Acute effects of antimony exposure on adult zebrafish (Danio rerio): From an oxidative stress and intestinal microbiota perspective

Effect of microplastic binding capacity on antioxidant and immune responses of Korean rockfish Sebastes schlegeli in a co-exposure environment with microplastics and Streptococcusiniae

Korean rockfish (Sebastes schlegeli) aquaculture, which predominantly occurs in coastal regions, encounters challenges such as reduced productivity owing to microplastics and bacterial contamination. Microplastic adsorb bacteria and accumulates in fish, inducing alterations in antioxidant and immune responses. Numerous studies have examined the interaction between microplastics and external pollutants such as heavy metals and physiological changes in fish; however, studies on the effects of combined exposure to microplastics and bacteria on physiological changes in fish remain limited. Therefore, we investigated the effects of combined exposure to microbead (MB) and Streptococcus iniae (S. iniae) on the antioxidant and immune responses of Korean rockfish. Korean rockfish were exposed to single and combined environments of 0.2 μm MB at 5 and 50 beads/L and S. iniae at 1 × 105 and 1 × 107 CFU/mL for 5 days. MB accumulation in gill and intestine tissues was examined, and copy number changes of S. iniae in liver and spleen tissues were analyzed. The mRNA expression levels of antioxidant enzymes (SOD and CAT) and immune-related genes (IL-1β, IL-6, CCL25, and TNF-α) were analyzed in the liver tissue, while changes in plasma MDA and lysozyme levels were evaluated as an additional immune-related factor. Combined exposure to high concentrations of MB and S. iniae increased the accumulation of MB and the copy number of S. iniae than that of a single exposure. This also increased the mRNA expression of antioxidant enzymes and immune response genes. These results indicate that the accumulation of MB in Korean rockfish, depending on its concentration, can bind with S. iniae, inducing changes in the copy number of S. iniae and affecting antioxidant and immune responses. This study is expected to provide fundamental academic data for understanding the physiological and immunological responses of marine organisms exposed to the combined effects of MB and S. iniae.

Polystyrene microplastics (PS-MPs) harness copper presence and promote impairments in early zebrafish (Danio rerio) larvae: Developmental, biochemical, transcriptomic approaches and nontargeted metabolomics approaches

Due to their large specific surface area and strong hydrophobicity, microplastics (MPs) are highly susceptible to adsorb environmental pollutants, of which heavy metals (HMs) are the most representative inorganic pollutants. However, there is controversy in different studies as to whether the toxic effects of the combined action of MPs and HMs on zebrafish larvae are antagonistic or synergistic. Herein, we firstly evaluated the combined effects of 10 μm polystyrene MPs (PS-MPs) on zebrafish larvae after exposure for 96 h at two different concentrations (5 mg/L, 0.5 mg/L) and Cu2+ (0.05 mg/L). Our study primarily showed that the combined exposure of PS-MPs and Cu2+ could induce developmental toxicity, oxidative stress, immunotoxicity and neurotoxicity. Furthermore, LC/MS-based nontargeted metabolomics analysis demonstrated that the combined exposure of PS-MPs with Cu2+ induced metabolic disturbances. Furthermore, our results showed that the combined exposure of 10 μm PS-MPs with Cu2+ exhibited a synergistic effect on the toxicity of zebrafish larvae. In conclusion, this study provides a reference for future research related to combined exposure of PS-MPs and Cu2+ on fish.

Dietary L-glutamate modulates intestinal mucosal immunity of juvenile hybrid striped bass (Morone saxatilis ♀ × Morone chrysops ♂)

Introduction

L-Glutamate is a conditionally essential amino acid, meaning it can become essential under specific conditions, like stress or disease. It is an abundant intracellular amino acid crucial in immune responses. Supplementation of feed with key amino acids, such as glutamate, can optimize growth and have other health benefits for production animals. Most research on dietary amino acid supplementation has focused on mammalian models, thus this research turned to hybrid striped bass, a teleost fish of growing importance to the aquaculture industry. The study investigated the effects of dietary supplementation with 0% or 5% glutamate in hybrid striped bass on intestinal mucosal immunity.

Methods

The basal purified diet contained crystalline amino acids, including 3% L-glutamate. After an 8-week period of dietary supplementation with 5% glutamate followed by lipopolysaccharide stimulation, the intestinal mucosa was analyzed at the cellular and molecular levels to compare with the head kidney to assess potential changes in immune reactivity.

Results

One week after lipopolysaccharide stimulation, glutamate supplementation enhanced (P < 0.05) the whole-body growth of fish without lipopolysaccharide challenge, total respiratory burst (the sum of O2 - and H2O2 production) in head kidney leukocytes, the net production of H2O2 in intestinal mucosal leukocytes, and upregulation of expression of mRNAs for IL-1β, TNF-α, and IgT in the gut mucosa.

Discussion

Dietary supplementation with 5% L-glutamate may modulate intestinal mucosal immunity and improve growth in HSB to enhance disease resistance. Further research is needed to clarify the mechanism and cost-effective application.

Metal mixtures and adiposity indicators in women from Northern Mexico

Exposure to individual metals has been inconsistently associated with adiposity. However, populations are exposed to more than one metal at a time, thus recent studies have been conducted to assess more comprehensively metal exposure through a mixture approach. To explore the association between Body Mass Index (BMI), Waist-Hip Ratio (WHIR) and Waist-Height Ratio (WHER) with urinary metal concentrations, using individual and mixture approaches, as well as identifying the most important metals within the mixtures, in women from Northern Mexico. This is a secondary cross-sectional analysis that included 439 women residents of five states in Northern Mexico. We weighed and measured participants to estimate BMI, WHIR, and WHER. We determined the concentrations of 19 urinary metals using inductively coupled plasma triple quadrupole. We used Weighted Quantile Sum regression to evaluate the association between adiposity indicators and metal mixtures, as well as to identify the metals of concern within the mixtures. We identified a mixture of metals that was negatively associated with BMI (ß:-0.96, 95% CI:-1.90,-0.01), where the most prominent were lead, molybdenum and magnesium. Furthermore, WHIR was negatively and suggestively associated with a mixture where the predominant metals were aluminum, cadmium, arsenic and nickel (ß:- 7.12, 95% CI: - 1.75,0.00), likewise WHER was associated with a mixture where the important metals were arsenic and nickel (ß: - 1.03, 95% CI: - 2.24,0.00). Our results provide evidence about the associations between metal mixtures and some anthropometric indicators of adiposity. Experimental studies are warranted to identify the underlying biological mechanisms.

