Tissue Se Research Articles

Effects of in situ Selenium Exposure and Maternal Transfer on Survival and Abnormalities of Yellowstone Cutthroat Trout (oncorhynchus clarkii bouvieri) Fry.

Offspring of adult Yellowstone cutthroat trout (YCT) exposed to a range of selenium (Se) concentrations in situ were reared in a laboratory setting to assess effects on survival, growth and abnormalities. Maternal whole body Se concentrations ranged from 2.6 to 25.7 mg/kg dry weight (dw) for Site fish while corresponding Se concentrations in embryos ranged from 3.4 to 47.6 mg/kg dw. A significant relationship was found between egg and whole-body tissue concentrations. Endpoints were evaluated at hatch to swim up and hatch to test termination for survival and abnormalities (e.g., deformities and edema). Dose response models were developed to visualize the data distribution and predicted EC10 (the effect concentration where a 10% effect is observed) values for survival and abnormality endpoints relative to egg Se concentrations. EC10s for the survival endpoint were nearly identical, ranging from 35.1 to 35.6 mg/kg dw while EC10s for the abnormality endpoint ranged from 10.6 to 35.3 mg/kg dw. Using the best fit models for survival and abnormality endpoints the EC10 for survival was 35.1 mg/kg dw and the EC10 for abnormalities was 35.2 mg/kg dw. The EPA's evaluation of these data, based on the abnormality data alone, suggested effects to YCT were likely greater than 30 mg/kg dw. The EPA suggested conversion factor for YCT is 1.96 based on a median value of the paired maternal whole body and egg tissue Se data available. However, a reanalysis of these data presented in the paper indicates a ratio of 1.43 is more appropriate; therefore, the egg to whole-body conversion factor for YCT recommended is 1.43 which results in a whole-body tissue EC10 of is 24.55 mg/kg dw at an egg tissue EC10 of 35.1 mg/kg dw.

Relative bioavailability of selenium yeast, selenomethionine, hydroxyl-selenomethionine and nano-selenium for broilers.

Selenium (Se) is an essential trace element for humans and animals. Development and application of new forms of Se sources with lower toxicity and higher bioavailability has been attracting more attention. However, the bioavailabilities of Se from several new Se sources for broilers remain unclear. Therefore, the aim of this study was to assess the relative bioavailabilities of Se from Se yeast (SY), selenomethionine (SM), hydroxyl-selenomethionine (SO) and nano-Se (NS) relative to sodium selenite (SS) for broilers fed a conventional corn-soybean meal diet. A total of 576 one-day-old Arbor Acres commercial male broilers were randomly assigned to 16 treatments with 6 replicate cages per treatment in a completely randomized design involving a 5 (Se sources: SY, SM, SO, NS and SS) × 3 (added Se levels: 0.15, 0.30 and 0.45 mg Se/kg) factorial design of treatments plus 1 (a Se-unsupplemented control) for 21 d. The relative bioavailabilities of Se sources were estimated based on plasma or tissue Se concentrations as well as selenoprotein mRNA expressions and activities in broilers. The results showed that the Se concentrations and glutathione peroxidase (GPX) activities in plasma, liver, breast muscle, pancreas and kidney as well as Se concentration in erythrocytes of broilers, and Gpx1 and Selenop mRNA expressions in pancreas increased linearly (p < 0.03) as added Se level increased. Furthermore, the differences (p < 0.05) among different Se sources were detected for the Se concentrations in liver, breast muscle, pancreas and erythrocytes, GPX activities in pancreas and kidney. Based on slope ratios from the multiple linear regressions of the above indices, the Se bioavailabilities of SY, SM, SO, NS relative to SS (100%) were 78 to 367%, 67.8 to 471%, 57 to 372%, and 45 to 92%, respectively. The results from this study indicated that the Se from SM, SY and SO are more available to broilers than the Se from SS in enhancing the Se concentrations in liver, breast muscle, pancreas and erythrocytes and GPX activity in pancreas, and the Se from SM had the highest while the Se from NS had the lowest relative bioavailability.

