The antidiabetic effect and potential mechanisms of natural polysaccharides based on the regulation of gut microbiota

Advances in the treatment of type 2 diabetes mellitus by natural plant polysaccharides through regulation of gut microbiota and metabolism: A review

The prevalence and impact of type 2 diabetes mellitus (T2DM) is a major global health problem. The treatment process of T2DM is long and difficult to cure. Therefore, it is necessary to explore alternative or complementary methods to deal with the various challenges brought by T2DM. Natural plant polysaccharides (NPPs) have certain potential in the treatment of T2DM. However, many studies have not considered the relationship between the structure of NPPs and their anti-T2DM activity. This paper reviews the relevant anti-T2DM mechanisms of NPPs, including modulation of insulin action, promotion of glucose metabolism and modulation of postprandial glucose levels, anti-inflammation and modulation of gut microbiota (GM) and metabolism. This paper provides an in-depth study of the conformational relationships of NPPs and facilitates the development of anti-T2DM drugs or dietary supplements with NPPs.

The regulatory effect of polysaccharides on the gut microbiota and their effect on human health: A review

Polysaccharides with low toxicity and high biological activities are a kind of biological macromolecule. Recently, growing studies have confirmed that polysaccharides could improve obesity, diabetes, tumors, inflammatory bowel disease, hyperlipidemia, diarrhea, and liver-related diseases by changing the intestinal micro-environment. Moreover, polysaccharides could promote human health by regulating gut microbiota, enhancing production of short-chain fatty acids (SCFAs), improving intestinal mucosal barrier, regulating lipid metabolism, and activating specific signaling pathways. Notably, the biological activities of polysaccharides are closely related to their molecular weight, monosaccharide composition, glycosidic bond types, and regulation of gut microbiota. The intestinal microbiota can secrete glycoside hydrolases, lyases, and esterases to break down polysaccharides chains and generate monosaccharides, thereby promoting their absorption and utilization. The degradation of polysaccharides can produce SCFAs, further regulating the proportion of gut microbiota and achieving the effect of preventing and treating various diseases. This review aims to summarize the latest studies: 1) effect of polysaccharides structures on intestinal flora; 2) regulatory effect of polysaccharides on gut microbiota; 3) effects of polysaccharides on gut microbe-mediated diseases; 4) regulation of gut microbiota on polysaccharides metabolism. The findings are expected to provide important information for the development of polysaccharides and the treatment of diseases.

Extraction, purification, structural characterization and pharmacological activities of polysaccharides from sea buckthorn (Hippophae rhamnoides L.): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Sea buckthorn (Hippophae rhamnoides L.) is an edible fruit with a long history in China as a medicinal plant. The fruits of H. rhamnoides are rich in a variety of nutrients and pharmacological active compounds. As one of the most important active ingredients in sea buckthorn, polysaccharides have attracted the attention of researchers due to their antioxidant, anti-fatigue, and liver protective qualities.

AIM OF THE REVIEW

This review summarizes recent studies on extraction, purification, structural characterization and pharmacological activities of polysaccharides from sea buckthorn. In addition, the relationship between the structure and the activities of sea buckthorn polysaccharides (SBPS) were discussed. This review would provide important research bases and up-to-date information for the future in-depth development and application of sea buckthorn polysaccharides in the field of pharmaceuticals and functional foods.

MATERIALS AND METHODS

By inputting the search term "Sea buckthorn polysaccharides", relevant research information was obtained from databases such as Web of Science, Google Scholar, PubMed, China Knowledge Network (CNKI), China Master Theses Full-text Database, and China Doctoral Dissertations Full-text Database.

RESULTS

The main extraction methods of SBPS include hot water extraction (HWE), ultrasonic assisted extraction (UAE), microwave-assisted extraction (MAE), flash extraction (FE), and ethanol extraction. More than 20 polysaccharides have been isolated from sea buckthorn fruits. The chemical structures of sea buckthorn polysaccharides obtained by different extraction, isolation, and purification methods are diverse. Polysaccharides from sea buckthorn display a variety of pharmacological properties, including antioxidant, anti-fatigue, liver protection, anti-obesity, regulation of intestinal flora, immunoregulation, anti-tumor, anti-inflammatory, and hypoglycemic activities.

