Selenium Differentially Regulates Flavonoid Accumulation and Antioxidant Capacities in Sprouts of Twenty Diverse Mungbean(Vigna radiata(L.)Wilczek)Genotypes

Seed germination with selenium(Se)is promising for producing Se-biofortified foods.Mungbean(Vigna radiata(L.)Wilczek)sprout is freshly eaten as a salad dressed with sauce,making it superior for Se biofortification.Since the Se safety range for the human body is extremely narrow,it is imperative to evaluate the genotypic responses of mungbean sprouts to Se.This study evaluated the Se enrichment capacity and interaction withflavonoids and antioxidant systems in sprouts of 20 mungbean germplasms.Selenium treatment was done by immersing mung-bean seeds in 20μM sodium selenite solution for 8 h.Afterward,the biomass,Se amounts,flavonoid(particularly vitexin and isovitexin)contents,antioxidant capacity,and key biosynthetic gene expressions were measured.Sprout Se content was 2.0-7.0μg g^(-1) DW among the 20 mungbean germplasms.Selenium treatment differentially affected the biomass,totalflavonoid,vitexin,isovitexin,antioxidant enzyme activities,and antioxidant capacities of the mungbean germplasms.Eight germplasms showed increased biomass(p<0.05),the highest increasing by 127%,but 13 did not phenotypically respond to Se treatment.Seven and six germplasms showed varied levels of vitexin and isovitexin increment after Se treatment,the highest measuring 2.67-and 2.87-folds for vitexin and isovitexin,respectively.Two mungbeanflavonoid biosynthesis genes,chalcone synthase(VrCHS)and chalcone isomerase(VrCHI)were significantly up-regulated in the germplasms with increased vitexin and isovitexin levels(p<0.05).Moreover,Se enrichment capacity was significantly correlated with the vitexin,isovitexin,and antiox-idant capacities.In conclusion,mungbean sprouts could be a useful Se-biofortified food,but the Se enrichment capacity and nutritional response must be determined for each germplasm before commercialization.

Selenium,Type-2 Diabetes,and the Possible Protective Role of Vitamin D

Diabetes is a pervasive and serious global health issue.According to the International Diabetes Federation report,463 million adults worldwide were living with diabetes in 2019,and this number is projected to reach 700 million in 2045^([1]).

Enhanced protective effect of selenium-biofortified peptide RYNA(Se)MNDYT compared with its native peptide RYNAMNDYT in lipopolysaccharide-injured murine gut microbiota

Selenopeptides may be a valuable bioactive compound to promote gut microbiota-targeted therapeutic methods for intestinal disease and hepatopathy.However,limited information is available on the utilization of selenopeptides by gut microbiota,especially Selenium(Se)function.For this purpose,the present study aimed to investigate the protective effect of selenopeptide(RYNA(Se)MNDYT,Se-P2,purity of≥95%)and its original peptide(RYNAMNDYT,P2,purity of≥95%)in vivo by the microbiota-metabolite axis and further analyze the potential contribution of Se biofortification to Se-P2 bioactivity.The results showed that Se-P2 exhibits a higher protective effect on lipopolysaccharide(LPS)-induced inflammation than P2,including pathology of the colon and liver,which suggested that the bioactivity of P2 was promoted by the organic combination of Se.Notably,gut microbiota composition tended to be a healthy structure by Se-P2 pretreatment in LPS-injured mice,which had a positive effect on LPS-induced gut microbiota dysbacteriosis.Additionally,only Se-P2 promoted an increase in the relative abundance of Lactobacillus,Alistipes,and Roseburia and a decrease in the relative abundance of Akkermansia,Erysipelatoclostridium,and Bacteroides in LPS-injured mice.The changes in gut microbiota were obviously correlated with the changes in metabolites and affected the metabolic pathways of valine,leucine,isoleucine,phenylalanine,tyrosine,and tryptophan biosynthesis and phenylalanine metabolism.This may be one of the key reasons for Se-P2 to exert bioactivity through the microbiota-metabolite axis.Furthermore,Se-biofortification in Se-enriched Cordyceps militaris affected the parental proteins of Se-P2 to modulate mitogen-activated protein kinase,GPI anchored protein,and carbohydrate metabolism,translation,folding,sorting and degradation,which may contribute to the bioactivity of Se-P2.Our study provides information on the effect of Se on selenopeptides in vivo,which further promotes the prospective applications of selenopeptides as dietary supplements.

