Protective Effects of Three Flavonoids from Dendrobium huoshanense Flowers on Alcohol-Induced Hepatocyte Injury via Activating Nrf2 and Inhibiting NF-κB Pathways.

Dendrobium huoshanense flowers have been widely used for liver protection in China. This work was aimed to discover the natural products with activity of mitigating alcoholic hepatocyte injury from Dendrobium huoshanense flowers via bioactivity-guided isolation, and to clarify the underlying mechanisms of these natural products. As a result, three flavonoids, 3'-O-methylquercetin-3-O-ß-D-galactopyranoside (1), 3'-O-methylquercetin-3-O-ß-D-glucopyranoside (2) and quercetin-3-O-ß-D-glucopyranoside (3), were firstly isolated from D. huoshanense flowers. Results exhibited that flavonoids 1-3 could enhance the cell viability, decrease the expression of ALT and AST, inhibit the cell apoptosis, alleviate the oxidative stress, and mitigate the inflammatory response of alcohol-induced L02 cells. Mechanism study exhibited that flavonoids 1-3 could increase the expression of Nrf2 as well as its downstream antioxidation genes of alcohol-induced L02 cells, while ML-385 (Nrf2 inhibitor) could abolish the inhibitory effects of 1-3 on alcohol-induced hepatocyte injury. Flavonoids 1-3 could also reduce the phosphorylation levels of IκBα and NF-κB p65 of alcohol-induced L02 cells, while SC75741 (NF-κB inhibitor) could not enhance the inhibitory effects of 1-3 on alcohol-induced L02 cells injury. The data above indicated that flavonoids 1-3 could inhibit alcohol-induced hepatocyte injury, which might be attributed to alleviating oxidative stress and mitigating inflammatory response by activating Nrf2 and inhibiting NF-κB pathways.

[Study on chemical constituents of Dendrobium huoshanense stems and their anti-inflammatory activity].

Three bibenzyls 1-3 and six other compounds 4-9 were firstly isolated from Dendrobium huoshanense stems. They were identified as 3',4-dihydroxy-3,5'-dimethoxybibenzyl(1), batatasin Ⅲ(2), 3,4'-dihydroxy-5-methoxy bibenzyl(3), dihydroconiferyl dihydro-p-coumarate(4), syringaresinol(5), 3-(4-hydroxyphenyl)-propionic acid ethyl ester(6),(3-ethylphenyl)-1,2-ethanediol(7),(S)-5-hydroxy-3,4-dimethyl-5-pentylfuran-2(5H)-one(8) and loliolide(9). Anti-inflammation assay showed that bibenzyls 1-3 could significantly inhibit the production of nitric oxide(NO) and the expression of tumor necrosis factor α(TNF-α) and interleukin 1ß(IL-1ß) mRNA in LPS-induced RAW264.7 macrophages. Mechanism study exhibited that the phosphorylation of nuclear factor kappa B(NF-κB) p65, inhibitor of κB(IκB), extracellular regulatedprotein kinase(ERK), c-Jun N-terminalkinase(JNK), p38 and Akt of LPS-induced RAW264.7 macrophages could be remarkably reduced by 1. These results suggested that the inflammatory response of LPS-induced RAW264.7 macrophages could be significantly inhibited by 1-3. Additionally, the anti-inflammatory effect of 1 might be contributed to its ability on the regulation of NF-κB, MAPKs and Akt signaling pathways.

Renoprotective Effect of Laminaria japonica Polysaccharide in Adenine-Induced Chronic Renal Failure.

Chronic renal failure (CRF) is a major public health problem worldwide. In this work, we investigated the effects of a purified Laminaria japonica polysaccharide (LJP61A) on renal function using an adenine-induced CRF mice model. Results exhibited that adenine treatment caused serious renal pathological damages and elevation of serum creatinine and blood urea nitrogen of mice. However, these changes could be significantly reversed by the administration of LJP61A in a dose-dependent manner. Additionally, LJP61A could dramatically reduce weight loss, improve the urine biochemical index, and regulate the electrolyte disturbance of CRF mice. These results suggest that the renal function of adenine-induced CRF mice can be improved by LJP61A, which might be developed into a potential therapeutic agent for CRF patients.

Advances on Bioactive Polysaccharides from Medicinal Plants.