Potentially toxic trace elemental levels in the malignant and non-malignant tissues of lungs: a comparative study by multivariate analysis from Pakistan

ABSTRACT Lung cancer is the most prevalent and main cause of tumour-related deaths across the world. Exposure to environmental and occupational toxicants such as toxic trace elements is an important cause of lung carcinoma. Keeping in view, the current investigation was aimed to measure the concentrations of 10 elements Mn, Mg, Ni, Zn, Se, Cr, Cd, Fe, Pb and Cu in the malignant tissues and non-malignant tissues samples of lungs of patients. The samples were digested in HNO3 and HClO4 solutions and analysed by using atomic absorption spectrophotometric technique. On the average, significantly elevated levels of copper , lead , cadmium and chromium were detected in the malignant tissues than the non-malignant tissues of patients. Most of the elements exhibited noticeably disparities in their concentrations based on sex, nutritional habits, habitat and smoking habits of donor groups. The correlation coefficients between the elements in malignant tissues and non-malignant tissues were significantly diversed. Based on lung cancer types, zinc and cadmium were raised in adenocarcinoma, whereas copper and cadmium were elevated in squamous cell carcinoma patients. Average magnesium, zinc and lead were highest in stage IV, while nickel and iron were maximum in stage-III of the malignant tissues. The chromium and manganese referred to be maximum at stage-II while selenium, copper and cadmium were elevated at stage-I. Multivariate statistical methods based on the elemental concentrations exhibited clearly divergent groupings which may be linked to alter the metabolism of the metals in the tumour tissues and non tumour tissues of lungs.

Effects of high-dose selenium-enriched Saccharomyces cerevisiae on growth performance, antioxidant status, tissue fat content and selenium concentration, and selenoenzyme mRNA expression in chicks

Selenium-enriched Saccharomyces cerevisiae (SSC) as organic selenium (Se) has been shown to have better advantages and is approved for use in animal feed rather than inorganic Se, however, there is little available data on the toxic effects of SSC on poultry. The present study was conducted to investigate the effects of high-dose SSC on growth performance, antioxidant status, tissue fat content and Se concentration, and selenoenzyme mRNA expression in chicks. A total of 500, 1-day-old SPF chicks were randomly divided into 5 groups with 10 replicates of 10 chicks each. Group 1 served as a control and was fed a basal diet supplemented with 0.15 mg/kg Se from sodium selenite (SS), group 2 was fed the basic diet supplemented with 1.5 mg/kg Se from SS, while groups 3, 4, and 5 were fed the basal diet supplemented with 1.5, 5 and 10 mg/kg Se from SSC, respectively. The results showed that SS and SSC supplementation significantly affected the average daily feed intake (ADFI), feed/gain ratio (FCR), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, tissue fat content and Se concentration, and GPx1 and GPx4 mRNA levels compared with the control group (P < 0.05). Compared with group 2, group 3 exhibited higher GPx and SOD activities, tissue Se concentration, and lower MDA content on d 30, and higher Se concentration, GPx1 mRNA levels in liver and breast muscle and GPx4 mRNA levels in liver and thigh muscle, and lower MDA content on d 60 (P < 0.05). The results of correlation analysis showed that high-dose SSC supplementation was positively correlated with AFDI, FCR, MDA content, and tissue Se concentration, and negatively correlated with GPx and SOD activities, T-AOC, GPx1 and GPx4 mRNA levels in tissues. In conclusion, up to 1.5 mg/kg Se from SSC in diet may be a safe concentration for chicks that exhibited better biological effects than SS, the toxic effects of high-dose SSC supplementation mainly exhibited growth decrease, peroxidation and lipid metabolism disturbance, and became stronger with the increase of dietary Se levels.

The relationship between cellular protein content and selenium accumulation in freshwater microalgae.

Variability in the bioconcentration of selenium (Se) by primary producers at the base of the food web results in uncertainty in predictions of bioaccumulation and ecological risk to higher trophic level organisms. Water chemistry, speciation of Se, and periphyton community composition have all been suggested as factors that contribute to variability in bioconcentration by primary producers; however, the role of physiological composition of periphyton species in influencing the bioconcentration of Se has not been previously evaluated. To determine if a relationship exists between algal protein content and Se accumulation, Parachlorella kessleri, Chlorella vulgaris, and Raphidocelis subcapitata were exposed to Se (as selenate) and analyzed for total protein and tissue Se content in the exponential and stationary growth phases. Protein content and Se accumulation in R. subcapitata in the stationary phase were also measured under two light intensities. No relationship between cellular protein content and Se accumulation was found for algae in the exponential phase; however, a strong relationship was found in the stationary phase among species and for R. subcapitata under differing light intensities. Absolute Se accumulations by P. kessleri, C. vulgaris, and R. subcapitata in the stationary phase were statistically different; however, the concentrations of Se in protein were similar across species. These results suggest that cellular protein content in microalgae influences Se bioconcentration and that algal protein content may improve Se bioaccumulation modeling in food webs. Integr Environ Assess Manag 2024;00:1-10. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Dynamics of selenium-mercury interaction under mercury stress in high and low selenium rice genotypes

