Characterization of selenium-containing polysaccharide from Spirulina platensis and its protective role against Cd-induced toxicity

Valorizing Arthrospira cell residues into polysaccharides: Characterization and application in yogurt

This study aimed to extract and characterize polysaccharides from Arthrospira cell residue and evaluate their application in yogurt. Four Arthrospira polysaccharides (APP-50, APP-60, APP-70, and APP-80) were obtained by different ethanol concentrations. With the increase in ethanol concentration, the component peaks of polysaccharide became less and the components were simpler. The results showed that APP-60 had the highest neutral sugar content and the densest spherical structure. APP-50 had the highest protein content, the strongest antioxidant capacity, the porous structure, and the structure was incomplete. The addition of polysaccharides increased the viscosity, storage modulus, loss modulus, and particle size of yogurt, and improved the stability of yogurt during long-term storage. The microstructure of yogurt with added polysaccharides was tighter and more orderly than that of the control yogurt. This study demonstrated that Arthrospira polysaccharides could be used as functional ingredients to enhance the quality and nutritional value of yogurt.

Oxygen-generating hydrogels combined with electrical stimulation: A dual approach for promoting diabetic wound healing

Chronic wounds resulting from hyperglycemia and hypoxia are common complications in diabetic patients, posing significant challenges for clinical treatment. In this study, we developed a hydrogel (PVNP-SP) using [VBIM]Br, NIPAM, PEGDA, and spirulina, which exhibited strong antioxidant properties. The incorporation of [VBIM]Br endowed the hydrogel with electrical conductivity, allowing it to activate voltage-gated ion channels under an external electric field, thereby promoting cell survival and migration. The hydrogel also enhanced cellular antioxidant capacity by providing sustained oxygenation, inhibiting HIF-1α nuclear translocation, and activating the Nrf2/HO-1 pathway. Notably, in a chronic wound model, the combined effects of oxygen production and electrical stimulation from the PVNP-SP hydrogel significantly reduced wound inflammation, promoted collagen deposition and angiogenesis, and facilitated early wound closure. This therapeutic strategy, which mitigates hypoxia while integrating electrical stimulation, offers a highly effective strategy for improving chronic wound healing in diabetic patients. STATEMENT OF SIGNIFICANCE: Inspired by photoautotrophic organisms, we combined microalgae with a conductive hydrogel and we demonstrated the synergistic promotion of chronic wound healing by electrical stimulation combined with microalgae oxygen-producing hydrogel. The approach of combining microalgae hydrogel patches with electrical stimulation demonstrates the feasibility of delivering oxygen to tissues while combining electrical stimulation for synergistic tissue repair. The hydrogel is easy to fabricate and handle, and may be suitable for a variety of treatments, such as myocardial infarction, lower limb ischemia, and drug delivery. The potential applicability of this hydrogel in a variety of treatments suggests that it has promising applications in regenerative medicine.

Comprehensive Review of the Latest Investigations of the Health-Enhancing Effects of Selected Properties of Arthrospira and Spirulina Microalgae on Skin

Arthospira platensis and Spirulina platensis microalgae are a rich source of pro-health metabolites (% d.m.): proteins (50.0-71.3/46.0-63.0), carbohydrates (16.0-20.0/12.0-17.0), fats (0.9-14.2/6.4-14.3), polyphenolic compounds and phenols (7.3-33.2/7.8-44.5 and 4.2/0.3 mg GAE/g), and flavonoids (1.9/0.2 QUE/g) used in pharmaceutical and cosmetic formulations. This review summarises the research on the chemical profile, therapeutic effects in dermatological problems, application of Arthrospira and Spirulina microalgae, and contraindications to their use. The pro-health properties of these microalgae were analysed based on the relevant literature from 2019 to 2024. The antiviral mechanism of microalgal activity involves the inhibition of viral replication and enhancement of immunity. The anti-acne activity is attributed to alkaloids, alkanes, phenols, alkenes, phycocyanins, phthalates, tannins, carboxylic and phthalic acids, saponins, and steroids. The antibacterial activity generally depends on the components and structure of the bacterial cell wall. Their healing effect results from the inhibition of inflammatory and apoptotic processes, reduction of pro-inflammatory cytokines, stimulation of angiogenesis, and proliferation of fibroblasts and keratinocytes. The photoprotective action is regulated by amino acids, phlorotannins, carotenoids, mycosporins, and polyphenols inhibiting the production of tyrosinase, pro-inflammatory cytokines, and free oxygen radicals in fibroblasts and the stimulation of collagen production. Microalgae are promising molecular ingredients in innovative formulations of parapharmaceuticals and cosmetics used in the prophylaxis and therapy of dermatological problems. This review shows the application of spirulina-based commercial skin-care products as well as the safety and contraindications of spirulina use. Furthermore, the main directions for future studies of the pro-health suitability of microalgae exerting multidirectional effects on human skin are presented.

