Research Progress on the Protective Effect of Brown Algae-Derived Polysaccharides on Metabolic Diseases and Intestinal Barrier Injury

Sargassum fusiforme polysaccharides protect mice against Citrobacter rodentium infection via intestinal microbiota-driven microRNA-92a-3p-induced Muc2 production

Sargassum fusiforme, widely consumed in Asian countries, has been proven to have various biological activities. However, the impacts and mechanisms of Sargassum fusiforme polysaccharides (SFPs) on intestinal bacterial infection are not yet fully understood. Our findings indicate that SFPs pretreatment ameliorates intestinal inflammation by reducing C. rodentium colonization, increasing colon length and levels of IL-10 and IL-22, decreasing IL-1β, IL-6, TNF-α, and IL-17 levels, inhibiting colonic crypt elongation and hyperplasia, and enhancing the intestinal mucosal barrier. The protective effects against intestinal bacterial infection are linked to enhanced clearance of C. rodentium and improvements in the intestinal mucosal barrier and C. rodentium-induced intestinal microbiota dysbiosis. Fecal microbiota transplantation experiments were conducted to evaluate the functional impact of microbiota induced by SFPs. The results suggest that intestinal microbiota modified by SFPs effectively countered C. rodentium infection. In addition, our study identified that miRNA-92a-3p is partially complementary to the 3'-UTR of the Notch1 gene, thereby repressing the Notch1-Hes1 signaling pathway and enhancing Muc2 secretion. Taken together, these findings reveal that SFPs protect mice from C. rodentium infection by activating the miR-92a-3p/Notch1-Hes1 regulatory axis driven by the intestinal microbiota, which stimulates Muc2 production to maintain intestinal barrier homeostasis.

Brown Algae Polysaccharides Alleviate Diquat-Induced Oxidative Stress in Piglets and IPEC-J2 Cells via Nrf2/ARE Signaling Pathway

This study investigated the effect of Brown algae polysaccharides (BAPs) on diquat-induced oxidative stress in piglets and IPEC-J2 cells through Nrf2/ARE signaling pathway. In the in vivo model, 24 male piglets of the Duroc × Landrace × Large White breed were selected and divided into 4 groups (n = 6), including the CON group (basal diet), DIQ group (10 mg/kg Diquat), BAP group (1000 mg/kg BAP), and BAP+DIQ group (1000 mg/kg BAP + 10 mg/kg Diquat). Compared with the DIQ group, BAP improved growth performance and the BAP+DIQ group reduced the levels of IL-1β, IL-6, TNF-α, and DAO in plasma, increased VH and VCR, improved jejunal tissue morphology, decreased MDA levels, and increased T-AOC (p < 0.05). Additionally, the BAP+DIQ group elevated mRNA levels of ZO-1, and enhanced the protein levels of Occludin, Claudin1, CAT, SOD1, and HO-1 (p < 0.05). In the in vitro model, the BAP+DIQ group decreased MDA levels, increased T-AOC, elevated mRNA levels of ZO-1, CAT and SOD2, as well as protein levels of Claudin1, SOD1, HO-1, and total Nrf2 compared with the DIQ group (p < 0.05). Furthermore, BAP increased nuclear Nrf2 protein levels, and promoted the translocation of Nrf2 from the cytoplasm to the nucleus compared with the DIQ group (p < 0.05). In conclusion, BAPs are crucial for enhancing piglets' antioxidant capacity via Nrf2 pathway activation. These findings highlight BAP's potential as a natural feed additive to mitigate oxidative stress and improve overall health in piglets. Further research is warranted to explore BAPs as a dietary supplement to support gut health and reduce oxidative stress.

