Characterizing PBDEs in fish, poultry, and pig feeds manufactured in China

Nano‑selenium alleviates the pyroptosis of cardiovascular endothelial cells in chicken induced by decabromodiphenyl ether through ERS-TXNIP-NLRP3 pathway

Decabromodiphenyl ether (BDE-209) is one of the most widely used flame retardants that can infect domestic and wildlife through contaminated feed. Nano‑selenium (Nano-Se) has the advantage of enhancing the anti-oxidation of cells. Nonetheless, it remains uncertain whether Nano-Se can alleviate vascular Endothelial cells damage caused by BDE-209 exposure in chickens. Therefore, we established a model with 60 1-day-old chickens, and administered BDE-209 intragastric at a ratio of 400 mg/kg bw/d, and mixed Nano-Se intervention at a ratio of 1 mg/kg in the feed. The results showed that BDE-209 could induce histopathological and ultrastructural changes. Additionally, exposure to BDE-209 led to cardiovascular endoplasmic reticulum stress (ERS), oxidative stress and thioredoxin-interacting protein (TXNIP)-pyrin domain-containing protein 3 (NLRP3) pathway activation, ultimately resulting in pyroptosis. Using the ERS inhibitor 4-PBA in Chicken arterial endothelial cells (PAECs) can significantly reverse these changes. The addition of Nano-Se can enhance the body's antioxidant capacity, inhibit the activation of NLRP3 inflammasome, and reduce cellular pyroptosis. These results suggest that Nano-Se can alleviate the pyroptosis of cardiovascular endothelial cells induced by BDE-209 through ERS-TXNIP-NLRP3 pathway. This study provides new insights into the toxicity of BDE-209 in the cardiovascular system and the therapeutic effects of Nano-Se.

Feed as a source of polybrominated diphenyl ethers (PBDEs)

One of the most important routes for human exposure to polybrominated diphenyl ethers (PBDEs) is the ingestion of contaminated food. Food of animal origin safety is strongly related to feed quality. The aim of the study was the assessment of feeds and feed materials quality associated with ten PBDE congeners (BDE-28, 47, 49, 99, 100, 138, 153, 154, 183 and 209) contamination. The quality of 207 feed samples divided into eight categories (277/2012/EU) was checked using the gas chromatography-high resolution mass spectrometry (GC-HRMS). At least one congener was identified in 73% of the samples. All investigated fish oil, animal fat, and feed for fish were contaminated, and 80% of plant-origin feed samples were free of PBDEs. The highest median content of ∑10PBDE was found in fish oils (2260 ng kg-1) followed by fishmeal (530 ng kg-1). The lowest median was found in mineral feed additives, plant materials excluding vegetable oil and compound feed. BDE-209 was the most frequently detected congener (56%). All congeners except BDE-138 and BDE-183 were detected in 100% of the fish oil samples. Except for BDE-209, the congener detection frequencies did not exceed 20% in compound feed, feed of plant origin, and vegetable oils. Excluding BDE-209, similar congener profiles were found for fish oils, fishmeal and feed for fish, with BDE-47 in the highest concentration, followed by BDE-49 and BDE-100. Another pattern appeared in animal fat, with a higher median concentration of BDE-99 than BDE-47. Time-trend analysis of PBDE concentrations in fishmeal (n = 75) showed a 63% decrease in ∑10PBDE (p = 0.077) and a 50% decrease in the ∑9PBDE (p = 0.008) between 2017 and 2021. It proves the international legislation implemented to reduce PBDE environmental levels has been effective.