The extracellular polymeric substances (EPS) accumulation of Spirulina platensis responding to Cadmium (Cd2+) exposure

Spirulina platensis can secrete extracellular polymeric substances (EPS) helping to protect damage from stress environment, such as cadmium (Cd2+) exposure. However, the responding mechanism of S. platensis and the secreted EPS to exposure of Cd2+ is still unclear. This research focuses on the effects of Cd2+ on the composition and structure of the EPS and the response mechanism of EPS secretion from S. platensis for Cd2+ exposure. S. platensis can produce 261.37 mg·g-1 EPS when exposing to 20 mg·L-1 CdCl2, which was 2.5 times higher than the control group. The S. platensis EPS with and without Cd2+ treatment presented similar and stable irregularly fibrous structure. The monosaccharides composition of EPS in Cd2+ treated group are similar with control group but with different monosaccharides molar ratios, especially for Rha, Gal, Glc and Glc-UA. And the Cd2+ treatment resulted in a remarkable decline of humic acid and fulvic acid content. The antioxidant ability of S. platensis EPS increased significantly when exposed to 20 mg·L-1 CdCl2, which could be helpful for S. platensis protecting damage from high concentration of Cd2+. The transcriptome analysis showed that sulfur related metabolic pathways were up-regulated significantly, which promoted the synthesis of sulfur-containing amino acids and the secretion of large amounts of EPS.

Selenosugar, selenopolysaccharide, and putative selenoflavonoid in plants

Selenium (Se) is a naturally occurring essential micronutrient that is required for human health. Selenium supports cellular antioxidant defense and possesses bioeffects such as anti-inflammation, anti-cancer, anti-diabetic, and cardiovascular and liver protective effects arising from Se-enhanced cellular antioxidant activity. Past studies on Se have focused on elucidating Se speciation in foods, biofortification strategies to produce Se-enriched foods to address Se deficiency in the population, and the biochemical activities of Se in health. The bioavailability and toxicity of Se are closely correlated to its chemical forms and may exhibit varying effects on body physiology. Selenium exists in inorganic and organic forms, in which inorganic Se such as sodium selenite and sodium selenate is more widely available. However, it is a challenge for safe and effective supplementation considering inorganic Se low bioavailability and high cytotoxicity. Organic Se, by contrast, exhibits higher bioavailability and lower toxicity and has a more diverse composition and structure. Organic Se exists as selenoamino acids and selenoproteins, but recent research has provided evidence that it also exists as selenosugars, selenopolysaccharides, and possibly as selenoflavonoids. Different food categories contain various Se compounds, and their Se profiles vary significantly. Therefore, it is necessary to delineate Se speciation in foods to understand their impact on health. This comprehensive review documents our knowledge of the recent uncovering of the existence of selenosugars and selenopolysaccharides and the putative evidence for selenoflavonoids. The bioavailability and bioactivities of these food-derived organic Se compounds are highlighted, in addition to their composition, structural features, and structure-activity relationships.

