Digestive behavior of Dendrobium huoshanense polysaccharides in the gastrointestinal tracts of mice

Simulated digestion and gut microbiota fermentation of polysaccharides from Lactarius hatsudake Tanaka mushroom

Lactarius hatsudake Tanaka is a popular edible mushroom known for its delicious flavor and health benefits. Its polysaccharides (LHP) exhibit significant bioactivity, but their application is limited due to uncertainties in digestion. This study used in vitro simulated models to explore the dynamic changes of LHP during the digestive and fermentation process and validated them through mouse models. Results revealed that LHP cannot be digested by the simulated digestive system, but is primarily degraded into fatty acids by gut microbes, accompanied by reductions in molecular weight, carbohydrate content, and pH. Additionally, LHP promotes the proliferation of beneficial bacteria (Faecalibacterium, Bifidobacterium, Lactobacillus, etc.), while inhibiting harmful bacteria (Escherichia and Shigella). Metabolite analysis in serum indicated that LHP can regulate amino acid and lipid metabolism, enhancing overall health. These findings provide a theoretical foundation for developing LHP as a potential prebiotic, highlighting its considerable promise for disease prevention through improved intestinal health.

Novel glucomannan-like polysaccharide from Lycium barbarum L. ameliorates renal fibrosis via blocking macrophage-to-myofibroblasts transition

The macrophage to myofibroblasts transition (MMT) has been reported as a newly key target in renal fibrosis. Lycium barbarum L. is a traditional Chinese medicine for improving renal function, in which its polysaccharides (LBPs) are the mainly active components. However, whether the role of LBPs in treating renal fibrosis is related to MMT process remain unclear. The purpose of this study was to explore the relationship between the regulating effect on MMT process and the anti-fibrotic effect of LBPs. Initially, small molecular weight LBPs fractions (LBP-S) were firstly isolated via Sephadex G-100 column. Then, the potent inhibitory effect of LBP-S on MMT process was revealed on bone marrow-derived macrophages (BMDM) model induced by TGF-β. Subsequently, the chemical structure of LBP-S was elucidated through monosaccharide, methylation and NMR spectrum analysis. In vivo biodistribution characteristics studies demonstrated that LBP-S exhibited effectively accumulation in kidney via intraperitoneal administration. Finally, LBP-S showed a satisfactory anti-renal fibrotic effect on unilateral ureteral obstruction operation (UUO) mice, which was significantly reduced following macrophage depletion. Overall, our findings indicated that LPB-S could alleviate renal fibrosis through regulating MMT process and providing new candidate agents for chronic kidney disease (CKD) related fibrosis treatment.

In vivo absorption and fecal excretion of polysaccharides from the fruits of Lycium barbarum L. in rats through fluorescence labeling

In the present study, the in vivo absorption and fecal excretion of a purified fraction of polysaccharides from the fruits of Lycium barbarum L. (LBPs-4) in rats were investigated by labelling LBPs-4 with fluorescein isothiocyanate (FITC). It was found that the fluorescent labeled LBPs-4 (LBPs-4-FITC) was not detected in the plasma within 24 h following the administration of a single dose of LBPs-4-FITC (100 mg/kg of body weight) to rats, indicating that LBPs-4 was hardly absorbed in its prototype form. Instead, a smaller fragment dissociated from LBPs-4-FITC was observed in feces and was accumulated in a time-dependent manner, suggesting that LBPs-4 was excreted into the feces with a form of degradation. Meanwhile, we observed that LBPs-4-FTIC could modulate the fecal bacterial community profile via increasing the relative abundances of Bacteroides ovatus and Alistipes and promote the production of acetic acid. Furthermore, the monoculture experiment confirmed that LBPs-4 could be metabolized into smaller fragment by B. ovatus, producing acetic acid. Collectively, our study provides information on the destiny of LBPs-4 after oral administration: non-absorbed but moved to the large intestine and catabolized by gut microbiota, especially B. ovatus.

