The effect of selenium supplementation on disease activity and immune-inflammatory biomarkers in patients with mild-to-moderate ulcerative colitis: a randomized, double-blind, placebo-controlled clinical trial

Insights into the relationship between the acetylation of Dendrobium officinale polysaccharides and the ability to promote sIgA secretion

The acetyl group is a significant reactive component of Dendrobium officinale polysaccharide (DOP). In this study, we prepared DOPs with different degrees of acetyl substitution and investigated how the acetyl group, a naturally occurring characteristic of DOP, influences the immunomodulatory activity and the production of secretory IgA (sIgA) in the small intestine. Physical property measurements revealed significant changes in surface morphology and solubility of DOP caused by the addition or removal of acetyl groups. In vivo studies have demonstrated that DOP can mitigate Cyclophosphamide-induced immunosuppression by enhancing the immune organ index, promoting immunoglobulin secretion, and increasing the population of immune cells. Additionally, DOP can enhance sIgA production through multiple pathways, including enhanced IgA+ B cell class switch recombination, gut homing of IgA+ plasma cells, and upregulation of factors involved in sIgA composition and secretion. Correlation analysis revealed strong, piecewise-specific correlations between DOP acetylation and sIgA production at varying intervals of acetyl substitution. Based on this, we propose a theoretical framework in which the acetylation of DOP and the secretion of small intestinal sIgA demonstrate a "piecewise correlation". This framework illustrates the influence of DOP acetylation on immunomodulatory activity and provides a theoretical basis for enhancing the added value of Dendrobium officinale resources.

Supplementation of Glucosamine Selenium Ameliorates DSS-Induced Chronic Colitis in Mice via Affecting Gut Microbiota, Inhibiting Pyroptosis and Inactivating Chemokine Signaling Pathway

Introduction

Ulcerative colitis (UC) is a chronic disease that requires pharmacological therapy to achieve remission. This study aimed to evaluate the effect of glucosamine selenium (GASe) on chronic colitis and reveal the underlying regulatory mechanisms.

Methods

We evaluated the cumulative toxicity of GASe by gavage in mice for 40 days. Dextran sulfate sodium (DSS; 2.5%) was added to drinking water to induce chronic colitis, and GASe was administered to mice with chronic DSS colitis. 16S rRNA sequencing was performed to investigate the influence of GASe on gut microbiota, followed by diversity and LDA Effect Size (LEfSe) analyses. Differentially expressed genes (DEGs) associated with chronic DSS colitis were identified based on the expression profiling from the Gene Expression Omnibus (GEO) database and were subjected to functional enrichment analysis. Next, the effects of GASe on pyroptosis and chemokine signaling pathways were studied in vitro and in vivo.

Results

GASe had no significant toxicity in mice, and administration of low-GASe and high-GASe increased the length of the colon, inhibited the expression of IL-12, IL-6, and TNF-α, and improved colonic tissue structure. Low-GASe improved the diversity of the gut microbiota and mainly affected the Burkholderiaceae family, Paenalcaligenes genus, and Erysipelatoclostridium genus. Low-GASe and high-GASe suppressed the pyroptosis-related proteins NLRP3, GSDMD, and caspase-1. Furthermore, we identified 114 DEGs from the GSE87466 and GSE53306 datasets and these DEGs were mainly enriched in the chemokine signaling pathway and some inflammatory pathways. Further experiments showed that administration of GASe inhibited the chemokine signaling pathway in chronic DSS colitis mice and NCM460 cells.

Discussion

This study reveals abnormalities in the gut microbiota, pyroptosis, and chemokine signaling pathways involved in chronic colitis and may provide GASe as an alternative supplement for chronic colitis management.

A disturbed communication between hypothalamic-pituitary-ovary axis and gut microbiota in female infertility: is diet to blame?

Female infertility is a multifactorial condition influenced by various genetic, environmental, and lifestyle factors. Recent research has investigated the significant impact of gut microbiome dysbiosis on systemic inflammation, metabolic dysfunction, and hormonal imbalances, which can potentially impair fertility. The gut-brain axis, a bidirectional communication system between the gut and the brain, also plays a significant role in regulating reproductive functions. Emerging evidence suggests that the gut microbiome can influence brain functions and behavior, further emphasizing the importance of the microbiota-gut-brain axis in reproduction. Given their role as a major modulator of the gut microbiome, diet and dietary factors, including dietary patterns and nutrient intake, have been implicated in the development and management of female infertility. Hence, this review aims to highlight the impact of dietary patterns, such as the Western diet (WD) and Mediterranean diet (MD), and to decipher their modulatory action on the microbiota-gut-brain axis in infertile women. By contrasting the detrimental effects of WD with the therapeutic potential of MD, we emphasize the pivotal role of a balanced diet rich in nutrients in promoting a healthy gut microbiome. These insights underscore the potential of targeted dietary interventions and lifestyle modifications as promising strategies to enhance reproductive outcomes in subfertile women.