Preparation, Characterization, and Bioactivities of Polysaccharide-Nano-Selenium and Selenized Polysaccharides from Acanthopanax senticosus

Acanthopanax senticosus polysaccharide-nano-selenium (ASPS-SENPS) and A. selenopanax selenized polysaccharides (Se-ASPS) were synthesized, and their characterization and biological properties were compared. The acid extraction method was used to extract the polysaccharides of A. selenopanax, followed by decolorization using the hydrogen peroxide method and deproteinization based on the Sevage method, and the purification of A. senticosus polysaccharides (ASPS) was carried out using the cellulose DEAE-52 ion column layer analysis method. An A. senticosus polysaccharide-nano-selenium complex was synthesized by a chemical reduction method using ASPS as dispersants. The selenization of polysaccharides from A. selenopanax was carried out using the HNO3-Na2SeO3 method. The chemical compositions, scanning electron microscopy images, infrared spectra, and antioxidant properties of ASPS-SENPS and Se-ASPS were studied, and they were also subjected to thermogravimetric analysis. The results indicated that the optimal conditions for the synthesis of ASPS-SENPS include the following: when ASPS accounts for 10%, the ratio of ascorbic acid and sodium selenium should be 4:1, the response time should be 4 h, and the reaction temperature should be 50 °C. The most favorable conditions for the synthesis of Se-ASPS were as follows: m (Na2SeO3):m (ASPS) = 4:5, response temperature = 50 °C, and response time = 11.0 h. In the in vitro antioxidant assay, when the mass concentration of Se-ASPS and ASPS-SENPS was 5 mg/mL, the removal rates for DPPH free radicals were 88.44 ± 2.83% and 98.89 ± 3.57%, respectively, and the removal rates for ABTS free radicals were 90.11 ± 3.43% and 98.99 ± 1.73%, respectively, stronger than those for ASPS. The current study compares the physiological and bioactivity effects of ASPS-SENPS and Se-ASPS, providing a basis for future studies on polysaccharides.

Prevention of the Lachnum polysaccharide and its selenium derivatives on cisplatin-induced acute kidney injury in mice

To investigate the renal protective effects of the polysaccharide LEP-1a and derivatives of selenium (SeLEP-1a) from Lachnum YM38, cisplatin (CP) was used to establish an acute kidney model. LEP-1a and SeLEP-1a could effectively reverse the decrease in renal index and improved renal oxidative stress. LEP-1a and SeLEP-1a significantly reduced the contents of the inflammatory cytokines. They could inhibit the release of cyclooxygenase 2 (COX-2) and nitric oxide synthase (iNOS) and increase the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1). At the same time, the PCR results indicated that SeLEP-1a could significantly inhibit the mRNA expression levels of toll-like receptor 4 (TLR4), nuclear factor-kB (NF-κB) p65 and inhibitor of kappa B-alpha (IκBα). Western blot analysis showed that LEP-1a and SeLEP-1a significantly downregulated the expression levels of Bcl-2-associated X protein (Bax) and cleaved caspase-3 and upregulated phosphatidylinositol 3-kinase (p-PI3K), protein kinase B (p-Akt) and B-cell lymphoma 2 (Bcl-2) protein expression levels in the kidney. LEP-1a and SeLEP-1a could improve CP-induced acute kidney injury by regulating the oxidative stress response, NF-κB-mediated inflammation and the PI3K/Akt-mediated apoptosis signalling pathway.

The potential, challenges, and prospects of the genus Spirulina polysaccharides as future multipurpose biomacromolecules

Spirulina has been widely used worldwide as a food and medicinal ingredient for centuries. Polysaccharides are major bioactive constituents of Spirulina and are of interest because of their functional properties and unlimited application potential. However, the clinical translation and market industrialization of the polysaccharides from genus Spirulina (PGS) are retarded due to the lack of a further understanding of their isolation, bioactivities, structure-activity relationships (SARs), toxicity, and, most importantly, versatile applications. Herein, we provide an overview of the extraction, purification, and structural features of PGS; meanwhile, the advances in bioactivities, SARs, mechanisms of effects, and toxicity are discussed and summarized. Furthermore, the applications, potential developments, and future research directions are scrutinized and highlighted. This review may help fill the knowledge gap between theoretical insights and practical applications and guide future research and industrial application of PGS.