Interpreting the efficacy enhancement mechanism of Chinese medicine processing from a biopharmaceutic perspective

Chinese medicine processing (CMP) is a unique pharmaceutical technology that distinguishes it from natural medicines. Current research primarily focuses on changes in chemical components to understand the mechanisms behind efficacy enhancement in processing. However, this paper presents a novel perspective on the biopharmaceutics of CMP. It provides a comprehensive overview of the current research, emphasizing two crucial aspects: the role of 'heat' during processing and the utilization of processing adjuvants. The paper highlights the generation of easily absorbed components through the hydrolysis of glycosides by 'heat', as well as the facilitation of dissolution, absorption, and targeted distribution of active components through the utilization of processing adjuvants. From a biopharmaceutic perspective, this paper provides a lucid comprehension of the scientific foundation for augmenting the efficacy of CMP. Moreover, it proposes a three-dimensional research framework encompassing chemical reactions, phase transitions, and biopharmaceutical properties to further investigate the mechanisms involved in enhancing the efficacy of CMP.

Dendrobium officinale Polysaccharide Prevents Diabetes via the Regulation of Gut Microbiota in Prediabetic Mice

Dendrobium officinale polysaccharide (DOP), which serves as a prebiotic, exhibits a variety of biological activities, including hypoglycemic activities. However, the effects of DOP on diabetes prevention and its hypoglycemic mechanisms are still unclear. In this study, the effects of DOP treatment on the prediabetic mice model were studied and the mechanism was investigated. The results showed that 200 mg/kg/d of DOP reduced the relative risk of type 2 diabetes mellitus (T2DM) from prediabetes by 63.7%. Meanwhile, DOP decreased the level of LPS and inhibited the expression of TLR4 by regulating the composition of the gut microbiota, consequently relieving the inflammation and alleviating insulin resistance. In addition, DOP increased the abundance of SCFA (short chain fatty acid)-producing bacteria in the intestine, increased the levels of intestinal SCFAs, promoted the expression of short-chain fatty acid receptors FFAR2/FFAR3, and increased the secretion of the intestinal hormones GLP-1 and PYY, which helped to repair islet damage, suppress appetite, and improve insulin resistance. Our results suggested that DOP is a promising functional food supplement for the prevention of T2DM.

Dendrobium as a new natural source of bioactive for the prevention and treatment of digestive tract diseases: A comprehensive review with future perspectives

BACKGROUND

The incidence of diseases related to the digestive tract is on the rise, with many types of complex etiologies. Dendrobium nobile Lindl. is a famous Traditional Chinese Medicine (TCM) rich in many bioactives proven to be beneficial in several health diseases related to inflammation and oxidative stress.

PURPOSE

At present, despite the availability of various therapeutic clinical drugs used for the treatment of digestive tract diseases, resistance emergence and existence of several side effects warrant for the developing of novel drugs for improved effects on digestive tract diseases.

METHODS

"Orchidaceae", "Dendrobium", "inflammation", "digestive tract", and "polysaccharide" were used as search terms to screen the literature. The therapeutic use of Dendrobium related to digestive tract diseases relative to known polysaccharides and other bioactive compounds were derived from online databases, including Web of Science, PubMed, Elsevier, Science Direct, and China National Knowledge Infrastructure, as well as relevant information on the known pharmacological actions of the listed phytochemicals.

RESULTS

To better capitalize upon Dendrobium for preventing and treating diseases related to digestive tract, this review summarizes bioactives in Dendrobium reported of potential in digestive tract diseases management and their underlying action mechanisms. Studies revealed that Dendrobium encompasses diverse classes including polysaccharides, phenolics, alkaloids, bibenzyls, coumarins, phenanthrene and steroids, with polysaccharide as the major class. Dendrobium exerts various health effects on a variety of disease related to the digestive tract. Action mechanisms involve antioxidant, anti-inflammatory, anti-apoptotic, antioxidant, anticancer, alongside the regulation of some key signaling pathways.

CONCLUSION

Overall, Dendrobium appears as a promising TCM source of bioactives that has the potential to be further developed into nutraceuticals for digestive tract diseases compared to current drug treatments. This review highlights for Dendrobium potential effects with future perspectives for needed future research to maximize the use of bioactive compounds from Dendrobium for digestive tract disease treatment. A compile of Dendrobium bioactives is also presented alongside methods for their extraction and enrichment for potential incorporation in nutraceuticals.

