The Antagonistic Effect of Selenium on Lead Toxicity Is Related to the Ion Profile in Chicken Liver

Combined Effects of Cadmium and Lead on Growth Performance and Kidney Function in Broiler Chicken

Cadmium (Cd) and lead (Pb) are heavy metals prevalent in the environment and feed, and they reduce production performance of domestic animals, as well as they result in residue in animal tissues. The kidney is the target tissue for Cd and Pb. And the kidney is crucial for the reabsorption of calcium (Ca), which consequently influences bone strength. However, there are relatively few studies related to the effects of Cd and Pb exposure on performance, bone strength and kidney damage in livestock. The purpose of this experiment was to explore the combined effect of Cd and Pb on growth performance and renal impairment and the possible underlying mechanism. For this, 168 1-day-old Ross 308 broilers were randomly divided into four groups of six birds each, with seven replicates in each group: control group, 50 mg Cd/kg body weight group, 200 mg Pb/kg body weight group and 50 mg Cd/kg body weight + 200 mg Pb/kg body weight group. Feed intake was recorded daily and body weight was recorded weekly. The results show that at the end of the 3rd and 6th week, one broiler from each replicate was randomly selected for sampling. Boilers co-exposed to Cd and Pb for 3 weeks and 6 weeks had significantly decreased average daily feed intake (ADFI) and average daily body weight gain (ADG) than the control group, and the ratio of feed-to-weight gain (F/G) significantly increased after 6 weeks of co-exposure to Cd and Pb. Microscopic picture and ultrastructure analyses of the kidneys showed that Cd and Pb caused kidney damage to broiler chickens, and the damage was more serious in the Cd + Pb group, which was manifested by increased renal tubular epithelial degeneration and increased interstitial stasis points. Dietary exposure to Cd and Pb impaired production performance and induced renal oxidative damage in broilers. The combined effects of Cd and Pb on the kidneys are greater than their effects alone. The PERK-ATF4 pathway mediated endoplasmic reticulum stress participates the renal oxidative damage during chronic Cd and Pb exposure.

Effect of Germination on Mineral Content Changes in Brown Rice (Oryza sativa L.)

Minerals are the essential micronutrients for human health. Brown rice is a whole-grain food rich in minerals, with its bran portion limiting the application of minerals. In the present study, the changes in the contents of 23 different minerals (Na, Mg, K, Ca, B, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Sb, Ba, Li, Al, As, Cd, Sn, Hg, and Pb) in brown rice were evaluated during 17, 24, 30, 35, and 48 h of germination. The results showed that germination was associated with the decreased contents of Pb, Cd, As, Al, Li, Ba, Fe, Cr, Co, V, and Hg, and the increased content of Na in brown rice (p < 0.05). In contrast, this process was not significantly influential on the contents of Mg, K, Ca, B, Ni, Cu, Zn, Se, Sn, Sb, and Mn (p > 0.05). In addition, significant correlations were found among most of the mineral contents. Furthermore, according to the principal component analysis, three principal components of the different mineral contents were extracted to explain 96.60% of the cumulative variances. In summary, these findings demonstrated that germination represented a feasible approach to regulating and controlling the distribution of the mineral elements in brown rice, optimizing the levels of the mineral contents, and thus reducing the potential health risks.

Moderate selenium alleviates the pulmonary function impairment induced by cadmium and lead in adults: A population-based study

Selenium (Se) has been reported to have an antagonistic effect on heavy metals in animals. However, there is no epidemiological study investigating whether Se could protect against the pulmonary toxicity of Cadmium (Cd) and Lead (Pb). Data was collected from the 2011-2012 National Health and Nutrition Examination Survey (NHANES) cycle. Pulmonary function was assessed by Forced Vital Capacity (FVC), Forced Expiratory Volume 1st Second (FEV1) and FEV1/FVC. Blood concentrations of Cd, Pb, and Se were measured using inductively coupled plasma mass spectrometry. Linear regression, restricted cubic splines, and quantile-based g-computation (qgcomp) were performed to evaluate the individual and joint associations of Cd and Pb with pulmonary function and whether Se modified these associations. In the adjusted multi-metal model, every 1-unit increase in Cd, FEV1, FVC, and FEV1/FVC decreased by 76.437 mL (95 % CI: -110.928 to -41.947), 42.719 mL (95 % CI: -84.553 to -0.885), and 0.012 (95 % CI: -0.016 to -0.007), respectively. Meanwhile, FEV1 decreased by 9.37 mL (95 % CI: -18.61 to -0.13) for every 1 unit increase in Pb. Furthermore, we found an inverted U-shape association between Se and lung function, and participants in the second quartile Se group had the highest increases in FEV1 and FVC compared with participants in the lowest quartile. Qgcomp model also revealed that the toxic metal mixture (Cd and Pb) exhibited a significant inverse association with FEV1 and FEV1/FVC. Furthermore, we found that the inverse association of Pb and Cd, either alone or in combination, with pulmonary function first diminished with increasing Se levels but was re-enforced when blood Se concentrations were in the highest quartile. Our results indicated that moderate Se attenuated the harmful effects of Cd and Pb on lung function.

A combination of selenium and Bacillus subtilis improves the quality and flavor of meat and slaughter performance of broilers

This study aimed to investigate the effects of the combination of selenium and Bacillus subtilis (Se-BS) on the quality and flavor of meat and slaughter performance of broilers. A total of 240 one-day-old Arbor Acres broilers were randomly allotted to four treatments of a basal diet supplemented with no selenium (control), sodium selenite (SS), BS, or Se-BS and raised for 42 days. Compared with the control group, Se-BS significantly increased the carcass weight, the half-eviscerated weight, the completely eviscerated weight, the carcass rate, and redness in broiler muscles; improved the antioxidant state by increasing glutathione peroxidase (GPx) and glutathione S-transferase activities, the total antioxidant capacity, and GPx-1 and thioredoxin reductase 1 messenger RNA (mRNA) levels; promoted biological activity by increasing the contents of glutamate, phenylalanine, lysine, and tyrosine; and increased Se and five types of nitrogenous volatile substances in muscles. On the other hand, Se-BS treatment decreased the shear force, drip loss, and the malondialdehyde, glutathione, and lead contents in muscles. Se-BS exerted a better effect on slaughter performance, the physicochemical quality of meat, the redox status, the amino acid contents, the trace element contents, and volatile substances compared with SS and BS. In conclusion, Se-BS had a positive effect on the quality and flavor of meat and slaughter performance of broilers, suggesting that Se-BS may be a beneficial feed additive.

Heavy metal(loid) effect on multi-biomarker responses in apex predator: Novel assays in the monitoring of white stork nestlings

The goal of the present study was to investigate differences in biomarker responses related to metal(loid)s in white stork (Ciconia ciconia) nestling's blood from continental Croatia. To achieve this, a battery of biomarkers that can be affected by environmental pollutants, including metal(loid)s, was assessed (esterase activity, fluorescence-based oxidative stress biomarkers, metallothionein levels, glutathione-dependent enzyme activity). The research was conducted during the white stork breeding season in diverse areas (a landfill, industrial and agricultural sites, and an unpolluted area). White storks' nestlings near the landfill exhibited reduced carboxylesterase (CES) activity, elevated glutathione (GSH) concentration, as well as high Pb content in the blood. Increased As and Hg concentrations in blood were attributable to environmental contamination in agricultural area and an assumed unpolluted area, respectively. Furthermore, agricultural practices appeared to affect CES activity, as well as elevate Se levels. In addition to the successful implementation of biomarkers, present research showed that agricultural areas and a landfill are areas with increased metal(loid) levels possibly causing adverse effects on the white storks. This first-time heavy metal and metalloid analyses in the white stork nestlings from Croatia point to the necessary monitoring and future assessments of pollution impact to prevent irreversible adverse effects.