Selenium alleviates dextran sulfate sodium-induced colitis and inhibits ferroptosis of intestinal epithelial cells via upregulating glutathione peroxidase 4

BACKGROUND AND AIM

Selenium, an essential micronutrient for humans, has been shown to be protective against ulcerative colitis (UC), but the exact mechanism remains unclear. The role of selenium, protecting against ferroptosis of intestinal epithelial cells (IECs) in colitis, was investigated in this current study.

METHODS

Serum selenium level and ferroptosis-related gene expression in the colonic mucosa were measured in UC patients and healthy controls. The effects of sodium selenite supplementation on experimental colitis were investigated in dextran sulfate sodium (DSS)-treated mice. The influence of sodium selenite on IEC ferroptosis was evaluated through assessing cell death rate, intracellular ferrous iron content, lipid reactive oxygen species level, and mitochondrial membrane damage of DSS-treated Caco-2 cells. Moreover, glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long-chain family member 4, ferroptosis-related genes, were detected in Caco-2 cells and mouse intestines.

RESULTS

Serum selenium was decreased in UC patients in comparison with healthy individuals. Additionally, serum selenium level was negatively correlated with disease activity and was associated with clinical inflammation and nutrition indicators. The expression of GPX4 in the mucosa of UC was positively correlated with serum selenium level. The in vivo experiments showed that selenium treatment ameliorated DSS-induced colitis and inhibited ferroptosis in IECs. The in vitro results suggested that selenium supplementation inhibited DSS-induced ferroptosis in Caco-2 cells. GPX4 was upregulated after selenium supplementation both in vivo and in vitro.

CONCLUSIONS

Serum selenium level was associated with IEC ferroptosis in UC patients. Selenium supplementation alleviates DSS-induced colitis and inhibits ferroptosis in IECs by upregulating the expression of GPX4.

Antioxidant Therapy in Inflammatory Bowel Diseases: How Far Have We Come and How Close Are We?

Inflammatory bowel diseases (IBD) pose a growing public health challenge with unclear etiology and limited efficacy of traditional pharmacological treatments. Alternative therapies, particularly antioxidants, have gained scientific interest. This systematic review analyzed studies from MEDLINE, Cochrane, Web of Science, EMBASE, and Scopus using keywords like "Inflammatory Bowel Diseases" and "Antioxidants." Initially, 925 publications were identified, and after applying inclusion/exclusion criteria-covering studies from July 2015 to June 2024 using murine models or clinical trials in humans and evaluating natural or synthetic substances affecting oxidative stress markers-368 articles were included. This comprised 344 animal studies and 24 human studies. The most investigated antioxidants were polyphenols and active compounds from medicinal plants (n = 242; 70.3%). The review found a strong link between oxidative stress and inflammation in IBD, especially in studies on nuclear factor kappa B and nuclear factor erythroid 2-related factor 2 pathways. However, it remains unclear whether inflammation or oxidative stress occurs first in IBD. Lipid peroxidation was the most studied oxidative damage, followed by DNA damage. Protein damage was rarely investigated. The relationship between antioxidants and the gut microbiota was examined in 103 animal studies. Human studies evaluating oxidative stress markers were scarce, reflecting a major research gap in IBD treatment. PROSPERO registration: CDR42022335357 and CRD42022304540.

The Role of the Trace Element Selenium in Inflammatory Bowel Disease

One set of chronic gastrointestinal disorders called inflammatory bowel disease (IBD) is defined by persistent, non-specific inflammation. Abdominal pain, hematochezia, diarrhea, and other symptoms are among its clinical signs. Currently, managing and treating IBD remains a significant challenge. Patients with IBD frequently have deficits in trace elements. Selenium (Se) is one of the necessary trace elements for normal organismal function. It has several regulatory effects, including anti-oxidation, anti-inflammatory, and defensive properties, via inducing the synthesis of selenoproteins. Patients with IBD have been shown to have lower Se levels in epidemiologic research studies. Several experimental models of IBD suggest that Se or selenoproteins play a key role in microinflammation. We discuss the relationship between Se and IBD in this review, with an emphasis on a summary of potential mechanisms of action and applications of Se in IBD.

Selenium inhibits ferroptosis in ulcerative colitis through the induction of Nrf2/Gpx4

BACKGROUND AND AIM

Selenium, an essential micronutrient for human and has been reported to have a protective effect in ulcerative colitis (UC). However, the role of selenium in UC is unclear. Our aim was to investigate the mechanism of action of selenium in UC.

METHODS

Serum selenium levels were measured in UC patients and healthy controls. In addition, the effect of sodium selenite supplementation on experimental colitis in mice treated with dextran sulfate sodium (DSS) was investigated. The effect of sodium selenite on IECs ferroptosis was evaluated by observing the cell mortality, intracellular ferrous content, lipid reactive oxygen species and mitochondrial membrane damage in DSS-treated Caco2 cells. In addition, glutathione peroxidase 4 (Gpx4) and nuclear factor erythroid 2-like 2 (Nrf2) were detected in Caco2 cells and mouse intestines to explore their mechanisms.