Comparison and the lipid-lowering ability evaluation method discussion of Dendrobium officinale polysaccharides from different origins based on principal component analysis

As typical acetylated glucomannans, Dendrobium officinale polysaccharides (DOPs) from different origins differ in their structural characteristics and some of their physicochemical properties. To rapidly select D. officinale plants, we systematically investigate the differences among DOPs from different origins and analyzed the structural characteristics, such as the degree of acetylation and monosaccharide composition; the physicochemical properties, such as solubility, water absorption and apparent viscosity; and the lipid-lowering activity of the obtained DOPs. Principal component analysis (PCA), a method for analyzing multiple variables, was used to analyze the relationship between the physicochemical and structural properties, and lipid-lowering activity. It was found that the structural and physicochemical characteristics had significant effects on lipid-lowering activity, and DOPs with a high degree of acetylation, high apparent viscosity and large D-mannose-to-d-glucose ratio were associated with greater lipid-lowering activity. Therefore, this study provides a reference for the selection and application of D. officinale.

Dendrobium fimbriatum polysaccharide ameliorates DSS-induced intestinal mucosal injury by IL-22-regulated intestinal stem cell regeneration

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with unknown etiology and difficult treatment. In this study, the intervention effect of Dendrobium fimbriatum Hook polysaccharide (cDFPW1) on UC was verified by constructing a dextran sulfate sodium (DSS)-induced colitis mouse model, and the protective effect of cDFPW1 on intestinal mucosal integrity in UC was explored by the co-culture system consisting of intestinal organoids and lamina propria lymphocytes (LPLs) combined with the experiment of microbial depletion mice. Results showed that cDFPW1 significantly alleviated UC symptoms in mice and promoted the proliferation of intestinal epithelial cells. Importantly, cDFPW1 could directly improve DSS-induced morphological damage of intestinal organoids and increase the number of epithelial cells, which was validated in mice. During repair, an increase in the number of Lgr5⁺ cells in intestinal organoids and mouse intestines was promoted by cDFPW1. Meanwhile, cDFPW1 promoted intestinal stem cells (ISCs)-mediated intestinal epithelial regeneration by significantly upregulating IL-22 expression. We further confirmed that the secretion of IL-22 was mediated by LPLs. Together, these findings suggest that cDFPW1 promotes ISCs regeneration by LPLs-mediated up-regulation of IL-22 to protect the intestinal mucosal integrity, thereby playing an important role in improving UC.

Huangshan Floral Mushroom Polysaccharide Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice by Modulating Th17/Treg Balance in a Gut Microbiota-Dependent Manner

SCOPE

Ulcerative colitis (UC) is a common chronic recurrent inflammatory bowel disease. This study attempts to reveal the improvement mechanism of floral mushroom polysaccharide (FMPS) on UC from the perspective of coordinated interaction between intestinal microbes and intestinal helper T cell 17 (Th17)/regulatory T cell (Treg) balance.

METHODS AND RESULTS

Dextran sulfate sodium (DSS)-induced colitis mice model is used for the experiment. The results suggest that FMPS up-regulated the expression of occludin, ZO-1, and MUC2, and down-regulated the secretion of TNF-α, IL-1β, and IL-6 in colitis mice. Importantly, FMPS restores intestinal Th17/Treg balance. Meanwhile, FMPS can regulate intestinal microorganisms and improve the level of short-chain fatty acids (SCFAs) in colitis mice. Intestinal microbial depletion and fecal microbiota transplantation (FMT) experiments reveal that FMPS ameliorated UC is mediated by intestinal microbiome. Flow cytometry further proves that FMPS restores intestinal Th17/Treg balance in a microbial-dependent manner.

CONCLUSION

These results indicate that FMPS has the potential to improve UC, and its mechanism depends on the restoration of Th17/Treg balance mediated by intestinal microorganisms. Therefore, it is suggested that FMPS dietary supplement can be potentially used to intervene UC.