Selenium regulates Nrf2 signaling to prevent hepatotoxicity induced by hexavalent chromium in broilers

Hexavalent chromium (Cr(Ⅵ)) is considered to be a common environmental pollutant, which widely exists in industrial effluents and wastes and then potentially noxious effects to the health of the poultry. Studies have reported that selenium (Se), which is one of the essential trace elements of the poultry and participates in the oxidative metabolism, can alleviate Cr(Ⅵ)-induced organ damage by inhibiting oxidative stress, but its specific molecular mechanism remains unclear. Herein, animal models of Cr(Ⅵ)- and Se-exposure were constructed using broilers to investigate the antagonistic mechanism of Se to Cr(Ⅵ)-induced hepatotoxicity. In this experiment, the four groups of broiler models were used as the research objects: control, Se, Se plus Cr, and Cr groups. Histopathology and ultrastructure liver changes were observed. Liver-somatic index, serum biochemistry, oxidative stress, Nrf2 pathway related factors, and autophagy-related genes were also determined. Overall, Se was found to ameliorate the disorganized structure, hepatic insufficiency, and oxidative damage caused by Cr(Ⅵ) exposure. Electron microscopy analysis further showed that the number of autophagosomes was obviously decreased after Se treatment compared to Cr group. Furthermore, gene and protein expression analyses illustrated that the levels of Nrf2, glutathione peroxidase 1 (GPx-1), NAD(P)H: quinone oxidoreductase 1 (NQO1), and mechanistic target of rapamycin (mTOR) in the Se&Cr group was upregulated, along with decreased expression of Beclin 1, ATG5 and LC3 compared to the Cr group. These suggest that Se can repair the oxidative lesion and autophagy induced by Cr(Ⅵ) exposure in broiler livers by upregulating the Nrf2 signaling pathway.

Effects of Selenium Supplementation on the Ion Homeostasis in the Reproductive Organs and Eggs of Laying Hens Fed With the Diet Contaminated With Cadmium, Lead, Mercury, and Chromium

The objective of this study was to explore the toxic effects of different heavy metals in combination with their deposition and ion homeostasis in the reproductive organs and eggs of laying hens, as well as the alleviating action of selenized yeast. A total of 160 Lohmann pink-shell laying hens (63-week-old) were randomly allocated into four treatments with 10 replicates of four hens each. The four dietary treatments were the corn-soybean meal basal dietary (control; CON); the CON dietary supplemented with 0.4 mg/kg selenium from selenized yeast (Se); the CON dietary supplemented with 5 mg/kg Cd + 50 mg/kg Pb +3 mg/kg Hg + 5 mg/kg Cr (HEM), and the HEM dietary supplemented with 0.4 mg/kg selenium from selenized yeast (HEM+Se). The dietary HEM significantly increased Cd, Pb, and Hg deposition in the egg yolk and ovary, and Cd and Hg deposition in the oviduct and in the follicular wall (p < 0.05). The HEM elevated Fe concentration in the egg yolk, ovary, and oviduct (p < 0.05). The HEM decreased Mn concentration in the egg yolk, Fe, Mn, and Zn concentrations in the egg white, Cu concentration in the ovary, Mg concentration in the oviduct, as well as Ca, Cu, Zn, and Mg concentrations in the follicular walls (p < 0.05). Dietary Se addition elevated Se concentration in the egg yolk, oviduct, and follicular walls and Mg concentration (p < 0.05) in the oviduct, whereas it reduced Fe concentration in the oviduct compared with the HEM-treated hens. Some positive or negative correlations among these elements were observed. Canonical Correlation Analysis showed that the concentrations of Pb and Hg in the egg yolk were positively correlated with those in the ovary. The concentration of Cd in the egg white was positively correlated with that in the oviduct. In summary, dietary Cd, Pb, Hg, and Cr in combination caused ion loss and deposition of HEM in reproductive organs of laying hens. Dietary Se addition at 0.4 mg/kg from selenized yeast alleviated the negative effects of HEM on Fe and Mg ion disorder in the oviduct and follicle wall of hens.

Selenium Antagonizes Cadmium-Induced Inflammation and Oxidative Stress via Suppressing the Interplay between NLRP3 Inflammasome and HMGB1/NF-κB Pathway in Duck Hepatocytes

Cadmium (Cd) is a toxic heavy metal that can accumulate in the liver of animals, damaging liver function. Inflammation and oxidative stress are considered primary causes of Cd-induced liver damage. Selenium (Se) is an antioxidant and can resist the detrimental impacts of Cd on the liver. To elucidate the antagonism of Se on Cd against hepatocyte injury and its mechanism, duck embryo hepatocytes were treated with Cd (4 μM) and/or Se (0.4 μM) for 24 h. Then, the hepatocyte viability, oxidative stress and inflammatory status were assessed. The findings manifested that the accumulation of reactive oxygen species (ROS) and the levels of pro-inflammatory factors were elevated in the Cd group. Simultaneously, immunofluorescence staining revealed that the interaction between NOD-like receptor pyran domain containing 3 (NLRP3) and apoptosis-associated speck-like protein (ASC) was enhanced, the movement of high-mobility group box 1 (HMGB1) from nucleus to cytoplasm was increased and the inflammatory response was further amplified. Nevertheless, the addition of Se relieved the above-mentioned effects, thereby alleviating cellular oxidative stress and inflammation. Collectively, the results suggested that Se could mitigate Cd-stimulated oxidative stress and inflammation in hepatocytes, which might be correlated with the NLRP3 inflammasome and HMGB1/nuclear factor-κB (NF-κB) signaling pathway.

Effect of Dietary Enrichment with Flaxseed, Vitamin E and Selenium, and of Market Class on the Broiler Breast Meat-Part 1: Nutritional and Functional Traits

The effect of dietary enrichment with flaxseed, selenium and vitamin E, and market class on the nutritional and functional value of breast meat was evaluated. A completely randomized block design was set up, where the experimental unit (n = 6000 birds) received conventional or enriched diet and was slaughtered at 37 (light class), 47 (medium class), or 57 (heavy class) days of life. Hence, functional and standard Pectoralis major muscles from every market class were analyzed for FA composition, inorganic elements and vitamin E. Lipid metabolism indices and health lipid indicators were assessed along with the nutritional value. A multiple linear model revealed that in breasts, the dietary treatment significantly influenced (p < 0.05) the FA profile, lipid metabolism and health lipid indices, while the slaughtering weight was related (p < 0.05) to most of elements (e.g., Na, Mg, K, Mn, and Se) and vitamin E. The interdependence of the two factors had strong relations (p < 0.05) with total PUFAs, including linolenic acid, desaturase activities, health lipid indices, trace essential elements and vitamin E. Consequently, enriched meat from heavy chickens showed the best functional and nutritional traits. Overall, the study pointed out that both market class and dietary manipulation are two relevant factors to consider for producing breast meat with higher nutritional and functional value.