Recent studies have demonstrated that selenium (Se) reduces the accumulation of heavy metals in rice tissues. However, the interaction between Se and mercury (Hg) in rice genotypes with high Se content remains to be further investigated. In this study, we used high Se genotypes Z2057B and Z5097B and low Se genotype Yuenong to explore the dynamics of Se and Hg in various tissues. The results showed that high Se genotypes, coupled with low concentrations of exogenously applied Se, significantly reduced the uptake of Hg in rice plants. The findings indicated the following order of Hg accumulation: Roots> third leaf > second leaf > first leaf > stem > grains. Observations revealed that both high Se genotypes and Se supplementation significantly restricted the majority of Hg concentration in roots and minimized its translocation to the aerial parts of the rice plant. In high Se genotypes subjected to mercury stress, MDA accumulation was significantly reduced, and SOD antioxidant activity was enhanced in stem and leaves at jointing, booting, heading, and maturity stages as compared to low Se genotypes. The application of 1.0 mg of Se per kg soil significantly improved the agronomic and physiological characteristics, reduced the Hg contents in aerial parts, and increased the Se contents in polished rice grains. Hence, the results lead to the conclusion that (i) cultivating high Se rice genotypes is a viable approach to decrease the Hg accumulation in rice grains and serves as a crucial strategy to fulfill daily Se requirements, particularly for populations suffering from Se deficiency (ii) supplementing ordinary rice with 1–3 mg kg−1 of Se can effectively reduce Hg accumulation and improve the quality of the grains.

Raising root zone temperature improves plant productivity and metabolites in hydroponic lettuce production.

While it is commonly understood that air temperature can greatly affect the process of photosynthesis and the growth of higher plants, the impact of root zone temperature (RZT) on plant growth, metabolism, essential elements, as well as key metabolites like chlorophyll and carotenoids, remains an area that necessitates extensive research. Therefore, this study aimed to investigate the impact of raising the RZT on the growth, metabolites, elements, and proteins of red leaf lettuce. Lettuce was hydroponically grown in a plant factory with artificial light at four different air temperatures (17, 22, 27, and 30°C) and two treatments with different RZTs. The RZT was raised 3°C above the air temperature in one group, while it was not in the other group. Increasing the RZT 3°C above the air temperature improved plant growth and metabolites, including carotenoids, ascorbic acids, and chlorophyll, in all four air temperature treatments. Moreover, raising the RZT increased Mg, K, Fe, Cu, Se, Rb, amino acids, and total soluble proteins in the leaf tissue at all four air temperatures. These results showed that raising the RZT by 3°C improved plant productivity and the metabolites of the hydroponic lettuce by enhancing nutrient uptake and activating the metabolism in the roots at all four air temperatures. Overall, this research demonstrates that plant growth and metabolites can be improved simultaneously with an increased RZT relative to air temperature. This study serves as a foundation for future research on optimizing RZT in relation to air temperature. Further recommended studies include investigating the differential effects of multiple RZT variations relative to air temperature for increased optimization, examining the effects of RZT during nighttime versus daytime, and exploring the impact of stem heating. This research has the potential to make a valuable contribution to the ongoing growth and progress of the plant factory industry and fundamental advancements in root zone physiology. Overall, this research demonstrates that plant growth and metabolites can be improved simultaneously with an increased RZT relative to air temperature. This study serves as a foundation for future research on optimizing RZT in relation to air temperature. Further recommended studies include investigating the differential effects of multiple RZT variations relative to air temperature for increased optimization, examining the effects of RZT during nighttime versus daytime, and exploring the impact of stem heating. This research has the potential to make a valuable contribution to the ongoing growth and progress of the plant factory industry and fundamental advancements in root zone physiology.

