Effects of bisphenol-A on male reproductive success in adult Kadaknath chicken

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.

Chitosan nanoparticles alleviated endocrine disruption, oxidative damage, and genotoxicity of Bisphenol-A- intoxicated female African catfish

Bisphenol-A (BPA) is widely used in production of plastic products. It can reach the ecosystems affecting aquatic organisms most likely fishes. The purpose of this study was to study the toxic effects of BPA on the biochemical variables and oxidative stress in female African catfish, Clarias gariepinus and to estimate the protective role of chitosan nanoparticles (CSNPs) against BPA toxicity. Five groups in triplicates of fish were divided as follows: group I was control, group II was treated with CSNPs (0.66 ml/L), group III was exposed to BPA (1.43 μg/L), group IV was treated with BPA (1.43 μg/L) plus CSNPs (0.33 ml/L), and group V was treated with BPA (1.43 μg/L) plus CSNPs (0.66 ml/L) for 30 days. Blood and liver tissue samples were collected at the end of experiment for the biochemical and oxidative stress biomarkers analyses. Results exhibited that serum Follicle Stimulating Hormone (FSH) and 17-β Estradiol (E2) were significantly decreased in female catfish. While, serum Testosterone (T.) and Luteinizing Hormone (LH) were increased after exposure to BPA. Marked increment in superoxide dismutase (SOD) and malondialdehyde (MDA) levels of hepatic tissue of catfish exposed to BPA. Furthermore, significant reduction in hepatic catalase (CAT), glutathione peroxidase (GSH-px), total antioxidant capacity (TAC), reduced glutathione (GSH), and glutathione S-transferase (GST) levels were decreased significantly in BPA-exposed catfish compared to the control group. However, administration of female C. gariepinus with the low and high doses (0.33 ml/L and 0.66 ml/L) of CNPs restored the biochemical parameters to be close to the normal values of the control group and also, reduced oxidative stress induced by BPA toxicity. This improvement was evident in fish administrated with the high CSNPs dose (0.66 ml/L) compared to catfish exposed to BPA in group (III). Furthermore, the percentage of hepatic DNA damage was detected in group III exposed to BPA alone. However, it was declined after co- administration with both the low and high doses of CSNPs. The study has revealed that treatment with CSNPs has antagonistic functions against the toxicity of BPA in female African catfish.

Modulation of folliculogenesis in adult laying chickens by bisphenol A and bisphenol S: Perspectives on ovarian morphology and gene expression

Both bisphenol A (BPA) and its analog bisphenol S (BPS) are industrial chemicals that have been used to make certain plastic products applied in chicken farms, including food and water containers. They are endocrine disrupting chemicals (EDCs) with xenoestrogenic activities and affect reproductive success in many ways. It was hypothesized that BPA and BPS could adversely affect the folliculogenesis in chickens due to their disruption of the estrogen responses, using either genomic or non-genomic mechanisms. This study investigated the deleterious effects of BPA and BPS on the ovaries when adult layer chickens were orally treated with these EDCs at 50 μg/kg body weight, the reference dose for chronic oral exposure of BPA established by the U.S. EPA. The chickens in both BPA and BPS-treated groups showed a decreased number of the preovulatory follicles. BPA-treated chickens showed a significant decrease in the diameter of F1. Additionally, both BPA and BPS treatments increased the infiltrations of lymphocytes and plasma cells in ovaries. Moreover, it was found that the ovaries of BPS-treated chickens weighed the most among the groups. RNA sequencing and subsequent pathway enrichment analysis of differentially expressed genes revealed that both BPA- and BPS-treatment groups showed significant changes in gene expression and pathways related to reproduction, immune function and carcinogenesis. Taken together, both BPA and BPS are potentially carcinogenic and have deleterious effects on the fertility of laying chickens by inducing inflammation, suggesting that BPS may not be a safe replacement for BPA.

A review on contaminants of emerging concern in European raptors (2002-2020)

Raptors (birds of prey and owls) have been widely used as suitable bioindicators of environmental pollution. They occupy the highest trophic positions in their food chains and are documented to bioaccumulate high concentrations of persistent pollutants such as toxic metals and legacy persistent organic pollutants (POPs).Whereas raptors played a critical role in developing awareness of and policy for chemical pollution, they have thus far played a much smaller role in current research on contaminants of emerging concern (CECs). Given the critical knowledge obtained from monitoring 'legacy contaminants' in raptors, more information on the levels and effects of CECs on raptors is urgently needed. This study critically reviews studies on raptors from Europe reporting the occurrence of CECs with focus on the investigated species, the sampled matrices, and the bioanalytical methods applied. Based on this, we aimed to identify future needs for monitoring CECs in Europe. Perfluoroalkyl substances (PFASs), novel flame retardants (NFRs), and to a lesser extent UV-filters, neonicotinoids, chlorinated paraffins, parabens and bisphenols have been reported in European raptors. White-tailed Eagle (Haliaeetus albicilla), Peregrine falcon (Falco peregrinus) and Northern goshawk (Accipiter gentilis) were the most frequently studied raptor species. Among matrices, eggs, feathers and plasma were the most widely employed, although the potential role of the preen gland as an excretory organ for CECs has recently been proposed. This review highlights the following research priorities for pollution research on raptors in Europe: 1) studies covering all the main classes of CECs; 2) research in other European regions (mainly East Europe); 3) identification of the most suitable matrices and species for the analysis of different CECs; and 4) the application of alternative sample treatment strategies (e.g. QuEChERS or pressurized liquid extraction) is still limited and conventional solvent-extraction is the preferred choice.