The protection of selenium against cadmium-induced mitophagy via modulating nuclear xenobiotic receptors response and oxidative stress in the liver of rabbits

Cadmium (Cd) is a harmful heavy metal that can cause many health problems, while selenium (Se) is an essential nutrient for organisms that can protect them from heavy metal-induced damage. To explore the effects of Se on Cd-induced mitophagy in the liver, forty 3-month-old New Zealand white rabbits (2-2.5 kg), half male and half female, were randomly divided into four groups: the Control group, the Se (0.5 mg/kg body weight (BW)) group, the Cd (1 mg/kg BW) group and the Se+Cd group. After 30 days, the toxicity from Cd in the liver was assessed in terms of the nuclear xenobiotic receptor (NXR) response, oxidative stress and mitophagy. It was found that Cd decreased the activities of CYP450 enzymes and antioxidant enzymes and increased the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) and also increased the consumption of reduced glutathione (GSH). Moreover, the mRNA levels of NXRs (CAR, PXR, AHR and Nrf2), some mitochondrial function factors (PGC-1α, Sirt1, Sirt3, Nrf1 and TFAM) and mitochondrial fusion factors (Mfn1, Mfn2 and OPA1) were downregulated, but the mRNA levels of other mitochondrial function factors (VDAC1, Cyt C and PRDX3), mitochondrial fission factors (Fis1 and MFF) and those in the PINK1/Parkin-mediated mitophagy pathway (p62, Bnip3 and LC3) were upregulated under Cd exposure. The protein expression levels of Nrf2, SOD2, PGC-1α, PINK1 and Parkin were consistent with the mRNA expression levels in the Cd group. Se alleviated the changes in the abovementioned factors induced by Cd. In conclusion, the results indicate that Cd can cause oxidative stress in rabbit livers by inhibiting NXRs and the antioxidation response leading to mitophagy, and these harmful changes caused by Cd can be alleviated by Se.

Selenium triggers Nrf2-AMPK crosstalk to alleviate cadmium-induced autophagy in rabbit cerebrum

Cadmium (Cd) is a toxic heavy metal that accumulates in the brain and causes a series of histopathological changes. Selenium (Se) exerts a crucial function in protecting damage caused by toxic heavy metals, but its potential mechanism is rarely studied. The main purpose of this study is to explore the protective effects of Se on Cd-induced oxidative stress and autophagy in rabbit cerebrum. Forty rabbits were randomly divided into four groups and treated as follows: Control group, Cd (1 mg/kg⋅BW) group, Se (0.5 mg/kg⋅BW) group and Cd (1 mg/kg⋅BW)+Se (0.5 mg/kg⋅BW) group, with 30 days feeding management. Our results suggested that Se treatment significantly suppressed the Cd-induced degenerative changes including cell necrosis, vacuolization, and atrophic neurons. In addition, Se decreased the contents of MDA and H₂O₂ and increased the activities of CAT, SOD, GST, GSH and GSH-Px, alleviating the imbalance of the redox system induced by Cd. Furthermore, Cd caused the up-regulation of the mRNA levels of autophagy-related genes (ATG3, ATG5, ATG7, ATG12 and p62), AMPK (Prkaa1, Prkaa2, Prkab1, Prkab2, Prkag2, Prkag3) and Nrf2 (Nrf2, HO-1 and NQO1) signaling pathway, and the expression levels of LC3II/LC3I, p-AMPK/AMPK, Beclin-1, Nrf2 and HO-1 proteins, which were alleviated by Se, indicated that Se inhibited Cd-induced autophagy and Nrf2 signaling pathway activation. In conclusion, our study found that Se antagonized Cd-induced oxidative stress and autophagy in the brain by generating crosstalk between AMPK and Nrf2 signaling pathway.

Moringa oleifera Lam. extract rescues lead-induced oxidative stress, inflammation, and apoptosis in the rat cerebral cortex

In this study, we investigate the potential protective effect of Moringa oleifera Lam. extract (MOE) against lead-induced neurotoxicity. Wistar rats were allocated equally into (a) a control group, (b) a lead acetate (PbAc) group intraperitoneally injected with 20 mg/kg PbAc, (c) a MOE group orally gavaged with MOE (250 mg/kg), and (d) a MOE + PbAc group orally gavaged with MOE 3 hr before receiving intraperitoneal injections of PbAc. All rats were treated for 14 days. Our results revealed that PbAc-induced brain injury, accompanied by increased levels of oxidative stress markers. Moreover, Pb enhanced the inflammatory response and triggered neuronal apoptosis, as well as significantly depleted glutathione content and inhibited antioxidant enzyme activity. Interestingly, concurrent treatment with MOE ameliorated oxidative stress, inflammation, and apoptosis in the brain cortex. The current study provides evidence that MOE has the potential to protect neuronal tissues in PbAc-exposed rats via attenuation of nuclear factor-kappa B (NF-κB) signaling. PRACTICAL APPLICATIONS: This study reports the potential neuroprotective effect of Moringa oleifera Lam. (MOE) against lead-induced cortical brain toxicity. Our data reveal that PbAc-induced oxidative stress, neuroinflammation, and apoptosis in cortical tissues. However, simultaneous treatment of rats with MOE abrogated cortical brain inflammatory biomarkers, mitigated cortical tissue damage, and restrained oxidative stress, programmed cell death, and nuclear factor-kappa B (NF-κB) translocation. In addition, MOE stimulated detoxifying enzymes in PbAc-treated rats. These findings provide evidence that simultaneous treatment with MOE has the potential to attenuate PbAc-induced brain damage in rats by restraining oxidative stress, neuroinflammation, and apoptosis via attenuation of NF-κB signaling.

Selenium Prevents Lead-Induced Necroptosis by Restoring Antioxidant Functions and Blocking MAPK/NF-κB Pathway in Chicken Lymphocytes

Recent studies have identified a new existence of a genetically programmed and regulated cell death characterized by necrotic cell death morphology, termed necroptosis. Lead (Pb) is a ubiquitously distributed environmental pollutant that is highly toxic to animals and human beings. However, no detailed report has been conducted on the necroptosis in lymphocytes caused by Pb. Selenium (Se), a trace element in the body, has been shown to exert cytoprotective effect in numerous pathological injury caused by heavy metals. Here, lymphocytes isolated from chicken spleen were divided into four groups, control group, Se group, Pb group, and Pb + Se co-treatment group to investigate the potential mechanism in the necroptosis triggered by Pb and in the antagonistic effect of Se on Pb toxicity. Flow cytometry analysis and AO/EB staining showed Pb caused typical necrosis characteristics in the lymphocytes. The expression of RIP1, RIP3, and MLKL was increased, whereas the level of caspase 8 was declined in Pb group, which proved the occurrence of necroptosis. Meanwhile, Pb exposure disrupted the antioxidant enzyme (SOD, GSH-Px, and CAT) balance, promoted the expression of MAPK/NF-κB pathway factors (ERK, JNK, p38, NF-κB, and TNF-α), and activated HSPs (HSP27, HSP40, HSP60, HSP70, and HSP90). However, those Pb-induced changes were significantly alleviated in Se + Pb group. Our study revealed that Pb could trigger lymphocyte necroptosis through MAPK/NF-κB pathway activated by oxidative stress and that Se could antagonize Pb-induced necroptosis in chicken lymphocytes.

Effects of acute oral lead exposure on the levels of essential elements of mice: a metallomics and dose-dependent study

BACKGROUND AND OBJECTIVES

Lead (Pb) has been reported to disturb the metabolism of essential elements, such as calcium (Ca), magnesium (Mg), iron (Fe) and zinc (Zn) in vivo. This study focused on the relationship between various dose of Pb and the essential elements.

METHODS

50 healthy male C57BL/6 mice underwent oral administration of 0.2 mL lead acetate trihydrate solution (0, 20, 100, 500, and 1000 mg Pb/day/kg body weight) for 3 days. The concentrations of Pb and four essential elements (Ca, Zn, Fe and Mg) in the blood, kidney, liver, bone and brain were quantified with inductively coupled plasma mass spectrometry.