Selenoproteins in Health

Selenium (Se) is a naturally occurring essential micronutrient that is required for human health. The existing form of Se includes inorganic and organic. In contrast to the inorganic Se, which has low bioavailability and high cytotoxicity, organic Se exhibits higher bioavailability, lower toxicity, and has a more diverse composition and structure. This review presents the nutritional benefits of Se by listing and linking selenoprotein (SeP) functions to evidence of health benefits. The research status of SeP from foods in recent years is introduced systematically, particularly the sources, biochemical transformation and speciation, and the bioactivities. These aspects are elaborated with references for further research and utilization of organic Se compounds in the field of health.

Therapeutic Potentials of Microalgae and Their Bioactive Compounds on Diabetes Mellitus

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to impaired insulin secretion, insulin resistance, or both. Oxidative stress and chronic low-grade inflammation play crucial roles in the pathophysiology of diabetes mellitus. There has been a growing interest in applying natural products to improve metabolic derangements without the side effects of anti-diabetic drugs. Microalgae biomass or extract and their bioactive compounds have been applied as nutraceuticals or additives in food products and health supplements. Several studies have demonstrated the therapeutic effects of microalgae and their bioactive compounds in improving insulin sensitivity attributed to their antioxidant, anti-inflammatory, and pancreatic β-cell protective properties. However, a review summarizing the progression in this topic is lacking despite the increasing number of studies reporting their anti-diabetic potential. In this review, we gathered the findings from in vitro, in vivo, and human studies to discuss the effects of microalgae and their bioactive compounds on diabetes mellitus and the mechanisms involved. Additionally, we discuss the limitations and future perspectives of developing microalgae-based compounds as a health supplement for diabetes mellitus. In conclusion, microalgae-based supplementation has the potential to improve diabetes mellitus and be applied in more clinical studies in the future.

Ganoderma lucidum polysaccharide alleviates Cd toxicity in common carp (Cyprinus carpio): Neuropeptide, growth performance and lipid accumulation

Cadmium (Cd) is the most common heavy metal and is easily detected in aquatic environments on a global scale. Common carp (Cyprinus carpio) is a common cultural species in aquaculture. This study aimed the polysaccharide from Ganoderma lucidum in ameliorating Cd-induced toxicity in common carp. The study included a blank control group (CK, without Cd and GPL) and LGPL group (2 g/kg LGPL + 0.5 mg/L Cd) and HGPL group (4 g/kg HGPL + 0.5 mg/L Cd). The fish were sampled at 2 and 4 weeks, and bioaccumulation, neurotransmitters, lipid accumulation, and growth performance were measured. Ganoderma lucidum polysaccharide administration can significant protect against Cd toxicity by reducing Cd bioaccumulation in tissues, regulating neurotransmitters, decreasing lipid accumulation, and enhancing growth performance. Our results suggested that administering Ganoderma lucidum polysaccharides can alleviate waterborne Cd toxicity in common carp.

Polysaccharides from Spirulina platensis: Extraction methods, structural features and bioactivities diversity

Spirulina platensis, a well-known blue-green microalga cultivated and consumed in China and United States, is traditionally used as a food supplement and medical ingredient. Increasing evidence has confirmed that the Spirulina platensis polysaccharides (SPPs) are vital and representative pharmacologically active biomacromolecules and exhibit multiple health-promoting activities both in vivo and in vitro, such as those of anti-cancer, anti-oxidant, immunomodulatory, hypolipidemic and hypoglycemic, anti-thrombotic, anti-viral, regulation of the gut microbiota properties and other biological activity. The purpose of this review aims to comprehensively and systematically outline the extraction and purification methods, structural features, biological activities, underlying mechanisms, and toxicities of SPPs to support their potential utilization value in pharmaceuticals fields and functional foods. The structural and activities relationship of SPPs is also discussed. Besides, new valuable insights for future research with SPPs have also been proposed in the important areas of structural characterization and pharmacological activities.