CONCLUSIONS

Sea buckthorn has a long medicinal history and characteristics of an ethnic medicine and food. Polysaccharides are one of the main active components of sea buckthorn, and they have received increasing attention from researchers. Sea buckthorn polysaccharides have remarkable pharmacological activities, health benefits, and broad application prospects. In addition, further exploration of the chemical structure of SBPS, in-depth study of their pharmacological activities, identification of their material basis, characterization of disease resistance mechanisms, and potential health functions are still directions of future research. With the accumulation of research on the extraction and purification processes, chemical structure, pharmacological effects, molecular mechanisms, and structure-activity relationships, sea buckthorn polysaccharides derived from natural resources will ultimately make significant contributions to human health.

Role of gut microbiota on regulation potential of Dendrobium officinale Kimura & Migo in metabolic syndrome: In-vitro fermentation screening and in-vivo verification in db/db mice

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium officinale Kimura & Migo (DEN) is a traditional medicine in China since Han dynasty. Decoction of its stem is often used in the treatment of Type-II diabetes (T2D), which is a typical metabolic disease accompanied with the impaired metabolic function of blood glucose and lipid.

AIM OF THE STUDY

Our study aimed to investigate the role of gut microbiota in differentiating DEN from different sources and its related pathway in the alleviation of metabolic syndromes induced by T2D.

MATERIALS AND METHODS

The aqueous extracts of four commercially available Dendrobium (DEN-1∼4) were prepared and screened through an in-vitro fermentation system. Based on their alterations in monosaccharide composition and short chain fatty acids (SCFA) formation during fermentation with db/db faecal fluid, one DEN extract was selected for further in vivo verification. The selected Dendrobium (DEN-4) was orally administered to db/db mice for 16 days once daily at the dosage of 200 mg/kg followed by evaluating its effect on blood glucose level, liver function and intestinal microenvironment including alterations of intestinal integrity and gut microbiota composition. In addition, liver metabolomics analysis was employed to reveal the related metabolic pathways.

RESULTS

Different extent of SCFA formation and utilization of monosaccharides were observed for the extracts of four DEN from different sources with a negative correlation between SCFA level and the ratio of Utilized glucose/Utilized mannose observed in the in-vitro fermentation system with db/db faecal fluid. DEN-4 with the highest SCFA formation during the in-vitro fermentation was selected and exhibited significantly hypoglycaemic effect in db/db mice with the alleviation of hepatic steatosis and impaired lipid homeostasis. Further mechanistic studies revealed that orally administered DEN-4 could improve the intestinal integrity of db/db mice via elevating their tight junction protein (ZO-1 and Occludin) expression in the colon and improve the diversity of gut microbiota with enhanced formation of SCFA. Moreover, metabolomics and KEGG pathway analysis of liver tissues suggested that the alleviated metabolic syndrome in db/db mice by DEN-4 might possibly be achieved through activation of PPAR pathway.

CONCLUSION

Our current study not only revealed the potential of gut microbiota in differentiating DEN from different sources, but also demonstrated that DEN exhibited its beneficial effect on the T2D induced metabolic syndrome possibly through enhancement of intestinal integrity and activation of PPAR pathway via gut-liver axis in db/db mice.

Advancements and Perspectives in Polysaccharide-Based Nanoparticles for Theranostic Nanomedicine

It is with great enthusiasm [...].

A Comprehensive Review of the Effects of Glycemic Carbohydrates on the Neurocognitive Functions Based on Gut Microenvironment Regulation and Glycemic Fluctuation Control

Improper glycemic carbohydrates (GCs) consumption can be a potential risk factor for metabolic diseases such as obesity and diabetes, which may lead to cognitive impairment. Although several potential mechanisms have been studied, the biological relationship between carbohydrate consumption and neurocognitive impairment is still uncertain. In this review, the main effects and mechanisms of GCs' digestive characteristics on cognitive functions are comprehensively elucidated. Additionally, healthier carbohydrate selection, a reliable research model, and future directions are discussed. Individuals in their early and late lives and patients with metabolic diseases are highly susceptible to dietary-induced cognitive impairment. It is well known that gut function is closely related to dietary patterns. Unhealthy carbohydrate diet-induced gut microenvironment disorders negatively impact cognitive functions through the gut-brain axis. Moreover, severe glycemic fluctuations, due to rapidly digestible carbohydrate consumption or metabolic diseases, can impair neurocognitive functions by disrupting glucose metabolism, dysregulating calcium homeostasis, oxidative stress, inflammatory responses, and accumulating advanced glycation end products. Unstable glycemic status can lead to more severe neurological impairment than persistent hyperglycemia. Slow-digested or resistant carbohydrates might contribute to better neurocognitive functions due to stable glycemic response and healthier gut functions than fully gelatinized starch and nutritive sugars.

