Oral Macrocystis pyrifera Fucoidan Administration Exhibits Anti-Inflammatory and Antioxidant Properties and Improves DSS-Induced Colitis in C57BL/6J Mice

Exochorda racemosa attenuates DSS-induced colitis in C57BL/6 J mice by regulating inflammatory factors, reducing oxidative stress, and modulating intestinal flora

BACKGROUND

Exochorda racemosa is a member of the genus Exochorda in the Rosaceae family. Its tender leaves and buds are favored as a unique wild vegetable by people in central China.

PURPOSE

This study systematically evaluated the pharmacological safety and anti-inflammatory efficacy of E. racemosa extracts, with concurrent identification and characterization of their primary bioactive components.

METHODS

The chemical composition of E. racemosa extract (ERE) was analyzed using HPLC and LC-MS techniques. The safety and in vivo anti-inflammatory effects of ERE were evaluated using the maximum tolerated dose (MTD) in ICR mice and a dextran sodium sulfate-induced ulcerative colitis model in C57BL/6 J mice.

RESULTS

HPLC and LC-MS analyses revealed that ERE contained abundant flavonoid active ingredients. MTD study confirmed that ERE exhibited good safety. The symptoms of persistent weight loss, DAI, and shortened colon length in UC mice were suppressed by ERE. Pathological damage in colon tissues was attenuated by ERE, with a considerable reduction in histopathological scores and a substantial increase in the number of goblet cells. The levels of IL-6, IL-1β, and TNF-α in serum were significantly decreased following ERE treatment. Moreover, nitric oxide (NO) levels and myeloperoxidase (MPO) activity in colon tissues decreased, whereas glutathione (GSH) levels and superoxide dismutase (SOD) activity in colon tissues increased after ERE treatment. Furthermore, ERE could regulate the intestinal microbial composition and maintain intestinal flora homeostasis, thereby inhibiting inflammatory responses.

CONCLUSION

ERE exhibited a favorable safety profile and alleviated UC through multiple mechanisms. It is expected to serve as a promising low-toxicity natural product for adjuvant treatment in UC.

Fucoidan improves intestinal peristaltic function in rats with postoperative ileus

The effect of fucoidan on postoperative ileus (POI) has not been studied. In this study, how fucoidan ameliorates POI in a rat POI model was investigated. The results showed that in the model animals, when the first defecation time was prolonged, the amount of food consumed decreased, the small intestinal propulsion rate dramatically slowed, and the motility index (MI%) of the small intestine decreased. In vitro experiments revealed that the contractile response of small intestinal smooth muscle strips to carbachol (CCh) was reduced. Immunohistochemistry revealed evident macrophage infiltration in the intestinal muscularis. However, after oral pretreatment with fucoidan, the time to first defecation decreased, and food intake, the small intestinal propulsion rate, and MI% of the small intestine increased. Additionally, the contractile response of the intestinal strips to CCh became stronger, and macrophage infiltration decreased. Mechanistically, fucoidan alleviated POI by exerting anti-inflammatory and antioxidant effects as well as likely through the TrkB/ERK1/2/Akt signalling pathways. When POI occurred, the expression levels of inflammatory factors in the intestines significantly increased while the phosphorylation of TrkB, ERK1/2, and Akt significantly decreased; malondialdehyde (MDA) levels in the intestines increased but the levels of superoxide dismutase (SOD) and glutathione (GSH) decreased. In contrast, after pretreatment with fucoidan, the expression levels of inflammatory factors decreased; the phosphorylation levels of TrkB, ERK1/2, and Akt increased; the MDA level decreased; and SOD and GSH levels increased. Thus, fucoidan alleviated POI-induced impairment of rat intestinal motility through anti-inflammatory and antioxidant effects possibly associated with the TrkB/ERK1/2 and Akt signalling pathways.