The protective mechanism of a novel polysaccharide from Lactobacillus-fermented Nostoc commune Vauch. on attenuating cadmium-induced kidney injury in mice

A novel polysaccharide (NCVP-F) from Lactobacillus-fermented Nostoc commune Vauch. was obtained to investigate its underlying mechanism in cadmium-induced kidney injury. Results indicated that in comparison with NCVP, NCVP-F with lower molecular weight of 365.369 kDa, exhibited higher mole percentage of Man and Glc-UA, whereas slightly lower mole percentage of other monosaccharides. NCVP-F is a α-pyran polysaccharide similar to NCVP. Meanwhile, NCVP-F can more effectively alleviate hepatorenal injury (ALT, AST, TG, BUN and SCr) and kidney tissue lesions in Cd-injured mice model by increasing antioxidant enzyme activity (SOD, GSH and GSH-Px), inhibiting cytokines levels (IL-6, IL-1β, TNF-α and IL-18). In addition, NCVP-F effectively inhibited apoptosis proteins (Bax, cytochrome c, a-caspase-9 and a-caspase-3) and enhanced anti-apoptotic protein (Bcl-2) probably via activating PI3K/AKT/mTOR pathway in the Cd-injury kidney. Furthermore, 16S rRNA sequencing results indicated that NCVP-F better enriched Lachnospiraceae, reduced Muribaculaceae, Alloprevotella and Blautia to regulate Cd-induced gut microbiota disorders, which was probably down-regulated 7 pathways including apoptosis and lipopolysaccharide biosynthesis, and up-regulated 63 pathways, such as carbohydrate metabolism and lipid metabolism. This study suggested that applying functional NCVP-F prepared by biotransformation with low molecular weight might be more beneficial.

Selenium-containing polysaccharide from Spirulina platensis alleviates Cd-induced toxicity in mice by inhibiting liver inflammation mediated by gut microbiota

Selenium-containing polysaccharide from Spirulina platensis (Se-SPP) has been demonstrated to help in inhibiting cadmium-induced injury in mice, but the underlying mechanism has not been determined. This study aimed to investigate the beneficial effects of Se-SPP on alleviating Cd-induced toxicity in mice by targeting liver inflammatory and gut microbiota. Se-SPP supplementation for 28 days in Cd-induced toxic mice significantly mitigated liver pathological damage and inflammation, which was correlated to the upregulation of antioxidant enzyme activity. Furthermore, Se-SPP effectively restored Cd-induced disruption of the intestinal barrier compared to model group, as indicated by the depletion of Muribaculaceae and the enrichment of Ruminococcaceae. Spearman's correlation analysis revealed that the Se-SPP-altered microbes were highly correlated with inflammation-related indexes in Cd-induced toxic mice. Noteworthily, the modulation of Se-SPP on the Ruminococcaceae population contributed to the improvement of Cd-induced inflammation-related diseases by downregulating the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in the liver. These findings suggested that Se-SPP may act as prebiotics for ameliorating Cd-induced toxicity in mice by inhibiting liver inflammation mediated by gut microbiota, and target-specific microbiota of Cd-induced inflammation-related diseases deserve further attention.

Selenium-containing polysaccharides isolated from Rosa laevigata Michx fruits exhibit excellent anti-oxidant and neuroprotective activity in vitro

Selenium-containing polysaccharides have potential as an organic selenium dietary supplement, owing to their low toxicity, few side effects, and easy absorption attributes. In this study, we isolated two novel homogeneous selenium-containing polysaccharides from Rosa laevigata Michx fruits (Se-RLFPs). Results from primary structural analysis revealed that Se-RLFPs were α - pyranose, and were both composed of rhamnose, xylose, glucose with an average molecular weight of 24 and 16 KDa, respectively. Selenium contents in Se-RLFP-I and Se-RLFP-II were 16.49 μg/g and 21.61 μg/g, respectively. Results from analysis of antioxidant and neuroprotective activity of the polysaccharides revealed that Se-RLFPs had a radical scavenging effect. Specifically, they effectively protected SH-SY5Y cells from H₂O₂-induced damage by enhancing antioxidant enzyme activities (SOD), total antioxidant capacity (T-AOC) and suppressing malondialdehyde (MDA) levels. Western blots showed that the underlying mechanisms of action may be related to the Nrf2/HO-1 signaling pathway. Taken together, these results suggested that Se-RLFPs have potential as a pharmaceutical agent for treatment of neurodegenerative diseases (NDDs) or as a selenium-complementary ingredient in functional foods.

