 2) in exposed fish. Data demonstrated that exposure to 2,4-DCP resulted in histopathological lesions, oxidative stress, and compromised immune system in C. gariepinus.

Concentrations, sources and health risk of bisphenols in red swamp crayfish (Procambarus clarkii) from South-Eastern China

Bisphenol analogs (BPs) are extensively employed in commercial and industrial products and they have been found in a variety of environmental matrices and human samples. The red swamp crayfish (Procambarus clarkii) has been a trendy food in China in recent decades. However, the levels of BPs in Chinese crayfish and the associated hazards of human exposure remain unknown. Thus, in this study, the levels of eight BPs in crayfish gathered from five major provinces engaged in crayfish within the Yangtze River Basin were analyzed. Additionally, the health risks for humans by ingesting crayfish were calculated. BPs were frequently detected in crayfish tissues, indicating the wide occurrence of these chemicals. In comparison to other substitutions, BPA remains the dominant bisphenol analog. Most of the BPs were observed to accumulate in the hepatopancreas compared to the muscle, so consuming the hepatopancreas of crayfish is not recommended. With the exception of BPS, the Estimated Daily Intakes (EDIs) of the remaining BPs exceeded the Tolerable Daily Intake (TDI) specified by the European Food Safety Authority (EFSA) by a factor of 1.75-69.0. The mean hazard index (HI) values exceeded 1 for both hepatopancreas and muscle in all provinces, and the mean HI values for hepatopancreas were significantly higher than those for muscle, indicating potential health risks for local consumers.

Tissue Accumulation, Cytotoxicity, Oxidative Stress, and Immunotoxicity in African Catfish, Clarias gariepinus Exposed to Sublethal Concentrations of Hexavalent Chromium

Hexavalent chromium (Cr6+) is one of the stable oxidation states of chromium that has been reported to elicit various toxic effects in aquatic organisms. However, the mechanisms of Cr6+ toxicity are still poorly understood. Thus, the present study investigated the tissue accumulation, cytotoxic, oxidative stress, and immunotoxic effects of Cr6+ in juvenile Clarias gariepinus. The fish were exposed to waterborne Cr6+ concentrations (0, 0.42, 0.84, and 1.68 mg/L) for 28 days, after which they were sacrificed and various organs were harvested for the determination of Cr6+ levels. Other parameters that were indicators of oxidative stress, cytotoxicity, and immunotoxicity were measured. Cr6+ accumulated more in the kidney and liver of the exposed fish, especially at the highest concentration. The levels of lipid peroxidation and DNA fragmentation increased significantly in the exposed fish. The activities of superoxide dismutase and lactate dehydrogenase increased significantly in exposed fish compared to the control. The total white blood cells, lymphocytes, and neutrophils counts were significantly higher in the exposed fish compared to the control fish. The respiratory burst activity decreased significantly in the exposed fish while the myeloperoxidase content did not differ significantly. There were upregulations of TNF-α and HSP 70 while CYP II and MHC 2 were downregulated in the exposed fish. Also, exposure to Cr6+ resulted in various histopathological alterations in the architecture of the head kidney. The results indicate concentration-dependent toxic effects of Cr6+ in C. gariepinus. The study reveals the potentials of Cr6+ to accumulate in the different tissues of fish and caused cytotoxic, oxidative stress, and immunotoxic effects in the exposed fish.

The protective effects of date seeds, in either conventional or nanoformulation, against bisphenol A-induced testicular toxicity: involvement of testicular expression of CYP11A1, Nrf-2 and Bax/Bcl-2 ratio

Background

Bisphenol A (BPA), an endocrine-disrupting chemical (EDC), is ubiquitous in our environment and poses a significant threat to male fertility. Date seeds (DSs) are used in folk medicine due to their antioxidant activity.

Aim

The purpose of this study was to assess the beneficial effects of DSs, whether in powder or nanoparticle form, against BPA-induced testicular oxidative challenges and apoptosis, aided by inspection of specific genes linked to fertility, oxidative stress and intrinsic mitochondrial pathway of apoptosis.