Assessment of Selenium Contamination in Sediments of the Aby and Tendo Lagoons in Côte d’Ivoire

Selenium is a trace element that can have both beneficial and harmful effects on aquatic life. The Aby Lagoon is a coastal environment in Côte d’Ivoire that receives selenium inputs from various natural and anthropogenic sources. The aim of this study was to assess the levels of selenium in the sediments of the Aby Lagoon and its tributaries, the Tanoe River and the Tendo Lagoon, and to examine the spatial and seasonal variations of selenium concentrations. Sediment samples were collected from different sites and seasons, and selenium concentrations were measured by atomic fluorescence spectrometry. The results showed that the average concentration of selenium in the sediments of the Aby Lagoon was 0.82 mg/kg, indicating moderate contamination. The concentration of selenium varied between sites and seasons, with higher values in the channel of the Tendo Lagoon and during the dry season. The study highlighted the complexity of selenium dynamics in aquatic ecosystems, and the need to take into account seasonal and spatial variability as well as interactions between environmental factors. The study also suggested potential ecotoxicological risks for some sensitive organisms in certain areas of the lagoon. This study contributes to the knowledge of the dynamics of selenium in lagoon ecosystems and to the assessment of the environmental risks associated with its presence.

Synthesis of chitosan oligosaccharide selenium and its antitumor activity

Background:Polysaccharides have various biological activities;the complexation of polysaccharides with trace element ions can produce synergistic effects,improving the original biological activities of sugars and trace elements.Methods:The preparation process of chitosan oligosaccharide selenium(COSSe)was optimized by the response surface method,followed by a detailed analysis of the resultant compound’s characteristics.The anti-cancer activity of COSSe was studied using the human ovarian cancer cell line SKOV3 as a cell model.Results:The prepared COSSe response surface was well predicted,indicating successful chitosan oligosaccharide binding with selenium.Response surface method analyses identified the optimal synthesis conditions for COSSe:the reaction time of 5.08 h,the reaction temperature of 71.8°C,and mass ratio(Na2SeO3:chitosan oligosaccharide)of 1.02.Under the optimal conditions,the final product,the selenium content,reached 1.302%.The results of cell experiments showed that COSSe significantly inhibited SKOV3 proliferation in a concentration-dependent manner.RNA-seq results showed that chitosan oligosaccharide and COSSe significantly modulated the expression of genes’DNA metabolic processes and cell cycle in SKOV3 cells.Gene enrichment analysis showed the inhibition of the cell cycle,and the results of flow cytometry showed that SKOV3 cells increased in the S phase and decreased in the G2/M phase,with a noted suppression in the protein expression of cyclin-dependent kinase 2(CDK2)and cyclin A1(CCNA1).Conclusion:COSSe has a stronger effect than chitosan oligosaccharide,leading to the arrest of the cell cycle in the S phase.Thus,COSSe may be an effective candidate for the treatment of ovarian cancer.

Vitamin D, selenium in type 2 diabetes and Hashimoto's thyroiditis: Is it effective?

The study by Feng et al,explores treatment approaches for these coexisting conditions.It emphasizes the potential advantages of selenium and vitamin D supplementation but also raises methodological and patient selection concerns.Findings indicate a complex interplay between interventions and disease markers,prompting the need for further research.Despite limitations,the study offers valuable insights into managing the intricate relationship between type 2 diabetes mellitus and Hashimoto's thyroiditis.The authors'contributions shed light on potential treatment avenues,although careful consideration of study design and patient characteristics is warranted for future investigations in this domain.

In Vivo Studies and Flow Cytometric Investigation on Anticancer Potential of Selenium Nanoparticles Synthesized via Aqueous Extract of Clerodendron phlomidis