A Study on the Time-Effect and Dose-Effect Relationships of Polysaccharide from Opuntia dillenii against Cadmium-Induced Liver Injury in Mice

The purpose of this study was to evaluate the protective effect of Opuntia dillenii (Ker-Gaw) Haw. polysaccharide (ODP) against cadmium-induced liver injury. Cadmium chloride (CdCl2) was used to construct a mice evaluation model, and the indicators chosen included general signs, liver index, biochemical indicators, blood indicators, and pathological changes. A dose of 200 mg/kg ODP was applied to the mice exposed to cadmium for different lengths of time (7, 14, 21, 28, and 35 days). The results showed that CdCl2 intervention led to slow weight growth (reduced by 13−20%); liver enlargement; significantly increased aspartate aminotransferase (AST, 45.6−52.0%), alanine aminotransferase (ALT, 26.6−31.3%), and alkaline phosphatase (ALP, 38.2−43.1%) levels; and significantly decreased hemoglobin (HGB, 13.1−15.2%), mean corpuscular hemoglobin (MCH, 16.5−19.3%), and mean corpuscular hemoglobin concentrations (MCHC, 8.0−12.7%) (p < 0.01). In addition, it led to pathological features such as liver cell swelling, nuclear exposure, central venous congestion, apoptosis, and inflammatory cell infiltration. The onset of ODP anti-cadmium-induced liver injury occurred within 7 days after administration, and the efficacy reached the highest level after continuous administration for 14 days, a trend that could continue until 35 days. Different doses (50, 100, 200, 400, and 600 mg/kg) of ODP have a certain degree of protective effect on cadmium-induced liver injury, showing a good dose−effect relationship. After 28 days of administration of a 200 mg/kg dose, all pathological indicators were close to normal values. These findings indicated that ODP had positive activity against cadmium-induced liver injury and excellent potential for use as a health food or therapeutic drug.

A Novel Selenium Polysaccharide Alleviates the Manganese (Mn)-Induced Toxicity in Hep G2 Cells and Caenorhabditis elegans

Manganese (Mn) is now known to have a variety of toxicities, particularly when exposed to it in the workplace. However, there are still ineffective methods for reducing Mn's hazardous effects. In this study, a new selenium polysaccharide (Se-PCS) was developed from the shell of Camellia oleifera to reduce Mn toxicity in vitro and in vivo. The results revealed that Se-PCS may boost cell survival in Hep G2 cells exposed to Mn and activate antioxidant enzyme activity, lowering ROS and cell apoptosis. Furthermore, after being treated with Se-PCS, Caenorhabditis elegans survived longer under Mn stress. daf-16, a tolerant critical gene, was turned on. Moreover, the antioxidant system was enhanced as the increase in strong antioxidant enzyme activity and high expression of the sod-3, ctl-2, and gst-1 genes. A variety of mutations were also used to confirm that Se-PCS downregulated the insulin signaling pathway. These findings showed that Se-PCS protected Hep G2 cells and C. elegans via the insulin/IGF-1 signaling pathway and that it could be developed into a promising medication to treat Mn toxicity.

In Vitro Immunomodulation of the Polysaccharides from Yam (Dioscorea opposita Thunb.) in Response to a Selenylation of Lower Extent