DHPW1 attenuation of UVB-induced skin photodamage in human immortalized keratinocytes

Ultraviolet radiation (UVB) can result in photodamage to the skin and can seriously threaten health, particularly in the elderly. Oxidative stress and the inflammatory response have been shown to play a significant role in the process. In a previous study, we isolated, purified and identified a polysaccharide from the extract of Dendrobium huoshanense (DHPW1). In this study we evaluated the effect of DHPW1 on ameliorating the UVB photodamage of human immortalized keratinocytes (HaCaT). Cell proliferation and cell scratch assays were used to evaluate the viability of the HaCaT treated with DHPW1, and a fluorescent probe and Western blot analysis were used to examine the production of reactive oxygen species (ROS) and the expression of proinflammatory factors IL-1β, IL-6, and NF-κB(p65). The results show that, compared with the control group (UVB irradiation only), DHPW1 significantly improved the viability of UVB-irradiated HaCaT and enhanced the migration rate of the cell scratch after 24 h. The scratch-healing rate reached 90 % after 36 h. DHPW1 also significantly inhibited UVB-induced oxidative stress and expression of proinflammatory factors . Compared with the control group, the production of ROS decreased by 49.11 %, and the relative protein expression of IL-6 and NF-κB(p65) decreased by up to 13.30 % and 31.02 %, respectively. It is concluded that DHPW1 can significantly improve viability and wound closure rate of UVB-irradiated HaCaT. In addition, it can reduce the expression of IL-1 and IL-6 by inhibiting the transcription of NF-κB(p65), thereby reducing inflammation and oxidative stress in UVB-irradiated HaCaT.

Dendrobium huoshanense C.Z.Tang et S.J.Cheng: A Review of Its Traditional Uses, Phytochemistry, and Pharmacology

Dendrobium huoshanense, a traditional medicinal and food homologous plant, belongs to the family Orchidaceae and has a long history of medicinal use. It is reported that the stem of D. huoshanense has a variety of bioactive ingredients such as polysaccharides, flavonoids, sesquiterpenes, phenols, etc. These bioactive ingredients make D. huoshanense remarkable for its pharmacological effects on anti-tumor, immunomodulation, hepatoprotective, antioxidant, and anticataract activities. In recent years, its rich pharmacological activities have attracted extensive attention. However, there is no systematic review focusing on the chemical compositions and pharmacological effects of D. huoshanense. Therefore, the present review aims to summarize current research on the chemical compositions and pharmacological activities of D. huoshanense. This study provides valuable references and promising ideas for further investigations of D. huoshanense.

Tracking the gastrointestinal digestive and metabolic behaviour of Dendrobium officinale polysaccharides by fluorescent labelling

Recently, Dendrobium officinale polysaccharide (DOP), a typical acetylated glucomannan, has been widely applied in functional foods owing to its excellent bioactivity. However, the insufficiency of studies on in vivo process severely limits the further utilization of DOP. The aim of this study was to systematically investigate the gastrointestinal digestive behaviour of DOP after oral administration by labelling it with two fluorescein aminopyrene-1,3,6-trisulfonic acids, trisodium salt (APTS) and cyanine 7.5 (Cy7.5). Combining the results of NIR imaging and HPGPC, we found that DOP was poorly absorbed directly in the prototype form; instead, DOP moved with the intestinal contents to the distal part of the intestine, where Bacteroides aggregated for a prolonged time and was metabolized to oligosaccharide-like substances. In contrast, the digestive degradation of DOP in pseudo-sterile mice with a targeted clearance of Bacteroides significantly weakened, which provided the basis and direction for the subsequent search for more specific metabolic pathways of DOP in vivo.

Protective effect of homogeneous polysaccharides of Wuguchong (HPW) on intestinal mucositis induced by 5-fluorouracil in mice

BACKGROUND

In hospitalized patients, drug side effects usually trigger intestinal mucositis (IM), which in turn damages intestinal absorption and reduces the efficacy of treatment. It has been discovered that natural polysaccharides can relieve IM. In this study, we extracted and purified homogenous polysaccharides of Wuguchong (HPW), a traditional Chinese medicine, and explored the protective effect of HPW on 5-fluorouracil (5-FU)-induced IM.