The p23 co-chaperone is a succinate-activated COX-2 transcription factor in lung adenocarcinoma tumorigenesis

P23, historically known as a heat shock protein 90 (HSP90) co-chaperone, exerts some of its critical functions in an HSP90-independent manner, particularly when it translocates into the nucleus. The molecular nature underlying how this HSP90-independent p23 function is achieved remains as a biological mystery. Here, we found that p23 is a previously unidentified transcription factor of COX-2, and its nuclear localization predicts the poor clinical outcomes. Intratumor succinate promotes p23 succinylation at K7, K33, and K79, which drives its nuclear translocation for COX-2 transcription and consequently fascinates tumor growth. We then identified M16 as a potent p23 succinylation inhibitor from 1.6 million compounds through a combined virtual and biological screening. M16 inhibited p23 succinylation and nuclear translocation, attenuated COX-2 transcription in a p23-dependent manner, and markedly suppressed tumor growth. Therefore, our study defines p23 as a succinate-activated transcription factor in tumor progression and provides a rationale for inhibiting p23 succinylation as an anticancer chemotherapy.

Curcumin alleviates spleen immunotoxicity induced by decabrominated diphenyl ethers (BDE-209) by improving immune function and inhibiting inflammation and apoptosis in broilers

This study was conducted to assess the mitigating effects of curcumin (Cur) on immunotoxicity in the spleen of broilers induced by the polybrominated diphenyl ether BDE-209. Eighty one-day-old broilers were allocated to the following four groups: control group, BDE-209 (0.4 g/kg) group, BDE-209 (0.4 g/kg) + Cur (0.3 mg/kg) group, and Cur (0.3 mg/kg) group. Growth performance, immunological function, inflammation, and apoptosis were assessed after 42 days of treatment. The findings demonstrate that firstly, Cur restored spleen damage caused by BDE-209 by increasing body weight, decreasing feed-to-gain ratio, correcting the spleen index, and improving the histopathological structure of the spleen. Secondly, Cur relieved BDE-209-induced immunosuppression by increasing the levels of the immunoglobulins IgG, IgM, and IgA in the serum, as well as the levels of white blood cells and lymphocytes. The levels at which GATA binding protein 3, T-box expressed in T cells, interferon-γ, and interleukin (IL)- 4 are expressed were controlled. The ratio of T helper (Th) type 1 (Th1) to Th2 cells in the spleen of broilers was also controlled. Thirdly, Cur reduced the expression of Toll like receptor (TLR) 2, TLR4, nuclear factor (NF)-κB, IL-8, IL-6, and IL-1β, which alleviated BDE-209-induced inflammation in broilers. Cur reduced BDE-209-induced apoptosis by increasing the expression of the bcl-2 protein, decreasing the expression of cleaved caspase-3 and bax proteins, decreasing the bax/bcl-2 protein ratio, and decreasing the mean optical density of TUNEL. These results suggest that Cur protects broiler spleens from BDE-209-induced immunotoxicity via modulating humoral immunity, the equilibrium between Th1 and Th2 cells, the TLRs/NF-κB inflammatory pathway, and the apoptotic pathway.

Occurrence of some legacy and emerging contaminants in feed and food and their ranking priorities for human exposure

The "feed-to-food" pathway is one of the most important routes for human exposure to manmade contaminants. The contaminants could threaten human health through the "feed-to-food" route and have recently become of great public concern. This review selects the representative legacy and emerging contaminants (ECs), such as polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), organophosphate esters (OPEs), short-chain chlorinated paraffins (SCCPs), and per- and polyfluoroalkyl substances (PFASs), regarding their occurrence in feed and food, as well as their metabolites and transport in farming and livestock ecosystems. Factors that might influence their presence and behavior are discussed. This review raises an approach to rank the priority of ECs using the EC concentrations in feed and food and using the hazard quotient (HQ) method for human health. Although SCCPs have the highest levels in feed and food, their potential risks appear to be the lowest. PFASs have the highest HQs on account of human exposure risk. Future research should pay more attention to the combined effects of multiple ECs.