Selenium levels in colorectal cancer: A systematic review and meta-analysis of serum, plasma, and colorectal specimens

BackgroundColorectal cancer (CRC) is a growing public health problem. Several clinical studies have shown a potentially protective effect of selenium (Se), but the reports are inconsistent. The objective of the study was to examine the evidence for relation between serum/tissue Se status and CRC. Method and materialsIn this Systematic Review and Meta-Analysis, we searched Cochrane Library, EBSCOhost, EMBASE, ProQuest, PubMed/MEDLINE, Scopus, and Web of Science for studies reporting serum/plasma/whole blood/tissue Se concentrations in CRC patients and controls for articles published till August 2023. Meta-analysis was performed, and study quality, heterogeneity, and small study effects were assessed. Based on a random effects model, summary mean differences in serum levels of Se between CRC patients and healthy controls, and Se levels between malignant and matched non-malignant tissue specimens were assessed. ResultsAfter initial screening, a total of 24 studies (18 serum and 6 tissue studies) with a pooled total of 2640 participants were included in the meta-analysis. CRC patients had significantly lower serum Se levels than healthy controls, being the difference between the two equal to 3.73 µg/dl (95% CI: 6.85–0.61). However, the heterogeneity was very high, I2= 99% (p < 0.01). Our meta-analysis showed higher Se levels in CRC cancerous specimens than in matched healthy colon tissue: the increase was equal to 0.07 µg/g wet tissue weight (95% CI: 0.06–0.09; p= 0.02). ConclusionsCRC patients have lower serum and higher colon cancerous tissue Se levels. Some factors, such as Se levels in different tumor grades of CRC need to be further considered for a more conclusive association between Se levels and risk of CRC.

The association between trace metals in both cancerous and non-cancerous tissues with the risk of liver and gastric cancer progression in northwest China

Liver cancer and gastric cancer have extremely high morbidity and mortality rates worldwide. It is well known that an increase or decrease in trace metals may be associated with the formation and development of a variety of diseases, including cancer. Therefore, this study aimed to evaluate the contents of aluminium (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) in cancerous liver and gastric tissues, compared to adjacent healthy tissues, and to investigate the relationship between trace metals and cancer progression. During surgery, multiple samples were taken from the cancerous and adjacent healthy tissues of patients with liver and gastric cancer, and trace metal levels within these samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS). We found that concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in tissues from patients with liver cancer were significantly lower than those in healthy controls (P < 0.05). Similarly, patients with gastric cancer also showed lower levels of Cd, Co, Cr, Mn, Ni, and Zn—but higher levels of Cu and Se—compared to the controls (P < 0.05). In addition, patients with liver and gastric cancers who had poorly differentiated tumours and positive lymph node metastases showed lower levels of trace metals (P < 0.05), although no significant changes in their concentrations were observed to correlate with sex, age, or body mass index (BMI). Logistic regression, principal component analysis (PCA), Bayesian kernel regression (BKMR), weighted quantile sum (WQS) regression, and quantile-based g computing (qgcomp) models were used to analyse the relationships between trace metal concentrations in liver and gastric cancer tissues and the progression of these cancers. We found that single or mixed trace metal levels were negatively associated with poor differentiation and lymph node metastasis in both liver and gastric cancer, and the posterior inclusion probability (PIP) of each metal showed that Cd contributed the most to poor differentiation and lymph node metastasis in both liver and gastric cancer (all PIP = 1.000). These data help to clarify the relationship between changes in trace metal levels in cancerous liver and gastric tissues and the progression of these cancers. Further research is warranted, however, to fully elucidate the mechanisms and causations underlying these findings.

Toxic Metal and Essential Element Concentrations in the Blood and Tissues of Pancreatic Ductal Adenocarcinoma Patients.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal neoplasm, and it has an average 5-year survival rate of less than 10%. Although the factors that influence PDAC development remain unclear, exposure to toxic metals or the imbalance in essential elements may have a role in PDAC-associated metabolic pathways. This study determined the concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se and Zn in whole blood, cancer and non-cancer tissues of patients affected by PDAC, and compared them with levels in healthy controls using inductively coupled plasma mass spectrometry. Results of the whole blood showed significantly higher levels of Cr, Cu and Cu/Zn ratio in PDAC patients compared to the controls. In addition, the concentrations of Cu, Se, Fe and Zn significantly increased in cancer tissue compared to the healthy counterparts. This study revealed evidence of altered metal levels in the blood and pancreatic tissues of PDAC patients with respect to healthy controls. These changes may contribute to multiple mechanisms involved in metal-induced carcinogenesis, including oxidative stress, DNA damage, genetic alteration, decreased antioxidant barriers and inflammatory responses. Thus, the analysis of metals can be used in the diagnosis and monitoring of PDAC neoplasms.

Relationships among tissues, biofluids, and otolith selenium concentrations in wild female burbot (Lota lota).