Alteration of intestinal microbiota-intestinal barrier interaction interferes with intestinal health after microcystin-LR exposure in Lithobates catesbeianus tadpoles

There remains uncertainty regarding the influence of microcystin-leucine arginine (MC-LR) on amphibian intestinal health, specifically how MC-LR interferes with intestinal microbiota following exposure to environmental concentrations. In this study, Lithobates catesbeianus tadpoles were exposed to varying MC-LR concentrations (0, 0.5, and 2 µg/L) over a 30-day period. The aim was to investigate how altered interactions between tadpole intestinal microbiota and the intestinal barrier influence intestinal health following MC-LR exposure. Following exposure to the MC-LR at low ambient concentrations, tadpole intestinal tissue was damaged. It had increased permeability, reduced pathogen inhibition capacity, and impaired digestive function. Additionally, there was a significant increase in lipopolysaccharide content and upregulation of downstream response genes, including TLR4, MyD88, and NF-κB, within the intestinal tissue. Therefore, eosinophils' count and pro-inflammatory cytokines' expression increased. In addition, MC-LR exposure induced oxidative stress and mitochondrial structural damage by increasing the levels of reactive oxygen species in intestinal tissue. CytoC and Bax transcription, as well as caspase 9 and caspase 3 activities, increased significantly. Significant downregulation of Bcl-2 transcription promoted apoptosis in tadpole intestinal cells. MC-LR exposure disrupted intestinal microbiota and metabolism in tadpoles. Correlation analysis revealed a strong association between intestinal microbiota and oxidative stress, inflammation, immunity, and tissue damage in the intestine. Conclusively, this study provides the first demonstration that MC-LR significantly affects amphibian intestinal microbiota, highlighting tadpoles' susceptibility to environmental risks posed by MC-LR.

The combined metabolism and transcriptome of tail muscles reveal the effects of antimony pulse exposure on swimming behavior of Pelophylax nigromaculatus tadpoles

Due to the periodic emission of pollutants, the exposure mode of contaminants in water bodies is mostly pulse exposure, and the toxic effects of fluctuating exposure on aquatic animals are not consistent with traditional toxicological experiments of constant exposure. The toxic effects of heavy metal antimony (Sb) on the swimming behavior of Pelophylax nigromaculatus tadpoles after pulse exposure (PESb) and continuous exposure (CESb) for 28 days were explored. The mechanisms were analyzed from the perspectives of tail muscle metabolism and transcriptomics. Compared to the control group, PESb and CESb decreased the average speed of P. nigromaculatus tadpoles by 25.72 % and 18.08 %, respectively. PESb and CESb led to changes in 70 and 24 metabolites of tail muscle, respectively. PESb led to alterations in metabolic pathways related to pyrimidine metabolism, arginine biosynthesis, and glycerophospholipid metabolism. In contrast, CESb altered metabolic pathways such as alanine, aspartate, and glutamate metabolism. Compared to the control, 1225 and 1139 DEGs were identified for PESb and CESb, respectively. These DEGs were mainly associated with functions such as immune response, DNA replication, protein digestion, and absorption. It can be seen that PESb and CESb can alter the metabolism and transcriptome of the tail muscle of P. nigromaculatus tadpoles, leading to differential expression of individual movements.

Effects of water immersion on immune, intestinal flora and metabolome of Chinese mitten crab (Eriocheir sinensis) after air exposure

Air exposure stress can induce stress response of Eriocheir sinensis and affect its normal life activities. The goal of this study was to investigate the effects of water immersion on the recovery of hepatopancreas immune-related enzyme activity, intestinal microbial diversity and metabolic level of Chinese mitten crabs after exposure to air. The results show that immersion can effectively alleviate the adverse effects of air exposure on the antioxidant capacity and immune capacity of Chinese mitten crabs, and the longer the time of immersion, the more obvious the recovery effect. Among them, the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase significantly increased after exposure to air (P < 0.05), reached a peak at 3 h, began to decline after immersion, and returned to a level close to the initial value at 24 h (P < 0.05). In addition, after exposure to air, the glucose and total cholesterol in haemolymph of Eriocheir sinensis were significantly different from the initial values (P < 0.05), gradually recovered to the initial level after re-immersion. However, changes in intestinal flora and hepatopancreas metabolism caused by air exposure did not fully recover after water exposure, and its negative effects did not completely disappear. The sequencing results showed that the species composition and diversity of intestinal microorganisms of Chinese mitten crab changed after air exposure and immersion treatment. The relative abundance of Actinomycetes increased significantly, while that of Proteobacteria and Firmicutes decreased significantly. Metabolomics analysis showed that air exposure and immersion destroyed the metabolic balance of amino acids and carnitine, reduced the level of carnitine metabolism, hindered the absorption of nutrients, and led to the accumulation of harmful substances.

Phthalates esters disrupt demersal fish behavior: Unveiling the brain-gut axis impact

The widespread use of plasticizers like phthalate esters (PAEs) has led to environmental and health concerns. The neurobehavioral toxicity of these compounds in marine environments, particularly regulated by the "brain-gut" axis, remains unclear, especially concerning wild demersal fish of high ecological value. Our investigation into the behavioral effects of three common PAEs, i.e., dimethyl phthalate (DMP), di-n-butyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), and their molecular mechanisms on juvenile Sebastes schlegelii, revealed alarming results from molecular to population levels. After a 20-day foodborne exposure at a low marine environmental concentration (1.0 μg g-1), we observed that all three PAEs significantly increased the thigmotaxis (behavioral tendency to stay close to physical boundaries) and mobility of juvenile fish by 28.2-59.4 % and 23.3-74.5 %, respectively, indicating anxiety-like behavior of fish. DEHP exhibited the most pronounced effects, followed by DBP and DMP. PAEs accumulated in the juvenile fish in the order of brain > liver > gut > muscle, with DEHP showing the highest brain concentrations (23.2 ± 2.98 μg g-1). This accumulation led to oxidative damage, inflammatory responses, and neurodegenerative changes in the optic tectum, resulting in cholinergic system dysfunction. In the gut, PAEs caused inflammatory lesions, disrupted the gut barrier, and altered the gut microbiome, exacerbating the neurotoxicity via "brain-gut" communication. These findings underscore the significant neurobehavioral toxicity of PAEs, emphasizing their critical impact on fish behavior. We also stress the crucial need for further research on fish and other marine species beyond the laboratory scale to fully understand the broader implications of PAE exposure in marine ecosystems and to guide future conservation efforts.

Toxicity of antimony in housefly after whole-life-cycle exposure: Changes in growth, development, redox homeostasis, mitochondrial function, and fecundity

The increasing utilization of antimony (Sb) in manufacturing industries has led to the emergence of Sb contamination in the environment as a significant public health concern. To elucidate the toxicity of Sb and its mechanism of action, this study aimed to investigate the adverse effects of Sb on a cosmopolitan insect, housefly (Musca domestica), under a whole life cycle (from embryonic to adult stage) exposure through the examination of a suite of parameters, including biological, physiological, behavioral, and molecular endpoints. A range of Sb concentrations, including moderate contamination (0.07 mM), heavy contamination (0.7 mM), and extreme contamination (7 and 70 mM), were conducted in the study. The results indicated that the houseflies could maintain their health when exposed to 0.07 mM Sb. The exposure of Sb (0.7-70 mM) to houseflies resulted in a range of adverse effects, including developmental retardation, locomotor inhibition, gut damage, oxidative stress, and mitochondrial dysfunction in the houseflies. Significantly, Sb demonstrated reproductive toxicity in the houseflies, as evidenced by reduced reproductive capacity, DNA damage, and ovarian abnormalities. The disturbance of hormonal synthesis and the MAPK pathway induced by Sb treatment may contribute to reproductive toxicity. These comprehensive toxicological data provide insight into the prediction of toxicity and the assessment of the ecological risk of Sb.

