Extraction, purification, and determination of the gastroprotective activity of glucomannan from Bletilla striata

Immune Basis of Therapeutic Effects of Solanum tuberosum L. Polysaccharide on Chronic Peptic Ulcer Healing

Background/Objectives: Polysaccharides are complex molecules with a wide range of biological activities that can be used in various biomedical applications. In this work, the antiulcer effect and influence on the level of pro- and anti-inflammatory cytokines of Solanum tuberosum L. polysaccharide (STP) were studied. Methods: The antiulcer effect of STP was studied in the Okabe chronic peptic ulcer model by evaluating the influence of STP on the ulcer index in Wistar rats, comparing it to omeprazole and ranitidine. Dose-effect analysis was also carried out. The level of pro- and anti-inflammatory cytokines was studied using ELISA kits. Results: After treatment in the polysaccharide groups, ulcer healing is observed in 60-80% of cases, in the omeprazole group in 50%, and in the ranitidine group in 25%. STP intravenous injections lead to the formation of a more differentiated mucous membrane; no coarse scar tissue is formed, which is typical for control and comparison drugs. Glycan causes a significant acceleration of the healing of experimental peptic ulcers in rats. STP appears to modulate pro- and anti-inflammatory cytokines. On the fourth and tenth days, a significant decrease in the levels of pro-inflammatory cytokines IL-1b and IFN-γ was noted in the polysaccharide group compared to the control group, while the level of anti-inflammatory cytokine IL-4 significantly increased. Conclusions: Intravenous administration of STP leads to the restoration of functionality and effective tissue regeneration. The antiulcer activity of STP is based on the regulation of the pro- and anti-inflammatory balance.

Bletilla oligosaccharides improved 5-fluorouracil-induced intestinal mucositis in mice by activating NF-κB signalling pathway and regulating intestinal microbiota

Introduction

The Bletilla oligosaccharides (BO) are active compounds extracted from Bletilla striata and have the strong protective effect on the gastrointestinal tract. Chemotherapeutic intestinal mucositis (CIM) is one of the toxic side effects of chemotherapeutic agents on the gastrointestinal tract. The aim of this study was to identify the structure of BO and evaluate the therapeutic effect of BO on 5-fluorouracil-induced intestinal mucosal inflammation.

Methods

BO were purified from DEAE52 cellulose. The structure of BO were characterised by HPGPC, GC-MS and NMR. In vivo, the mouse model of intestinal mucositis was established by intraperitoneal injection of 5-FU. The effect of BO on intestinal mucositis in mice was detected by assessing the levels of intestinal flora, ZO-1, occludin, and MUC-2, and inflammatory cytokines (IL-1β, IL-6, IL-10, and TNF-α).

Results

Structural characterisation showed that BO were the neutral polysaccharide composed mainly of glucose and mannose. The backbone of BO consisted of→4)-β-Manp-(1→, →4)-β-Glcp-(1→ and small →3,4)-α-Manp-(1→. The results of the in vivo experiment showed that the symptoms of diarrhoea, haematochezia and colonic mucosal lesions improved after administration of BO. Further experiments showed that BO not only reduced the levels of pro-inflammatory factors such as IL-1β, IL-6 and TNF-α, but also improved the expression of intestinal barrier protein and intestinal microbial community after BO treatment.

Conclusion

BO can relieve the progress of intestinal mucositis by relieving inflammation, protecting the intestinal epithelial barrier and regulating the intestinal microbiota. These data provide experimental evidence for the application of BO in chemotherapeutic intestinal mucositis.

Bletilla striata polysaccharides alleviate metabolic dysfunction-associated steatotic liver disease through enhancing hepatocyte RelA/ HNF1α signaling

BACKGROUND

Bletilla striata polysaccharides (BSP) have antioxidant, immune regulation, and anti-fibrotic activities. However, the therapeutic effect and mechanisms underlying the action of BSP in metabolic dysfunction-associated steatotic liver disease (MASLD) have not been fully understood.

AIM

To investigate the therapeutic effects and mechanisms of BSP on MASLD by centering on the hepatocyte nuclear factor kappa B p65 (RelA)/hepatocyte nuclear factor-1 alpha (HNF1α) signaling.