In recent decades, the polysaccharides from the medicinal plants have attracted a lot of attention due to their significant bioactivities, such as anti-tumor activity, antioxidant activity, anticoagulant activity, antidiabetic activity, radioprotection effect, anti-viral activity, hypolipidemic and immunomodulatory activities, which make them suitable for medicinal applications. Previous studies have also shown that medicinal plant polysaccharides are non-toxic and show no side effects. Based on these encouraging observations, most researches have been focusing on the isolation and identification of polysaccharides, as well as their bioactivities. A large number of bioactive polysaccharides with different structural features and biological effects from medicinal plants have been purified and characterized. This review provides a comprehensive summary of the most recent developments in physiochemical, structural features and biological activities of bioactive polysaccharides from a number of important medicinal plants, such as polysaccharides from Astragalus membranaceus, Dendrobium plants, Bupleurum, Cactus fruits, Acanthopanax senticosus, Angelica sinensis (Oliv.) Diels, Aloe barbadensis Miller, and Dimocarpus longan Lour. Moreover, the paper has also been focused on the applications of bioactive polysaccharides for medicinal applications. Recent studies have provided evidence that polysaccharides from medicinal plants can play a vital role in bioactivities. The contents and data will serve as a useful reference material for further investigation, production, and application of these polysaccharides in functional foods and therapeutic agents.

A polysaccharide from Dendrobium huoshanense prevents hepatic inflammatory response caused by carbon tetrachloride.

Dendrobium huoshanense is a precious herbal medicine in China, which exhibits a variety of restorative and therapeutic effects. This study aimed at investigating the hepatoprotective effects of a polysaccharide (DHP1A) isolated from D. huoshanense via water extraction, diethylaminoethyl (DEAE) cellulose anion exchange and size exclusion chromatography. The animal experiment indicated that the oral administration of DHP1A obviously reduced the levels of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and 8-hydroxy-2'-deoxyguanosine in the serum of mice treated with carbon tetrachloride (CCl4), suggesting the hepatoprotective potential of this polysaccharide. Moreover, DHP1A decreased the expressions of tumor necrosis factor-α, interleukin-1ß, monocyte chemoattractant protein-1, macrophage inflammatory protein-2, CD68 and phosphorylated IκBα (p-IκBα) in the CCl4-treated mice. These results revealed that the hepatoprotective effect of DHP1A was partly attributed to its anti-inflammatory action.

Tea Polysaccharide Ameliorates High-Fat Diet-Induced Renal Tubular Ectopic Lipid Deposition via Regulating the Dynamic Balance of Lipogenesis and Lipolysis.

Renal tubular ectopic lipid deposition (ELD) plays a significant role in the development of chronic kidney disease, posing a great threat to human health. The present work aimed to explore the intervention effect and potential molecular mechanism of a purified tea polysaccharide (TPS3A) on renal tubular ELD. The results demonstrated that TPS3A effectively improved kidney function and slowed the progression of tubulointerstitial fibrosis in high-fat-diet (HFD)-exposed ApoE-/- mice. Additionally, TPS3A notably suppressed lipogenesis and enhanced lipolysis, as shown by the downregulation of lipogenesis markers (SREBP-1 and FAS) and the upregulation of lipolysis markers (HSL and ATGL), thereby reducing renal tubular ELD in HFD-fed ApoE-/- mice and palmitic-acid-stimulated HK-2 cells. The AMPK-SIRT1-FoxO1 axis is a core signal pathway in regulating lipid deposition. Consistently, TPS3A significantly increased the levels of phosphorylated-AMPK, SIRT1, and deacetylation of Ac-FoxO1. However, these effects of TPS3A on lipogenesis and lipolysis were abolished by AMPK siRNA, SIRT1 siRNA, and FoxO1 inhibitor, resulting in exacerbated lipid deposition. Taken together, TPS3A shows promise in ameliorating renal tubular ELD by inhibiting lipogenesis and promoting lipolysis through the AMPK-SIRT1-FoxO1 signaling pathway.