Human exposure to polybrominated diphenyl ethers (PBDEs) through the diet: An update of the scientific literature

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame-retardants (BFRs). As for other persistent organic pollutants, dietary intake (followed by dust inhalation) is the main route of human exposure to PBDEs. In 2012, we reviewed the scientific literature on the concentrations of PBDEs in foodstuffs and their dietary exposure. The current review is aimed at updating the results of recent studies (2012-2022) focused on determining the levels of PBDEs in food samples, as well as the dietary intake of these compounds. We have revised studies conducted over the world. The current information on the concentrations of PBDEs in food and their dietary intake is now much more notable than that available in our previous review, being China the country contributing with the highest number of studies. Because of the important differences in materials and methods used in the available studies, the comparison of results is certainly complicated. However, there seems to be a general trend towards a decrease in the levels of PBDEs in foods, and consequently, in the dietary intake of these contaminants. The lack of tolerable daily intakes of PBDEs is an issue that needs to be solved for assessing human health risks of these BFRs.

Occurrence and levels of polybrominated diphenyl ethers (PBDEs) in deep-sea sharks from Suruga Bay, Japan

Few studies have investigated the prevalence of polybrominated diphenyl ethers (PBDEs) in deep-sea sharks. In this study, the levels and profiles of PBDEs were determined in liver samples of eight different species of deep-sea sharks collected in Suruga Bay, Japan. Widespread contamination of PBDEs in the deep-sea environment was reconfirmed in this study as these persistent organic pollutants (POPs) were detected in all specimens analyzed. Mean ΣPBDE levels in the deep-sea sharks ranged from 7 to 517 ng/g of lipid weight. The distribution patterns of BDE homologues were similar in all species where tetra-BDEs provided the dominant contribution to total PBDEs (46%). PBDEs levels were similar to, or higher than, those seen in other deep-sea sharks from different regions. The levels of PBDEs were likely to reflect their feeding preferences as higher PBDE levels were seen in species with higher trophic positions.

Bromine in chicken eggs, feed, and water from different regions of Ukraine

The purpose of these studies was to analyse and compare the content of bromine in samples of chicken eggs, feed, and water from different regions of Ukraine in the dynamics of 2016 – 2020: with an increased risk of bromine in products (Kharkiv, Poltava, Dnipropetrovsk and Mykolaiv regions) and outside the risk zone (Volyn, Vinnytsia and Zaporizhzhia). Studies of bromine content in eggs, feed, and water were performed in the laboratory of toxicological monitoring of the National Scientific Center "Institute of Experimental and Clinical Veterinary Medicine" (Kharkiv) using X-ray fluorescence analysis. As a result of the conducted researches, the increase of the bromine content in chicken eggs in the dynamics of 2016 – 2020 was established: the bromine content increased regardless of the region of the poultry farm location. The highest bromine concentration in chicken eggs was found in Kharkiv, Dnipropetrovsk, Mykolaiv, and Zaporizhia regions. Bromine source in poultry products is the excessive intake of bromine in the poultry body with alimentary environmental factors (feed and water). Bromine content in feed for chickens increased in the research dynamics (from 35.1% in the Poltava region to 2.5 times in the Zaporizhzhia region). It exceeded the established EFSA (4.4% of the total) and the average in Ukraine (51.2% of the total number of samples). In addition, the average bromine content in feed from poultry farms of the studied regions of Ukraine correlated with the number of registered and approved bromine-containing pesticides. The average bromine concentration in water sources in the studied regions of Ukraine had no significant differences compared to the beginning of the study but exceeded the maximum allowable concentration by 21.7% in 2016, 34.8% in 2018 and 39.1% in 2020. The maximum bromine concentration was in water sources in Mykolayiv, Kharkiv, and Dnipropetrovsk regions.