Undaria pinnatifida fucoidan contributes to anti-inflammation activity of Bacteroides in fiber-deficient mice via modulation of gut microbiota and protection of intestinal barrier integrity

Bacteroides as potential probiotics has several health benefits to the host, but its practical application faces many challenges due to its inherent properties. In this study, Bacteroides strains isolated from human feces alleviated colonic inflammation in mice, as evidenced by increased colon length and reduced tissue damage. Further study showed that anti-inflammation activity of Bacteroides strains was disturbed by dietary fiber deficiency (FD), which disrupted the balance between gut microbiota and colonic mucus layer, leading to a thinning of colonic mucus layer. A combination of Bacteroides strains and Undaria pinnatifida fucoidan (UPF) better alleviated colonic inflammation than either of them, including increases in the densities of goblet cells and glycoproteins and reduction in intestinal epithelial damage, pro-inflammatory cytokines and oxidative stress. The underlying mechanisms can be attributed to that UPF-induced alterations of mucosal microbiota cannot only directly benefit host health but also create an ecological condition that facilitates Bacteroides strains exert their healthy properties. In addition, both Bacteroides strains and UPF improved FD-induced lipid metabolism abnormality, mainly involving glycerophospholipid metabolism pathway. This study suggests that the application of Bacteroides has certain limitations, and UPF can be developed as a probiotic adjuvant for Bacteroides to enhance human health.

Gut microbiota: A magical multifunctional target regulated by medicine food homology species

BACKGROUND

The relationship between gut microbiota and human health has gradually been recognized. Increasing studies show that the disorder of gut microbiota is related to the occurrence and development of many diseases. Metabolites produced by the gut microbiota are responsible for their extensive regulatory roles. In addition, naturally derived medicine food homology species with low toxicity and high efficiency have been clearly defined owing to their outstanding physiological and pharmacological properties in disease prevention and treatment.

AIM OF REVIEW

Based on supporting evidence, the current review summarizes the representative work of medicine food homology species targeting the gut microbiota to regulate host pathophysiology and discusses the challenges and prospects in this field. It aims to facilitate the understanding of the relationship among medicine food homology species, gut microbiota, and human health and further stimulate the advancement of more relevant research.

KEY SCIENTIFIC CONCEPTS OF REVIEW

As this review reveals, from the initial practical application to more mechanism studies, the relationship among medicine food homology species, gut microbiota, and human health has evolved into an irrefutable interaction. On the one hand, through affecting the population structure, metabolism, and function of gut microbiota, medicine food homology species maintain the homeostasis of the intestinal microenvironment and human health by affecting the population structure, metabolism, and function of gut microbiota. On the other hand, the gut microbiota is also involved in the bioconversion of the active ingredients from medicine food homology species and thus influences their physiological and pharmacological properties.

Polysaccharides from the hard shells of Juglans regia L. modulate intestinal function and gut microbiota in vivo

This study aimed to investigate the modulatory effects of polysaccharides from the hard shells ofJuglans regiaL. (JRP) on intestinal function and gut microbiota of mice. The results showed that JRP could increase the colonic length and colonic index, and ameliorate the histological characteristics of colon. JRP had a positive effect on immunity of mice by improving immune organ indexes. Owing to enhancement of intestinal peristalsis and increase of colonic fecal moisture by JRP, the defecation time was significantly reduced. After gastrointestinal digestion and absorption, JRP was metabolized by intestinal microorganisms to produce short chain fatty acids, thereby lowering the pH of intestine. Through microbial community analysis, the composition of gut microbiota was modulated by JRPvia increasing theabundances of beneficial bacteriaand decreasing the richness of harmful bacteria. This study suggests that JRP can be served as an excellent prebiotic to promote intestinal health.