Fucoidan alleviated colitis aggravated by fiber deficiency through protecting the gut barrier, suppressing the MAPK/NF-κB pathway, and modulating gut microbiota and metabolites

Insufficient dietary fiber intake has become a global public health issue, affecting the development and management of various diseases, including intestinal diseases and obesity. This study showed that dietary fiber deficiency enhanced the susceptibility of mice to colitis, which could be attributed to the disruption of the gut barrier integrity, activation of the NF-κB pathway, and oxidative stress. Undaria pinnatifida fucoidan (UPF) alleviated colitis symptoms in mice that fed with a fiber deficient diet (FD), characterized by increased weight gain and reduced disease activity index, liver and spleen indexes, and histological score. The protective effect of UPF against FD-exacerbated colitis can be attributed to the alleviation of oxidative stress, the preservation of the gut barrier integrity, and inhibition of the MAPK/NF-κB pathway. UPF ameliorated the gut microbiota composition, leading to increased microbiota richness, as well as increased levels of Muribaculaceae, Lactobacillaceae, and Bifidobacterium and reduced levels of Proteobacteria, Bacteroidetes, and Bacteroides. Metabolomics analysis revealed that UPF improved the profile of microbiota metabolites, with increased levels of carnitine and taurine and decreased levels of tyrosine and deoxycholic acid. This study suggests that UPF has the potential to be developed as a novel prebiotic agent to enhance human health.

AHR activation relieves deoxynivalenol-induced disruption of porcine intestinal epithelial barrier functions

Mycotoxins are ubiquitous natural pollutants that pose a serious threat to public health. Deoxynivalenol (DON) as one of the most prominent mycotoxins has a noticeable adverse effect on intestinal barrier function, which depends on the intestinal barrier integrity. However, the potential mechanisms and effective therapeutic strategies remain unclear. Aryl hydrocarbon receptor (AHR) has been implicated in the modulation of intestinal barrier function and inflammation. The study aims to investigate the unique role of AHR in mediating DON-induced intestinal epithelial barrier function. In the current study, we revealed that DON triggered mitochondrial structural damage and functional impairment, leading to oxidative stress and apoptosis in porcine jejunal epithelial cells (IPEC-J2). DON altered the integrity of IPEC-J2 cells by disrupting the distribution and function of tight junction proteins. Additionally, DON activated TNF-α/NF-κB/MLCK signaling pathway, thereby eliciting inflammatory response. Notably, DON inhibited AHR nuclear translocation and attenuated xenobiotic response element promoter activity and its target genes. However, overexpression of AHR mitigated DON-induced disruption of intestinal epithelial barrier functions by suppressing TNF-α/NF-κB/MLCK pathway in IPEC-J2 cells. Our findings indicate that AHR regulates intestinal epithelial barrier function and therefore is a novel therapeutic molecule for intestinal disorders.

The role of dietary inflammatory index in metabolic diseases: the associations, mechanisms, and treatments

In recent years, the prevalence of metabolic diseases has increased significantly, posing a serious threat to global health. Chronic low-grade inflammation is implicated in the development of most metabolic diseases, such as type 2 diabetes mellitus (T2DM), obesity, dyslipidemia, and cardiovascular disease, serving as a link between diet and these conditions. Increasing attention has been directly toward dietary inflammatory patterns that may prevent or ameliorate metabolic diseases. The Dietary Inflammatory Index (DII) was developed to assess the inflammatory potential of dietary intake. Consequently, a growing body of research has examined the associations between the DII and the risk of several metabolic diseases. In this review, we explore the current scientific literature on the relationships between the DII, T2DM, obesity, and dyslipidemia. It summarizes recent findings and explore potential underlying mechanisms from two aspects: the interaction between diet and inflammation, and the link between inflammation and metabolic diseases. Furthermore, this review discusses the therapeutic strategies, including dietary modifications, prebiotics, and probiotics, and discusses the application of the DII in metabolic diseases, as well as future research directions.