METHODS AND RESULTS

First, we identified the physical and chemical properties of the extracted homogeneous polysaccharides. The molecular weight of HPW was 616 kDa, and it was composed of 14 monosaccharides. Then, a model of small IM induced by 5-FU (50 mg/kg) was established in mice to explore the effect and mechanism of HPW. The results showed that HPW effectively increased histological indicators such as villus height, crypt depth and goblet cell count. Moreover, HPW relieved intestinal barrier indicators such as D-Lac and diamine oxidase (DAO). Subsequently, western blotting was used to measure the expression of Claudin-1, Occludin, proliferating cell nuclear antigen, and inflammatory proteins such as NF-κB (P65), tumour necrosis factor-α (TNF-α), and COX-2. The results also indicated that HPW could reduce inflammation and protect the barrier at the molecular level. Finally, we investigated the influence of HPW on the levels of short-chain fatty acids, a metabolite of intestinal flora, in the faeces of mice.

CONCLUSIONS

HPW, which is a bioactive polysaccharide derived from insects, has protective effects on the intestinal mucosa, can relieve intestinal inflammation caused by drug side effects, and deserves further development and research.

Dendrobium officinale leaf polysaccharides ameliorated hyperglycemia and promoted gut bacterial associated SCFAs to alleviate type 2 diabetes in adult mice

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Fractions of LDOP show the hypoglycemic effect and can restore histological function of T2D mice.

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There is a difference in the anti-T2D effect between LDOP-A and LDOP-B.

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LDOP-A modulated the gut microbiota composition of T2D mice.

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LDOP-A promotes the formation of SCFAs in T2D mice, especially butyric acid.

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Compared with LDOP-B, LDOP-A shows greater potential to ameliorate T2D.

The present study aimed to explore the possible mechanisms underlying Dendrobium officinale leaf polysaccharides of different molecular weight to alleviate glycolipid metabolic abnormalities, organ dysfunction and gut microbiota dysbiosis of T2D mice. An ultrafiltration membrane was employed to separate two fractions from Dendrobium officinale leaf polysaccharide named LDOP-A and LDOP-B. Here, we present data supporting that oral administration of LDOP-A and LDOP-B ameliorated hyperglycemia, inhibited insulin resistance, reduced lipid concentration, improved β-cell function. LDOP-A with lower molecular weight exhibited improved effect on diabetes than LDOP-B, concurrent with increased levels of colonic short-chain fatty acids (SCFAs) i.e., butyrate, decreased ratio of Firmicutes to Bacteroidetes phyla, and increased abundance of the gut beneficial bacteria i.e., Lactobacillus, Bifidobacterium and Akkermansia. These results suggest that LDOP-A possesses a stronger effect in ameliorating T2D than LDOP-B which may be related to the distinct improved SCFAs levels produced by the change of intestinal flora microstructure.

A Systematic Review on Polysaccharides from Dendrobium Genus: Recent Advances in the Preparation, Structural Characterization, Bioactive Molecular Mechanisms, and Applications

Dendrobium polysaccharides (DPSs) have aroused people's increasing attention in recent years as a result of their outstanding edible and medicinal values and non-toxic property. This review systematically summarized recent progress in the different preparation techniques, structural characteristics, modification, various pharmacological activities and molecular mechanisms, structure-activity relationships, and current industrial applications in the medicinal, food, and cosmetics fields of DPSs. Additionally, some recommendations for future investigations were provided. A variety of methods were applied for the extraction and purification of DPSs. They possessed primary structures (e.g., glucomannan, rhamnogalacturonan I type pectin, heteroxylan, and galactoglucan) and conformational structures (e.g., random coil, rod, globular, and a slight triple-helical). And different molecular weights, monosaccharide compositions, linkage types, and modifications could largely affect DPSs' bioactivities (e.g., immunomodulatory, anti-diabetic, hepatoprotective, gastrointestinal protective, antitumor, anti-inflammatory, and anti-oxidant activities). It was worth mentioning that DPSs were significant pharmaceutical remedies and therapeutic supplements especially due to their strong immunity enhancement abilities. We hope that this review will lay a solid foundation for further development and applications of Dendrobium polysaccharides.