RESULTS

Various doses of Pb led to significant increases in the contents of Ca, Fe and Zn in the liver, and decreased contents of Mg and Fe in the blood in a dose-dependent pattern. The Pb dose of 20 mg/kg reduced the concentration of bone Ca, which did not continue to show an obvious decline with continued increases in the oral Pb dose. Pb also caused alterations in the Mg distribution pattern, and decreased the correlation of Mg, Ca and Zn in the brain, both findings were dose-dependent. In addition to the changes in metallomics, the related oxidative stress was exacerbated, but no significant changes were detected in hepatic and renal histopathological lesions after a short period of Pb exposure.

CONCLUSIONS

This study contributes to a thorough analysis of the Pb-poisoning mechanism, and indicates that the concentrations of essential elements could be used as sensitive toxicological indicators of Pb exposure.

The antagonistic effect of selenium on lead-induced necroptosis via MAPK/NF-κB pathway and HSPs activation in the chicken spleen

Recent studies identified a novel programmed and regulated cell death that was characterized by a necrotic cell death morphology, termed necroptosis. Lead (Pb) is known as a persistent inorganic environmental pollutant that affects the health of humans and animals worldwide. However, there are no detailed reports of Pb-induced necroptosis of immune tissue. Selenium (Se) is a trace element that antagonizes the toxicity of heavy metals. Here, chickens were randomly divided into four groups, treated with Pb ((CH₃OO)₂Pb, 150 mg/kg) and/or Se (Na₂SeO₃, 2 mg/kg), aim to study the effect and mechanism of necroptosis in Pb-induced spleen injury and the antagonistic effects of Se on Pb toxicity. Our results showed that Pb exposure evidently increased the accumulation of Pb in spleen and caused necroptosis by upregulating the expression of RIP1, RIP3 and MLKL, and decreasing Caspase8 expression. Meanwhile, Pb treatment inhibited the activities of SOD, GPX, and CAT, caused the accumulation of NO and MDA, and induced oxidative stress, which promoted the expression of MAPK/NF-κB pathway genes (ERK, JNK, P38, NF-κB and TNF-α) and activated HSPs (HSP27, HSP40, HSP60, HSP70 and HSP90). However, the increased content of Pb in spleen and Pb-caused necroptosis were inhibited by Se cotreatment. Overall, we conclude that Se can prevent Pb-induced necroptosis by restoring antioxidant functions and blocking the MAPK/NF-κB pathway and HSPs activation in chicken spleen.

Selenium-Cultured Potamogeton maackianus in the Diet Can Alleviate Oxidative Stress and Immune Suppression in Chinese Mitten Crab (Eriocheir sinensis) Under Copper Exposure

Selenium (Se) is an essential trace element for aquatic animals. The aquatic plant Potamogeton maackianus is an important natural food of Chinese mitten crab (Eriocheir sinensis). The aim of this study was to determine whether the antioxidant and immune responses of Chinese mitten crab are affected by including Se-cultured P. maackianus in the diet. Three groups of P. maackianus were cultured at levels of 0.02 mg/kg Se, 8.83 mg/kg Se, and 16.92 mg/kg Se, and the plants in these groups were used in experimental diets fed to crabs (dietary Se content of 0.05, 0.43, and 0.82 mg/kg, respectively). Compared with crabs in the 0.05 mg/kg group, those in the 0.82 mg/kg group showed significantly increased specific growth rate, protease and lipase activities, triglyceride and cholesterol contents, and Se content in the hepatopancreas and muscle (P < 0.05); increased activities of glutathione peroxidase, glutathione reductase, and catalase in the antioxidant system; increased transcript levels of MT (encoding metallothionein); and decreased malondialdehyde content (P < 0.05). At the end of the rearing experiment, the crabs in the different groups were exposed to copper (Cu²⁺) stress for 96 h. All the juvenile crabs in the 0.43 and 0.82 mg/kg groups survived 96 h of Cu²⁺ stress. Crabs in the 0.82 mg/kg group showed enhanced antioxidant responses under Cu²⁺ stress, increased transcript levels of MT and LYZ, and increased resistance. Therefore, supplementation of the diet of Chinese mitten crab with increased levels of Se-cultured P. maackianus can reduce oxidative stress under Cu²⁺ exposure, activate the immune response, and benefit growth.

Interactions Between Different Selenium Compounds and Essential Trace Elements Involved in the Antioxidant System of Laying Hens

The purpose of this study was to investigate the interactions between different selenium (Se) compounds including sodium selenite (SS), selenium-enriched yeast (SY), and nano-selenium (NS) and various essential trace elements involved in the antioxidant systems, and to evaluate the effects on laying performance and egg quality. A total of 288 21-week-old Hyline Sophie hens were allotted to four dietary treatments: (1) basal diet without Se supplementation; (2) basal diet supplemented with 0.3 mg/kg Se of SS; (3) basal diet supplemented with 0.3 mg/kg Se of SY; (4) basal diet supplemented with 0.3 mg/kg Se of NS. Each treatment had eight replicates with nine hens per replicate. The trial lasted for 35 days. Results demonstrated that NS supplementation decreased the egg production (EP) and increased the feed conversion rate (FCR) and eggshell thickness and that SY changed the egg shape index (p < 0.05). Supplementation with three Se compounds significantly increased serum Se concentration and glutathione peroxidase (GSH-Px) activity in all treatment groups, as well as total superoxide dismutase (T-SOD) activity in the SY and NS groups. Yolk iron (Fe) and copper (Cu) concentrations in the NS group were also increased with Se supplementation. While the serum zinc (Zn) concentration decreased in the NS and SY groups, as well as the yolk manganese (Mn) concentration in the SY group. And the total antioxidant capability (T-AOC) of yolk with 3 days of storage in the SY and NS groups, malondialdehyde (MDA) value in the NS group, and the T-SOD activity and MDA value of yolk with 10 days of storage in the SY group also decreased. Thus, the source of Se compounds may influence the balance between Se and other trace elements including Zn, Mn, Fe, and Cu, which is important for proper antioxidant defense in blood and egg yolk of laying hens.

Effect of selenium antagonist lead-induced damage on Th1/Th2 imbalance in the peripheral blood lymphocytes of chickens

Lead (Pb) is a type of toxic metal that can hurt the immune system. Selenium (Se) can reduce the damage caused by heavy metals. To investigate the effects of Se against Pb on bird immune cells, as well as the immunotoxin mechanism of Pb, Se supplementation and/or Pb poisoning chicken models were established. One hundred eighty 1-year-old broiler chickens were randomly divided into four groups (n = 6). The four groups were the control group, the selenium-rich group (Se group), the Pb supplementation group (Pb group) and the Se and Pb compound group (Se + Pb group). The peripheral blood lymphocytes of chickens were collected to test the selenoproteins and cytokine mRNA levels at 30 and 60 d. Determination of the content of Se and Pb in the serum, principal component analysis and ingenuity pathway analysis were performed at the two time points. As a result, Pb exposure increased the content of Pb, activating the Th1/Th2 pathway in peripheral blood lymphocytes. Additionally, this experiment showed that Se supplementation and Pb exposure could influence the mRNA levels of selenoproteins and cytokines in the peripheral blood lymphocytes of chickens. However, all of the parameters that we detected in the experiment indicated that Se supplementation could alleviate the increase of selenoproteins and cytokine mRNA levels and the Th1/Th2 imbalance induced by Pb in peripheral blood lymphocytes. In summary, Se can alleviate the toxic effects caused by Pb in the peripheral blood lymphocytes of chickens, suggesting the antagonism between Se and Pb.