A novel polysaccharide from Rubus chingii Hu unripe fruits: Extraction optimization, structural characterization and amelioration of colonic inflammation and oxidative stress

Raspberry is used as a medicine food homology species and its polysaccharides are worthy being investigated and developed. In the present study, a novel polysaccharide of unripe raspberry fruits (pRCP) was extracted and characterized. The results show that pRCP was an acidic heteropolysaccharide and its Mw value was 74.86 kDa with a high homogeneity. The main chain of pRCP consisted of → 3,6)-β-Galp(1 → and → 5)-α-Araf(1→, and its side chain was composed of α-Araf(1 → linked to the C3 position of → 3,6)-β-Galp(1 →. In addition, pRCP supplementation increased the gut microbial diversity and reduced harmful bacteria including Erysipelatoclostridium and Negativibacillus in high-fat diet (HFD)-fed mice. Treatment with pRCP also alleviated HFD-induced colonic inflammation and oxidative stress in mice. These beneficial effects can be transferred to recipient mice by faecal microbiota transplantation from pRCP-treated mice. Therefore, our study suggests that pRCP could be used as a potential prebiotics to improve intestinal health by modulating the gut microbiota.

Hypoglycemic effects of different molecular weight konjac glucomannans via intestinal microbiota and SCFAs mediated mechanism

The hypoglycemic effects of konjac glucomannans (KGMs) are well recognized, and our previous study showed KGMs with different molecular weight have different hypoglycemic effects on diabetes rats, but the detailed mechanisms still remain unclear. In this study, KGMs with medium molecular weight (KGM-M, 757.1 kDa) and low molecular weight (KGM-L, 87.3 kDa) were utilized to investigate the possible mechanism on hypoglycemic effects of type 2 diabetic (T2DM) rats. The results revealed that KGM-M had better effects than KGM-L on decreasing fasting blood glucose, mitigating insulin resistance and improving inflammation. Further mechanism analysis showed that KGM-M better enriched gut flora diversity and the abundance of Ruminococcus and Lachnoclostridium, which was accompanied by increased short chain fatty acids (SCFAs) production and expression of G protein-coupled receptors (GPCRs), and improved regulation on bile acid synthesis. Antibiotics treatment eliminated the beneficial effects of KGMs on gut flora, SCFAs, GPCRs and bile acid synthesis. By contrast, fecal microbiota transplantation (FMT) treatment restored the structure of intestinal microbiota. And after FMT treatment, KGM-M displayed higher hypoglycemic activity than KGM-L, probably due to the better effects on intestinal microbiota, SCFAs production, GPCRs expression and bile acid synthesis inhibition.

Managing metabolic diseases: The roles and therapeutic prospects of herb-derived polysaccharides

Metabolic diseases have become a public health problem worldwide. Effective, novel and natural therapies are urgently needed to treat metabolic diseases. As natural bioactive compounds, polysaccharides have many physiological and medicinal properties. Recently, herb-derived polysaccharides have shown beneficial effects in the treatment of metabolic diseases, but the underlying mechanisms remain unclear. This review comprehensively summarizes the pharmacological progress and clinical evidence of herb-derived polysaccharides in the treatment of three metabolic diseases, namely type 2 diabetes mellitus, nonalcoholic fatty liver disease and obesity, and more importantly, discusses the molecular mechanism involved. Existing evidence has proved that herb-derived polysaccharides can maintain glucose homeostasis, promote insulin secretion, improve insulin resistance, reduce weight gain and hepatic steatosis, inhibit lipogenesis, alleviate oxidative stress and inflammation, and improve gut microbiota disorders in rodents with metabolic diseases. Notably, so far, human clinical trials of herb-derived polysaccharides for these three metabolic diseases remain rare. All in all, herb-derived polysaccharides may have good potential as drug candidates for the prevention and management of metabolic diseases. More high-quality clinical trials are needed to further validate its effectiveness and safety in human subjects.

A tetrapeptide from maize combined with probiotics exerted strong anti-inflammatory effects and modulated gut microbiota in DSS-induced colitis mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by recurrent gastrointestinal inflammation caused by abnormal immune response, and patients usually have intestinal flora imbalance. At present, the pathogenesis of UC is not well understood, and it appears that there is chronic activation of the immune and inflammatory cascade in genetically susceptible individuals. Some food supplements such as specific peptides and probiotics have been investigated and shown the potential for the treatment of UC. The purpose of this study is to investigate the therapeutic effect and potential mechanism of tetrapeptide from maize (TPM) and probiotic treatment on dextran sulfate sodium (DSS)-induced UC in C57BL/6J mice. Our results indicated that the therapeutic effects of TPM and probiotics are positively associated with a reduction in pro-inflammatory cytokine levels and restoration of the gut microbiota. Treatment with TPM or probiotics effectively alleviated the adverse effects of UC, including weight loss, shortened colon length, and colon and kidney tissue damage in mice. Additionally, both TPM and probiotics significantly reduced pro-inflammatory cytokine levels and oxidative stress in UC mice, and the effect was more pronounced when both were used together. Moreover, co-treatment with TPM and probiotics increased the diversity of gut microbes in UC mice, reduced the ratio of Firmicutes to Bacteroidetes (F/B) and increased the abundance of bacterial species, including Muribaculaceae, Alistipes, Ligilactobacillus and Lactobacillus, and has been shown to be beneficial for a variety of pathological conditions.