Comparative analysis of chemical constituents by HPLC-ESI-MSn and antioxidant activities of Dendrobium huoshanense and Dendrobium officinale

Dendrobium huoshanense is a Chinese medicinal herb that has high quality and excellent efficacy. However, the chemical basis of its activity is still unclear. Of note, Dendrobium officinale is the most widely utilized among the Dendrobium species. Therefore, the current study systematically investigated the chemical constituents of methanolic extracts and different polar fractions of aqueous extracts from the two herbs by HPLC-ESI-MSⁿ , and then compared in vitro antioxidant activities of their five different polar extracts. Consequently, 61 and 49 compounds were identified from D. huoshanense and D. officinale, respectively, of which 43 compounds were common to both species. In addition, 17 out of 22 different compounds were identified only in D. huoshanense. Moreover, the peak areas of some shared identical compounds of D. huoshanense were significantly larger than that of D. officinale. In vitro antioxidant evaluation results showed that the n-BuOH-soluble fraction of the two herbs exhibited remarkable antioxidant activities. Furthermore, the antioxidant activities of different fractions of D. huoshanense were separately superior to that of D. officinale, which may be attributed to its variable and high contents of flavonoids, bibenzyls and phenanthrenes. These results provide the evidence for the high quality and efficacy of D. huoshanense.

Effect of in vitro simulated gastrointestinal digestion on structural characteristics and anti-proliferative activities of the polysaccharides from the shells of Juglans regia L

The present research was designed to investigate the effects of simulated gastrointestinal digestion in vitro on the structural characteristics and anti-proliferative activities of polysaccharides from the shells of Juglans regia L. (JRP). Results suggested that JRP was composed of glucose, ribose, galactose, mannose, arabinose and rhamnose in a molar ratio of 10.7:4.9:16.4:2.3:10.8:2.3, with the molecular weight distributed from 3.21 × 10⁵ to 4.55 × 10⁵ Da. JRP belonged to non-crystalline substance, with irregular, smooth and compact morphological characteristics. Nevertheless, during gastrointestinal digestion in vitro, the physicochemical properties of JRP including molecular weight, monosaccharide composition, crystalline properties and morphology were significantly changed, accompanying with the increase of reducing sugar in digestive juice. Through measurements of anti-proliferation activities, the results showed that the digested JRP could remarkably inhibit the viabilities of HeLa cells by induction of apoptosis as a result of the excessive ROS accumulation and cell cycle arrest at G2/M phase, all of which were pronouncedly stronger than the ones induced by undigested JRP. These findings suggested that JRP processed by gastrointestinal digestion possessed more potential anti-proliferative applications that need to be exploited.

Coptis chinensis Franch polysaccharides provide a dynamically regulation on intestinal microenvironment, based on the intestinal flora and mucosal immunity

ETHNOPHARMACOLOGICAL RELEVANCE

Coptis chinensis Franch is one of the most widely used traditional Chinese herbs in China and was firstly recorded in "Shennong's Classic of Materia Medica" in the Han Dynasty. The medical records in past thousands years have fully confirmed the clinical efficacies of Coptis chinensis Franch against intestinal diseases. The polysaccharides in herbal medicines can be digested by the flora and uptaken by the Peyer's patches (PPs) in intestine. It can be reasonably presumed that the polysaccharides in Coptis chinensis Franch (CCP) should be one of the critical element in the regulation of intestinal microenvironment.

AIM OF THE STUDY

This study intended to explore the dynamic regulation of CCP on intestinal microenvironment from the perspective of the intestinal mucosal immunity and the intestinal flora, in order to provide a new research perspective for the pharmacological mechanism of Coptis chinensis Franch.

MATERIALS AND METHODS

The absorption and distribution of CCP in intestinal tissues were observed after the perfusion of FITC labeled CCP. The influences of CCP on intestinal flora were evaluated by the 16sRNA gene illumina-miseq sequencing after gavage. The regulations of CCP on intestinal mucosal immunity were evaluated by the immunohistochemical analysis of the interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-17 (IL-17) and transforming growth factor-β (TGF-β) secretion in PPs and intestinal epithelial tissue.