Selenium and zinc protections against metal-(loids)-induced toxicity and disease manifestations: A review

Metals are ubiquitous in the environment due to huge industrial applications in the form of different chemicals and from extensive mining activities. The frequent exposures to metals and metalloids are crucial for the human health. Trace metals are beneficial for health whereas non-essential metals are dangerous for the health and some are proven etiological factors for diseases including cancers and neurological disorders. The interactions of essential trace metals such as selenium (Se) and zinc (Zn) with non-essential metals viz. lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) in biological system are very critical and complex. A huge number of studies report the protective role of Se and Zn against metal toxicity, both in animal and cellular levels, and also explain the numerous mechanisms involved. However, it has been considered that a tiny dyshomeostasis in the metals/trace metals status in biological system could induce severe deleterious effects that can manifest to numerous diseases. Thus, in this particular review, we have demonstrated the critical protection mechanism/s of Se and Zn against Cd, Pb, As and Hg toxicity in a one by one manner to clarify the up-to-date findings and perspectives. Furthermore, biomolecular consequences are comprehensively presented in light of particular cellular/biomolecular events which are somehow linked to a subsequent disease. The analyzed reports support significant protection potential of Se and Zn, either alone or in combination with other agents, against each of the abovementioned non-essential metals. However, Se and Zn are still not being used as detoxifying agents due to some unexplained reasons. We hypothesized that Se could be a potential candidate for detoxifying As and Hg regardless of their chemical speciations, but requires intensive clinical trials. However, particularly Zn-Hg interaction warrants more investigations both in animal and cellular level.

Ameliorative Effects of Selenium on Cadmium-Induced Injury in the Chicken Ovary: Mechanisms of Oxidative Stress and Endoplasmic Reticulum Stress in Cadmium-Induced Apoptosis

Despite the well-established toxicity of cadmium (Cd) to animals and the ameliorative effects of selenium (Se), some specific mechanisms in the chicken ovary are not yet clarified. To explore the mechanism by which the toxicity effect of Cd is induced and explore the effect of supranutritional Se on Cd toxicity in female bird reproduction, forty-eight 50-day-old Isa Brown female chickens were divided randomly into four groups. Group I (control group) was fed the basic diet containing 0.2 mg/kg Se. Group II (Se-treated group) was fed the basic diet supplemented with sodium selenite (Na₂SeO₃), and the total Se content was 2 mg/kg. Group III (Se + Cd-treated group) was fed the basic diet supplemented with Na₂SeO₃; the total Se content was 2 mg/kg, and it was supplemented with 150 mg/kg cadmium chloride (CdCl₂). Group IV (Cd-treated group) was with the basic diet supplemented with 150 mg/kg CdCl₂. The Cd, estradiol (E2), and progestogen (P4) contents changed after subchronic Cd exposure in chicken ovarian tissue; subsequently, oxidative stress occurred and activated the endoplasmic reticulum (ER) pathway to induce apoptosis. Further, Se decreased the accumulation of Cd in ovarian tissue, increased the E2 and P4 contents, alleviated oxidative stress, and reduced apoptosis via the ER stress pathway. The present results demonstrated that Cd could induce apoptosis via the ER stress pathway in chicken ovarian tissue and that Se had a significant antagonistic effect. These results are potentially valuable for finding a strategy to prevent Cd poisoning.

CHOP/caspase-3 signal pathway involves in mitigative effect of selenium on lead-induced apoptosis via endoplasmic reticulum pathway in chicken testes

Lead (Pb) is an environmental pollutant. Selenium (Se) has alleviative effect on Pb poisoning. However, mitigative effect of Se on Pb-induced apoptosis has not been unclear via endoplasmic reticulum (ER) pathway in chicken testes. The aim of this study was to investigate mitigative effect of Se on apoptosis induced by Pb poisoning via ER pathway in chicken testes. Sixty male chickens (7-day-old) were randomly divided into the control group offered drinking water (DW) and basic diet (BD) (0.49 mg/kg Se), the Se group offered DW and BD containing Na₂SeO₃ (SeBD) (1.00 mg/kg Se), the Pb group offered DW containing (CH₃OO)₂Pb (PbDW) (350.00 mg/L Pb) and BD, and the Pb + Se group offered PbDW and SeBD; and were fed for 90 days. The following contents were performed as follows: histology; antioxidant indexes (reduced glutathione (GSH), malondialdehyde (MDA), glutathione peroxidase (GPx), glutathione S-transferase (GST), and superoxide dismutase (SOD)); mRNA expressions of ER-related genes (glucose-related protein 78 (GRP78), protein kinase-like ER kinase (PERK), eukaryotic initiation factor 2α (eIF2α), activating transcription factor 4 (ATF4), and enhancer-binding protein homologous protein (CHOP)); and apoptosis-related genes (cysteine-aspartic protease (caspase)-3 and caspase-12) in chicken testes. The results indicated that Pb poisoning caused histological changes; increased MDA content; decreased the content of GSH and the activities of GPx, GST, and SOD; and upregulated mRNA expressions of the above five ER-related genes and two apoptosis-related genes in the chicken testes. Se alleviated Pb-induced oxidative stress, ER stress, and apoptosis via CHOP/caspase-3 signal pathway in the chicken testes.

Effect of Selenium on Ion Profiles and Antioxidant Defense in Mice Livers

Se entering the mammalian body from diverse sources shows different liver accumulation patterns. However, the effects of Se from diverse sources on the body's I on spectrum and the relationship between the changes in the ion spectrum and antioxidant function are not clear. In this study, 80 3-week-old female mice were randomly divided into four groups: a control group, sodium selenite group, yeast Se group, and seaweed Se group. The estimated Se contents were 0.03, 0.23, 0.23, and 0.23 mg/kg, respectively. The liver was collected from mice on day 60. The results showed that, compared with the control group, sodium selenite significantly reduced Na and Li contents and significantly increased Cr, Ni, Se, and Sb contents (P < 0.05); yeast Se significantly increased Mg, Ca, Si, Cr, Fe, Co, Cu, Se, Sb, and Al contents, and significantly reduced Tl, As, and Hg contents (P < 0.05); seaweed Se significantly increased B, Si, Cr, Fe, Se, As, and Hg contents, and significantly reduced Zn and Tl contents (P < 0.05). The results of antioxidant parameter analysis showed that Se from three sources increased total superoxide dismutase content and significantly reduced malondialdehyde content (P < 0.05), whereas no clear effect was observed on total antioxidant capacity (P > 0.05). Combined with the ion spectrum and antioxidant test results, yeast Se was found to most effectively promote the accumulation of beneficial elements, enhance antioxidant capacity, and reduce the concentration of toxic elements. The variety of ion spectrum antioxidants followed a similar trend, which indicated that the ion spectrum might be related to antioxidant activity.