PAT exposure caused human hepatocytes apoptosis and induced mice subacute liver injury by activating oxidative stress and the ERS-associated PERK pathway

With the widespread use of antimony compounds in synthetic materials and processing, the occupational exposure and environmental pollution caused by antimony have attracted the attention of researchers. Studies have shown that antimony compounds can cause liver damage, but the mechanism has not yet been elucidated. In this study, we used the trivalent potassium antimony tartrate (PAT) to infect L02 hepatocytes and Kunming (KM) mice to establish an antimony-induced apoptosis model of L02 cells and a subacute liver injury model of KM mice. We found that PAT exposure caused hepatocyte apoptosis and was accompanied by oxidative stress and endoplasmic reticulum stress (ERS), and the ERS-associated PERK pathway was activated. Further experimental results showed that N-acetyl-l-cysteine (NAC) pretreatment or silencing of the PERK gene in L02 cells reduced PAT-induced apoptosis. The activity of SOD and CAT in treated L02 cells was increased, the malondialdehyde content in L02 cells and liver tissues was decreased, and the content of ERS-related proteins GRP78 and CHOP, as well as the content of PERK-pathway-related proteins p-PERK/PERK, p-eif2α/eif2α and ATF4 protein were significantly reduced. Overall, PAT exposure triggered hepatocyte apoptosis and liver injury by inducing oxidative stress and activating the ERS-associated PERK pathway; however, this effect could be alleviated by NAC intervention or silencing of PERK in hepatocytes.

Association of metalloestrogens exposure with depression in women across reproductive lifespan

BACKGROUND

Exposure to metal could impact women's depression risk. However, the connection and mechanisms between metalloestrogens exposure and depression are still not fully understood. We aim to explore the associations between metalloestrogens and the risk of depression in women across reproductive lifespan.

METHODS

Using data from NHANES 2011-2018, we employed logistic regression and baknernel machine regression (BKMR) to study links between metalloestrogen exposure and depression in US women. We analyzed how contraceptive use affects this relationship.

RESULTS

The study involved 3,374 adult women, with 345 of them experiencing depression. Our research revealed that certain metalloestrogens like Ba, Ca, Pb, Sb, and Sn were linked to higher depression risk in women, while Hg was associated with lower depression risk in older women. For women aged 18-44, a blend of metalloestrogens showed a significant positive correlation with depression risk, and the likelihood of depression in later years notably rose when the metal mixture concentration reached or exceeded the 60th percentile. Oral contraceptives would have an effect on the impact of metalloestrogen mixture exposure on depression in women during the reproductive stage.

CONCLUSIONS

Our study indicates a significant link between metalloestrogen exposure and a higher risk of depression in adult women in the United States. This finding can aid in identifying the connection and enhancing women's mental well-being.

Chemistry of Antimony in Radiopharmaceutical Development: Unlocking the Theranostic Potential of Sb Isotopes

Antimony-119 (119Sb) holds promise for radiopharmaceutical therapy (RPT), emitting short-range Auger and conversion electrons that can deliver cytotoxic radiation on a cellular level. While it has high promise theoretically, experimental validation is necessary for 119Sb in vivo applications. Current 119Sb production and separation methods face robustness and compatibility challenges in radiopharmaceutical synthesis. Limited progress in chelator development hampers targeted experiments with 119Sb. This review compiles literature on the toxicological, biodistribution and redox properties of Sb, along with existing Sb complexes, evaluating their suitability for radiopharmaceuticals. Sb(III) is suggested as the preferred oxidation state for radiopharmaceutical elaboration due to its stability in vivo and lack of skeletal uptake. While Sb complexes with both hard and soft donor atoms can be achieved, Sb thiol complexes offer enhanced stability and compatibility with the desired Sb(III) oxidation state. For 119Sb to find application in RPT, scientists need to make discoveries and advancements in the areas of isotope production, and radiometal chelation. This review aims to guide future research towards harnessing the therapeutic potential of 119Sb in RPT.

Antimony trioxide nanoparticles promote ferroptosis in developing zebrafish (Danio rerio) by disrupting iron homeostasis

The widespread use of antimony trioxide (ATO) and ATO nanoparticles (nATO) has led to increasing ecological and health risks. However, there is relatively insufficient research on the aquatic ecotoxicology of nATO. This study revealed that nATO affects the development of zebrafish embryos and mainly induces ferroptosis through the dissolution of Sb(III). The size of nATO ranged from 50 to 250 nm, and it generated free radicals in water. It can be ingested and accumulate in zebrafish larvae and affects normal development. Compared with those in the control group, the levels of reactive oxygen species (ROS), cell apoptosis, mitochondrial damage and iron content in the group exposed to high concentrations of nATO were increased. The transcriptomics results indicated that nATO significantly altered the expression levels of key genes related to glutathione metabolism and ferroptosis. Quantitative polymerase chain reaction consistently demonstrated the reliability of the transcriptome data and revealed that nATO induced ferroptosis by disrupting iron homeostasis and the key factor is the dissolution of Sb(III). Furthermore, ferrostatin-1, an inhibitor of ferroptosis, decreased the levels of ROS, apoptosis and mitochondrial damage induced by nATO, which further prove that nATO can promote ferroptosis. This work deepens the understanding of the ecological toxicological effects of nATO in aquatic environments and its mechanisms, which is highly important for the development of antimony management strategies.

Toxicity and related molecular mechanisms of Sb(III) in the embryos and larvae of zebrafish (Danio rerio)

Antimony (Sb) pollution poses a severe threat to humans and ecosystems due to the extensive use of Sb in various fields. However, little is known about the toxic effects of Sb and its aquatic ecotoxicological mechanism. This study aimed to reveal the toxicity and related molecular mechanisms of trivalent Sb (Sb(III)) in zebrafish embryos/larvae. Sb(III) accumulated in larvae, which correlated with the exposure concentration. Although no significant lethal or teratogenic effects were observed, normal growth and development were affected. Exposure to 10 or 20 mg/L Sb(III) increased the levels of reactive oxygen species in the larvae while enhancing catalase activity and increasing cell apoptosis. Transcriptomic analysis revealed that Sb(III) promoted glutathione metabolism and the ferroptosis pathway. In addition, symptoms associated with ferroptosis, including mitochondrial damage, biochemical levels of related molecules and increased tissue iron content, were detected. Quantitative polymerase chain reaction (qPCR) analyses further confirmed that Sb(III) significantly altered the transcription levels of genes related to the ferroptosis pathway by disrupting iron homeostasis. Furthermore, ferrostatin-1 (Fer-1) mitigated the toxic effects induced by Sb(III) in zebrafish. Our research fills the gap in the literature on the toxicity and mechanism of Sb(III) in aquatic organisms, which is highly important for understanding the ecological risks associated with Sb.