Hepatotoxicity Induced by Methyl Eugenol: Insights from Toxicokinetics, Metabolomics, and Gut Microbiota

Due to continuous application as a flavoring agent in the pesticide, pharmaceutical, and food industries, methyl eugenol (ME) persists in the environment and causes deleterious impacts including cytotoxicity, genotoxicity, and liver damage. This study utilized a comprehensive approach, integrating toxicokinetics, metabolomics, and gut microbiota analysis, to explore the mechanisms behind ME-induced hepatotoxicity in mice. The study observed significant rises in ALT and AST levels, along with significant weight loss, indicating severe liver damage. Toxicokinetic data showed delayed Tmax and plasma accumulation after 28 days of repeated ME exposure at doses of 20 mg/kg, 40 mg/kg, and 60 mg/kg. The metabolomic analysis pinpointed four critical pathways-TCA cycle; alanine, aspartate, and glutamate metabolism; arginine biosynthesis; and tyrosine metabolism-linked to 20 potential biomarkers. Gut microbiota analysis revealed that extended ME exposure led to microbial imbalance, particularly altering the populations of Akkermansia, Prevotella, and Ruminococcus, which are key to amino acid metabolism and the TCA cycle, thus contributing to hepatotoxicity. However, the causal relationship between changes in gut microbiota and liver metabolite levels still requires further in-depth research. This study underscores the significant role of liver metabolites and gut microbiota in ME-induced liver damage.

Alginate oligosaccharide improves 5-fluorouracil-induced intestinal mucositis by enhancing intestinal barrier and modulating intestinal levels of butyrate and isovalerate

Chemotherapy-induced mucositis (CIM) is the typical side effect of chemotherapy. This study investigates the potential of alginate oligosaccharide (AOS) in ameliorating CIM induced by 5-fluorouracil (5-FU) in a murine model and its underlying mechanisms. AOS effectively mitigated body weight loss and histopathological damage, modulated inflammatory cytokines and attenuated the oxidative stress. AOS restored intestinal barrier integrity through enhancing expression of tight junction proteins via MLCK signaling pathway. AOS alleviated intestinal mucosal damage by inhibiting TLR4/MyD88/NF-κB signaling pathway, downregulating the pro-apoptotic protein Bax and upregulating the anti-apoptotic protein Bcl-2. Moreover, AOS significantly enriched intestinal Akkermansiaceae and increased the production of short-chain fatty acids (SCFAs), most notably butyrate and isovalerate. Pre-treatment with butyrate and isovalerate also alleviated 5-FU-induced CIM. In conclusion, AOS effectively mitigated CIM through strenghthening intestinal barrier, attenuating inflammation, and modulating gut microbiota and intestianl levels of butyrate and isovalerate. These finding indicate that AOS could be potentially utilized as a supplemental strategy for prevention or mitigation of CIM.

Exploring the Therapeutic Potential of Green-Synthesized Gold Nanoparticles and Ericaria selaginoides Extract for Inflammatory Bowel Disease

Addressing disease remission and treatment adherence in inflammatory bowel diseases (IBDs), such as Crohn's disease, poses significant challenges due to underlying oxidative and inflammatory processes. Nanotechnology emerges as a promising avenue for enhancing therapeutic outcomes in IBD by optimizing drug bioactivity, reducing toxicity, and extending circulation time. Gold nanoparticles, known for their resistance to gastrointestinal pH and possessing antioxidant and anti-inflammatory properties, offer particular promise. They can be produced by green synthesis with seaweed Ericaria selaginoides (ES), itself associated with gastroprotective and anti-inflammatory activities. In a murine model of Crohn's disease induced with 8% acetic acid, pretreatment with dexamethasone (0.2 mL/30 g) or Au@ES (25 and 50 mg/kg) effectively mitigated inflammatory features. Notably, ES (50 mg/kg) and Au@ES (50 mg/kg) administration resulted in significant reductions in both macroscopic and microscopic inflammation scores compared to the disease control group. Furthermore, these treatments normalized inflammatory cytokine expression while safeguarding myenteric plexus glial cells. They also impeded neutrophil activation, leading to reduced myeloperoxidase activity and lipid peroxidation, coupled with increased glutathione levels. In conclusion, ES and Au@ES exhibit potent efficacy in counteracting inflammation and oxidation processes in an experimental Crohn's disease model, suggesting their potential as alternative therapeutic strategies for IBD.