RESULTS

The serum selenium content of UC patients was lower than that of healthy subjects. In addition, serum selenium levels were negatively correlated with disease activity. The in vivo results showed that selenium treatment could improve colitis induced by DSS and inhibit IECs ferroptosis. The in vitro results further showed that selenium inhibited the ferroptosis of Caco-2 cells induced by DSS. Nrf2/Gpx4 was up-regulated after selenium supplementation in vivo and in vitro.

CONCLUSIONS

Serum selenium level is associated with IECs ferroptosis in UC patients. Selenium can relieve DSS-induced colitis and inhibit IECs ferroptosis by up-regulating the expression of Nrf2/Gpx4.

Selenium, Immunity, and Inflammatory Bowel Disease

Dietary intervention is a subject of growing interest in the management of inflammatory bowel disease (IBD), as new incident cases across the globe are rapidly rising, suggesting environmental factors as contributing elements. Dietary components and micronutrients have been associated with IBD pathogenesis or reductions in disease severity. Selenium, a diet-derived essential micronutrient that is important for proper immune system function, has received limited attention in the context of IBD. Selenium deficiency is a common finding in patients with IBD, but few clinical trials have been published to address the consequences of this deficiency. Here, we review the physiological and immunological roles of selenium and its putative role in IBD, and draw attention to knowledge gaps and unresolved issues, with the goal of stimulating more research on selenium in IBD.

Mannose coated selenium nanoparticles normalize intestinal homeostasis in mice and mitigate colitis by inhibiting NF-κB activation and enhancing glutathione peroxidase expression

Impaired intestinal homeostasis is a major pathological feature of inflammatory bowel diseases (IBD). Mannose and selenium (Se) both demonstrate potential anti-inflammatory and anti-oxidative properties. However, most lectin receptors bind free monosaccharide ligands with relatively low affinity and most Se species induce side effects beyond a very narrow range of dosage. This has contributed to a poorly explored therapies for IBD that combine mannose and Se to target intestinal epithelial cells (IECs) for normalization gut homeostasis. Herein, a facile and safe strategy for ulcerative colitis (UC) treatment was developed using optimized, mannose-functionalized Se nanoparticles (M-SeNPs) encapsulated within a colon-targeted hydrogel delivery system containing alginate (SA) and chitosan (CS). This biocompatible nanosystem was efficiently taken up by IECs and led to increased expression of Se-dependent glutathione peroxidases (GPXs), thereby modulating IECs' immune response. Using a mouse model of DSS-induced colitis, (CS/SA)-embedding M-SeNPs (C/S-MSe) were found to mitigate oxidative stress and inflammation through the inhibition of the NF-kB pathway in the colon. This stabilized mucosal homeostasis of IECs and ameliorated colitis-related symptoms, thereby providing a potential new approach for treatment of IBD.

The Immunomodulatory Effects of Selenium: A Journey from the Environment to the Human Immune System

Selenium (Se) is an essential nutrient that has gained attention for its impact on the human immune system. The purpose of this review is to explore Se's immunomodulatory properties and to make up-to-date information available so novel therapeutic applications may emerge. People acquire Se through dietary ingestion, supplementation, or nanoparticle applications. These forms of Se can beneficially modulate the immune system by enhancing antioxidant activity, optimizing the innate immune response, improving the adaptive immune response, and promoting healthy gut microbiota. Because of these many actions, Se supplementation can help prevent and treat pathogenic diseases, autoimmune diseases, and cancers. This review will discuss Se as a key micronutrient with versatile applications that supports disease management due to its beneficial immunomodulatory effects. Further research is warranted to determine safe dosing guidelines to avoid toxicity and refine the application of Se in medical treatments.

Antioxidant Therapy in Inflammatory Bowel Disease: A Systematic Review and a Meta-Analysis of Randomized Clinical Trials

The objective of this study is to assess the effectiveness of treatment for inflammatory bowel diseases in modulating oxidative stress biomarkers and cytokine levels. A systematic review of clinical trials was conducted, searching electronic databases including PubMed, Science Direct, and Scopus. After excluding articles that did not meet the inclusion criteria, 19 studies were included in the systematic review and 8 in the meta-analysis (6 for antioxidant capacity, 6 for superoxide dismutase (SOD), and 5 for lipid peroxidation analyzed through malondialdehyde (MDA) levels). SOD was significantly modulated (RR = 0.3764, 95% CI [0.0262 to 0.7267], p = 0.035) but not antioxidant capacity (RR = 0.3424, 95% CI [0.0334 to 0.7183], p = 0.0742) or MDA (RR = -0.8534, 95% CI [-1.9333 to 0.2265], p = 0.1214). Nonetheless, studies investigating oxidative stress biomarkers and cytokines in the context of alternative therapies for IBD treatment are still scarce. This review highlights the potential of antioxidant supplementation in IBD management and underscores the need for further investigations into its effects on oxidative stress biomarkers and cytokines to improve therapeutic approaches for IBD patients.