Nowadays,doctors and nutritionists recommend individuals incorporate selenium-rich foods such as nuts,cereals,and mushrooms into their regular diet to maintain fitness and overall health.Selenium nanoparticles(SeNPs)exhibit strong chemopreventive capabilities.The anticipations for SeNPs with enhanced and tunable bioactive activities have led to a keen interest in phytofabrication.In this study,the aqueous extract of Clerodendron phlomidis plant leaves was utilized for the synthesis of SeNPs.In traditional Indian medicine,this plant extract is recognized as a significant anti-diabetic agent.The flavonoids tetrahydroxylflavone,7-hydroxyflavanone,and 6,4’-dimethyl-7-acetoxy-scutellarein present in this plant leaf extract demonstrate excellent anticancer activity.These secondary metabolites exhibit the ability to reduce sodium selenite into SeNPs.At a concentration of 13μg/mL,the synthesized SeNPs effectively inhibited the proliferation of the HepG2 cell line.The results suggest that the SeNPs possess promising anti-cancer potential against liver cancer and can be considered as a therapeutic agent for liver cancer treatment.Additionally,the cell cycle arrest induced by SeNPs was further confirmed by the fluorescence-activated cell sorting(FACS)method,indicating that SeNPs could efficiently differentiate cancer cells from normal cells.Notably,it showed a significant improvement in diethylnitrosamine(DEN)-induced Swiss Wistar rat groups.This scientific investigation highlights the high anti-cancer potential of SeNPs,positioning them as a promising therapeutic agent for liver cancer treatment.

Exploration for a Natural Selenium Supplement——Characterization and Bioactivities of Se-containing Polysaccharide from Garlic

A Se—containing polysaccharide(Se-GPS),with average molecular weight of 1.5×10~4 was isolated from Hubei Enshi garlic(Allium sativum L.)and purified by means of Sephadex G25 to G200 chromatographies.Its chemical homogeneity and composition were studied by optical rotation,HPLC and paper chromatographical methods.The abilities of scavenging active oxygen free radicals and inhibiting the damage of erythrocyte membrane by SiO_2 were established by spin trapping ESR studies.Se-GPS was shown to inhibit human cytomegalovirus by plague reduction assays and cytopathogenic effect tests.

The Effect of Nivalenol on Metabolism of Cultured Chondrocytes and the Protection of Selenium

Objective: To investigate the possible effect of nivalenol on metabolism ofthe cultured chondrocytes and the protection of selenium. Methods: The quantitative analyses ofmetabolism in single- layer cultured chondrocytes were performed by biocliemical means and theimpairment of DNA was observed by both of the single cell microgel electrophoresis assay and theagarose gel electrophoresis assay. Results: In the media containing different concentrations ofnivalenol (0. 000 5-0. 020 0 mg/L), the amounts of DNA and proteoglycan in matrix of thechondrocytes were decreased. The syn-thesis of protein was reduced and the impairment of DNAdeteriorated with the increase of the concentrations of nivalenol in tlte given dose. When seleniumwas added into the media, the impairment by nivalenol was decreased. In the media containingdifferent concentrations of nivalenol, however, the lipid peroxidation of the chondrocytes was notaffected by nivalenol, yet the amount of lipid peroxides significantly declined. Conclusion:Nivalenol may evidently cause impairment of the chondrocytes when its concentrations are in thepresent experimental range. Selenium can protect cultured cliondrocytes, but cannot prevent theirDNA from being impaired.

Effects of Selenium Dioxide on Apoptosis, Bcl-2 and P53 Expression, Intracellular Reactive Oxygen Species and Calcium Level in Three Human Lung Cancer Cell Lines

Objective: To evaluate the anti-tumor effects of SeO2 and its mechanisms on three human lung cancer cell lines. Methods: Three lung cancer cells A549, GLC-82 and PG were treated with 3-30 μmol/L SeO2. Flow cytometry was used to detect apoptosis, and analyze the changes of expression of p53 and Bcl-2, as well as ROS and Ca2+ level within cells. Results:SeO2 markedly inhibited cell proliferation and viability, and prompted apoptosis after 48 h treatment. SeO2 at 10 μmol/L induced 47.8% apoptosis in A549 cells, 40.8% in GLC-82 cells, 18.2% in PG cells. SeO2 at 30 μmol/L induced 37.8% apoposis in PG cells,but did not increase apoptotic raes in other two cells. SeO2 could down-regulate the mean fluorescent intensity of Bcl-2 from 65.8 to 9.6 in A549, but not in GLC-82 and in PG cells, up-regulate wild type p53 level in all three cells. SeO2 decreased the ROS and Ca2+ level markedly within three tested cells. Conclusion: SeO2 showed anti-tumor effect via apoptosis pathway in three lung cancer cell lines. The decrease of ROS and Ca2+ level within cells as well as regulation of Bcl-2 and p53 expression may play important roles in above apoptotic procedure.