Fucoidan alleviates high sucrose-induced metabolic disorders and enhances intestinal homeostasis through modulation of Notch signaling

INTRODUCTION

The therapeutic potential of fucoidan (FUC), a natural polysaccharide, in metabolic disorders is recognized, yet its underlying mechanisms remain unclear.

METHODS

We conducted investigations into the therapeutic mechanisms of FUC sourced from Sargassum fulvellum concerning metabolic disorders induced by a high-sucrose diet (HSD), employing Drosophila melanogaster and mice models. Drosophila larvae were subjected to HSD exposure to monitor growth inhibition, reduced pupation, and developmental delays. Additionally, we examined the impact of FUC on growth- and development-related hormones in Drosophila. Furthermore, we assessed the modulation of larval intestinal homeostasis by FUC, focusing on the regulation of Notch signaling. In mice, we evaluated the effects of FUC on HSD-induced impairments in intestinal epithelial barrier integrity and gut hormone secretion.

RESULTS

FUC supplementation significantly enhanced pupal weight in Drosophila larvae and effectively countered HSD-induced elevation of glucose and triglyceride levels. It notably influenced the expression of growth- and development-related hormones, particularly augmenting insulin-like peptides production while mitigating larval growth retardation. FUC also modulated larval intestinal homeostasis by negatively regulating Notch signaling, thereby protecting against HSD-induced metabolic stress. In mice, FUC ameliorated HSD-induced impairments in ileum epithelial barrier integrity and gut hormone secretion.

CONCLUSIONS

Our findings demonstrate the multifaceted therapeutic effects of FUC in mitigating metabolic disorders and maintaining intestinal health. FUC holds promise as a therapeutic agent, with its effects attributed partly to the sulfate group and its ability to regulate Notch signaling, emphasizing its potential for addressing metabolic disorders.

Seaweeds as Nutraceutical Elements and Drugs for Diabetes Mellitus: Future Perspectives

Diabetes mellitus is a chronic metabolic condition marked by high blood glucose levels caused by inadequate insulin synthesis or poor insulin use. This condition affects millions of individuals worldwide and is linked to a variety of consequences, including cardiovascular disease, neuropathy, nephropathy, and retinopathy. Diabetes therapy now focuses on controlling blood glucose levels through lifestyle changes, oral medicines, and insulin injections. However, these therapies have limits and may not successfully prevent or treat diabetic problems. Several marine-derived chemicals have previously demonstrated promising findings as possible antidiabetic medicines in preclinical investigations. Peptides, polyphenols, and polysaccharides extracted from seaweeds, sponges, and other marine species are among them. As a result, marine natural products have the potential to be a rich source of innovative multitargeted medications for diabetes prevention and treatment, as well as associated complications. Future research should focus on the chemical variety of marine creatures as well as the mechanisms of action of marine-derived chemicals in order to find new antidiabetic medicines and maximize their therapeutic potential. Based on preclinical investigations, this review focuses on the next step for seaweed applications as potential multitargeted medicines for diabetes, highlighting the bioactivities of seaweeds in the prevention and treatment of this illness.

Fermentation of micro- and macroalgae as a way to produce value-added products

Fermentation of both microalgae and macroalgae is one of the most efficient methods of obtaining valuable value-added products due to the minimal environmental pollution and the availability of economic benefits, as algae do not require arable land and drift algae and algal bloom biomass are considered waste and must be recycled and their fermentation waste utilized. The compounds found in algae can be effectively used in the fuel, food, cosmetic, and pharmaceutical industries, depending on the type of fermentation used. Products such as methane and hydrogen can be produced by anaerobic digestion and dark fermentation of algae, and lactic acid and its polymers can be produced by lactic acid fermentation of algae. Article aims to provide an overview of the different types potential of micro- and macroalgae fermentation, the advantages and disadvantages of each type considered, and the economic feasibility of algal fermentation for the production of various value-added products.