Immuno-protective role of biologically synthesized dietary selenium nanoparticles against multiple stressors in Pangasinodon hypophthalmus

An environment friendly and sustainable approach is being emerged in the area of nanotechnology for accelerated growth and development of culturable aquatic animals hence green chemistry is gaining momentum in recent years. The present study has been carried out to delineate the effects of selenium nanoparticles (Se-NPs) on growth performance, antioxidative status and immunity of fish reared under lead (Pb) and high temperature (34 °C). Three hundred and fifteen fish were equally distributed in seven treatments in triplicates. Three isocaloric and isonitrogenous experimental diets viz. control (Se-NPs-0 mg/kg), Se-NPs at 1 mg/kg and Se-NPs at 2 mg/kg were formulated. The fish were reared under lead (Pb, 1/21st of LC₅₀ (4 ppm)) and high temperature (34 °C) stress and fed with or without dietary Se-NPs. The effects of dietary Se-NPs were studied in terms of growth performance (Weight gain %, feed conversion ratio, protein efficiency ratio and specific growth rate), antioxidative status (catalase, superoxide dismutase, glutathione-S-transferase and glutathione peroxidase), neurotransmitter enzymes (AChE), stress biomarkers (heat shock protein 70, serum cortisol, blood glucose, vitamin C), immunological status (total protein, A/G ratio and respiratory burst activity) in Pangasinodon hypophthalmus post challenge with Aeromonas veronii biovar sobria. Results of the investigation demonstrated significant improvement of growth performance, antioxidative status, neurotransmitter enzyme activity, stress markers and more importantly enhanced immunity of the fish with dietary incorporation of Se-NPs at 1 mg/kg. In addition, post bacterial infection, the relative % survival increased and cumulative mortality % decreased in the group fed with Se-NPs at 1 mg/kg diet. Pb and high temperature treated and fed with control diet group showed devastating impact on the growth performance, antioxidative status, stress markers and immunity of the fish. Similarly, application of Se-NPs at 2 mg/kg showed poor growth performance and elevated level of oxidative stress and other stress biomarkers including other biochemical attributes. Inclusive results indicated that, Se-NPs at 1 mg/kg has capability to enhance overall performance and alleviate multiple stresses in P. hypophthalmus. Hence, Se-NPs at optimum level have ability to develop green chemistry in feed industry for better growth performance of the fish.

Effects of Se and Cd Co-treatment on the Morphology, Oxidative Stress, and Ion Concentrations in the Ovaries of Laying Hens

This study aims at revealing the effects of the combined treatment of selenium and cadmium on ovary morphology, oxidative stress, and 28 kinds of ion concentrations in laying hens. In this experiment, 128 healthy 31-week-old chickens were selected and divided into four treatment groups, three of which were separately fed the basic diets supplemented with either Se or Cd or both Se and Cd for 90 days, and the remaining group was fed the basic diet and treated as a control. The chickens were sacrificed for collecting ovarian tissues. Morphological structure and ultrastructure analysis of ovaries in the Cd-treated group revealed ovarian damage, with decreased activities of SOD and GPx, along with increased levels of MDA and H₂O₂. Cd treatment also resulted in disturbances in ion balance. The concentrations of Ca, Ti, Cu, Zn, and Ba were significantly reduced, while the concentrations of Fe, Mo, and Cd were significantly increased when compared with the control group. Interestingly, the damages caused by cadmium were alleviated in the Se+Cd-treated group. These results indicate that selenium can alleviate cadmium-induced ovarian damages.

Antagonistic effects of selenium on lead-induced autophagy by influencing mitochondrial dynamics in the spleen of chickens

Lead (Pb) may damage the immune function in human and animal. Selenium (Se) has antagonistic effects on Pb. In our study, brown layer chickens were randomly allocated to control group, Se group (1 mg/kg Se), Se+Pb group (1 mg/kg Se and 350 mg/kg Pb), and Pb group (350 mg/kg Pb). The chickens were sacrificed on the 90^th day; spleen tissues were subjected to observation of ultrastructure and detection of spleen-related indexes. The results revealed that in the Pb group, expression levels of the cytokines IL-1 and TNF-α significantly increased, and expression levels of IL-2 and INF-γ significantly decreased; activities of antioxidant enzyme GPX, SOD and CAT significantly decreased, and expression level of malondialdehyde (MDA) significantly increased; expression levels of mitochondrial fission-related genes (Mff and Drp1) significantly increased, and expression levels of mitochondrial fusion-related genes (Opa1, Mfn1 and Mfn2) significantly decreased; expression of autophagy-related genes (Beclin 1, Dynein, Atg 5, LC3-I and LC-II) was upregulated, while expression of mammalian target of rapamycin (mTOR) was downregulated. The results of transmission electron microscopy indicated that Pb induced mitochondrial fragmentation, and triggered autophagy in the spleen of chickens. The Se and Pb co-treatment remarkably alleviated these injuries induced by Pb in the spleen of chickens. In conclusion, Pb can induce the oxidative stress to influence the mitochondrial dynamics balance and lead to autophagy, which triggers the immune dysfunction in the spleen of chickens; the Se exhibits the antagonistic effects on lead-induced autophagy by influencing mitochondrial dynamics in the spleen of chickens.

Selenium Supplementation Changes the Ion Profile in the Pancreas of Chickens Treated with Cadmium

Increasing evidence indicates that selenium (Se) could antagonize metal toxicity, including cadmium (Cd) toxicity. However, the effects of Se on Cd-induced changes in the ion profile in the pancreas of chickens have not been reported. In the present study, 128 Hy-Line brown laying chickens were divided into the control group, Se-treated group, Se/Cd-treated group, and Cd-treated group, and we detected the concentrations of 28 ions in the four groups by inductively coupled plasma mass spectrometry. In the Cd-treated group, the accumulation of Cd in the pancreas was 836.8 times higher that than in the control group (27,353.71 ppb/32.69 ppb). Meanwhile, the Ca, Ti, Fe, Mo, Li, Al, and Pb levels increased and the Cr, Mn, Ni, Cu, Zn, Se, Sr, and Sb levels decreased due to sub-chronic Cd poisoning. The Fe, Mo, Ba, and Pb levels decreased in the Se/Cd-treated group. Our findings suggest that Cd can accumulate in the chicken pancreas and affect the ion profiles, whereas Se can ameliorate the accumulation of Cd and change the ion profiles in the chicken pancreas.

Assessment of toxicity of selenium and cadmium selenium quantum dots: A review

This paper reviews the current understanding of the toxicity of selenium (Se) to terrestrial mammalian and aquatic organisms. Adverse biological effects occur in the case of Se deficiencies, associated with this element having essential biological functions and a narrow window between essentiality and toxicity. Several inorganic species of Se (-2, 0, +4, and +6) and organic species (monomethylated and dimethylated) have been reported in aquatic systems. The toxicity of Se in any given sample depends not only on its speciation and concentration, but also on the concomitant presence of other compounds that may have synergistic or antagonistic effects, affecting the target organism as well, usually spanning 2 or 3 orders of magnitude for inorganic Se species. In aquatic ecosystems, indirect toxic effects, linked to the trophic transfer of excess Se, are usually of much more concern than direct Se toxicity. Studies on the toxicity of selenium nanoparticles indicate the greater toxicity of chemically generated selenium nanoparticles relative to selenium oxyanions for fish and fish embryos while oxyanions of selenium have been found to be more highly toxic to rats as compared to nano-Se. Studies on polymer coated Cd/Se quantum dots suggest significant differences in toxicity of weathered vs. non-weathered QD's as well as a significant role for cadmium with respect to toxicity.

Selenium deficiency-induced alterations in ion profiles in chicken muscle

Ion homeostasis plays important roles in development of metabolic diseases. In the present study, we examined the contents and distributions of 25 ions in chicken muscles following treatment with selenium (Se) deficiency for 25 days. The results revealed that in chicken muscles, the top ranked microelements were silicon (Si), iron (Fe), zinc (Zn), aluminum (Al), copper (Cu) and boron (B), showing low contents that varied from 292.89 ppb to 100.27 ppm. After Se deficiency treatment, essential microelements [Cu, chromium (Cr), vanadium (V) and manganese (Mn)], and toxic microelements [cadmium (Cd) and mercury (Hg)] became more concentrated (P < 0.05). Elements distribution images showed generalized accumulation of barium (Ba), cobalt (Co), Cu, Fe and V, while Cr, Mn, and Zn showed pin point accumulations in muscle sections. Thus, the ion profiles were generally influenced by Se deficiency, which suggested a possible role of Se deficiency in muscle dysfunctions caused by these altered ion profiles.