First insight of the intergenerational effects of tri-n-butyl phosphate and polystyrene microplastics to Daphnia magna

As an emerging organic pollutant, tributyl phosphate (TnBP) can be easily adsorbed by microplastics, resulting in compound toxic effects. In the present work, the effects of polystyrene microplastics (PS-MPs) and TnBP on the survival, growth, reproduction and oxidative stress of Daphnia magna (D. magna) have been evaluated through multigenerational test. Compared with the alone exposure groups, the somatic growth rate and the expression values of growth related genes rpa1, mre11, rnha, and rfc3_5 in the F1 generation of the combined exposure groups were significantly lower (p < 0.05), indicating synergistic effect of PS-MPs and TnBP on the growth toxicity and transgenerational effects. In addition, compared with the PS-MPs groups, significantly lower average number of offspring and expression values of reproduction related genes ccnb, mcm2, sgrap, and ptch1 were observed in the combined exposure group and TnBP group (p < 0.05), indicating TnBP might be the major factor causing reproductive toxicity to D. magna. Although PS-MPs and TnBP alone or in combination also had toxic impacts on the growth, survival and reproduction of D. magna in generations F0 and F2, the effects were less than F1 generation. Regarding oxidative stress, the activity of SOD, CAT and GSH-Px and MDA content in the generations F0 and F1 of combined exposure groups were higher than the TnBP group but lower than the PS-MPs groups, suggesting that PS-MPs might be the dominant cause of the oxidative damage in D. magna and the presence of TnBP would alleviate oxidative stress by reducing the bioaccumulation of PS-MPs. The present work will provide a theoretical basis for further understanding of the toxic effects and ecological risks of combined TnBP and microplastic pollution on aquatic organisms.

The Potential of Defatted Yellow Mealworm (Tenebrio molitor) Meal as an Alternative Protein Source for Juvenile Chinese Mitten Crab (Eriocheir sinensis)

This study was aimed to investigate the effects of replacing dietary fish meal (FM) with defatted yellow mealworm (Tenebrio molitor) meal (DYM) on growth performance, intestinal health, serum immune, and antioxidant indexes of juvenile Chinese mitten crab (Eriocheir sinensis). Four hundred juvenile Chinese mitten crabs (4.94 ± 0.08 g) were randomly distributed into five groups in quadruplicate (20 crabs per tank), and each group was fed with diets that replaced FM with DYM at 0% (CON, containing 200 g/kg FM), 25% (DYM25), 50% (DYM50), 75% (DYM75), and 100% (DYM100) for 8 weeks, respectively. The results showed that the growth, serum immune and antioxidant indexes, digestive enzyme activities, intestinal histology, and microbiota composition of DYM25, DYM50, and DYM75 groups all reached the similar level as the CON group. While when 100% fishmeal was replaced, significantly decreased the final body weight (FBW), weight gain (WG), serum alkaline phosphatase (AKP), acid phosphatase (ACP), lysozyme (LZM), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) activities, hepatopancreas protease activity, mid-intestine folds height and number (P < 0.05), significantly increased the feed conversion ratio (FCR), serum malondialdehyde (MDA) content, and the abundance of intestinal harmful bacteria Shewanella (P < 0.05). Overall, these results suggest that 75% dietary FM (150 g/kg) can be effectively replaced by DYM without negative impact on the growth performance, intestinal health, serum immune, and antioxidant indexes of juvenile E. sinensis.

Combined transcriptome and metabolome analysis reveals the toxic effects of antimony on the earthworm

Antimony (Sb) poses a significant ecological threat. This study combines biochemical, pathological, transcriptome, and metabolome analyses to assess the short-term (14-day) toxic impact of two Sb levels (25 mg/kg and 125 mg/kg) on earthworms (Eisenia fetida). Higher Sb concentration caused severe intestinal damage, elevated metallothionein (MT) levels, and reduced antioxidant capacity. Metabolome analysis identifies 404 and 1698 significantly differential metabolites in the two groups. Metabolites such as S(-)-cathinone, N-phenyl-1-naphthylamine, serotonin, 4-hydroxymandelonitrile, and 5-fluoropentylindole contributed to the metabolic responses to Sb stress. Transcriptome analysis shows increased chitin synthesis as a protective response, impacting amino sugar and nucleotide sugar metabolism for cell wall synthesis and damage repair. Integrated analysis indicated that 5 metabolite-gene pairs were found in two Sb levels and 11 enriched pathways were related to signal transduction, carbohydrate metabolism, immune system, amino acid metabolism, digestive system, and nervous system. Therefore, the integration of multiomics approaches enhanced our comprehension of the molecular mechanisms underlying the toxicity of Sb in E. fetida.

Alteration in oxidative stress markers, digestive physiology and gut microbiota of Heteropneustes fossilis and Clarias batrachus exposed to eriochrome black T

Synthetic dyes are the primary cause of water pollution in industrial regions. Azo dyes account for 60-70% of such dyes used in the textile sector due to their numerous beneficial characteristics. Nevertheless, there is a dearth of knowledge regarding the toxicity of Eriochrome Black T (EBT), a widely used azo dye in the textile industry. Therefore, the current study was designed to investigate the effect of EBT exposure on two catfish species, Heteropneustes fossilis and Clarias batrachus. Following 96 h exposure to 1, 10 and 20 mgL-1 of EBT, the MDA content and activities of SOD, CAT and GR exhibited a rising trend. However, as the concentration of EBT increased in both species, GPx showed decreased activity. EBT exposure also altered gut morphometry as well as the three main digestive enzymes activity (increase in lipase and trypsin activity, while decrease in amylase activity). In addition, the exposure of EBT had a significant impact on the gut microbiota of both species. C. batrachus demonstrated the suppression or absence of beneficial gut commensals (Bacillus and Cetobacterium), whereas H. fossilis revealed the proliferation and appearance of beneficial commensal microbes (Bacillus, Bacteroides, Prevotella, and Megashaera). Furthermore, the expansion or absence of these microbial communities indicated that the gut microbiota of both species was involved in dye digestion, immunity and detoxification. Overall, the percent change calculation of all the selected biomarkers, together with gut microbiota analysis, indicates that C. batrachus was more vulnerable to EBT exposure than H. fossilis. The present investigation effectively demonstrated the toxic impact of EBT on fish health by employing oxidative stress markers, digestive enzymes, and the fish gut microbiota as a promising tool for screening the impact of dye exposure on digestive physiology in toxicological research.