Protective Effects of Fucoidan on Iodoacetamide-Induced Functional Dyspepsia via Modulation of 5-HT Metabolism and Microbiota

As the major polysaccharide in brown algae, fucoidan possesses broad biological abilities and has been reported to improve gastrointestinal health. Functional dyspepsia, a common non-organic disease, is a complex of symptoms mainly characterized by pathogenesis, such as visceral hypersensitivity, gastric dysmotility, and inflammation. To date, the effects of fucoidan in regulating functional dyspepsia with visceral sensitivity remains unclear. In the current study, iodoacetamide was employed to establish a mouse model of visceral hypersensitivity. Meanwhile, fucoidan was orally administrated for fourteen days. Indicators were conducted to evaluate the potential of fucoidan as the ingredient of complementary and alternative medicine for functional dyspepsia, such as levels of serum hormones, expression of receptors, and gut microbial profile. The results show that oral administration of fucoidan led to significant reductions in the secretion of 5-hydroxytryptamine, cortisol, and corticosterone. Additionally, it decreased the expression of 5-hydroxytryptamine-3 receptors, with regulation of 5-hydroxytryptamine metabolism and improvement of gut microbial imbalance. The above results suggest fucoidan could ameliorate visceral hypersensitivity by modulating 5-HT metabolism and microbiota. The current findings indicate that fucoidan has potential as a biological component in the adjuvant treatment of functional dyspepsia and for its expanded utilization in the food and medical fields.

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.

Anti-Inflammatory Effects of Algae-Derived Biomolecules in Gut Health: A Review

Under physiological conditions, the inflammatory response acts as a biological defense against tissue damage or infection, and is rapidly resolved once the infection is cleared. However, chronic inflammatory diseases, including inflammatory bowel disease (IBD), have become increasingly widespread in the last decades, placing a burden on the quality of life of affected people and on healthcare systems worldwide. Available drug therapies are often ineffective due to the chronic nature of these diseases, and prolonged administration of drugs can result in severe side effects for the patient or a lack of efficacy. In addition, there is the growing problem of bacterial resistance to synthetic antibiotics. Together, these factors have led to a strong research focus on the discovery of natural products capable of treating IBD. Recently, there has been a growing interest in compounds derived from marine sources, mainly algae, due to their bioactive secondary metabolites with anti-inflammatory properties well known in the literature. Based on this evidence, this review aimed to evaluate the anti-inflammatory potential of algae-derived biomolecules in IBD. In particular, interesting species from green algae (e.g., Chlorella vulgaris and Ulva pertusa), brown algae (e.g., Macrocystis pyrifera and Ecklonia cava) and red algae (e.g., Porphyra tenera and Grateloupia turuturu) are included in this review due to their proven anti-inflammatory properties. For this purpose, an extensive literature search was conducted using several databases. The results suggest that both macroalgae and microalgae have remarkable potential for IBD therapy due to the anti-inflammatory and antioxidant activities of their bioactive compounds. However, while the preclinical evidence is encouraging, further and long-term clinical studies are needed to better understand their mechanisms of action in order to determine the true efficacy of marine algae in the treatment of IBD.

Deer oil improves ulcerative colitis induced by DSS in mice by regulating the intestinal microbiota and SCFAs metabolism and modulating NF-κB and Nrf2 signaling pathways

BACKGROUND

Deer oil (DO), a byproduct of deer meat processing, possesses high nutritional value. This study aims to evaluate the protective effects of DO on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice and to explore its potential mechanisms of action.

RESULTS

DO was found to inhibit weight loss and colon shortening in colitis mice, significantly reduce disease activity index scores, and notably enhance the levels of tight junction proteins in colon tissues, thus improving intestinal barrier function. ELISA results indicated that DO markedly alleviated the mice's oxidative stress and inflammatory responses. Western blot analysis further demonstrated that DO significantly inhibited the phosphorylation of NF-κB while up-regulating the expression levels of Nrf2 and HO-1 proteins. Additionally, DO increased the abundance of beneficial bacteria such as Odoribacter, Blautia, and Muribaculum, reduced the abundance of harmful bacteria such as Bacteroides, Helicobacter, and Escherichia-Shigella, and promoted the production of short-chain fatty acids.

CONCLUSION

Our study provides the first evidence that DO can effectively improve DSS-induced UC in mice. The underlying mechanisms may involve maintaining intestinal barrier function, inhibiting inflammation, alleviating oxidative stress, and modulation of gut microbiota. These findings offer valuable insights for developing DO as an adjunct treatment for UC and as a functional food. © 2024 Society of Chemical Industry.