RESULTS

With the self-aggregation into particles morphology, CCP can be up-taken by PPs and promote the IFN-γ, IL-4, IL-17 and TGF-β secretion in PPs in a dose-dependent manner. The CCP can also be utilized by the intestinal flora and dynamically regulate the diversity, composition and distribution of the intestinal flora. The temporal regulations of CCP on IFN-γ, IL-4, IL-17 and TGF-β secretions in intestinal epithelial tissues are consistent with the variation tendency of intestinal flora.

CONCLUSION

CCP can provide effective, dynamical and dose-dependent regulations on intestinal microenvironment, not only the intestinal flora but also the PPs and intestinal epithelium related immune response. These may be involved in the multiple biological activities of Coptis chinensis Franch.

Protective Activities of Dendrobium huoshanense C. Z. Tang et S. J. Cheng Polysaccharide against High-Cholesterol Diet-Induced Atherosclerosis in Zebrafish

Cardiovascular disease is the highest cause of death, and atherosclerosis (AS) is the primary pathogenesis of many cardiovascular diseases. In this study, we aim to investigate the possible pharmaceutical effects of Dendrobium huoshanense C. Z. Tang et S. J. Cheng polysaccharide (DHP) in AS. We fed zebrafish with high-cholesterol diet (HCD) to establish a zebrafish AS model and treated with DHP and observed plaque formation and neutrophil counts under a fluorescence microscope. Next, a parallel flow chamber was utilized to establish low shear stress- (LSS-) induced endothelial cell (EC) dysfunction model. We observed that DHP significantly improved HCD-induced lipid deposition, oxidative stress, and inflammatory response, mainly showing that DHP significantly increased superoxide dismutase (SOD) activity, decreased plaque formation, and decreased neutrophil recruitment and the levels of total cholesterol (TC), triglyceride (TG), malondialdehyde (MDA), and reactive oxygen species (ROS). Furthermore, DHP significantly improved LSS-induced oxidative stress and EC dysfunction. Our results indicated that DHP can exert treatment effects on AS, which may attribute to its hypolipidemic, antioxidant, anti-inflammatory activities and improving LSS-induced EC dysfunction. DHP has promising potential for further development as a functional natural medicine source targeted at AS prevention.

Polygonatum cyrtonema Hua Polysaccharide Promotes GLP-1 Secretion from Enteroendocrine L-Cells through Sweet Taste Receptor-Mediated cAMP Signaling

Glucagon-like peptide-1 (GLP-1) secreted from enteroendocrine L-cells is a pleiotropic hormone with beneficial potential related to islet function, diet control, glucose homeostasis, inflammation relief, and cardiovascular protection. The present study aimed at investigating the effect of Polygonatum cyrtonema polysaccharide (PCP) after structural identification on GLP-1 secretion and the possible mechanism involved in the PCP-stimulated secretion of GLP-1. It was found that GLP-1 secretion was effectively promoted (p < 0.01) by PCP both in rats with oral administration for 5 weeks (13.9 ± 0.3-35.8 ± 0.3 pmol/L) and ileal administration within 2 h (13.6 ± 0.4-34.1 ± 1.1 pmol/L) and in enteroendocrine NCI-H716 cells with direct stimulation within 24 h (2.05 ± 0.3-20.7 ± 0.2 pmol/L). The sweet taste receptor T1R2/T1R3 was identified to be essential for NCI-H716 cells to directly recognize PCP. The intervention experiments showed that PCP-stimulated GLP-1 secretion was significantly depressed (p < 0.01) not only by antibodies, siRNA, and the inhibitor of T1R2/T1R3 but also by an adenylate cyclase inhibitor. These results suggest that PCP stimulates GLP-1 secretion from enteroendocrine cells possibly through activation of the T1R2/T1R3-mediated cAMP signaling pathway.