Gut microbiota mediated hypoglycemic effect of Astragalus membranaceus polysaccharides in db/db mice

Gut microbiota has been reported to be closely associated with Type-II diabetes. Restoration of disordered gut microbiota ecosystem has been developed into a therapeutic strategy and gradually applied on Type-II diabetes treatment with both western drugs and herbal polysaccharides. Although Astragalus membranaceus polysaccharides (AMP) have also been used to treat Type-II diabetes, no study investigated correlations between gut microbiota regulation and its hypoglycemic effect. In the present study, the role of gut microbiota on the hypoglycemic effect of AMP in db/db mice was investigated for the first time. Sixteen days treatment of AMP at the dosage of 600 mg/kg in db/db mice not only alleviated its diabetic symptoms significantly but also restored its gut microbiota community with increased production of fecal short chain fatty acids (SCFA). Our further Pearson correlation analyses revealed that the relative abundance of two intestinal bacteria, Akkermansia and Faecalibaculum, were significantly positively correlated with the hypoglycemic effect of AMP as well as fecal SCFA production. It was also noted that treatment of AMP resulted in increased secretion of glucagon-like peptide-1 (GLP-1) in serum and enhanced intestinal integrity. Further mechanistic study revealed that the increased SCFA after AMP treatment could stimulate GLP-1 secretion and improve intestinal integrity via enhancing the expression of G protein-coupled receptors 41/43 and tight junction proteins (Occudin and ZO-1), respectively, leading to the alleviation of diabetic symptoms in db/db mice.

Evidence-Based Anti-Diabetic Properties of Plant from the Occitan Valleys of the Piedmont Alps

Data on urban and rural diabetes prevalence ratios show a significantly lower presence of diabetes in rural areas. Several bioactive compounds of plant origin are known to exert anti-diabetic properties. Interestingly, most of them naturally occur in different plants present in mountainous areas and are linked to traditions of herbal use. This review will aim to evaluate the last 10 years of evidence-based data on the potential anti-diabetic properties of 9 plants used in the Piedmont Alps (North-Western Italy) and identified through an ethnobotanical approach, based on the Occitan language minority of the Cuneo province (Sambucus nigra L., Achillea millefolium L., Cornus mas L., Vaccinium myrtillus L., Fragaria vesca L., Rosa canina L., Rubus idaeus L., Rubus fruticosus/ulmifolius L., Urtica dioica L.), where there is a long history of herbal remedies. The mechanism underlying the anti-hyperglycemic effects and the clinical evidence available are discussed. Overall, this review points to the possible use of these plants as preventive or add-on therapy in treating diabetes. However, studies of a single variety grown in the geographical area, with strict standardization and titration of all the active ingredients, are warranted before applying the WHO strategy 2014-2023.

Construction of in vitro fermentation model using gut microbiota relating to glucose and lipid metabolism: a supplementary method for initial screening of polysaccharides with hypoglycemic potentials

BACKGROUND

Besides in vitro fecal fermentation model, a few supplementary methods have been constructed for high-throughput screening of polysaccharides with hypoglycemic potentials. The purpose of this study was to establish a co-culture fermentation model constructed by gut microbiota relating to glucose and lipid metabolism as a supplementary method for comparatively evaluating the proliferative effects and hypoglycemic potentials of typical plant polysaccharides, e.g. konjac glucomannan, Lycium barbarum L. polysaccharide, oat glucan and alga-derived fucoidan.

RESULTS

The results showed that the mixing culture medium of butyrate-producing bacteria, Bacteroides, Bifidobacterium and Lactobacillus at a ratio of 50:40:9:1 was optimal. This testing model in line with quantitative polymerase chain reaction (qPCR) and metabolite analysis multi-dimensionally differentiated four polysaccharides possessing different behaviors on proliferation of total bacteria and specific genus or strain and accumulation of short chain fatty acids.

CONCLUSION

Our study provided crucial data for establishing an initial screening method for proliferative effect/specific structure-oriented extraction of polysaccharide with hypoglycemic potential. © 2022 Society of Chemical Industry.