Influence of Dietary Addition of Mineral Shungite and Fucus vesiculosus on Production Performance, Egg Quality, Nutrients Digestibility, and Immunity Status of Laying Hens

The main purpose of this study was to assess the impact of using the thermally modified mineral adsorbent shungite (MAS) and the dried seaweed meal Fucus vesiculosus (DSM) with different doses in Brown Nick cross laying hens' diet on their productivity, nutrient digestibility, morphological and blood profile, immunity status, and egg quality. A total of 261,720 hens were used in this experiment at the age of 63 weeks, and they were randomly divided into 5 groups (feeding program) with six repetitions of 8724 chickens in each. The first served (control) as a control group where laying hens were fed the basal diet that was used on the farm only; the second and the third groups represented MAS+ and MAS++, where they received the basal diet supplemented by 0.1% and 0.25% (or 1.0 kg/t and 2.5 kg/t of feed) of the mineral adsorbent shungite (MAS) which was provided in the feed in powder form (5 microns) and was added to the feed at the feed mill; the fourth and fifth groups represented DSM+ and DSM++, which received the basal diet provided with 0.1% and 0.25% (or 1.0 kg/t and 2.5 kg/t of feed) of dried seaweed meal of F. vesiculosus algae (DSM). The average egg weight over the entire period of the experiment revealed significant differences between the experimental groups and represented in the control group 65.20 vs. 66.88, 66.87 and 68.10 and 68.13 g in the MAS+ and MAS++, and DSM+ and DSM++ groups, respectively. Once the dried seaweed meal F. vesiculosus (DSM) was used, the crude protein increased significantly (p < 0.05) in egg yolk by 2.64 and 2.67%, carotenoids by 1.13 and 1.20 mg/g DM. The inclusion of both MAS and DSM feed additives revealed a significant decrease in the level of crude fat (lipids) in their liver when compared with the control group. The level of erythrocytes (RBCs) increased (p < 0.05) in the MAS+ and MAS++ and DSM+ and DSM++ groups when compared to the control group. Similarly, a significant increase was noted in hemoglobin when DSM was supplemented when compared to the control one. Moreover, the number of heterophils increased (p < 0.05) in groups of MAS and DSM when compared to the control group. The percentage of phagocytic activity increased significantly by 5.39, 6.90, and 7.18% in MAS++, DSM+, and DSM++, respectively, relative to the control group. On the other hand, the phagocytic number decreased (p < 0.05) by 1.15 and 1.12 conditional units in MAS+ and MAS++ and by 1.03 and 0.83 conditional units in DSM+ and DSM++ when compared to the control group, respectively. Consequently, the inclusion of thermally modified mineral adsorbent shungite and the dried seaweed meal F. vesiculosus with different doses in Brown Nick cross laying hen diets improves the egg weight and egg quality, crude protein, carotenoids and vitamin A in the egg mass, the utilization of lysine and methionine nutrients, hemoglobin content, immunity status, while decreases the incidence of fatty liver occurrence.

Polysaccharides from Holothuria leucospilota Relieve Loperamide-Induced Constipation Symptoms in Mice

A vital bioactive component of marine resources is Holothuria leucospilota polysaccharides (HLP). This study examined whether HLP could regulate intestinal flora to treat loperamide-induced constipation. Constipated mice showed signs of prolonged defecation (up by 60.79 min) and a reduced number of bowel movements and pellet water content (decreased by 12.375 and 11.77%, respectively). The results showed that HLP treatment reduced these symptoms, reversed the changes in related protein expression levels in the colon, and regulated the levels of active peptides associated with the gastrointestinal tract in constipated mice, which significantly improved water-electrolyte metabolism and enhanced gastrointestinal motility. Meanwhile, it was found that intestinal barrier damage was reduced and the inflammatory response was inhibited through histopathology and immunohistochemistry. As a means to further relieve constipation symptoms, treatment with low, medium, and high HLP concentrations increased the total short-chain fatty acid (SCFA) content in the intestine of constipated mice by 62.60 μg/g, 138.91 μg/g, and 126.51 μg/g, respectively. Moreover, an analysis of the intestinal flora's gene for 16S rRNA suggested that the intestinal microbiota was improved through HLP treatment, which is relevant to the motivation for the production of SCFAs. In summary, it was demonstrated that HLP reduced loperamide-induced constipation in mice.