Selenium-catalyzed oxidative carbonylation of 2-aminobenzyl alcohol to give 1,4-dihydro-2H-3,1-benzoxazin-2-one

An efficient,economical,and phosgene-free approach was developed for the preparation of l,4-dihydro-2H-3,l-benzoxazin-2-one from 2-aminobenzyl alcohol.In terms of its key features,this reaction uses the cheap and recyclable non-metal selenium as a catalyst instead of the noble metal palladium;carbon monoxide as a carbonylation agent instead of virulent phosgene or one of its derivatives;and oxygen as an oxidant.The selenium-catalyzed oxidative carbonylation reaction of2-aminobenzyl alcohol proceeded efficiently in a single pot in the presence of triethylamine to afford l,4-dihydro-2H-3,l-benzoxazin-2-one in 87%yield.Furthermore,the selenium catalyst was readily recovered and recycled,affording a product yield of 80%after five cycles.

基于Selenium WebDriver的B/S架构软件的自动化测试研究

介绍了B/S架构软件自动化测试的主要技术,以及使用Selenium WebDriver工具进行B/S架构软件的自动化测试的情况,通过一个具体案例来阐述自动化测试的过程,说明了使用Selenium WebDriver进行B/S架构软件的自动化测试的好处,给软件测试工程师提供了指导和借鉴意义。

负压封闭引流联合保留臀上动脉浅支的臀大肌肌皮瓣修复骶尾部IV期压疮的临床效果

目的:探讨负压封闭引流联合保留臀上动脉浅支的臀大肌旋转肌皮瓣修复骶尾部压疮的临床效果。方法:选取2019年6月—2023年10月温州医科大学附属第一医院收治的12例骶尾部压疮患者,其中男7例,女5例,年龄31~86岁。入院后I期予行负压封闭引流术,4~7 d后行保留臀上动脉浅支的臀大肌肌皮瓣修复创面。观察术后皮瓣成活情况、并发症发生情况,随访观察皮瓣外形、压疮复发情况。结果:本组12例患者,均因长期卧床致骶尾部受压出现IV期压疮,压疮病因:截瘫患者5例,各种原因所致的长期卧床患者7例,其中脑梗死后遗症患者2例,帕金森病患者3例,老年痴呆症患者1例,股骨颈骨折患者1例。病程2周至8年,清创后创面面积为5.0 cm×5.0 cm~10.0 cm×12.0 cm。12例患者术后皮瓣均完全成活,无皮瓣坏死、静脉淤血、创缘开裂等发生。术后随访2~6个月,皮瓣外形较佳、骶尾部软组织饱满、压疮无复发。结论:保留臀上动脉浅支的臀大肌旋转肌皮瓣血运可靠,设计、操作简单,皮瓣可修复面积大,切取不需要离断臀上动脉浅支,供瓣区一般能直接缝合,修复骶尾部压疮效果较佳。

Effects of Selenium and Zinc on Renal Oxidative Stress and Apoptosis Induced by Fluoride in Rats

Objective To study the effects of selenium and zinc on oxidative stress, apoptosis, and cell cycle changes in rat renal cells induced by fluoride. Methods Wistar rats were given distilled water containing sodium fluoride （50 mg/L NaF） and were gavaged with different doses of selenium-zinc preparation for six months. Four groups were used and each group had eight animals （four males and four females）. Group one, sham-handled control; group two, 50 mg/L NaF; group three, 50 mg/L NaF with a low dose of selenium-zinc preparation （0.1 mg/kg Na2 SeO3 and 14.8 mg/kg ZnSO4 · 7H2O）; and group four, 50 mg/L NaF with a high dose of selenium-zinc preparation （0.2 mg/kg Na2 SeO3 and29.6 mg/kg ZnSO4 · 7H20）. The activities of serum glutathione peroxidase （GSH-Px）, kidney superoxide dismutase （SOD）, and the levels of malondialdehyde （MDA） and glutathione （GSH） in the kidney were measured to assess the oxidative stress. Kidney cell apoptosis and cell cycle were detected by flow cytometry. Results NaF at the dose of 50 mg/L increased excretion of fluoride in urine, promoted activity of urine γ -glutarnyl transpeptidase （ γ -GT）, inhibited activity of serum GSH-PX and kidney SOD, reduce kidney GSH content, and increased kidney MDA. NaF at the dose of 50 mg/L also induced rat renal apoptosls, reduced the cell number of G2/M phase in cell cycle, and decreased DNA relative content significantly. Selenium and zinc inhibited effects of NaF on oxidative stress and apoptosis, promoted the cell number of G2/M phase in cell cycle, but failed to increase relative DNA content significantly. Conclusion Sodium fluoride administered at the dose of 50 mg/L for six months induced oxidative stress and apoptosis, and changes the cell cycle in rat renal cells. Selenium and zinc antagonize oxidative stress, apoptosis, and cell cycle changes induced by excess fluoride.