Fucoidan from Undaria pinnatifida Enhances Exercise Performance and Increases the Abundance of Beneficial Gut Bacteria in Mice

Fucoidans, known for their diverse biological properties such as anti-inflammatory, antiviral, antitumor, and immune stimulatory effects, have recently gained attention for their potential benefits in exercise endurance, muscle mass, and anti-fatigue. However, the mechanisms by which fucoidans enhance exercise performance are still unclear. To investigate these effects, we administered 400 mg/kg/day of fucoidan extract derived from Undaria pinnatifida to 64 C57BL/6J mice over 10 weeks. We evaluated changes in running activity, mitochondrial-related gene expression in skeletal muscle, and alterations in the intestinal microbiome. Our results showed that fucoidan supplementation significantly increased daily running distance and muscle mass by 25.5% and 10.4%, respectively, in mice on a standard chow diet, and with more modest effects observed in those on a high-fat diet (HFD). Additionally, fucoidan supplementation led to a significant increase in beneficial gut bacteria, including Bacteroides/Prevotella, Akkermansia muciniphila, and Lactobacillus, along with a notable reduction in the Firmicutes/Bacteroidetes ratio, indicating improved gut microbiome health. Mechanistically, fucoidan supplementation upregulated the mRNA expression of key genes related to mitochondrial biogenesis and oxidative capacity, such as COX4, MYH1, PGC-1α, PPAR-γ, and IGF1, in both standard chow and HFD-fed mice. Our findings suggest that fucoidan supplementation enhances exercise performance, improves muscle function, and positively modulates the gut microbiome in mice, regardless of diet. These effects may be attributed to fucoidans' potential prebiotic role, promoting the abundance of beneficial gut bacteria and contributing to enhanced exercise performance, increased muscle strength, and improved recovery.

Marine-Derived Fucose-Containing Carbohydrates: Review of Sources, Structure, and Beneficial Effects on Gastrointestinal Health

Fucose, fucose-containing oligosaccharides, and fucose-containing polysaccharides have been widely applied in the fields of food and medicine, including applications in Helicobacter pylori eradication and renal function protection. Fucose-containing carbohydrates (FCCs) derived from marine organisms such as seaweed, invertebrates, microalgae, fungi, and bacteria have garnered growing attention due to their diverse bioactivities and potential therapeutic applications. Marine-derived FCCs characterized by high fucose residue content and extensive sulfate substitution, including fucoidan, fucosylated chondroitin sulfate, and fucose-rich microbial exopolysaccharides, have demonstrated significant potential in promoting gastrointestinal health. This review describes the unique structural features of FCCs and summarizes their health benefits, including regulation of gut microbiota, modulation of microbial metabolism, anti-adhesion activities against H. pylori and gut pathogens, protection against inflammatory injuries, and anti-tumor activities. Additionally, this review discusses the structural characteristics that influence the functional properties and the limitations related to the activity research and preparation processes of FCCs, providing a balanced perspective on the application potential and challenges of FCCs with specific structures for the regulation of gastrointestinal health and diseases.

Carrageenan as a Potential Factor of Inflammatory Bowel Diseases

Carrageenan is a widely used food additive and is seen as a potential candidate in the pharmaceutical industry. However, there are two faces to carrageenan that allows it to be used positively for therapeutic purposes. Carrageenan can be used to create edible films and for encapsulating drugs, and there is also interest in the use of carrageenan for food printing. Carrageenan is a naturally occurring polysaccharide gum. Depending on the type of carrageenan, it is used in regulating the composition of intestinal microflora, including the increase in the population of Bifidobacterium bacteria. On the other hand, the studies have demonstrated the harmfulness of carrageenan in animal and human models, indicating a direct link between diet and intestinal inflammatory states. Carrageenan changes the intestinal microflora, especially Akkermansia muciniphilia, degrades the mucous barrier and breaks down the mucous barrier, causing an inflammatory reaction. It directly affects epithelial cells by activating the pro-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) pathway. The mechanism is based on activation of the TLR4 receptor, alterations in macrophage activity, production of proinflammatory cytokines and activation of innate immune pathways. Carrageenan increases the content of Bacteroidetes bacteria, also causing a reduction in the number of short chain fatty acid (SCFA)-producing bacteria. The result is damage to the integrity of the intestinal membrane and reduction of the mucin layer. The group most exposed to the harmful effects of carrageenan are people suffering from intestinal inflammation, including Crohn disease (CD) and ulcerative colitis (UC).