Methods

Thirty-five adult male albino rats were equally divided into 5 groups including control, BPA, BPA + date seeds powder "DSP", BPA + date seed nanoparticle 1/10 (DSNP 1/10) and BPA + DSNP 1/20 groups.

Results

TEM showed that the ball-mill method was effective to form DSNP with an average size of 20 nm. BPA significantly impaired sperm motility, morphology, viability and concentration. It also reduced serum testosterone levels and evoked marked oxidative stress in the testes. Additionally, serum levels of triiodothyronine and thyroxine were extremely reduced. Moreover, testicular mRNA relative expression levels of CYP11A1 and Nrf-2 were markedly downregulated. Testicular apoptosis was also promoted whereas Bax/Bcl-2 ratio was profoundly elevated. Histological pictures of the testes, epididymis, seminal vesicles and prostate confirmed the unfavorable effects of BPA. Surprisingly, we first demonstrated that DSs, specifically the nanoparticle form, strongly alleviated all of BPA's negative effects, with DSNP 1/20 achieving the best results.

Conclusion

Therefore, DSNP in both doses could be regarded as an ideal candidate for abating the male reproductive challenges caused by BPA.

PBTK-TD model of the phagocytosis activity in three-spined stickleback exposed to BPA

Due to the high production volume and persistence in the environment of bisphenol A (BPA) and its substitutes, realistic exposure scenarii were proposed in some species to better understand the relationship between external and internal concentrations. For example, a recent PBTK model has been developed and adapted to BPA ADME (Absorption, Distribution, Metabolization, and Excretion) processes in three-spined stickleback. These substances have an impact on organism physiology including reproductive and immune functions. In this context, physiologically-based toxicokinetic models coupled with toxicodynamics (PBTK-TD) have proven to be valuable tools to fill the knowledge gap between external exposure and effect dynamics. The aim of the current work was to explain the impact of BPA on the immune response by determining its temporality. In addition, the relationship between BPA dose and these responses was investigated using a PBTK-TD model. Two experiments were performed on stickleback to characterize their biomarker responses, (i) a short exposure (14 days) at 0, 10 and 100 µg/L, including a depuration phase (7 days), and (ii) a long exposure (21 days) at 100 µg/L to measure the immunomarker dynamic over a long period. The fish spleens were sampled to analyze immune responses of stickleback at various times of exposure and depuration: leucocyte distribution, phagocytic capacity and efficiency, lysosomal presence and leucocyte respiratory burst index. At the same date, blood, muscle, and liver were sampled to quantify BPA and their metabolites (BPA monoglucuronide and BPA monosulfate). All these data enabled the development of the indirect pharmacodynamic models (PBTK-TD) by implementing the responses of biomarkers in the existing BPA PBTK of stickleback. The results shown a high induction of phagocytosis activity by BPA in the two exposure conditions. Furthermore, the immunomarkers exhibit very different temporal dynamics. This study demonstrates the need of a thorough characterization of biomarker response for a further use in Environmental Biomonitoring.

ROS mediated pyroptosis-M1 polarization crosstalk participates in inflammation of chicken liver induced by bisphenol A and selenium deficiency

The earth's natural environmental factors and man-made industrial pollution often lead to the co-occurrence of environmental pathogenic factors and malnutrition. Bisphenol A (BPA) is a serious environmental endocrine disruptor, and its exposure can cause liver tissue damage. Selenium (Se) deficiency is a worldwide problem that afflicts thousands of people, and Se deficiency can cause M1/M2 imbalance. In addition, the crosstalk between hepatocyte and immune cell is closely related to the occurrence of hepatitis. Therefore, this study found for the first time that the combined exposure of BPA and Se deficiency caused liver pyroptosis and M1 polarization through ROS, and the crosstalk between pyroptosis and M1 polarization aggravated liver inflammation in chicken. In this study, the BPA or/and Se deficiency chicken liver, single and co-culture model of LMH and HD11 cells were established. The results displayed that BPA or Se deficiency induced liver inflammation accompanied by pyroptosis and M1 polarization through oxidative stress, and increased expressions of chemokines (CCL4, CCL17, CCL19, and MIF) and inflammatory factors (IL-1β and TNF-α). The vitro experiments further verified the above changes and showed that LMH pyroptosis promoted M1 polarization of HD11 cells, and vice versa. NAC counteracted pyroptosis and M1 polarization caused by BPA and low-Se, reducing the release of inflammatory factors. In brief, BPA and Se deficiency treatment can exacerbate liver inflammation by increasing oxidative stress to induce pyroptosis and M1 polarization.