Effects of Different Levels of Carbohydrates on Growth Performance, Hepatic and Intestinal Health, and Intestinal Microflora of Juvenile Pikeperch (Sander lucioperca)

Pikeperch (Sander lucioperca) is a species with great potential for aquaculture in Eurasian countries, while feed costs limit the scale of pikeperch farming. Adding carbohydrates to the feed as an energy source is a viable approach to reduce costs and to improve the culture status of pikeperch. In this study, in order to determine the optimal carbohydrate requirement of pikeperch, three tapioca starch (8%, 10%, and 12%) added feeds were produced with isonitrogenous (51%) and isolipidic (11%). For 8 weeks, body weight was 1.20 ± 0.01 g, pikeperch were manually fed the trio of experimental diets until they seemed fully satisfied. The finding revealed that pikeperch can utilize dietary carbohydrate, but excessive dietary carbohydrate will adversely affect the growth performance. The growth and survival rate were decreased in pikeperch in S12 (P < 0.05). The α-amylase activity of S12 reduced in the intestine and lipid deposition was observed in the liver compared with the S8. In addition, proinflammatory cytokines, interleukin 1 beta (il1-β), interleukin 8 (il8), and tumor necrosis factor beta (tnf-β), in the liver and intestine elevate and anti-inflammatory cytokines, interleukin 10 (il10) and transforming growth factor beta (tgf-β), decrease with increasing dietary carbohydrate levels. Hepatic and intestinal antioxidant capacity were also adversely affected, with S12 significantly increasing malondialdehyde (MDA) contents and decreasing glutathione (GSH) and total antioxidant capacity (T-AOC) (P < 0.05). The intestinal barrier function is also damaged, the height and width of intestinal villi decreased, and the expression of occludin-a, occludin-b, and zonula occludens-2 (zo-2) genes was decreased. Elevated levels of starch intake led to harm to gut microflora, reducing bacterial populations, simultaneously boosting the presence of detrimental bacteria (Proteobacteria, Actinobacteriota, Achromobacter, and Rhodococcus) and diminishing the beneficial bacteria (Firmicutes). In conclusion, moderate addition of starch as an energy source can reduce feed costs; however, over addition can bring about organism damage and is recommended to be added at less than 10%.

Effects of four types of natural bait on water quality, feeding, growth, and antioxidant enzyme activity of Monopterus albus in a recirculating aquaculture system

Monopterus albus is one of China's renowned and superior aquaculture species, with its seedlings mainly sourced from wild capture. One of the bottlenecks in M. albus aquaculture is the high mortality rate and low feeding initiation rate from stocking wild fry to the initiation of feeding. In production, trash fish is commonly used to wean M. albus juveniles onto feeding. In this study, we introduced three other natural feeds, earthworms (EW), yellow mealworms (YMW), and fly maggots (FM), with frozen trash fish (TF) serving as the control group, to evaluate the effects of these four natural feeds on the survival rate, feeding initiation, antioxidant enzymes activity, and body composition of M. albus juveniles under recirculating water aquaculture conditions. The experiment comprised four treatments, each with three replicates. Each replicate consisted of stocking 150 M. albus juveniles weighing 10.02 ± 0.89 g in size, raised for 5 weeks. The survival rate of the YMW group was 73.33%-85.33%, which was significantly higher than that of the other three bait groups (p < 0.05). The four bait groups showed no significant differences in final body weight and specific growth rate (SGR) (p > 0.05). The EW group showed the highest final body weight, with an average SGR of 2.73, whereas the YMW group had an average SGR of 1.87. The average daily feeding amount was significantly higher in EW and YMW groups than in the other two groups (p < 0.05). The percentage of feeding amount to fish weight in the EW group reached 7.3% in the fifth week. After 5 weeks of cultivation, NO2 --N content was significantly higher in the waters of the TF and EW groups than in the waters of the FM and YMW groups (p < 0.05), there was no significant difference in TAN content among the treatment groups (p > 0.05). Liver malondialdehyde content was significantly higher in the TF group than in the other bait groups (p < 0.05). GSH-Px activity was significantly higher in the EW group than in the FM group and YMW group. No significant differences in SOD and CAT activity and T-AOC were observed among the bait groups (p > 0.05). The increase in crude protein content was significantly higher in the TF group than in the FM group, but the increase in crude ash content was significantly lower in the TFgroup. In conclusion, Tenebrio molitor could potentially serve as one of the alternative feeds during the initial stages of M. albus juveniles stocking.

Endocrine system, cell growth and death, and energy metabolism induced by Sb(III) exposure in earthworm (Pheretima guillemi) revealed by transcriptome and metabolome analysis

Antimony (Sb) is known for its severe and extensive toxicity, and earthworms are considered important indicator organisms in soil ecosystems. Therefore, the present study investigated the mechanism of toxicity of the Sb at different concentrations (50, 200 mg/kg) on earthworms using biochemical indicators, pathological sections, as well as metabolomics and transcriptomics analyses. The results showed that as the exposure concentration increased, both the antioxidant system of earthworms, extent of intestinal damage, and their metabolomic characteristics were significantly enhanced. In the 50 and 200 mg/kg Sb treatment group, 30 and 177 significant differentially changed metabolites (DCMs) were identified, respectively, with the most DCMs being down- and up-regulated, respectively. Metabolomics analysis showed that the contents of dl-tryptophan, glutamic acid, glycine, isoleucine, l-methionine, involved in the protein digestion and absorption as well as aminoacyl-tRNA biosynthesis were significantly up-regulated under the 200 mg/kg treatment. At the transcriptional level, Sb mainly affected the immune system, nervous system, amino acid metabolism, endocrine system, and carbohydrate metabolism in earthworms. The integration of transcriptomic and metabolomic data indicated that high doses of Sb regulated the metabolites and genes related to the oxidative phosphorylation pathway in earthworms. Overall, these results revealed global responses beyond the scope of conventional toxicity endpoints and facilitated a more in-depth and comprehensive assessment of the toxic effects of Sb.

Comparative studies on the intestinal health of wild and cultured ricefield eel (Monopterus albus)

Fish intestinal health under intensive aquaculture mode plays an important role in growth, development, and immune function. The present study was aimed to systematically investigate the differences of intestinal health between wild and cultured Monopterus albus by biochemical parameters, histomorphology, and molecular biology. A total of 15 healthy M. albus per group, with an average body weight of 45 g, were sampled to analyze intestinal health parameters. Compared with wild fish, the cultured M. albus in the foregut had lower trypsin, lipase, SOD, CAT, T-AOC, and GSH-Px activities (P < 0.05) and higher amylase activity and MDA content (P < 0.05). The villus circumference and goblet cells in the cultured group were significantly lower than those in the wild group (P < 0.05). In addition, the cultured fish showed lower relative expression levels of occludin, zo-1, zo-2, claudin-12, claudin-15, mucin5, mucin15, lysozyme, complement 3, il-10, tgf-β1, tgf-β2, and tgf-β3 (P < 0.05) and higher il-1β, il-6, il-8, tnf-a, and ifnγ mRNA expressions than those of wild fish (P < 0.05). In terms of gut microbiota, the cultured group at the phylum level displayed higher percentages of Chlamydiae and Spirochaetes and lower percentages of Firmicutes, Bacteroidetes, Actinobacteria, Cyanobacteria, and Verrucomicrobia compared to the wild group (P < 0.05). At the genus level, higher abundances of Pseudomonadaceae_Pseudomonas and Spironema and lower abundances of Lactococcus and Cetobacterium were observed in the cultured group than in the wild group (P < 0.05). To our knowledge, this is the first investigation of the intestinal health status between wild and cultured M. albus in terms of biochemistry, histology, and molecular biology levels. Overall, the present study showed significant differences in intestinal health between wild and cultured M. albus and the main manifestations that wild M. albus had higher intestinal digestion, antioxidant capacity, and intestinal barrier functions than cultured M. albus. These results would provide theoretical basis for the subsequent upgrading of healthy aquaculture technology and nutrient regulation of intestinal health of cultured M. albus.