The antagonistic effect of selenium on lead-induced apoptosis via mitochondrial dynamics pathway in the chicken kidney

Selenium (Se) is known to have antagonistic effects against lead (Pb) toxicity in animal. The aim of this study was to evaluate the roles of mitochondrial dynamics on Pb-induced apoptosis in the chicken kidney and investigate the antagonistic effect of Se. In the present study, brown layer chickens were randomly allocated to four groups, and each group were exposed to a basic diet (0.2 mg kg^-1 Se and 0.5 mg kg^-1 Pb), a Se-adequate diet (1 mg kg^-1 Se and 0.5 mg kg^-1 Pb), a Se and Pb compound diet (1 mg kg^-1 Se and 350 mg kg^-1 Pb) or a Pb supplemented diet (0.2 mg kg^-1 Se and 350 mg kg^-1 Pb). On the 90^th day, the kidney was removed to determine the activities of mitochondrial respiratory chain complexes, ATPases and oxidative indexes. The expression levels of mitochondrial dynamics and apoptosis-related genes were also determined. The results showed that Pb treatment significantly decreased the activities of mitochondrial complexes and ATPases, and increased oxidative stress, and mitochondrial dynamics and anti-apoptosis-related genes had a lower expression, whereas mitochondrial pro-apoptosis related genes presented higher expressions in the Pb group compared with control group (P < 0.05). However, the co-treatment of Se and Pb significantly alleviated those changes compared with the Pb group (P < 0.05). In conclusion, we speculated that Pb could increase the oxidative stress and promote the apoptosis via regulating mitochondrial dynamics and apoptosis-related genes, and Se exhibited antagonistic roles against the Pb-induced apoptosis in the kidney of chickens.

Antagonistic effects of selenium on cadmium-induced apoptosis by restoring the mitochondrial dynamic equilibrium and energy metabolism in chicken spleens

The aim of this study was to investigate the mechanism of cadmium-induced apoptosis in chicken spleens and the antagonistic effects of selenium. We duplicated the selenium-cadmium interaction model and examined the expression of apoptosis-, immune-, mitochondrial dynamics- and energy metabolism-related genes. The results demonstrated that after treatment with cadmium, the frequency of apoptosis was significantly increased, and the morphological characteristics of apoptosis were observed. The expression of pro-apoptotic genes was increased, and that of anti-apoptotic genes was decreased. The mRNA levels of tumor necrosis factor-α and interlenkin-1β were observably increased, but the interlenkin-2 and interferon-γ levels were markedly decreased. Furthermore, the mRNA and protein levels of dynamin-related protein 1 and mitochondrial fission factor were significantly enhanced, whereas mitofusin 1, mitofusin 2, and optic atrophy 1 were markedly decreased. The expression of hexokinase 1, hexokinase 2, aconitase 2, lactate dehydrogenase A, lactate dehydrogenase B, succinatedehydrogenase B, pyruvate kinase and phosphofructokinase were also reduced. Selenium supplements remarkably attenuated cadmium-induced effects (p < 0.05). Based on the above results, conclude that the cadmium treatment promoted a mitochondrial dynamic imbalance and reduced energy metabolism, leading to apoptosis and immune dysfunction in chicken spleens, and selenium had an antagonistic effect on Cd-induced apoptosis.

Ameliorative Effects of Dietary Selenium Against Cadmium Toxicity Is Related to Changes in Trace Elements in Chicken Kidneys

The ameliorative effects of selenium (Se) against cadmium (Cd)-induced toxicity have been reported extensively. However, few studies have assessed the effects of multiple ions simultaneously on the variations of elements. In this study, the changes in Se, Cd, and 26 other element concentrations were investigated in chicken kidneys. One hundred and twenty-eight 31-week-old laying hens were fed a diet supplemented with either Se, Cd, or both Se and Cd for 90 days. The ion content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). We found that the Se, Cd, and combined Se and Cd treatments significantly affected the trace elements in the chicken kidneys. The Cd supplement caused ion profile disorders, including reduced concentrations of V, Cr, Mn, Mo, As, Ba, Hg, Ti, and Pb and increased Si, Cu, Li, Cd, and Sb. The Se supplement reduced the contents of Co, Mo, and Pb and increased the contents of Cr, Fe, and Se. Moreover, Se also increased the concentrations of Cr, Mn, Zn, and Se and decreased those of Li and Pb, which in contrast were induced by Cd. Complex interactions between elements were analyzed, and both positive and negative correlations among these elements are presented. The present study indicated that Se can help against the negative effects of Cd and may be related to the homeostasis of the trace elements in chicken kidneys.

Alleviation of lead-induced oxidative stress and immune damage by selenium in chicken bursa of Fabricius

We investigated lead (Pb)-induced oxidative stress and immune damage in the chicken bursa of Fabricius (BF) and the ameliorative effect of selenium (Se). Seven-day-old male chickens were randomly divided into four groups and were provided standard diet and drinking water, Na₂SeO₃ added to the standard diet and drinking water, standard diet and (CH₃COO)₂Pb added to drinking water, and Na₂SeO₃ added to the standard diet and (CH₃COO)₂Pb added to drinking water for 30, 60, and 90 days. The presence of Pb inhibited total antioxidant capacity (T-AOC), glutathione peroxidase (GPx), glutathione S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities; decreased glutathione (GSH) content; increased malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents; inhibited interleukin (IL)-2 and interferon-γ (IFN-γ) messenger RNA (mRNA) expression; and increased IL-4, IL-6, IL-10, IL-12β, and IL-17 mRNA expression. The presence of Se relieved all of the above Pb-induced changes. There were close correlations among GSH, CAT, T-AOC, SOD, GPx, MDA, and H₂O₂ and among IL-2, IL-4, IL-6, IL-12β, IL-17, and IFN-γ. Our data showed that Pb caused oxidative stress and immune damage in the chicken BF. Se alleviated Pb-induced oxidative stress and immune damage in the chicken BF.

Selenium supplementation can protect from enhanced risk of keel bone damage in laying hens exposed to cadmium

The aim of this study was to investigate whether selenium (Se) supplementation can provide protection from an enhanced risk of keel bone damage (KBD) in laying hens due to the cadmium (Cd) toxicity associated with sub-chronic exposure.

Antagonistic effect of selenium on lead-induced inflammatory injury through inhibiting the nuclear factor-κB signaling pathway and stimulating selenoproteins in chicken hearts

In the chicken model of Pb and Se, Se alleviated Pb-induced the changes of inflammatory factors, selenoproteins, and histology. Se alleviated Pb-induced inflammatory injury through inhibiting NF-κB signaling pathway and stimulating selenoproteins in the chicken hearts.

Effects of Selenium and Cadmium on Ion Profiles in the Brains of Chickens

Antagonistic effects of selenium (Se) in cadmium (Cd)-induced toxicity have been frequently reported in previous studies. However, little was known about the interactions of Se and Cd on ion profiles in the brains of poultry. The aim of this study was to investigate the interaction between Se and Cd in the ion profile of the chicken brain. In the present study, a total of 128 laying hens were fed a Se-, Cd-, or Se + Cd-supplemented diet for 90 days. Levels of 28 ions were detected in chicken brains using ICP-MS. We found that Cd exposure significantly increased the content of Cd in the brain; furthermore, the content of lithium (Li), stannum (Sn), and stibium (Sb) increased, but the content of kalium (K) decreased. The content of Se in the brain was not altered by Se supplementation; however, Se reduced the concentrations of Sn and Sb, which in contrast were increased by Cd exposure. Complex interactions between ions were analyzed by principal component analysis, and both positive and negative correlations between different ions were found after prolonged exposure to Se and Cd. These findings suggest that Se and Cd supplementation influences the ion profiles in the chicken brain, and moreover, Se may have an antagonistic effect under longer exposure to Cd.