Bisphenol P exposure in C57BL/6 mice caused gut microbiota dysbiosis and induced intestinal barrier disruption via LPS/TLR4/NF-κB signaling pathway

Despite being one of the most world's widely used and mass-produced compounds, bisphenol A (BPA) has a wide range of toxic effects. Bisphenol P (BPP), an alternative to BPA, has been detected in many foods. The effects of BPP dietary exposure on gut microbiota and the intestinal barrier were unclear. We designed three batches of animal experiments: The first studied mice were exposed to BPP (30 µg/kg BW/day) for nine weeks and found that they gained weight and developed dysbiosis of the gut microbiota. The second, using typical human exposure levels (L, 0.3 µg/kg BW/day BPP) and higher concentrations (M, 30 µg/kg BW/day BPP; H, 3000 µg/kg BW/day BPP), caused gut microbiota dysbiosis in mice, activated the Lipopolysaccharide (LPS) /TLR4/NF-κB signaling pathway, triggered an inflammatory response, increased intestinal permeability, and promoted bacterial translocation leading to intestinal barrier disruption. The third treatment used a combination of antibiotics and alleviated intestinal inflammation and injury. This study demonstrated the mechanism of injury and concentration effects of intestinal damage caused by BPP exposure, providing reference data for BPP use and control and yielding new insights for human disease prevention.

Cineole regulates Wnt/β-catenin pathway through Nrf2/keap1/ROS to inhibit bisphenol A-induced apoptosis, autophagy inhibition and immunosuppression of grass carp hepatocytes

Bisphenol A (BPA), an environmental pollutant, can cause multiple organ tissue damage by inducing oxidative stress. Cineole (CIN) is a terpene oxide existing in a variety of plant essential oils, which has anti-inflammatory, analgesic, and antioxidant effects. This study examined the effects of 200 nM BPA and 20 μM CIN on apoptosis, autophagy, and immunology in grass carp hepatocytes (L8824). The treatments were categorized as NC, CIN, BPA + CIN, and BPA. The findings demonstrated that BPA exposure could increase ROS levels and oxidative stress-related indicators, decrease the expression of the Nrf2/keap1 pathway and the Wnt/β-catenin pathway, increase the expression of genes involved in the apoptotic pathway (Bax and Caspase3), and decrease the expression of the anti-apoptotic gene Bcl-2 by lowering mitochondrial membrane potential. BPA also reduced the expression of genes linked to autophagy (ATG5, Beclin1, LC3). Changes in immunological function after BPA exposure were also shown by changes in the amounts of antimicrobial peptides (HEPC, β-defensin, LEAP2) and cytokines (INF-γ, IL-1β, IL-2, and TNF-α). After the co-treatment of CIN and BPA, CIN can inhibit BPA-induced apoptosis and recover from autophagy and immune function to a certain extent by binding to keap1 to exert an anti-oxidative regulatory effect of Nrf2 incorporation into the nucleus. Molecular docking provides strong evidence for the interaction of CIN ligands with keap1 receptors. Therefore, these results indicated that CIN could inhibit BPA-induced apoptosis, autophagy inhibition and immunosuppression in grass carp hepatocytes by regulating the Wnt/β-catenin pathway with Nrf2/keap1/ROS. This study provided further information to the risk assessment of the neuroendocrine disruptor BPA on aquatic organisms and offered suggestions and resources for further research into the function of natural extracts in the body's detoxification process.