In the Lake Koocanusa-Kootenai River system (Montana, USA and British Columbia, Canada), selenium (Se) contamination has become an international concern and is suspected to contribute to the observed burbot (Lota lota) population collapse. Due to our limited ability to sample burbot in Lake Koocanusa for monitoring studies, we used a reference population to develop tools to model tissue Se disposition for a focal species in systems with elevated Se. Total Se concentrations in otoliths, biofluids (blood and endolymph), and tissues (muscle, liver, and ovary) from burbot in reference lakes in northwestern Ontario, Canada, were measured to document tissue-to-tissue Se relationships and evaluate the potential for otoliths to retrace Se exposure in fish. Among burbot tissue, Se concentrations were the highest in the ovary (mean ± SD = 4.55 ± 2.23 μg g-1 dry mass [dm]), followed by the liver (2.69 ± 1.96 μg g-1 dm) and muscle (1.87 ± 1.14 μg g-1 dm), and decreased with body size (p < 0.05). In otoliths, Se was detected at low levels (<1 μg g-1 ). Selenium concentrations in burbot samples were positively correlated among muscle, ovary, liver, and endolymph tissues, but not for the most recent annually averaged or lifetime-averaged Se concentrations in otoliths. We hypothesize that Se concentrations were too low in this study to establish links between otoliths and other fish tissues and to detect significant lifetime variation in individuals, and that further validation using archived otoliths from burbot exposed to elevated Se levels in Lake Koocanusa-Kootenai River is needed to reconstruct exposure histories. However, intercompartmental models proved valuable for estimating Se concentrations in burbot tissues only available by means of lethal sampling (i.e., ovary), although additional work should confirm whether the established models are reliable to predict concentrations in Se-impaired systems as tissue distributions are likely to differ with increasing Se levels. Integr Environ Assess Manag 2023;00:1-11. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

112 Effect of Selenium Sources on Sow Productive and Reproductive Performance and Their Progeny

Abstract Dietary selenium (Se) supplementation is a standard practice, using either an inorganic form, such as sodium selenite (SS) or organic forms, like SeYeasts (SY) or pure forms of selenomethionine (SeMet). Hydroxy-selenomethionine (OH-SeMet) is a chemically synthesized organic Se form and has been proven to be efficient in transferring Se from the diet to muscle compared with SS or SY products. The transfer of Se in tissues, in fact, leads to the buildup of a Se reserve as SeMet in the body that participates in maintaining effective antioxidant defenses and supports animal performance, particularly under challenging conditions. This trial aimed to determine the effects of different Se sources on the productive and reproductive performance of sows and on their progeny. Sows (n = 120) were allocated in individual cages in one of the three treatments according to the number of parities, number of piglets in previous parturition, body condition score and initial body weight. The experiment lasted 141 days (from the insemination of sows up to the weaning of the piglets at 21 days). A corn-soybean-based basal diet was formulated to meet the nutrient requirements of the sows during gestation and lactation. The Se supplementation was 0.35 ppm of Se either from SS, SY or OH-SeMet. The number of total piglets born showed a tendency (P = 0.06) for treatments fed organic Se sources (15.6 OH-SeMet; 15.4 SY vs 14 SS) with no differences on the litter weight at birth. However, sows fed OH-SeMet weaned more piglets (13.4) than the other treatments (12.5 SY and 12.2 SS, respectively, P &amp;lt; 0.01). The litter weight at weaning showed no differences among treatments (73.4, 70.4 and 75.9kg for SS, SY and OH-SeMet, respectively). The feed conversion of the sows during lactation was also affected by the Se source, in which OH-SeMet showed a significantly reduced FCR of 2.6 vs 3.0 and 3.1 for SS and SY, respectively (P &amp;lt; 0.01). Piglets fed organic sources showed a decreased diarrhea incidence (scores 2 and 3) compared with SS (P &amp;lt; 0.001), respectively, 5.68 vs 3.28 and 3.27%. The Se concentration of sows’ colostrum and milk of sows were numerically improved from SS to SY, but only significantly greater on OH-SeMet treatment. The same pattern of Se concentration in the milk was observed in the serum of piglets 48 h after birth (142, 122 and 228 μg/kg for SS, SY and OH-SeMet, respectively) and at weaning (85, 85 and 117 μg/kg for SS, SY and OH-SeMet, respectively). Feeding pure forms of organic Se, such as OH-SeMet supports the productive and reproductive performance of sows and improve the Se status of the progeny. Organic Se also reduces the diarrhea of piglets, compared with SS.