Simultaneous analysis 26 mineral element contents from highly consumed cultured chicken overexposed to arsenic trioxide by inductively coupled plasma mass spectrometry

This study assessed the impacts of dietary arsenic trioxide (As₂O₃) on 26 mineral element contents in the liver and kidney of chicken. A total of 100 male Hy-line cocks were randomly divided into 2 groups (50 chickens in each group), including an arsenic-treated group (basic diet supplemented with As₂O₃ at 30 mg/kg) and a control group (basal diet). The feeding experiment lasted for 90 days and the experimental animals were given free access to feed and water. We determined 26 mineral elements in the liver and kidney by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that nine element levels (Al, Mn, Co, Cu, Zn, Se, Cd, Ba, and Pb) were significantly decreased (P < 0.05) in the liver of chickens exposed to As₂O₃ compared to the control chickens where three element levels (Ni, As, and Hg) increased significantly (P < 0.05). The results in the kidney showed that nine element levels (Al, K, Ca, Cr, Mn, Ni, Sb, Ba, and Pb) were significantly decreased (P < 0.05) in the chickens exposed to As₂O₃ compared to the control chickens where four element levels (Mo, As, Cd, and Hg) increased significantly (P < 0.05). These results suggest that supplementation of high levels of arsenic affected trace mineral levels in the liver and kidney of chicken, and the effects vary from organ to organ. The aim of this study is to provide references for further study of heavy metal poisoning by detecting the contents of minerals induced by arsenic in chicken.

The Antagonistic Effect of Selenium on Lead-Induced Inflammatory Factors and Heat Shock Protein mRNA Level in Chicken Cartilage Tissue

Selenium (Se) is recognized as a necessary trace mineral in animal diets, including those of birds. Lead (Pb) is a toxic heavy metal and can damage organs in humans and animals. Complex antagonistic interactions between Se and heavy metals have been reported in previous studies. However, little is known regarding the effects of Se on Pb-induced toxicity and the expression of inflammatory factors and heat shock proteins (HSPs) in the cartilage of chickens. In this present study, we fed chickens either with Se or Pb or both Se and Pb supplement and later analyzed the mRNA expressions of inflammatory factors (inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2)) and HSPs (Hsp27, Hsp40, Hsp60, Hsp70, and Hsp90). The results showed that Se and Pb influenced the expression of inflammatory factors and HSP genes in the chicken cartilage tissues. Additionally, we also found that antagonistic interaction existed between Se and Pb supplementation. Our findings suggested that Se could exert a antagonistic effect on Pb in chicken cartilage tissues.

Effect of Selenium Against Lead-Induced Damage on the Gene Expression of Heat Shock Proteins and Inflammatory Cytokines in Peripheral Blood Lymphocytes of Chickens

The possible beneficial role of selenium (Se) in heat shock proteins (HSPs) and inflammation damage induced by lead (Pb) in chickens is unclear. Therefore, the aim of this study was to investigate the effect of Se against Pb on the messenger RNA (mRNA) expression levels of HSPs (HSP 27, 40, 60, 70, and 90); heme oxygenase-1 (HO-1); and the inflammatory cytokines nuclear factor kappa B (NF-κB), tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in the peripheral blood lymphocytes of chickens. A total of 360 1-day-old broiler chickens were randomly allocated into four groups (n = 90/group). The control group was fed a basic diet containing 0.2 mg/kg Se and 0.5 mg/kg Pb; the Se supplementation group (+Se group) was fed a Se-adequate (sodium selenite) diet containing 1 mg/kg Se and 0.5 mg/kg Pb; the Pb-supplemented group (+Pb group) was fed a Pb acetate diet containing 0.2 mg/kg Se and 350 mg/kg Pb; and the Se and Pb compound group (Se + Pb group) was fed a diet containing 1 mg/kg Se and 350 mg/kg Pb. The blood was collected and examined for the mRNA levels of HSP and inflammatory cytokine genes at 30 and 60 days old. The results showed that Pb poisoning induced the mRNA expression of HSPs and inflammatory cytokines in the peripheral blood lymphocytes of chickens. In addition, Se alleviated the Pb-induced increase in HSP and inflammatory cytokine mRNA levels in chicken peripheral blood lymphocytes. In conclusion, Se can antagonize the toxic effects of Pb on chickens and protect the chickens' peripheral blood lymphocytes in normal physiological function.

Effects of Dietary Selenium Against Lead Toxicity Are Related to the Ion Profile in Chicken Muscle

Complex antagonistic interactions between Selenium (Se) and heavy metals have been reported in previous studies. However, little is known regarding the effects of Se on lead (Pb)-induced toxicity and the ion profile in the muscles of chickens. In this present study, we fed chickens either Se or Pb or both Se and Pb supplement and later analyzed the concentrations of 26 ions in chicken muscle tissues. We determined that a Se- and Pb-containing diets significantly affected microelements in chicken muscle. Treatment with Se increased the content of Se but resulted in a reduced concentration of Cu, As, Cd, Sn, Hg, and Ba. Treatment with Pb increased concentrations of Ni while reducing those of B, V, Cr, Fe, Co, Cu, Zn, and Mo. Moreover, Se also reduced the concentration of Pb, Zn, Co, Fe, V, and Cr, which in contrast were induced by Pb. Additionally, we also found that synergistic and antagonistic interactions existed between Se and Pb supplementation. Our findings suggested that Se can exert a negative effect on Pb in chicken muscle tissues and may be related to changes in ion profiles.

Effects of Dietary Selenium Against Lead Toxicity on mRNA Levels of 25 Selenoprotein Genes in the Cartilage Tissue of Broiler Chicken

The interactions between the essential element selenium (Se) and the toxic element lead (Pb) have been reported extensively; however, little is known about the effect of Se on Pb toxicity and the expression pattern of selenoproteins in the cartilage of chicken. To investigate the effects of Se on Pb toxicity and the messenger RNA (mRNA) expressions of selenoproteins in cartilage tissue, an in vitro study was performed on 1-day-old broiler chickens (randomly allocated into four groups) with diet of different concentration of Se and Pb. After 90 days, the meniscus cartilage and sword cartilage tissue were examined for the mRNA levels of 25 selenoprotein genes. The results showed that Se and Pb influenced the expression of selenoprotein genes in the chicken cartilage tissue. In detail, Se could alleviate the downtrend of the expression of Gpx1, Gpx2, Gpx4, Txnrd2, Txnrd3, Dio1, Dio2, Seli, Selu, Sepx1, Selk, Selw, Selo, Selm, Sep15, Sepnn1, Sels, and Selt induced by Pb exposure in the meniscus cartilage. In the sword cartilage, Se alleviated the downtrend of the expression of Gpx2, Gpx3, Gpx4, Txnrd1, Txnrd2, Dio2, Dio3, Seli, Selh, SPS2, Sepx1, Selk, Selw, Selo, Selm, Sep15, Selpb, Sepn1, and Selt induced by Pb exposure. The present study provided some compensated data about the roles of Se against Pb toxicity in the regulation of selenoprotein expression.