The immunomodulation of chemically selenylated polysaccharides has been attracting more attention recently, but the corresponding performance of the yam polysaccharides (YPS) with lower selenylation extent remains, thus far, unsolved. In this study, the YPS was selenylated with Na₂SeO₃ under acidic conditions generated by HNO₃ to reach two lower selenylation extents, yielding two selenylated YPSs, namely SeYPS-1 and SeYPS-2 with selenium contents of 715 and 1545 mg/kg, respectively. The results indicated that YPS, SeYPS-1, and SeYPS-2 all had in vitro immuno-modulation when using RAW 264.7 macrophages and murine splenocytes as cell models. In detail, the three polysaccharide samples at dose levels of 5–160 μg/mL showed insignificant cytotoxicity to the macrophages and splenocytes with cell exposure times of 12–24 h, because of the measured values of cell viability larger than 100%. However, Na₂SeO₃ at dose levels of 1.3–3.25 μg/mL mostly caused obvious cytotoxic effects on the cells, resulting in reduced cell viability values or cell death, efficiently. The results demonstrated that, compared with YPS, both SeYPS-1 and SeYPS-2 at a lower dose level (5 μg/mL) were more active at promoting phagocytosis activity, increasing the CD4⁺/CD8⁺ ratio of the T-lymphocyte sub-population in the murine splenocyte, improving cytokine secretion, including interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α in the macrophages, or increasing interferon-γ secretion, but suppressing IL-4 production in the splenocytes. Consistently, SeYPS-2 has more potential than SeYPS-1 at exerting these assessed bioactivities in the cells. Thus, we conclude that a chemical modification of YPS using trace element Se at a lower selenylation extent could bring about higher immunomodulatory activity towards macrophages and splenocytes, while selenylation extent of YPS is a critical factor used to govern the assessed activity changes of YPS.

The interaction between selenium and cadmium in the soil-rice-human continuum in an area with high geological background of selenium and cadmium

Natural selenium (Se)-rich areas in China are generally characterized by high geological background of cadmium (Cd). However, the interaction between Se and Cd in the soil-rice-human continuum in such areas remains elusive. The concentrations, bioaccessibilities, and biomarkers of Se and Cd in a typical Se-Cd rich area were determined through chemical analysis, in vitro digestion model and cross-sectional study, respectively. The results showed that the molar ratio of available Se/Cd in the soil was averaged at 0.55 and soil Se did not reduce Cd accumulation and transportation in rice. Se bioaccessibility increased from the gastric phase to the intestinal phase, but the opposite was the case for Cd bioaccessibility. Moreover, bioaccessible concentration of Cd was positively correlated to corresponding total concentration in rice but negatively associated with the logarithm of molar ratio of Se/Cd. The risk of Cd-induced nephrotoxicity for the exposure group was not higher than the reference group, which could be ascribed to the mitigative effect of Se. Males and elders were at higher risk of Cd-induced injury owing to higher urinary Cd (U-Cd) and β2-microglobulin (U-β2-MG), and lower urinary Se (U-Se). Our results suggested that Cd-induced health risk should be assessed from a soil-rice-human perspective and the interaction between Se and Cd should be taken into account.

Selenium-Containing Polysaccharides—Structural Diversity, Biosynthesis, Chemical Modifications and Biological Activity

Selenosugars are a group of sugar derivatives of great structural diversity (e.g., molar masses, selenium oxidation state, and selenium binding), obtained as a result of biosynthesis, chemical modification of natural compounds, or chemical synthesis. Seleno-monosaccharides and disaccharides are known to be non-toxic products of the natural metabolism of selenium compounds in mammals. In the case of the selenium-containing polysaccharides of natural origin, their formation is also postulated as a form of detoxification of excess selenium in microorganisms, mushroom, and plants. The valency of selenium in selenium-containing polysaccharides can be: 0 (encapsulated nano-selenium), IV (selenites of polysaccharides), or II (selenoglycosides or selenium built into the sugar ring to replace oxygen). The great interest in Se-polysaccharides results from the expected synergy between selenium and polysaccharides. Several plant- and mushroom-derived polysaccharides are potent macromolecules with antitumor, immunomodulatory, antioxidant, and other biological properties. Selenium, a trace element of fundamental importance to human health, has been shown to possess several analogous functions. The mechanism by which selenium exerts anticancer and immunomodulatory activity differs from that of polysaccharide fractions, but a similar pharmacological effect suggests a possible synergy of these two agents. Various functions of Se-polysaccharides have been explored, including antitumor, immune-enhancement, antioxidant, antidiabetic, anti-inflammatory, hepatoprotective, and neuroprotective activities. Due to being non-toxic or much less toxic than inorganic selenium compounds, Se-polysaccharides are potential dietary supplements that could be used, e.g., in chemoprevention.