Pharmacological Activation of TRPC6 Channel Prevents Colitis Progression

We recently reported that transient receptor potential canonical (TRPC) 6 channel activity contributes to intracellular Zn2+ homeostasis in the heart. Zn2+ has also been implicated in the regulation of intestinal redox and microbial homeostasis. This study aims to investigate the role of TRPC6-mediated Zn2+ influx in the stress resistance of the intestine. The expression profile of TRPC1-C7 mRNAs in the actively inflamed mucosa from inflammatory bowel disease (IBD) patients was analyzed using the GEO database. Systemic TRPC3 knockout (KO) and TRPC6 KO mice were treated with dextran sulfate sodium (DSS) to induce colitis. The Zn2+ concentration and the mRNA expression levels of oxidative/inflammatory markers in colon tissues were quantitatively analyzed, and gut microbiota profiles were compared. TRPC6 mRNA expression level was increased in IBD patients and DSS-treated mouse colon tissues. DSS-treated TRPC6 KO mice, but not TRPC3 KO mice, showed severe weight loss and increased disease activity index compared with DSS-treated WT mice. The mRNA abundances of antioxidant proteins were basically increased in the TRPC6 KO colon, with changes in gut microbiota profiles. Treatment with TRPC6 activator prevented the DSS-induced colitis progression accompanied by increasing Zn2+ concentration. We suggest that TRPC6-mediated Zn2+ influx activity plays a key role in stress resistance against IBD, providing a new strategy for treating colitis.

CPW partially attenuates DSS-induced ulcerative colitis in mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) of the gastrointestinal tract. The etiology is not fully understood, but environmental, microbial, and immunologic factors, as well as a genetic predisposition, play a role. UC is characterized by episodes of abdominal pain, diarrhea, bloody stools, weight loss, severe colonic inflammation, and ulceration. Despite the increase in the frequency of UC and the deterioration of the quality of life, there are still patients who do not respond well to available treatment options. Against this background, natural products such as polysaccharides are becoming increasingly important as they protect the intestinal mucosa, promote wound healing, relieve inflammation and pain, and restore intestinal motility. In this study, we investigated the effect of a polysaccharide isolated from the biomass of Campomanesia adamantium and Campomanesia pubescens (here referred to as CPW) in an experimental model of acute and chronic ulcerative colitis induced by dextran sulfate sodium (DSS). CPW reversed weight loss, increased disease activity index (DAI), bloody diarrhea, and colon shortening. In addition, CPW reduced visceral mechanical hypersensitivity, controlled oxidative stress and inflammation, and protected the mucosal barrier. CPW is not absorbed in the intestine, does not inhibit cytochrome P450 proteins, and does not exhibit AMES toxicity. These results suggest that CPW attenuates DSS-induced acute and chronic colitis in mice and may be a potential alternative treatment for UC.

Anti-Inflammatory Activity of Fucan from Spatoglossum schröederi in a Murine Model of Generalized Inflammation Induced by Zymosan

Fucans from marine algae have been the object of many studies that demonstrated a broad spectrum of biological activities, including anti-inflammatory effects. The aim of this study was to verify the protective effects of a fucan extracted from the brown algae Spatoglossum schröederi in animals submitted to a generalized inflammation model induced by zymosan (ZIGI). BALB/c mice were first submitted to zymosan-induced peritonitis to evaluate the treatment dose capable of inhibiting the induced cellular migration in a simple model of inflammation. Mice were treated by the intravenous route with three doses (20, 10, and 5 mg/kg) of our fucan and, 1 h later, were inoculated with an intraperitoneal dose of zymosan (40 mg/kg). Peritoneal exudate was collected 24 h later for the evaluation of leukocyte migration. Doses of the fucan of Spatoglossum schröederi at 20 and 10 mg/kg reduced peritoneal cellular migration and were selected to perform ZIGI experiments. In the ZIGI model, treatment was administered 1 h before and 6 h after the zymosan inoculation (500 mg/kg). Treatments and challenges were administered via intravenous and intraperitoneal routes, respectively. Systemic toxicity was assessed 6 h after inoculation, based on three clinical signs (bristly hair, prostration, and diarrhea). The peritoneal exudate was collected to assess cellular migration and IL-6 levels, while blood samples were collected to determine IL-6, ALT, and AST levels. Liver tissue was collected for histopathological analysis. In another experimental series, weight loss was evaluated for 15 days after zymosan inoculation and fucan treatment. The fucan treatment did not present any effect on ZIGI systemic toxicity; however, a fucan dose of 20 mg/kg was capable of reducing the weight loss in treated mice. The treatment with both doses also reduced the cellular migration and reduced IL-6 levels in peritoneal exudate and serum in doses of 20 and 10 mg/kg, respectively. They also presented a protective effect in the liver, with a reduction in hepatic transaminase levels in both doses of treatment and attenuated histological damage in the liver at a dose of 10 mg/kg. Fucan from S. schröederi presented a promising pharmacological activity upon the murine model of ZIGI, with potential anti-inflammatory and hepatic protective effects, and should be the target of profound and elucidative studies.