The effect of zinc and/or vitamin E supplementation on biochemical parameters of selenium-overdosed rats

The normotensive (Wistar) and spontaneously hypertensive (SHR) rats were examined to assess the response of the organism to selenium (Se) overdose. Moreover, the effect of zinc (Zn) and vitamin E, i.e. dietary components interacting in many biochemical processes with Se, on the Se uptake was evaluated. The control group was fed an untreated diet, and the diets of two other groups were overdosed with Se in the form of sodium selenite (9 mg/kg) and supplemented with Zn (13 mg/kg). Two experimental groups were fed a diet supplemented with Zn (13 mg/kg) and Se at an adequate level (0.009 mg/kg); a half of the animals was supplemented with vitamin E. The results showed significant differences in the Se contents between the rat strains in case of Se-overdosed groups, where in the liver and kidney tissue Se contents of SHR rats exceeded 3- and 7-fold the normotensive ones. The Se uptake was altered by the vitamin E; no effect of Zn was observed. Activities of antioxidant enzymes were determined in the animal tissues indicating different patterns according to rat strain, tissue analysed, and administered Se dose. Thus, Se overdose, for instance, via an incorrectly prepared dietary supplement, can result in serious imbalances of the biochemical status of the animals.

Trace elements dyshomeostasis in liver and brain of weanling mice under altered dietary selenium conditions

BackgroundA balanced diet containing selenium (Se) and other trace elements is essential for normal development and growth. Se has been recognized as an essential trace element; however, its interaction with other elements has not been fully investigated. In the present study, sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), Se and rubidium (Rb), were analysed in liver and brain regions under altered dietary Se intake in weanling mice to identify major discriminatory elements. MethodsThe study investigated the effects of different levels of Se intake on the elemental composition in liver and brain tissues of weaned mice. After 24 weeks of feeding with Se adequate, deficient, and excess diets, elemental analysis was performed on the harvested tissues using Inductively coupled plasma mass spectrometry (ICP-MS). Statistical analysis that included analysis of covariance (ANCOVA), correlation coefficient analysis, principal component analysis, and partial least squares discriminant analysis were performed. ResultsThe ANCOVA showed statistically significant changes and correlations among the analysed elements under altered dietary Se status. The multivariate analysis showed differential changes in elements in liver and brain regions. The results suggest that long-term dietary Se alternations lead to dyshomeostasis in trace elements that are required in higher concentrations compared to Se. It was observed that changes in the Fe, Co, and Rb levels were similar in all the tissues studied, whereas the changes in Mg, Cr, and Mn levels were different among the tissues under altered dietary Se status. Additionally, the changes in Rb levels correlated with the dietary Se intake but had no relation with the tissue Se levels. ConclusionsThe findings suggest interactions between Mg, Cr, Mn, Fe, Co, and Se under altered Se status may impact cellular functions during postnatal development. However, the possible biological significance of alterations in Rb levels under different dietary Se paradigms needs to be further explored.

Transfer of Se from sediments to the western mosquitofish Gambusia affinis: Tissue distribution, accumulation, and effects on the antioxidant physiology

Selenium (Se) has been shown to cause various toxicities in predatory species (i.e., fish and birds) in Se-contaminated aquatic environments. However, trophic transfer of Se from abiotic environments to freshwater fish has been relatively less addressed. In this study, 2-month-old mosquitofish (Gambusia affinis) were fed Se-enriched oligochaete (Lumbriculus variegatus, exposed to different concentrations of Se(IV) at 0.0, 3.0, 10.0, and 30.0 µg/g dry weight for 7 days) for 45 days. Tissue distribution, Se speciation, and effects on the antioxidant physiology in G. affinis were assessed. The results showed Se was rapidly accumulated in the oligochaete, with 6.30 ± 1.20, 16.20 ± 2.10, and 34.50 ± 2.40 µg/g dw of total Se levels in the worms exposed to 3.0, 10.0, and 30.0 µg/g of Se(IV), respectively. Total Se levels were increased in a dose-dependent manner in fish tissues and Se(IV) from sediments was maternally transferred to the fish embryos. Se-Met-and Se-Cys-were the predominant Se species in the worm and fish tissues, accounting for a minimum of 91.01% of the total Se. Furthermore, increased lipid peroxidation and altered the activities of antioxidant enzymes and levels of GSH were noticed in G. affinis fed the Se-enriched L. variegatus. This study has demonstrated that Se(IV) is transferred from an abiotic vector to freshwater organisms, disturbing the antioxidant physiology in G. affinis and potentially their offspring. This study highlights the importance of dietary exposure on the accumulation and toxicity of Se in aquatic organisms.