Therapeutic potential of non-starch polysaccharides on type 2 diabetes: from hypoglycemic mechanism to clinical trials

Non-starch polysaccharides (NSPs) have been reported to exert therapeutic potential on managing type 2 diabetes mellitus (T2DM). Various mechanisms have been proposed; however, several studies have not considered the correlations between the anti-T2DM activity of NSPs and their molecular structure. Moreover, the current understanding of the role of NSPs in T2DM treatment is mainly based on in vitro and in vivo data, and more human clinical trials are required to verify the actual efficacy in treating T2DM. The related anti-T2DM mechanisms of NSPs, including regulating insulin action, promoting glucose metabolism and regulating postprandial blood glucose level, anti-inflammatory and regulating gut microbiota (GM), are reviewed. The structure-function relationships are summarized, and the relationships between NSPs structure and anti-T2DM activity from clinical trials are highlighted. The development of anti-T2DM medication or dietary supplements of NSPs could be promoted with an in-depth understanding of the multiple regulatory effects in the treatment/intervention of T2DM.

Anti-diabetic and gut microbiota modulation effects of sacha inchi (Plukenetia volubilis L.) leaf extract in streptozotocin-induced type 1 diabetic mice

BACKGROUND

Sacha inchi (Plukenetia volubilis L.) tea has been used as an adjuvant treatment for diabetes in Pu'er, in the Yunnan province of China. The effects of sacha inchi tea on diabetes and the underlying mechanisms remain unknown. This study was conducted to investigate the influence of a water extract of sacha inchi (P. volubilis L.) leaves (PWE) on hypoglycemic activity and gut microbiota composition in mice with streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM). During the 6 weeks of the study, T1DM mice were administered PWE intragastrically at 400 mg kg^-1 body weight (BW) per day.

RESULTS

Treatment with PWE reduced excessive loss of BW and excessive intake of food. It significantly decreased blood glucose levels and improved oral glucose tolerance. The treatment caused protective histopathological transformations in sections of the pancreas, leading to decreased insulin resistance and improved insulin sensitivity. Treatment with PWE also significantly ameliorated disorders of the gut microbiota structure and increased the richness and diversity of intestinal microbial species in T1DM mice. At the genus level, the populations of several crucial bacteria, such as Akkermansia, Parabacteroides, and Muribaculum increased in the PWE treatment group but the abundance of Ruminiclostridium and Oscillibacter decreased.

CONCLUSIONS

Treatment with PWE can ameliorate hyperglycemic symptoms in STZ-induced T1DM mice, and the anti-diabetic effect of PWE was related to the amelioration of gut microbial structural disorder and the enrichment of functional bacteria. © 2022 Society of Chemical Industry.

Astragalus Shiitake—A Novel Functional Food with High Polysaccharide Content and Anti-Proliferative Activity in a Colorectal Carcinoma Cell Line

The chemical and nutritional constituents of mushrooms can alter significantly when grown on different substrates. Based on this fact, an approach was made to cultivate a new type of mushroom, Hengshan Astragalus Shiitake, by growing Shiitake mushrooms on beds supplemented with the roots of an edible herbal plant, Astragalus membranaceus. In this study, three green extraction techniques, including microwave-enzyme assisted (MEA), ultrasound-enzyme assisted (UEA) and microwave-ultrasound-enzyme assisted (MUEA) extractions, were used to compare both the yield and antiproliferative activity of the polysaccharide-rich extracts (PREs) from HAS in human colorectal carcinoma cells (HCT 116). Both HAS-A and HAS-B extracts contain significantly higher amounts of polysaccharides when compared to the control (Shiitake extract), regardless of the extraction methods. The PREs from HAS-B have significantly higher anti-proliferative activity in HCT 116 compared to the control when using the UEA extraction method. Our findings demonstrate that HAS-B can become a novel functional food with anti-proliferative activities and the optimization of UEA extraction would help to develop new active extract-based health products.

Protective effect of nimbolide against streptozotocin induced gestational diabetes mellitus in rats via alteration of inflammatory reaction, oxidative stress, and gut microbiota

BACKGROUND

Gestational diabetes mellitus (GDM) is a significant pregnancy-related condition, which showed effect on the development of fetal. Anti-inflammatory and antioxidant therapy commonly used for the treatment of GDM. Nimbolide already confirmed their anti-inflammatory and anti-oxidant effect against various animal disease model. Our objective in this research is to investigate the protective effect of nimbolide against STZ induced GDM and elucidate the mechanism.