Ganoderic acid A mitigates dopaminergic neuron ferroptosis via inhibiting NCOA4-mediated ferritinophagy in Parkinson's disease mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Ganoderma lucidum, a renowned tonic traditional Chinese medicine, is widely recognized for the exceptional activity in soothing nerves and nourishing the brain. It has been extensively employed to alleviate various neurological disorders, notably Parkinson's disease (PD). AIM OF THE STUDY: To appraise the antiparkinsonian effect of GAA, the main bioactive constituent of G. lucidum, and clarify the molecular mechanism through the perspective of ferritinophagy-mediated dopaminergic neuron ferroptosis. MATERIALS AND METHODS: PD mouse and cell models were established using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenylpyridinium (MPP+), respectively. Cell viability, behavioral tests and immunofluorescence analysis were performed to evaluate the neurotoxicity, motor dysfunction and dopaminergic loss, respectively. Biochemical assay kits were used to determine the levels of iron, lipid reactive oxygen species (ROS), malondialdehyde (MDA), total ROS and glutathione (GSH). Western blot and immunofluorescence were applied to detect the expressions of nuclear receptor co-activator 4 (NCOA4), ferritin heavy chain 1 (FTH1), p62 and LC3B. Additionally, NCOA4-overexpressing plasmid vector was constructed to verify the inhibitory effect of GAA on the neurotoxicity and ferroptosis-related parameters in PD models. RESULTS: GAA significantly mitigated MPP+/MPTP-induced neurotoxicity, motor dysfunction and dopaminergic neuron loss (p＜0.01 or p＜0.05). In contrast to MPP+/MPTP treatment, GAA treatment decreased the levels of iron, MDA, lipid and total ROS, while increasing the GSH level. GAA also reduced the levels of NCOA4 and LC3B, and enhanced the expressions of FTH1 and p62 in PD models (p＜0.01 or p＜0.05). However, the protective effect of GAA against the neurotoxicity, NCOA4-mediated ferritinophagy and ferroptosis in PD model was abolished by the overexpression of NCOA4 (p＜0.01). CONCLUSION: GAA exerted a protective effect on PD, and this effect was achieved by suppressing dopaminergic neuron ferroptosis through the inhibition of NCOA4-mediated ferritinophagy.

Codonopsis lanceolata polysaccharide ameliorates high-fat diet induced-postpartum hypogalactia via stimulating prolactin receptor-mediated Jak2/Stat5 signaling.

This study aims to investigate the ameliorative effect of Codonopsis lanceolata polysaccharide (PCL) on mice with hypogalatia induced by a high-fat diet (HFD) and the potential underlying mechanism. We found that oral administration of PCL demonstrated significant benefits in countering the negative effects of HFD, including weight gain, hepatic steatosis, mesenteric adipocyte hypertrophy, and abnormal glucose/lipid metabolism. In addition, PCL improved mammary gland development and enhanced lactogenesis performance. Histologically, PCL ameliorated the retardation of ductal growth, reduced mammary fat pad thickness, improved the incomplete linear encapsulation of luminal epithelium and myoepithelium, and increased the proliferation of mammary epithelial cells. Flow cytometry analysis showed that PCL mitigated the detrimental effects of HFD on mammary gland development by promoting the proliferation and differentiation of mammary epithelial cells. Mechanistic studies revealed that PCL upregulated the levels of prolactin (PRL) and its receptor (PRLR) in the mammary gland, activated JAK2/STAT5 signaling pathway, and increased the expression of p63, ERBB4, and NRG1. Overall, PCL can ameliorate HFD-induced hypogalactia by activating PRLR-mediated JAK2/STAT5 signaling. Our findings offer a methodological and theoretical foundation for investigating the functional constituents of traditional Chinese medicine in the treatment of hypogalactia.

Rapid Discovery of Aß42 Fibril Disintegrators from Ganoderma lucidum via Ligand Fishing and Their Neuroprotective Effects on Alzheimer's Disease.

An amyloid-ß (Aß) fibril is a vital pathogenic factor of Alzheimer's disease (AD). Aß fibril disintegrators possess great potential to be developed into novel anti-AD agents. Here, a ligand fishing method was employed to rapidly discover Aß42 fibril disintegrators from Ganoderma lucidum using Aß42 fibril-immobilized magnetic beads, which led to the isolation of six Aß42 fibril disintegrators including ganodermanontriol, ganoderic acid DM, ganoderiol F, ganoderol B, ganodermenonol, and ergosterol. Neuroprotective evaluation in vitro exhibited that these Aß42 fibril disintegrators could significantly mitigate Aß42-induced neurotoxicity. Among these six disintegrators, ergosterol and ganoderic acid DM with stronger protecting activity were further selected to evaluate their neuroprotective effect on AD in vivo. Results showed that ergosterol and ganoderic acid DM could significantly alleviate Aß42-induced cognitive dysfunction and hippocampus neuron loss in vivo. Moreover, ergosterol and ganoderic acid DM could significantly inhibit Aß42-induced neuron apoptosis and Nrf2-mediated neuron oxidative stress in vitro and in vivo.