Amounts of tissue magnesium and some trace elements in cats with mammary tumors related to various clinicopathological parameters

BackgroundMammary tumors are one of the major malignancies seen in cats. Researchers have indicated the similarity between the epidemiological and clinicopathological patterns of feline mammary tumors and human breast cancer (HBC). In recent years, the investigation of trace elements in cancer tissues becomes prevalent in HBC due to the role of these elements in biochemical and physiological processes. This study, it is aimed to evaluate some trace elements in feline mammary tumors according to clinical and pathological findings. MethodsA total of 60 tumoral masses from 16 female cats with mammary tumors were included in the study. The study groups were formed according to histopathology as malignant epithelial tumor (MET; n = 39) and hyperplasia and dysplasia (H&D; n = 21). Copper (Cu), Iron (Fe), Magnesium (Mg), Manganese (Mn), Selenium (Se) and Zinc (Zn) trace elements in mammary tissues were analyzed by using an inductively coupled plasma-optical emission spectrophotometer. ResultsThe mean age and weight of the cats were 11.75 ± 0.75 years and 3.35 ± 0.21 kg; respectively. Eleven of 16 cats were intact whereas the rest of them had been spayed. Metastases were observed in 10 cats. Tissue Mg level in group MET was significantly higher than in group H&D (P < 0.01) while the other elements had not significant differences between the groups. In group MET, analyzed elements were not statistically significant related to the inflammation, ulceration and invasion to the peripheral muscle (P > 0.05). However, tissue Fe level was significantly higher in T2 than in T3 (P < 0.05). The mean levels of tissue Fe, Mg and Mn had significant differences related to histological grading as P < 0.01, P < 0.05 and P < 0.001; respectively. A mild to severe correlation was found between tissue Zn and Se, Cu, Fe, Mg, and Mn levels. ConclusionTissue Mg and some trace elements were evaluated in feline mammary tumours in regard to various clinicopathological parameters. Tissue Mg level was sufficient to differentiate the malignant epithelial tumors from hyperplasia and dysplasia. However, Mn and Se tended to distinguish different tumor types. Tissue Fe, Mg and Mn had significant differences related to histological grading. Also, the Fe level was significantly higher in T2 than in T3 and Zn level tended to be higher in T3 than in T1. It was concluded that Mg, Se, Mn, Fe, Cu and Zn provided useful information on the pathogenesis of feline mammary tumors. Further research is needed on the tissue and serum concentrations of trace elements which may provide valuable information for the disease prognosis.

Toxicological mechanism of cadmium in the clam Ruditapes philippinarum using combined ionomic, metabolomic and transcriptomic analyses

Cadmium (Cd) contamination in marine environment poses great risks to the organisms due to its potential adverse effects. In the present study, the toxicological effects and mechanisms of Cd at environmentally relevant concentrations (5 and 50 μg/L) on clam Ruditapes philippinarum after 21 days were investigated by combined ionomic, metabolomic, and transcriptomic analyses. Results showed that the uptake of Cd significantly decreased the concentrations of Cu, Zn, Sr, Se, and Mo in the whole soft tissue from 50 μg/L Cd-treated clams. Significantly negative correlations were observed between Cd and essential elements (Zn, Sr, Se, and Mo). Altered essential elements homeostasis was associated with the gene regulation of transport and detoxification, including ATP-binding cassette protein subfamily B member 1 (ABCB1) and metallothioneins (MT). The crucial contribution of Se to Cd detoxification was also found in clams. Additionally, gene set enrichment analysis showed that Cd could interfere with proteolysis by peptidases and decrease the translation efficiency at 50 μg/L. Cd inhibited lipid metabolism in clams and increased energy demand by up-regulating glycolysis and TCA cycle. Osmotic pressure was regulated by free amino acids, including alanine, glutamate, taurine, and homarine. Meanwhile, significant alterations of some differentially expressed genes, such as dopamine-β-hydroxylase (DBH), neuroligin (NLGN), NOTCH 1, and chondroitin sulfate proteoglycan 1 (CSPG1) were observed in clams, which implied potential interference with synaptic transmission. Overall, through integrating multiple omics, this study provided new insights into the toxicological mechanisms of Cd, particularly in those mediated by dysregulation of essential element homeostasis.