Assessing the hepatotoxicity of phosphogypsum leachate in zebrafish (Danio rerio)

The improper disposal of large amounts of phosphogypsum generated during the production process of the phosphorus chemical industry (PCI) still exists. The leachate formed by phosphogypsum stockpiles could pose a threat to the ecological environment and human health. Nevertheless, information regarding the harmful effects of phosphogypsum leachate on organisms is still limited. Herein, the physicochemical characteristics of phosphogypsum leachate were analyzed, and its toxicity effect on zebrafish (Danio rerio), particularly in terms of hepatotoxicity and potential mechanisms, were evaluated. The results indicated that P, NH3-N, TN, F-, As, Cd, Cr, Co, Ni, Zn, Mn, and Hg of phosphogypsum leachate exceeded the V class of surface water environmental quality standards (GB 3838-2002) to varying degrees. Acute toxicity test showed that the 96 h LC50 values of phosphogypsum leachate to zebrafish was 2.08 %. Under exposure to phosphogypsum leachate, zebrafish exhibited concentration-dependent liver damage, characterized by vacuolization and infiltration of inflammatory cells. The increased in Malondialdehyde (MDA) content and altered activities of antioxidant enzymes in the liver indicated the induction of oxidative stress and oxidative damage. The expression of apoptosis-related genes (P53, PUMA, Caspase3, Bcl-2, and Bax) were up-regulated at low dosage group and down-regulated at medium and high dosage groups, suggesting the occurrence of hepatocyte apoptosis or necrosis. Additionally, phosphogypsum leachate influenced the composition of the zebrafish gut microbiota by reducing the relative abundance of Bacteroidota, Aeromonas, Flavobacterium, Vibrio, and increasing that of Rhodobacter and Pirellula. Correlation analysis revealed that gut microbiota dysbiosis was associated with phosphogypsum leachate-induced hepatotoxicity. Altogether, exposure to phosphogypsum leachate caused liver damage in zebrafish, likely through oxidative stress and apoptosis, with the intestinal flora also playing a significant role. These findings contribute to understanding the ecological toxicity of phosphogypsum leachate and promote the sustainable development of PCI.

Integrated physiological, intestinal microbiota, and metabolomic responses of adult zebrafish (Danio rerio) to subacute exposure to antimony at environmentally relevant concentrations

The available information regarding the impact of antimony (Sb), a novel environmental pollutant, on the intestinal microbiota and host health is limited. In this study, we conducted physiological characterizations to investigate the response of adult zebrafish to different environmental concentrations (0, 30, 300, and 3000 µg/L) of Sb over a period of 14 days. Biochemical and pathological changes demonstrated that Sb effectively compromised the integrity of the intestinal physical barrier and induced inflammatory responses as well as oxidative stress. Analysis of both intestinal microbial community and metabolome revealed that exposure to 0 and 30 µg/L of Sb resulted in similar microbiota structures; however, exposure to 300 µg/L altered microbial communities' composition (e.g., a decline in genus Cetobacterium and an increase in Vibrio). Furthermore, exposure to 300 µg/L significantly decreased levels of bile acids and glycerophospholipids while triggering intestinal inflammation but activating self-protective mechanisms such as antibiotic presence. Notably, even exposure to 30 µg/L of Sb can trigger dysbiosis of intestinal microbiota and metabolites, potentially impacting fish health through the "microbiota-intestine-brain axis" and contributing to disease initiation. This study provides valuable insights into toxicity-related information concerning environmental impacts of Sb on aquatic organisms with significant implications for developing management strategies.

Excessive dietary iron exposure increases the susceptibility of largemouth bass (Micropterus salmoides) to Aeromonas hydrophila by interfering with immune response, oxidative stress, and intestinal homeostasis

Iron is an essential cofactor in the fundamental metabolic pathways of organisms. Moderate iron intake can enhance animal growth performance, while iron overload increases the risk of pathogen infection. Although the impact of iron on the pathogen-host relationship has been confirmed in higher vertebrates, research in fish is extremely limited. The effects and mechanisms of different levels of iron exposure on the infection of Aeromonas hydrophila in largemouth bass (Micropterus salmoides) remain unclear. In this study, experimental diets were prepared by adding 0, 800, 1600, and 3200 mg/kg of FeSO4∙7H2O to the basal feed, and the impact of a 56-day feeding period on the mortality rate of largemouth bass infected with A. hydrophila was analyzed. Additionally, the relationships between mortality rate and tissue iron content, immune regulation, oxidative stress, iron homeostasis, gut microbiota, and tissue morphology were investigated. The results showed that the survival rate of largemouth bass infected with A. hydrophila decreased with increasing iron exposure levels. Excessive dietary iron intake significantly increased iron deposition in the tissues of largemouth bass, reduced the expression and activity of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, increased the content of lipid peroxidation product malondialdehyde, and thereby induced oxidative stress. Excessive iron supplementation could influence the immune response of largemouth bass by upregulating the expression of pro-inflammatory cytokines in the intestine and liver, while downregulating the expression of anti-inflammatory cytokines. Additionally, excessive iron intake could also affect iron metabolism by inducing the expression of hepcidin, disrupt intestinal homeostasis by interfering with the composition and function of the gut microbiota, and induce damage in the intestinal and hepatic tissues. These research findings provide a partial theoretical basis for deciphering the molecular mechanisms underlying the influence of excessive iron exposure on the susceptibility of largemouth bass to pathogenic bacteria.

Effects of elevated temperature and different crystal structures of TiO2 nanoparticles on the gut microbiota of mussel Mytilus coruscus

Coastal habitats are exposed to increasing pressure of nanopollutants commonly combined with warming due to the seasonal temperature cycles and global climate change. To investigate the toxicological effects of TiO2 nanoparticles (TiO2 NPs) and elevated temperature on the intestinal health of the mussels (Mytilus coruscus), the mussels were exposed to 0.1 mg/L TiO2 NPs with different crystal structures for 14 days at 20 °C and 28 °C, respectively. Compared to 20 °C, the agglomeration of TiO2 NPs was more serious at 28 °C. Exposure to TiO2 NPs led to elevated mortality of M. coruscus and modified the intestinal microbial community as shown by 16S rRNA sequence analysis. Exposure to TiO2 NPs changed the relative abundance of Bacteroidetes, Proteobacteria and Firmicutes. The relative abundances of putative mutualistic symbionts Tenericutes and Fusobacteria increased in the gut of M. coruscus exposed to anatase, which have contributed to the lower mortality in this group. LEfSe showed the combined stress of warming and TiO2 NPs increased the risk of M. coruscus being infected with potential pathogenic bacteria. This study emphasizes the toxicity differences between crystal structures of TiO2 NPs, and will provides an important reference for analyzing the physiological and ecological effects of nanomaterial pollution on bivalves under the background of global climate change.