Purification, structural characteristics and anti-atherosclerosis activity of a novel green tea polysaccharide.

A new homogeneous polysaccharide (TPS3A) was isolated and purified from Tianzhu Xianyue fried green tea by DEAE-52 cellulose and Sephacryl S-500 column chromatography. Structural characterization indicated that TPS3A mainly consisted of arabinose, galactose, galacturonic acid and rhamnose in a molar ratio of 5.84: 4.15: 2.06: 1, with an average molecular weight of 1.596 × 104 kDa. The structure of TPS3A was characterized as a repeating unit consisting of 1,3-Galp, 1,4-Galp, 1,3,6-Galp, 1,3-Araf, 1,5-Araf, 1,2,4-Rhap and 1-GalpA, with two branches on the C6 of 1,3,6-Galp and C2 of 1,2,4-Rhap, respectively. To investigate the preventive effects of TPS3A on atherosclerosis, TPS3A was administered orally to ApoE-deficient (ApoE-/-) mice. Results revealed that TPS3A intervention could effectively delay the atherosclerotic plaque progression, modulate dyslipidemia, and reduce the transformation of vascular smooth muscle cells (VSMCs) from contractile phenotype to synthetic phenotype by activating the expression of contractile marker alpha-smooth muscle actin (α-SMA) and inhibiting the expression of synthetic marker osteopontin (OPN) in high-fat diet-induced ApoE-/- mice. Our findings suggested that TPS3A markedly alleviated atherosclerosis by regulating dyslipidemia and phenotypic transition of VSMCs, and might be used as a novel functional ingredient to promote cardiovascular health.

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.

Laminaria japonica polysaccharide attenuates podocyte epithelial-mesenchymal transformation via TGF-ß1-mediated Smad3 and p38MAPK pathways.

In the present work, we explored the interventional effect and potential mechanism of a purified Laminaria japonica polysaccharide (LJP61A) on podocyte epithelial-mesenchymal transition (EMT) in TGF-ß1-induced podocytes and adriamycin-treated mice. Results showed that compared to the model groups, LJP61A significantly up-regulated the levels of epithelial markers (Nephrin, WT-1, podocin) and down-regulated the levels of mesenchymal markers (α-SMA, FN1) in vitro and in vivo, thus preventing EMT-like morphological changes of podocytes, proteinuria and kidney injury. Smad3 and p38MAPK are two central pathways mediating podocyte EMT activated by TGF-ß1. We found that LJP61A suppressed TGF-ß1-induced activation of Smad3, Smad4 and p38MAPK in vitro and in vivo. Moreover, the inhibitory actions of LJP61A on podocyte EMT were synergistically strengthened by Smad3 inhibitor SIS3 and p38MAPK inhibitor SB203580. Taken together, these findings revealed that LJP61A could prevent podocyte EMT, which might be related to the inhibition of TGF-ß1-mediated Smad3 and p38MAPK pathways.

Inhibition of Ca2+-calpain signaling is a new mechanism using Laminaria japonica polysaccharide to prevent macrophage foam cell formation and atherosclerosis.

The Ca2+-calpain signaling plays a pivotal role in regulating the upstream signaling pathway of cellular autophagy. The aim of the current work was to investigate the role of Ca2+-calpain signaling in the regulation of macrophage autophagy by a Laminaria japonica polysaccharide (LJP61A) in Ox-LDL induced macrophages and high fat diet fed atherosclerotic mice. Results revealed that the LJP61A markedly decreased the levels of intracellular Ca2+, calpain1, calpain2 and their downstream effectors (Gsα, cAMP and IP3), and simultaneously enhanced autophagy activity and lipid metabolism, thereby reducing lipid accumulation in the Ox-LDL stimulated macrophages and lipid-laden plaques in atherosclerotic mice. Moreover, BAPTA-AM (a Ca2+ chelator) and calpeptin (a calpain inhibitor) synergistically strengthened the beneficial effects of LJP61A on autophagy and lipid metabolism by decreasing the levels of intracellular Ca2+, calpain1, calpain2, and their downstream effectors (Gsα, cAMP and IP3) induced by Ox-LDL. These findings suggested that the LJP61A suppressed macrophage derived foam cell formation and atherosclerosis by modulating the Ca2+-calpain-mediated autophagy.