Toxic Organic Contaminants in Airborne Particles: Levels, Potential Sources and Risk Assessment

In the last years, many studies have focused on risk assessment of exposure of workers to airborne particulate matter (PM). Several studies indicate a strong correlation between PM and adverse health outcomes, as a function of particle size. In the last years, the study of atmospheric particulate matter has focused more on particles less than 10 μm or 2.5 μm in diameter; however, recent studies identify in particles less than 0.1 μm the main responsibility for negative cardiovascular effects. The present paper deals with the determination of 66 organic compounds belonging to six different classes of persistent organic pollutants (POPs) in the ultrafine, fine and coarse fractions of PM (PM < 0.1 µm; 0.1 < PM < 2.5 µm and 2.5 < PM < 10 µm) collected in three outdoor workplaces and in an urban outdoor area. Data obtained were analyzed with principal component analysis (PCA), in order to underline possible correlation between sites and classes of pollutants and characteristic emission sources. Emission source studies are, in fact, a valuable tool for both identifying the type of emission source and estimating the strength of each contamination source, as useful indicator of environment healthiness. Moreover, both carcinogenic and non-carcinogenic risks were determined in order to estimate human health risk associated to study sites. Risk analysis was carried out evaluating the contribution of pollutant distribution in PM size fractions for all the sites. The results highlighted significant differences between the sites and specific sources of pollutants related to work activities were identified. In all the sites and for all the size fractions of PM both carcinogenic and non-carcinogenic risk values were below acceptable and safe levels of risks recommended by the regulatory agencies.

Effects of Decabrominated Diphenyl Ether Exposure on Growth, Meat Characteristics and Blood Profiles in Broilers

Decabrominated diphenyl ether (BDE-209) is widely used as a flame retardant and is detected at high levels in the environment. Its toxicities have been reported and have attracted attention. In the present study, broilers were used to determine the response in growth performance, carcass traits, meat quality, blood profiles and antioxidant system to BDE-209 exposure at doses of 0, 0.02, 0.4 and 4 mg/kg. The results showed that BDE-209 exposure at levels of 0.02 or 0.4 mg/kg increased feed intake and decreased feed efficiency. BDE-209 altered the blood profiles, such as reducing the numbers of white blood cells, lymphocytes and neutrophilic granulocytes. As compared with the control, BDE-209 exposure significantly increased abdominal fat percentages of broilers at 64.9-159.5% and adversely affected the selected biochemical indicators, including alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine (CRE), which indicated its toxicity to liver and kidney functions. Moreover, BDE-209 exposure significantly increased plasma malondialdehyde (MDA) concentrations and decreased the activities of glutathione peroxidase (GSH-px) and superoxide dismutase (SOD), which implied aggravating oxidant stress and decline of antioxidant capacity in broilers. In conclusion, our data demonstrated that the environmental pollutant BDE-209 adversely influenced growth performance, increased the deposition of abdominal fat, impaired antioxidant capacity and the immune system and had potential toxicity to the liver and kidney of broilers.

Field study on bioaccumulation and translocation of polybrominated diphenyl ethers in the sediment-plant system of a national nature reserve, North China

Polybrominated diphenyl ethers (PBDEs) are the ubiquitous contaminants in the coastal wetlands, with high persistence and toxicity. Environmental behaviors of PBDEs in sediment-plant system is a hot research area, where much uncertainties still occurred in field environment. In this study, the sediments and Suaeda heteroptera were synchronously collected to investigate the bioaccumulation and translocation of PBDEs in Liaohe coastal wetland. Mean concentrations of PBDEs in sediments, roots, stems and leaves were 8.37, 6.64, 2.42 and 1.40 ng/g d.w., respectively. Tissue-specific accumulation of PBDEs were detected in Suaeda heteroptera, with predominant accumulation in roots. Congener patterns of PBDEs were similar between sediments and roots, demonstrating root uptake as the key pathway of PBDE bioaccumulation. The proportions of lower brominated congeners increased from roots to leaves, implying the congener-specific translocation. Meanwhile, the lower brominated congeners exhibited higher sediment-tissue bioaccumulation (AFs) and translocation factors (TFs) compared to higher brominated congeners in Suaeda heteroptera, further verifying their preferential translocation. AFs and TFs of PBDEs were both not correlated with their log K_ow, which was inconsistent with those of laboratory studies, reflecting the complicated behaviors of PBDEs in field environment. This is the first comprehensive report on bioaccumulation and translocation of PBDEs within Suaeda heteroptera in Liaohe coastal wetland.