Effects of endocrine disrupting chemicals in pigs

Endocrine-disrupting chemicals (EDCs) are compounds that interfere with the expression, synthesis, and activity of hormones in organisms. They are released into the environment from flame retardants and products containing plasticizers. Persistent pesticides, such as dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene, also disrupt the endocrine system through interaction with hormone receptors. Endogenous hormones, such as 17β-estradiol (E2), are released in the urine and feces of farm animals and seep into terrestrial and aquatic ecosystems through sewage. Pigs are widely used as animal models to determine the effects of EDCs because they are physiologically, biochemically, and histologically similar to humans. EDCs primarily disrupt the reproductive and nervous systems of pigs. Moreover, embryonic development during the prenatal and early postnatal periods is particularly sensitive to EDCs. Mycotoxins, such as zearalenone, are food contaminants that alter hormonal activities in pigs. Mycotoxins also alter the innate immune system in pigs, making them vulnerable to diseases. It has been reported that farm animals are exposed to various types of EDCs, which accumulate in tissues, such as those of gonads, livers, and intestines. There is a lack of an integrated understanding of the impact of EDCs on porcine reproduction and development. Thus, this article aims to provide a comprehensive review of literature regarding the effects of EDCs in pigs.

Fish and Seabird Gut Conditions Enhance Desorption of Estrogenic Chemicals from Commonly-Ingested Plastic Items

Plastic is ingested by over 100 bird species and 40 fish species. Once ingested, plastic may release endocrine-disrupting plastic additives in the animal; however, amounts transferred are poorly characterized. We exposed 16 commonly ingested plastic items to fish and seabird laboratory gut mimic models using the digestive enzyme pepsin at pH 2 and shook them for 16 h at either 28 °C (in saltwater) for fish or 40 °C (in freshwater) for seabirds. Gut liquid was then evaluated for estrogen receptor activity using an in vitro cell line, and plastic-additive concentrations were quantified using ultrahigh-performance liquid chromatography/tandem mass spectrometry. Both seabird ( p < 0.0001) and fish gut conditions ( p < 0.0001) significantly enhanced the biological estrogenicity of expanded polystyrene, polyethylene shopping bag, and polypropylene string relative to controls, resulting in up to a 10.6-fold increase in estrogenicity. Out of 12 plastic additives analyzed, bisphenol A (BPA) (204 ± 129%) and diethylhexyl phthalate (DEHP) (175 ± 97%) concentrations were significantly increased in seabird gut conditions relative to control and butylbenzyl phthalate (BBP) (132 ± 68%) was significantly increased in fish gut conditions relative to control. BPA, DEHP, and BBP did not adequately account for the increase in biological estrogenicity, suggesting that uncharacterized plastic additives may have been enhanced by gut conditions.

Gonadal and Endocrine Analysis of a Gynandromorphic Chicken

Birds have a ZZ male and ZW female sex chromosome system. The relative roles of genetics and hormones in regulating avian sexual development have been revealed by studies on gynandromorphs. Gynandromorphs are rare bilateral sex chimeras, male on one side of the body and female on the other. We examined a naturally occurring gynandromorphic chicken that was externally male on the right side of the body and female on the left. The bird was diploid but with a mix of ZZ and ZW cells that correlated with the asymmetric sexual phenotype. The male side was 96% ZZ, and the female side was 77% ZZ and 23% ZW. The gonads of this bird at sexual maturity were largely testicular. The right gonad was a testis, with SOX9+ Sertoli cells, DMRT1+ germ cells, and active spermatogenesis. The left gonad was primarily testicular, but with some peripheral aromatase-expressing follicles. The bird had low levels of serum estradiol and high levels of testosterone, as expected for a male. Despite the low percentage of ZW cells on that side, the left side had female sex-linked feathering, smaller muscle mass, smaller leg and spur, and smaller wattle than the male side. This indicates that these sexually dimorphic structures must be at least partly independent of sex steroid effects. Even a small percentage of ZW cells appears sufficient to support female sexual differentiation. Given the lack of chromosome-wide dosage compensation in birds, various sexually dimorphic features may arise due to Z-gene dosage differences between the sexes.