Research on the structural characteristics of a novel Chinese Iron Yam polysaccharide and its gastroprotection mechanism against ethanol-induced gastric mucosal lesion in a BALB/c mouse model

In this study, a triple-helix Chinese Iron Yam polysaccharide (CIYP) with a molecular weight of 1.67 × 10³ kDa was obtained. The CIYP was extracted with deionized water followed by deproteination, decoloration and purification using anion-exchange chromatography and size exclusion chromatography. Its structural characteristics and micromorphology were investigated by GC-MS, periodate oxidation and Smith degradation, FT-IR, NMR spectroscopy, SEM and AFM. The results showed that CIYP is a catenarian polysaccharide composed of rhamnose, arabinose, mannose, glucose, galactose and galacturonic acid in the ratio of 1 : 1.33 : 8.31 : 2.83 : 1.12 : 2.62. Meanwhile, the gastric mucosa protective effect of CIYP on an ethanol-injured BALB/c mouse model was investigated. It was found that the preventive CIYP-treatment groups (200 and 400 mg kg^-1 d^-1) showed gastric mucosa protective effects on the BALB/c mouse model. The lesion index and lesion inhibition rate of the CIYP and cimetidine treatment groups were significantly altered compared with the ethanol-induced gastric mucosal lesion (GML) group. Moreover, the administration of CIYP showed definite effects of increasing the NO, PGE2 and EGF levels, and SOD activities, and reducing the MDA levels of gastric mucosa tissues to prevent gastric oxidative stress. Histopathological analysis indicated that the microscopic morphology of gastric mucosal tissues was changed after being damaged by ethanol and the damage was significantly reduced after CIYP administration. Finally, the western blot and quantitative real-time polymerase chain reaction (qRT-PCR) results provided comprehensive evidence that the CIYP could repress gastric inflammation through the reduction of IL-1β, TNF-α and IL-6, prevent gastric oxidative stress through the inhibition of lipid peroxides, and favor cell survival via downregulating the TAK1, MKK3, P-p38 and Bax levels and upregulating the protein expression levels, compared with the CIM group.

The Antioxidant Activity of Polysaccharides Derived from Marine Organisms: An Overview

Marine-derived antioxidant polysaccharides have aroused extensive attention because of their potential nutritional and therapeutic benefits. However, the comprehensive comparison of identified marine-derived antioxidant polysaccharides is still inaccessible, which would facilitate the discovery of more efficient antioxidants from marine organisms. Thus, this review summarizes the sources, chemical composition, structural characteristics, and antioxidant capacity of marine antioxidant polysaccharides, as well as their protective in vivo effects mediated by antioxidative stress reported in the last few years (2013-2019), and especially highlights the dominant role of marine algae as antioxidant polysaccharide source. In addition, the relationships between the chemical composition and structural characteristics of marine antioxidant polysaccharides with their antioxidant capacity were also discussed. The antioxidant activity was found to be determined by multiple factors, including molecular weight, monosaccharide composition, sulfate position and its degree.

Dendrobium huoshanense polysaccharide regulates hepatic glucose homeostasis and pancreatic β-cell function in type 2 diabetic mice

In the present study, the hypoglycemic mechanism of a homogeneous Dendrobium huoshanense polysaccharide (GXG) was investigated using type 2 diabetic (T2D) mouse model. With a 5-week oral administration of GXG, the levels of fasting blood glucose, glycosylated serum protein and serum insulin in T2D mice were decreased, and the glucose tolerance and the insulin sensitivity were improved. The histological analysis, the periodic acid-schiff staining and the immunofluorescence staining of insulin, glucagon and apoptosis showed that the hypoglycemic effect of GXG was related to the improvement of pancreatic β-cell quantity and function and the regulation of hepatic glucose metabolism. Western blot analysis indicated that the up-regulated IRS1-PI3K-Akt phosphorylation followed by the down-regulated FoxO1/GSK 3β phosphorylation contributed to the enhanced glycogen synthesis and the decreased gluconeogenesis by GXG, suggesting that the response of insulin-mediated IRS1-PI3K-Akt-FoxO1/GSK 3β signaling to GXG might be the required mechanism for GXG-ameliorated development of type 2 diabetes.