Can antimony contamination in soil undermine the ecological contributions of earthworms?

As antimony (Sb) has been increasingly used in manufacturing industries (e.g., alloy, polymer and electronics industries), Sb contamination in the soil environment becomes widely reported and has drawn growing attention due to the toxicity of Sb to living organisms. Whether soil-dwelling organisms can tolerate Sb toxicity and maintain their ecological functions remains poorly understood. Using a cosmopolitan, ecologically important earthworm species (Eisenia fetida) as an ideal model organism, we examine the effects of Sb on the physiological, molecular and behavioural responses of earthworms to different levels of Sb contamination in soil (0, 10, 50, 100, 250 and 500 mg/kg). We found that earthworms could tolerate heavy Sb contamination (100 mg/kg) by boosting their antioxidant defence (POD and GST) and immune systems (ACP) so that their body weight and survival rate were sustained (c.f. control). However, these systems were compromised under extreme Sb contamination (500 mg/kg), leading to mortality. As such, earthworms exhibited avoidance behaviour to escape from the Sb-contaminated soil, implying the loss of their ecological contributions to the environment (e.g., increase in soil aeration and maintenance of soil structure). By measuring various types of biomarkers along a concentration gradient, this study provides a mechanistic understanding of how earthworms resist or succumb to Sb toxicity. Since extreme Sb contamination in soil (>100 mg/kg) is rarely found in nature, we are optimistic that the health and performance of earthworms are not influenced by Sb in most circumstances, but regular monitoring of Sb in soil is recommended to ensure the integrity and functioning of soil environment. Further studies are recommended to evaluate the long-term impact of Sb in the soil ecosystem through bioaccumulation and trophic transfer among soil-dwelling organisms.

A Drosophila model of gestational antimony exposure uncovers growth and developmental disorders caused by disrupting oxidative stress homeostasis

The toxic heavy metal antimony (Sb) is ubiquitous in our daily lives. Various models have shown that Sb induces neuronal and reproductive toxicity. However, little is known about the developmental toxicity of Sb exposure during gestation and the underlying mechanisms. To study its effects on growth and development, Drosophila stages from eggs to pupae were exposed to different Sb concentrations (0, 0.3, 0.6 and 1.2 mg/mL Sb); RNA sequencing was used to identify the underlying mechanism. The model revealed that prenatal Sb exposure significantly reduced larval body size and weight, the pupation and eclosion rates, and the number of flies at all stages. With 1.2 mg/mL Sb exposure in 3rd instar larvae, 484 genes were upregulated and 694 downregulated compared to controls. Biological analysis showed that the disrupted transcripts were related to the oxidative stress pathway, as verified by reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) and glutathione (GSH) intervention experiments. Sb exposure induced oxidative stress imbalance could be rectified by chelation and antioxidant effects of NAC/GSH. The Drosophila Schneider 2 (S2) model further demonstrated that NAC and GSH greatly ameliorated cell death induced by Sb exposure. In conclusion, gestational Sb exposure disrupted oxidative stress homeostasis, thereby impairing growth and development.

Immunonutrition: facilitating mucosal immune response in teleost intestine with amino acids through oxidant-antioxidant balance

Comparative animal models generate fundamental scientific knowledge of immune responses. However, these studies typically are conducted in mammals because of their biochemical and physiological similarity to humans. Presently, there has been an interest in using teleost fish models to study intestinal immunology, particularly intestinal mucosa immune response. Instead of targeting the pathogen itself, a preferred approach for managing fish health is through nutrient supplementation, as it is noninvasive and less labor intensive than vaccine administrations while still modulating immune properties. Amino acids (AAs) regulate metabolic processes, oxidant-antioxidant balance, and physiological requirements to improve immune response. Thus, nutritionists can develop sustainable aquafeeds through AA supplementation to promote specific immune responses, including the intestinal mucosa immune system. We propose the use of dietary supplementation with functional AAs to improve immune response by discussing teleost fish immunology within the intestine and explore how oxidative burst is used as an immune defense mechanism. We evaluate immune components and immune responses in the intestine that use oxidant-antioxidant balance through potential selection of AAs and their metabolites to improve mucosal immune capacity and gut integrity. AAs are effective modulators of teleost gut immunity through oxidant-antioxidant balance. To incorporate nutrition as an immunoregulatory means in teleost, we must obtain more tools including genomic, proteomic, nutrition, immunology, and macrobiotic and metabonomic analyses, so that future studies can provide a more holistic understanding of the mucosal immune system in fish.

Effects of antimony exposure on DNA damage and genome-wide variation in zebrafish (Danio rerio) liver

Antimony (Sb) is a potentially toxic and carcinogenic cumulative contaminant that poses a serious threat to aquatic ecosystems. To better clarify the genotoxicity of Sb and its mechanism of action. In this study, we investigated DNA damage and genome-wide variation in the liver of a model organism, zebrafish (Danio rerio), under subacute Sb exposure and explored its potential toxicological mechanisms. The results showed that medium and high concentrations of Sb significantly reduced the total antioxidant capacity and increased the content of reactive oxygen species in zebrafish liver, and further studies revealed that it increased oxidative DNA damage and DNA-DNA cross-link (DDC), but had little effect on DNA-protein cross-link (DPC). The result of resequencing showed that the mutation sites of the genes with high concentrations of Sb were higher than those with medium concentrations, and the mutation was mainly a single nucleotide. The pathways significantly enriched for nonsynonymous single nucleotide polymorphisms (SNPs) and insertion/deletion mutations (InDels) variant genes in the coding regions of both the medium and high Sb-treated groups were ECM-receptor interactions, and the high Sb-treated group also included lysine degradation, hematopoietic cell lineage, and cytokine-cytokine receptor interactions. This suggests that ECM-receptor interactions play an important role in the mechanism of antimony toxicity to the liver of zebrafish.