Gut Protective Effect from Newly Isolated Bacteria as Probiotics against Dextran Sulfate Sodium and Carrageenan-Induced Ulcerative Colitis

Gut microbiome dysbiosis might be linked to certain diseases such as inflammatory bowel diseases (IBDs), which are categorized by vigorous inflammation of the gastrointestinal tract. Several studies have shown the favorable anti-inflammatory effect of certain probiotics in IBD therapy. In the present investigation, the possible gut protective effects of commensal bacteria were examined in an IBD model mouse that was cost-effectively induced with low molecular weight dextran sulfate sodium (DSS) and kappa carrageenan. Our conclusions show that certain probiotic supplementation could result in the attenuation of the disease condition in the IBD mouse, suggesting a favorable therapeutic capability for considerably improving symptoms of gut inflammation with an impact on the IBD therapy. However, the molecular mechanisms require further investigation.

Gut Protective Effect from D-Methionine or Butyric Acid against DSS and Carrageenan-Induced Ulcerative Colitis

Microbiome dysbiosis resulting in altered metabolite profiles may be associated with certain diseases, including inflammatory bowel diseases (IBD), which are characterized by active intestinal inflammation. Several studies have indicated the beneficial anti-inflammatory effect of metabolites from gut microbiota, such as short-chain fatty acids (SCFAs) and/or D-amino acids in IBD therapy, through orally administered dietary supplements. In the present study, the potential gut protective effects of d-methionine (D-Met) and/or butyric acid (BA) have been investigated in an IBD mouse model. We have also built an IBD mouse model, which was cost-effectively induced with low molecular weight DSS and kappa-carrageenan. Our findings revealed that D-Met and/or BA supplementation resulted in the attenuation of the disease condition as well as the suppression of several inflammation-related gene expressions in the IBD mouse model. The data shown here may suggest a promising therapeutic potential for improving symptoms of gut inflammation with an impact on IBD therapy. However, molecular metabolisms need to be further explored.

Oxyberberine ameliorates TNBS-induced colitis in rats through suppressing inflammation and oxidative stress via Keap1/Nrf2/NF-κB signaling pathways

BACKGROUND

Ulcerative colitis (UC) is a chronic, unspecific inflammatory bowel disorder lacking effective therapeutic targets and radical drugs. Oxyberberine (OBB), a novel intestinal flora-elicited oxidative metabolite of berberine (BBR), has been revealed to exhibit diverse pharmacological properties.

PURPOSE

In this follow-up study, we attempted to shed light on the possible therapeutic effect and latent mechanism of OBB on 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-evoked UC in rats.

METHODS

UC rats were established via a gentle enema of TNBS. Rats were sacrificed after intragastric administration of drugs for seven days. The weight reduction, disease activity index, macroscopic and histological colonic alterations were assessed. Further investigation on molecular mechanisms was conducted by ELISA, qRT-PCR, immunohistochemistry, or Western blot.

RESULTS

OBB treatment remarkably decreased the weight loss, macroscopic scores, and colonal weight/length ratio, as well as mitigated the colonic pathological deterioration and MPO vitality in colitis rats, achieving a superior protective effect to BBR. Additionally, OBB modulated the disequilibrium between pro- and anti-inflammatory factors by promoting the production of IL-13 and IL-4, and lowering the contents of TNF-α, IL-2, IL-8, and IL-22. Furthermore, OBB pretreatment dramatically ameliorated oxidative stress via enhancing antioxidant defense genes expressions (including HO-1, GCLM, GCLC, and NQO-1), thereby increasing SOD and GSH, and decreasing MDA and ROS activities. Furthermore, OBB strikingly restrained the translocation of NF-κB p65 and phosphorylation of IκBα, promoted HO-1 expression, Keap1 degradation and Nrf2 nuclear translocation.

CONCLUSION

The study firstly indicated that OBB had a superior therapeutic effect than BBR against TNBS-elicited colitis in rats. The protective effect of OBB might be closely related to the modulation of Keap1/Nrf2/NF-κB-mediated inflammatory response and oxidant stress. The evidences highlight the potentiality of OBB as a prospective candidate for the amelioration of colitis.