Dendrobium huoshanense stem polysaccharide ameliorates alcohol-induced gastric ulcer in rats through Nrf2-mediated strengthening of gastric mucosal barrier.

This study aimed to explore whether Dendrobium huoshanense stem polysaccharide (cDHPS) ameliorates alcohol-induced gastric ulcer (GU) through the strengthening effect of the gastric mucosal barrier in rats and its potential mechanism. In normal rats, the pretreatment of cDHPS effectively strengthened gastric mucosal barrier by increasing mucus secretion and tight junction protein expression. In GU rats, cDHPS supplementation effectively alleviated alcohol-induced gastric mucosal injury and nuclear factor κB (NF-κB)-driven inflammation by strengthening gastric mucosal barrier. Moreover, cDHPS significantly activated nuclear factor E2-related factor 2 (Nrf2) signaling and promoted antioxidant enzymes activities in both normal and GU rats. These results suggested that the pretreatment of cDHPS could strengthen gastric mucosal barrier to inhibit oxidative stress and NF-κB-driven inflammation induced gastric mucosal injury, which was likely related to the activation of Nrf2 signaling.

Polygonatum cyrtonema Hua Polysaccharide Alleviates Fatigue by Modulating Osteocalcin-Mediated Crosstalk between Bones and Muscles.

Osteocalcin was reported to regulate muscle energy metabolism, thus fighting fatigue during exercise. The current work aimed to investigate the anti-fatigue effect and the underlying mechanism of a homogeneous polysaccharide (PCPY-1) from Polgonatum cyrtonema after structure characterization. In the exhaustive swimming mouse model and the co-culture system of BMSCs/C2C12 cells, PCPY-1 significantly stimulated BMSC differentiation into osteoblasts as determined by ALP activity, matrix mineralization, and the protein expressions of osteogenic markers BMP-2, phosphor-Smad1, RUNX2, and osteocalcin. Meanwhile, PCPY-1 remarkably enhanced myoblast energy metabolism by upregulating osteocalcin release and GPRC6A protein expression; the phosphorylation levels of CREB and HSL; the mRNA levels of GLUT4, CD36, FATP1, and CPT1B; and ATP production in vitro and in vivo. Accordingly, PCPY-1 exhibited good anti-fatigue capacity in mice as confirmed by fatigue-related indicators. Our findings indicated PCPY-1 could enhance osteocalcin-mediated communication between bones and muscles, which was conducive to muscle energy metabolism and ATP generation, thus alleviating fatigue in exhausted swimming mice.

[Comparison on physicochemical properties and immun activities of polysaccharides from cultures at different development stages of Dendrobium huoshanense].

OBJECTIVE: To compare the physicochemical properties and immun activities of polysaccharides extracted from cultures at different development stages of Dendrobium huoshanense. METHODS: Polysaccharides were extracted by hot water and alcohol precipitation, and isolated by anion exchange chromatography. The physicochemical properties of polysaccharides were analyzed by spectrophotometry, GC-MS, IR and fluorophore-assisted carbohydrate electrophoresis (FACE). ELISA was used to determine the immun activities of polysaccharides. RESULTS: The polysaccharides from cultures at different development stages of D. huoshanense had no obvious discrepancy in contents. 5 polysaccharides were isolated by anion exchange chromatography with the same elution conditions. GC-MS analysis showed that the polysaccharides from cultures at different development stages of D. huoshanense consisted of glucose, mannose and galactose. IR and FACE displayed that different polysaccharides had no significant change in chemical properties. In vitro experiments with spleen cells proved that the polysaccharides from cultures at different development stages had similar effects on stimulating IFN-gamma and TNF-alpha releases. CONCLUSION: No significant differences are found in the physico-chemical properties and immun activities of polysaccharides extracted from cultures at different development stages of D. huoshanense, suggesting that the polysaccharides of D. huoshanense have stability in quality to some extent during tissue culture.