METHODS

In this experimental study, pregnant female Wistar rats were used and STZ (40 mg/kg) was used to induce the GDM. Blood glucose level (BGL), body weight and plasma insulin were assessed at regular time (gestational day 0, 9, and 18). Water intake, food intake, fecal and urine output were also estimated. In the female rats, hemoglobin (Hb), glycalated hemoglobin (HbA1c), hepatic glycogen, fructosamine, adiponectin, leptin, lipid, antioxidant and inflammatory cytokines parameters were estimated. In the fetuses, the fetues weight, implementation loss, and fetal weight were estimated. At the completion of the protocol, biochemical parameters were calculated. Gut microbiota was estimated in end of the study.

RESULTS

Nimbolide treatment significantly (p < .001) improved the fetuses level and suppressed the fetal weight and implantation loss. Nimbolide treatment significantly (p < .001) suppressed the BGL and enhanced the body weight, insulin level. Nimbolide treatment suppressed the water intake, food intake, urinary and fecal output. Nimbolide significantly (p < .001) suppressed the fructosamine, leptin and enhanced the adiponectin level. Nimbolide treatment significantly (p < .001) decreased the malonaldehyde (MDA) level and boosted the total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST) and catalase (CAT); suppressed the level of TNF-α, IL-1β, IL-6, and boosted the level of IL-10. Furthermore, nimbolide treatment reversed the gut microbiota alteration induced via STZ in female rats. At the phylum level, the Firmicutes and Bacteroidetes relative abundance was altered via nimbolide treatment. The ratio of F/B boosted in GDM group and nimbolide treatment significantly (p < .001) suppressed. Nimbolide considerably suppressed the firmicutes and enhanced the Bacteroidetes, CAG-352, Lacnospirace.

CONCLUSION

Based on the findings, we may conclude that nimbolide protects the pregnant rats from GDM via alteration of inflammation, oxidative stress, and gut microbiota.

Long-term drench of exopolysaccharide from Leuconostoc pseudomesenteroides XG5 protects against type 1 diabetes of NOD mice via stimulating GLP-1 secretion

BACKGROUND

Type 1 diabetes is an autoimmune disease that results in the specific destruction of insulin-producing beta cells in the pancreas. The aim of this study was to investigate the mechanism of exopolysaccharide from Leuconostoc pseudomesenteroides XG5 (XG5 EPS) against type 1 diabetes.

RESULTS

Long-term drench of XG5 EPS delayed the onset of autoimmune diabetes and had fewer islets with high-grade infiltration (an insulitis score of 3 or 4) than untreated NOD mice. Oral administration of 50 mg kg^-1  d^-1 XG5 EPS increased the insulin and glucagon-like peptide-1 (GLP-1) levels of serum, stimulated GLP-1 secretion and upregulated gcg mRNA expression of colon in NOD mice. Moreover, oral administration of 50 mg kg^-1  d^-1 XG5 EPS significantly increased total short-chain fatty acids levels in the colon contents, especially those of acetic acid and butyric acid. In NCI-H716 cells, 500 and 1000 μmol L^-1 sodium butyrate promoted the secretion of GLP-1 and upregulated the mRNA expression of gcg and PC3, while XG5 EPS and sodium acetate did not stimulate the GLP-1 secretion. Therefore, long-term drench of XG5 EPS delayed the onset of autoimmune diabetes, which may be directly correlated with the increase of butyrate in the colon of NOD mice.

CONCLUSION

Long-term drench of 50 mg kg^-1  d^-1 XG5 EPS promoted the expression and secretion of GLP-1 by increasing the production of butyric acid, thereby delaying T1D onset in NOD mice. © 2021 Society of Chemical Industry.

Moutan Cortex polysaccharide ameliorates diabetic kidney disease via modulating gut microbiota dynamically in rats

Growing evidence suggests that polysaccharides from traditional Chinese medicine positively affect diabetic kidney disease (DKD) mainly through modulating gut microbiota. Previously, we demonstrated that supplementation with the polysaccharide from Moutan Cortex (MC-Pa) alleviated DKD in rats. The study intends to investigate the dynamic modulation of MC-Pa on DKD from the gut microbiota perspective. The DKD rat model was induced by a high-fat and high-sugar diet combined with streptozotocin (STZ). The rats were then supplemented with MC-Pa (80 and 160 mg/kg BW) for 12 weeks. The results showed that MC-Pa administration relieved hyperglycemia and renal injury in DKD rats. MC-Pa also reconstructed gut microbiota, improved intestinal barrier function, reduced serum proinflammatory mediators, and elevated the short-chain fatty acid (SCFAs) contents. In addition, the dynamics of Lactobacillus and Muribaculaceae_unclassified were in a dose- and time-dependent manner. Spearman correlation analysis found that a cluster of gut microbiota phyla and genera were significantly associated with DKD-related indicators. These results demonstrated that MC-Pa positively affected DKD rats by modulating gut microbiota dynamically and had potential as a prebiotic.