Inhibitory Effects of Selenium on Telomerase Activity and hTERT Expression in Cadmium-transformed 16HBE Cells

To investigate the effects of sodium selenite on telomerase activity and expression of hTERT mRNA in cadmium-transformed 16HBE cells. Methods Telomerase activity and expression of genes were measured after cultured cadmium-transformed 16HBE cells were exposed to sodium selenite at different doses （0.625, 1.25, 2.50, 5.00 pmol/L） for 24 hours. Results Selenium decreased telomerase activity in cadmium-transformed 16HBE cells. There existed an obvious dose-effect relationship between the selenium concentration and these changes. The expression of hTERT and c-myc mRNA also decreased but the expression of madl mRNA increased after exposure to selenium for 24 hours. No difference was found in expression of hTRF1 and hTRF2 mRNA after incubated with sodium selenite for 24 hours, compared with control group. Conclusion Selenium inhibits telomerase activity by decreasing hTERT and c-myc mRNA expression and increasing madl mRNA expression in cadmium-transformed 16HBE cells and selenium concentration is significantly correlated with these changes.

The positive function of selenium supplementation on reducing nitrate accumulation in hydroponic lettuce(Lactuca sativa L.)

High nitrate(NO3-) in vegetables, especially in leaf vegetables poses threaten to human health. Selenium(Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies. Exogenous Se shows positive function on plant growth and nutrition uptake under abiotic and/or biotic stresses. However, the influence of exogenous Se on NO3-accumulation in hydroponic vegetables is still not clear. In the present study, hydroponic lettuce plants were subjected to six different concentrations(0, 0.1, 0.5, 5, 10 and 50 μmol L–1) of Se as Na2 Se O3. The effects of Se on NO3-content, plant growth, and photosynthetic capacity of lettuce(Lactuca sativa L.) were investigated. The results showed that exogenous Se positively decreased NO3-content and this effect was concentration-dependent. The lowest NO3-content was obtained under 0.5 μmol L–1 Se treatment. The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate(Pn), stomatal conductance(Cs) and the transpiration efficiency(Tr) of lettuce. The transportation and assimilation of NO3-and activities of nitrogen metabolism enzymes in lettuce were also analysed. The NO3-efflux in the lettuce roots was markedly increased, but the efflux of NO3-from the root to the shoot was decreased after treated with exogenous Se. Moreover, Se application stimulated NO3-assimilation by enhancing nitrate reductase(NR), nitrite reductase(Ni R), glutamine synthetase(GS) and glutamate synthase enzyme(GOGAT) activities. These results provide direct evidence that exogenous Se shows positive function on decreasing NO3-accumulation via regulating the transport and enhancing activities of nitrogen metabolism enzyme in lettuce. We suggested that 0.5 μmol L–1 Se can be used to reduce NO3-content and increase hydroponic lettuce yield.

Influence of selenium induced oxidative stress on spermatogenesis and lactate dehydrogenase-X in mice testis

Aim: To evaluate the effect of oxidative stress on the spermatogenesis and lactate dehydrogenase-X (LDH-X) activity in mouse testis. Methods: For creating different levels of oxidative stress in mice, three selenium (Se) level diets were fed in separate groups for 8 weeks. Group 1 animals were fed yeast-based Se-deficient (0.02 ppm) diet. Group 2 and Group 3 animals were fed with the same diet supplemented with 0.2 ppm and 1 ppm Se as sodium selenite, respectively. After 8 weeks, biochemical and histopathological observations of the testis were carried out. LDH-X levels in the testis were analyzed by western immunoblot and ELISA. Results: A significant decrease in testis Se level was observed in Group 1 animals, whereas it was enhanced in Group 3 as compared to Group 2. The glutathione peroxidase (GSH-Px) activity was significantly reduced in both the liver and testis in Group 1, but not in Group 2 and 3. A significant increase in the testis glutathione-S-transferase (GST) activity was observed in Group 1, whereas no significant change was seen in Groups 2 and 3. Histological analysis of testis revealed a normal structure in Group 2. A significant decrease in the germ cell population in Group 1 was observed as compared to Group 2 with the spermatids and mature sperm affected the most. Decrease in the lumen size was also observed. In the Se-excess group (Group 3), displacement of germ cell population was observed. Further, a decrease in the LDH-X level in testis was observed in Group 1. Conclusion: Excessive oxidative stress in the Se deficient group, as indicated by changes in the GSH-Px/GST activity, affects the spermatogenic process with a reduction in mature sperm and in turn the LDH-X level.