Intervention and potential mechanism of non-starch polysaccharides from natural resources on ulcerative colitis: A review.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease of unknown etiology that affects the colon and rectum. It has evolved into a global burden due to the high incidence in developed countries and the highly-increased incidence in developing countries. Non-starch polysaccharides (NSPs) from natural resources, as a type of functional carbohydrates, have a significant therapeutic effect on UC because of their good anti-inflammatory and immunomodulatory activities. Based on the etiology and pathogenesis of UC, this review summarizes the intervention effects and mechanisms of NSPs in the prevention and treatment of UC. The results showed that NSPs can improve UC by protecting the intestinal mucosal barrier, regulating the immune response of the intestinal mucosa, and remodeling the intestinal flora and metabolites. These contents provide theoretical basis for the application of polysaccharides in the prevention and treatment of UC.

Dendrobium fimbriatum Hook polysaccharide ameliorates dextran-sodium-sulfate-induced colitis in mice via improving intestinal barrier function, modulating intestinal microbiota, and reducing oxidative stress and inflammatory responses.

The ameliorative effect of Dendrobium fimbriatum polysaccharide (cDFPW1) on ulcerative colitis (UC) was investigated using a dextran-sodium-sulfate-induced (DSS-induced) mouse model in the present study. The results showed that cDFPW1 effectively improved colitis in mice by ameliorating weight loss, disease activity index (DAI) and colonic pathological damage, and by protecting the intestinal barrier function integrity. Moreover, cDFPW1 modulated the composition and metabolism of intestinal microbiota through enhancing Romboutsia, Lactobacillus and Odoribacter, and reducing Parasutterella, Burkholderia-Caballeronia-Paraburkholderia and Acinetobacter in colitis mice. Notably, cDFPW1 significantly restored the homeostasis of Th17/regulatory T (Treg) cells and the expression of specific cytokines. Western blotting of colon tissues showed that cDFPW1 markedly up-regulated the expression of Nrf2 and inhibited the phosphorylation of NF-κB signaling. These results indicated that cDFPW1 possesses the potential of improving UC and its effect on palliating colitis may be connected with the regulation of Nrf2/NF-κB signaling.

Dendrobium officinale polysaccharide promotes M1 polarization of TAMs to inhibit tumor growth by targeting TLR2.

Promoting M1 polarization of tumor-associated macrophages (TAMs) is an effective pathway for malignant tumor therapy. In this study, we aimed to demonstrate whether homogeneous Dendrobium officinale polysaccharide (DOP) could promote M1 polarization of TAMs to inhibit tumor growth, and how it promoted. Results exhibited that DOP could inhibit the tumor growth and promote the M1 polarization of TAMs in tumor-bearing mice. Macrophage depletion and replenishment experiment clearly proved that the inhibitory effect of DOP on tumor growth is dependent on promoting M1 polarization of TAMs. Moreover, we found that DOP could reach tumor microenvironment (TME) and directly bind to TAMs to promote its M1 polarization via targeting toll-like receptor 2 (TLR2) after oral administration. These results clarified that DOP could remarkably inhibit the tumor growth of tumor-bearing mice via directly targeting the TLR2 of TAMs to promote its M1 polarization.

Bioactive polysaccharides and their potential health benefits in reducing the risks of atherosclerosis: A review.

Atherosclerosis is a kind of lipid-driven chronic inflammatory disease of arteries and is the principal pathological basis of life-threatening cardiovascular disease events, such as strokes and heart attacks. Clinically, statins are the most commonly prescribed drugs for the treatment of atherosclerosis, but prolonged use of these drugs exhibit many adverse reactions and have limited efficacy. Polysaccharides are important natural biomacromolecules widely existing in plants, animals, microorganisms and algae. They have drawn considerable attention worldwide due to their multiple healthy functions, along with their non-toxic property. Importantly, a growing number of studies have demonstrated that bioactive polysaccharides exhibit prominent efficiency in controlling atherosclerotic risk factors like hyperlipemia, hypertension, oxidative stress, and inflammation. In recent decades, various bioactive polysaccharides with different structural features and anti-atherosclerotic potential from natural sources have been isolated, purified, and characterized. The aim of this review is to focus on the research progress of natural polysaccharides in reducing the risks of atherosclerosis based on evidence of in vitro and in vivo studies from 1966 to 2022. PRACTICAL APPLICATIONS: In the future, it is still necessary to strengthen the research on the development and mechanism of polysaccharides with anti-atherosclerotic potential. These anti-atherosclerotic polysaccharides with different structural characteristics and physiochemical properties from different sources will constitute a huge source of materials for future applications, especially in functional foods and drugs. The information summarized here may serve as useful reference materials for further investigation, production, and application of these polysaccharides in functional foods and therapeutic agents.