Protective Effects of Almond Oil on Streptozotocin-Induced Diabetic Rats via Regulating Nrf2/HO-1 Pathway and Gut Microbiota

Almond oil has been used as a medicine substitution for its numerous health benefits. This study aimed to evaluate the effect of almond oil on streptozotocin- (STZ-) induced diabetic rats for 4 weeks. The results showed that the administration of almond oil could significantly increase body weight, attenuate abnormally elevated blood glucose, promote insulin secretion, and improve glucose tolerance. Almond oil treatment also suppressed oxidative stress, reduced inflammation reaction, improved liver and kidney function, upregulated the expressions of Nrf2, HO-1, and NQO1, while downregulating the expression of Keap1. Furthermore, almond oil reversed the gut microbiota change by STZ and regulated the gut microbiota associated with glucose metabolism. At the phylum level, the relative abundance of Firmicutes was decreased, while Bacteroidetes was increased by almond oil treatment. More importantly, the ratio of Firmicutes/Bacteroidetes was significantly increased. At the genus level, administration of almond oil increased the abundances of Lactobacillus, Bacteroides, and Lachnospiraceae_NK4A136_group, while decreased the abundances of Ruminococcaceae_UCG-014, Clostridium_sensu_stricto_1, and Fusicatenibacter. These results provided evidence for the regulating effect of almond oil on diabetic rats via the Nrf2/HO-1 pathway and gut microbiota.

Lycium barbarum polysaccharide combined with aerobic exercise ameliorated nonalcoholic fatty liver disease through restoring gut microbiota, intestinal barrier and inhibiting hepatic inflammation

Gut microbiota and intestinal permeability have been demonstrated to be the key players in the gut-liver cross talk in nonalcoholic fatty liver disease (NAFLD). Lycium barbarum polysaccharides (LBPs), which seem to be a potential prebiotic, and aerobic exercise (AE) have shown protective effects on NAFLD. However, their combined effects on intestinal microecology remain unclear. This study evaluated the effects of LBP, AE, and its combination (LBP + AE) on gut microbiota composition, intestinal barrier, and hepatic inflammation in NAFLD. LBP + AE showed high abundance and diversity of gut microbiota, restored the gut microbiota composition, increased some Bacteroidetes, short chain fatty acids, but decreased Proteobacteria and the ratio of Firmicutes/Bacteroidetes. Simultaneously, LBP, AE, and LBP + AE could restore the colonic and ileum tight junctions by increasing the expression of zonula occludens-1 and occludin. They also downregulated gut-derived lipopolysaccharides (LPSs), hepatic LPS-binding proteins, inflammatory factors, and related indicators of the LPS/TLR4/NF-κB signaling pathway for the liver. Our results implied that LBP could be considered a prebiotic agent, and LBP + AE might be a promising treatment for NAFLD because it could maintain gut microbiota balance, thereby restoring intestinal barrier and exerting hepatic benefits.

Health benefits of edible mushroom polysaccharides and associated gut microbiota regulation

Edible mushrooms have been an important part of the human diet for thousands of years, and over 100 varieties have been cultivated for their potential human health benefits. In recent years, edible mushroom polysaccharides (EMPs) have been studied for their activities against obesity, inflammatory bowel disease (IBD), and cancer. Particularly, accumulating evidence on the exact causality between these health risks and specific gut microbiota species has been revealed and characterized, and most of the beneficial health effects of EMPs have been associated with its reversal impacts on gut microbiota dysbiosis. This demonstrates the key role of EMPs in decreasing health risks through gut microbiota modulation effects. This review article compiles and summarizes the latest studies that focus on the health benefits and underlying functional mechanisms of gut microbiota regulation via EMPs. We conclude that EMPs can be considered a dietary source for the improvement and prevention of several health risks, and this review provides the theoretical basis and technical guidance for the development of novel functional foods with the utilization of edible mushrooms.