Selenium distribution and nitrate metabolism in hydroponic lettuce(Lactuca sativa L.): Effects of selenium forms and light spectra

A deficiency in selenium(Se) in the human diet is a worldwide problem. The intake of Se-rich vegetables can be a safe way to combat Se deficiency for humans. However, most leafy vegetables can accumulate a high content of nitrates, which poses a potential threat to human health. Light is an important environmental factor that regulates the uptake and distribution of mineral elements and nitrogen metabolism in plants. However, the effects of Se forms and light conditions, especially light spectra, on the uptake and translocation of Se and on nitrate reduction are poorly understood. In this study, lettuce(Lactuca sativa L.) was treated with exogenous Se applied as selenate(10 mmol L^-1) and selenite(0.5 mmol L^-1) and grown under five different light spectra: fluorescent light(FL), monochromatic red LED light(R), monochromatic blue LED light(B), and mixed red and blue LED light with a red to blue light ratio at 4(R/B=4), 8(R/B=8), and 12(R/B=12), respectively. The effects of light spectra and Se forms on plant growth, photosynthetic performance, Se accumulation and nitrate reduction were investigated. The results showed that the light spectra and Se forms had significant interactions for plant growth, foliar Se accumulation and nitrate reduction. The Se concentration and nitrate content in the leaves were negatively correlated with the percentage of red light from the light sources. Compared to Se applied as selenite, exogenous Se applied as selenate was more effective in reducing nitrate via promoting nitrate reductase and glutamate synthase activities. The lowest nitrate content and highest plant biomass were observed under R/B=8 for both the selenate and selenite treatments. The significant effect of the light spectra on the root concentration factor and translocation factor of Se resulted in marked variations in the Se concentrations in the roots and leaves. Compared with FL, red and blue LED light led to significant decreases in the foliar Se concentration. The results from this study suggest that the light spectra can contribute to Se distribution and accumulation to produce vegetables with better food quality.

基于CTI-TET和Selenium Webdriver的Web应用自动化测试框架的设计与实现

基于Web应用的自动化测试随着互联网科技的高速发展已然成为了许多互联网公司不可或缺的技术领域。但价格高昂的商业测试工具以及其繁冗复杂的使用说明也为不少公司带来了不小的额外成本。本文将以Solaris平台的Analytics Webui应用服务为例,介绍如何利用当前互联网上比较流行的开源软件和免费资源,开发出适合自身需求特点的Web应用自动化测试脚本。成功的Web应用服务的自动化测试脚本的开发不仅是测试团队的技术实力体现,更是对其应用服务产品本身开发的高质量监督和保证。

Effect of Selenium Supplementation on Activity and mRNA Expression of Type 1 Deiodinase in Mice With Excessive Iodine Intake

Objective To investigate the effect of selenium supplementation on the selenium status and selenoenzyme, especially the activity and mRNA expression of type 1 deiodinase （D1） in mice with excessive iodine （EI） intake and to explore the mechanism of selenium intervention on iodine-induced abnormities. Methods Weanling female BALB/c mice were given tap water or 3 mg/L of iodine or supplemented with 0.5 mg/L or 1.0 mg/L of selenium in the presence of excessive iodine for 5 months. Selenium status, thyroid hormone level, hepatic and renal D 1 activity and mRNA expression were examined. Results Excessive iodine intake significantly decreased the selenium concentration in urine and liver, and the activity of glutathione peroxidase （GSH-Px） in liver. Meanwhile, serum total T4 （TT4） increased while serum total T3 （TT3） decreased. Hepatic D1 enzyme activity and mRNA expression were reduced by 33% and 86%, respectively. Renal D1 enzyme activity and mRNA were reduced by 30% and 55%, respectively. Selenium supplementation obviously increased selenium concentration, activity of GSH-Px and D1 as well as mRNA expression of D1. However, increasing the supplementation of Se from 0.5 to 1.0 mg/L did not further increase selenoenzyme activity and expression. Conclusion Relative selenium deficiency caused by excessive iodine plays an essential role in the mechanism of iodine-induced abnormalities. An appropriate dose of selenium supplementation exercises a beneficial intervention.