Cardiovascular Effects of Environmental Metal Antimony: Redox Dyshomeostasis as the Key Pathogenic Driver

Significance: Cardiovascular diseases (CVDs) are the leading cause of death worldwide, which may be due to sedentary lifestyles with less physical activity and over nutrition as well as an increase in the aging population; however, the contribution of pollutants, environmental chemicals, and nonessential metals to the increased and persistent CVDs needs more attention and investigation. Among environmental contaminant nonessential metals, antimony has been less addressed. Recent Advances: Among environmental contaminant nonessential metals, several metals such as lead, arsenic, and cadmium have been associated with the increased risk of CVDs. Antimony has been less addressed, but its potential link to CVDs is being gradually recognized. Critical Issues: Several epidemiological studies have revealed the significant deleterious effects of antimony on the cardiovascular system in the absence or presence of other nonessential metals. There has been less focus on whether antimony alone can contribute to the pathogenesis of CVDs and the proposed mechanisms of such possible effects. This review addresses this gap in knowledge by presenting the current available evidence that highlights the potential role of antimony in the pathogenesis of CVDs, most likely via antimony-mediated redox dyshomeostasis. Future Directions: More direct evidence from preclinical and mechanistic studies is urgently needed to evaluate the possible roles of antimony in mitochondrial dysfunction and epigenetic regulation in CVDs. Antioxid. Redox Signal. 38, 803-823.

Association of urinary heavy metals co-exposure and adult depression: Modification of physical activity

OBJECTIVE

This study aimed to evaluate the association between urinary heavy metal mixture exposure and depression, and the modifying role of physical activity in the effects of heavy metal mixture on depression risk was also considered.

METHODS

Data of this study were derived from the National Health and Nutrition Examination Survey 2011-2016. Depression was measured by the Patient Health Questionnaire. We first selected 6 (cadmium, cobalt, tin, antimony, thallium, and mercury) from 14 heavy metals through elastic net regression for further analysis. Then binomial logistic regression, generalized additive model, environment risk score (ERS), and weighted quantile sum (WQS) regression were adopted to assess the effects of six metals individual and cumulative exposure on depression risk. Finally, we also examined whether physical activity could mitigate the effects of heavy metal co-exposure on depression risk.

RESULTS

Totally, 4212 participants were included and 7.40% of subjects were with depression. We found urinary tin and antimony were separately associated with increased odds of depression (Sb: OR = 1.285, 95% CI: 1.064-1.553; Sn: OR = 1.281, 95% CI: 1.097-1.495), and a linear dose-response relationship between tin and depression was also noticed (P < 0.05). Meanwhile, urinary heavy metals co-exposure was positively related to depression risk (ERS_Q4: OR = 2.691, 95% CI: 1.399-5.174; WQS_positive: OR = 1.465, 95% CI: 1.063-2.021), in which tin, antimony, and cadmium were identified with greater contributions to the overall mixture effect. In both ERS and WQS models, the significant positive association between the metal mixture and depression risk remained only in those who were inactive in physical activity.

CONCLUSION

Our study concluded the detrimental effect of heavy metals in combined exposure on the risk of depression, which might be attenuated by physical activity.

Dietary nano-selenium alleviates heat stress-induced intestinal damage through affecting intestinal antioxidant capacity and microbiota in rainbow trout (Oncorhynchus mykiss)

Heat stress-induced intestinal damage is a key event in fish pathology. Nano-selenium (nano-Se) shows remarkably high biological activity and low toxicity, making it an ideal and ecological Se formulation; however, to date, the protective effects of nano-Se against heat stress-induced intestinal injury and pertinent molecular mechanisms remain unknown. Herein, rainbow trout (Oncorhynchus mykiss) were fed either a basal diet or basal diet + 5 mg/kg nano-Se. Samples were collected before (18 °C for 9 days; CG18 and Se18 groups) and after (24 °C for 8 h; CG24 and Se24 groups) heat stress treatment. On heat stress exposure, intestinal villus height, muscularis thickness, and goblet cell number decreased, and expression of tight junction proteins (ZO-1, occludin, and claudin-8d) was downregulated; dietary supplementation with nano-Se alleviated these effects. Furthermore, in the presence of nano-Se, catalase activity was elevated, and expression of diverse heat shock proteins (Hsp70b, Hsp90α, and Hsp30), selenoproteins (Gpx1a, Gpx1b1, and Trx), and anti-inflammatory cytokine (TGF-β) was upregulated. In contrast, nano-Se supplementation significantly alleviated the increase of the expression of pro-inflammatory cytokines (IL-1β and TNF-α) and the malondialdehyde content. We also observed that heat stress markedly increased the relative abundance of Actinobacteria, Firmicutes, Methylobacterium, Akkermansia, and Deinococcus and decreased that of Proteobacteria; nano-Se supplementation restored these changes, making their distribution similar to that in the control group. Overall, our findings suggest that nano-Se plays a protective role against heat stress-induced intestinal damage in rainbow trout by promoting the recovery of antioxidant enzyme activity, enhancing protein repair, alleviating inflammatory responses, and restoring intestinal microbiota composition.

Efficient removal of Sb(III) from water using β-FeOOH-modified biochar:Synthesis, performance and mechanism

Since the toxicity of Sb(III) is 10 times as high as that of Sb(V) in the environment, it is urgent to find a way to cut down Sb(III). β-FeOOH-modified biochar (β-FeOOH/BC) was prepared and used to remove Sb(III). The characterization results suggested that oxygen-containing functional groups formed on β-FeOOH/BC, which increased the Sb(III) removal efficiency. Even under complex water matrix conditions, the outstanding adsorption performance of β-FeOOH/BC for Sb(III) was obtained. The adsorption reaction rapidly reached a high removal efficiency within 5 min and approached adsorption equilibrium in about 6 h. The adsorption process was fitted to pseudo-second-order kinetics. Amount of maximum adsorption was 202.53 mg g^-1 at 308 K according to Langmuir model. β-FeOOH/BC removed Sb(III) mainly through pore-filling complexation, cation-π and coordination exchange. The CO sites and persistent free radicals (PFRs) acted as electron acceptors, facilitating the electron transfer. In brief, β-FeOOH/BC adsorbent material could adsorb and oxidize Sb(III), which showed excellent prospects for reducing the risk of Sb(III).

The disruption on gut microbiome of Decabromodiphenyl ethane exposure in the simulator of the human intestinal microbial ecosystem (SHIME)

The health risks of Decabromodiphenyl ethane (DBDPE) with its cardiovascular toxicity, liver toxicity and cytotoxicity had been generally acknowledged. However, the influence on gut microbiome and short-chain fatty acids (SCFAs) metabolism caused by DBDPE exposure remained unknown. In this study, three exposure groups (5, 50, 500 mg/L) and control group were used to investigate the effect of DBDPE by using simulator of the human intestinal microbial ecosystem (SHIME). 16S rRNA gene high-throughput sequencing illustrated that high dose DBDPE exposure increased the α-diversity of gut microbiota, while reduced the abundance of Firmicutes and Proteobacteria. In addition, the low dose (5 mg/L) DBDPE inhibited the increasing of SCFAs, but the medium and high dose (50 and 500 mg/L) DBDPE promoted the advancement, especially in ascending colon. Notably, DBDPE exposure lead a similar changing of acetic acid and butyric acid contents in different sections of the colon. This study confirmed the alternation of composition and metabolic function in gut microbial community due to DBDPE exposure, indicating an intestinal damage and appealing for more attention concentrated on the health effects of DBDPE exposure.