Total Mercury and Selenium in wild Shrimp from Coastal Lagoons of Northwest Mexico: Human Health risk Assessment

This study analyzed total mercury (THg), and selenium (Se) in edible tissues of white shrimp (Litopenaeus vannamei), blue shrimp (L. stylirostris) and brown shrimp (F. californiensis), from three states of the Northwest of Mexico in September and October 2017. Concentrations of THg and Se in the muscle were between 0.026 and 0.829 and 0.126-1.741µg/g dry weight (dw), respectively. Significant differences were observed among Hg concentration of Sonora and Nayarit and among Se concentration of Sinaloa and Nayarit. In addition, the health risk assessment (HQ) in the three species of shrimp was between 0.550 and 0.607. All Se:Hg molar ratios were > 1 and positive HBVSe values that showed that shrimp from Northwest of Mexico does not represent a risk to human health.

Safflower (Carthamus tinctorius L.) Response to Cadmium Stress: Morpho-Physiological Traits and Mineral Concentrations.

Cadmium is a widely distributed heavy metal in agricultural soils that affects plant growth and productivity. In this context, the current study investigated the effects of different cadmium (Cd) doses (0, 25, 50, 75, and 100 mg L-1 of CdSO4) on the growth and physiological attributes of safflower (Carthamus tinctorius L.) including plant height (cm), root length (cm), fresh weight (g) of root, stem, and leaves, leaf number, macro and micro-nutrients, Se, and heavy metal (Cd, Cr, and Pb) content. The experiment was carried out in a completely randomized design (CRD) with four replicates. The results showed that Cd stress significantly negatively affected all growth indices, macro- and micro-nutrients, and heavy metal content. In addition, it increased the MDA and APX activities. The highest amounts of Fe, Mn, Ni, Pb, Zn, K, Na, Cd, Cr, and Cu were determined in plant roots, while the highest values of Ca and Mg were detected in plant stem tissues. High Cd doses decreased the content of Ca, K, Mg, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in safflower plant tissues by 45.47%, 39.33%, 79.28%, 68.21%, 37.06%, 66.67%, 45.62%, 50.38%, 54.37%, 33.33% and 65.87%, respectively, as compared to the control treatments.

Metal-amino acid complexes (Zn, Se, Cu, Fe and Mn) as a replacement of inorganic trace minerals in commercial diets for Nile tilapia (Oreochromis niloticus) reared under field conditions: Effects on growth, feed efficiency, gut microbiota, intestinal histology, and economic return

An 80-day trial was carried out to evaluate the effects of replacing dietary inorganic trace minerals (ITM), with metal-amino acid complexes (MAAC) on the growth rates, feed utilization, economic return, body composition and mineralization, gut microbiota, and intestinal histology of Nile tilapia (Oreochromis niloticus) reared in in-pond hapas, under commercial conditions. The fish (93.7 g) were stocked in 2-m3 hapas, in quadruplicates, at a density of 30 fish m−3 (60 fish hapa−1). Five isonitrogenous (30% CP), isoenergetic (17 MJ kg−1) extruded (floating) commercial tilapia diets were produced, containing 0, 25%, 50%, 75% and 100% MAAC as a replacement of the commercial ITM premix. In the beginning, the diets were fed to the fish at a daily rate of 3% of their body weight (BW), but the feeding rate was reduced to 2.7% BW at the beginning of the second month. The best growth performance and feed efficiency were achieved at 50% MAAC level, with no further improvement registered above this level. Except for lipid content, tissue proximate composition was significantly affected by MAAC supplementation. Economic analysis indicated that MAAC-based diets were more profitable than the control, ITM-supplemented diet, with 50% replacement showing the highest return (21% increase) over the control diet. Tissue Fe and Mn levels did not differ, while tissue Cu was higher in fish fed ITM than in those fed MAAC diets. Tissue Zn and Se increased with increasing MAAC up to 50% and 75% replacement and decreased with further MAAC supplementation. Bone Cu and Mn were not affected by dietary mineral premix; whereas Fe, Zn and Se were significantly altered. Bone Fe concentration significantly decreased at 75% and 100% MAAC levels, whereas bone Zn increased with increasing MAAC to 50%. Bone Se was lower in fish fed ITM than in those fed MAAC at 25% replacement, however, Se was not significantly affected by further increases in MAAC concentrations. Digestive enzyme activity was improved with increasing supplemental MAAC up to 50% substitution level. Fish fed MAAC showed significantly higher abundances of intestinal beneficial bacteria (Bacillus and Lactobacillus.) and lower abundances of putative pathogenic bacteria (Staphylococcus and Streptococcus) than the control group. The length of the intestinal folds and the number of goblet cell counts also significantly increased in fish fed MAAC up to 50% inclusion. Quadratic regression analyses revealed that about 50–55% MAAC is required for optimum performance, body mineralization, intestinal absorptive capacity, and beneficial intestinal microbiota.