METHODS

A mouse model of MASLD was induced by feeding with a high-fat-diet (HFD) and a hepatocyte model of steatosis was induced by treatment with sodium oleate (SO) and sodium palmitate (SP). The therapeutic effects of BSP on MASLD were examined in vivo and in vitro. The mechanisms underlying the action of BSP were analyzed for their effect on lipid metabolism disorder, endoplasmic reticulum (ER) stress, and the RelA/HNF1α signaling.

RESULTS

HFD feeding reduced hepatocyte RelA and HNF1α expression, induced ER stress, lipid metabolism disorder, and necroptosis in mice, which were significantly mitigated by treatment with BSP. Furthermore, treatment with BSP or BSP-containing conditional rat serum significantly attenuated the sodium oleate/sodium palmitate (SO/SP)-induced hepatocyte steatosis by decreasing lipid accumulation, and lipid peroxidation, and enhancing the expression of RelA, and HNF1α. The therapeutic effects of BSP on MASLD were partially abrogated by RELA silencing in mice and RELA knockout in hepatocytes. RELA silencing or knockout significantly down-regulated HNF1α expression, and remodeled ER stress and oxidative stress responses during hepatic steatosis.

CONCLUSION

Treatment with BSP ameliorates MASLD, associated with enhancing the RelA/HNF1α signaling, remodeling ER stress and oxidative stress responses in hepatocytes.

The synergistic gelation of novel Bletilla striata polysaccharide with hyaluronic acid: Characterization, rheology

Bletilla striata polysaccharide (BSP) has attracted considerable interest due to its diverse biological activities. In this research, a novel low-molecular-weight water-soluble polysaccharide (BSP-182) was isolated and purified from Bletilla striata tubers, and its structure was characterized. The findings indicated that BSP-182 is predominantly composed of β-1,4-linked glucose (Glc) and β-1,4-linked mannose (Man) in a molar ratio of approximately 7.8:2.2. Additionally, hyaluronic acid (HA)/BSP-182 hydrogels were synthesized, and their physicochemical properties and structure were examined. Rheological analysis revealed that HA and BSP-182 form hydrogels via hydrogen bonding, with concentration-dependent enhancements in rheological properties, textural attributes, and thermal stability. The hydrogels displayed significant shear-thinning behavior and viscoelasticity, which are beneficial for food processing and texture modification, especially in the development of easy-to-swallow foods. This research offers valuable insights for the development of innovative BSP-based hydrogels for dysphagia management.

The rhizosphere microbiome and its influence on the accumulation of metabolites in Bletilla striata (Thunb.) Reichb. f

BACKGROUND

Bletilla striata (Thunb.) Reichb. f. (B. striata) is a perennial herbaceous plant in the Orchidaceae family known for its diverse pharmacological activities, such as promoting wound healing, hemostasis, anti-inflammatory effects, antioxidant properties, and immune regulation. Nevertheless, the microbe-plant-metabolite regulation patterns for B. striata remain largely undetermined, especially in the field of rhizosphere microbes. To elucidate the interrelationships between soil physics and chemistry and rhizosphere microbes and metabolites, a comprehensive approach combining metagenome analysis and targeted metabolomics was employed to investigate the rhizosphere soil and tubers from four provinces and eight production areas in China.

RESULTS

Our study reveals that the core rhizosphere microbiome of B. striata is predominantly comprised of Paraburkholderia, Methylibium, Bradyrhizobium, Chitinophaga, and Mycobacterium. These microbial species are recognized as potentially beneficial for plants health. Comprehensive analysis revealed a significant association between the accumulation of metabolites, such as militarine and polysaccharides in B. striata and the composition of rhizosphere microbes at the genus level. Furthermore, we found that the soil environment indirectly influenced the metabolite profile of B. striata by affecting the composition of rhizosphere microbes. Notably, our research identifies soil organic carbon as a primary driving factor influencing metabolite accumulation in B. striata.

CONCLUSION

Our fndings contribute to an enhanced understanding of the comprehensive regulatory mechanism involving microbe-plant-metabolite interactions. This research provides a theoretical basis for the cultivation of high-quality traditional Chinese medicine B. striata.

Cow placenta extract ameliorates d-galactose-induced liver damage by regulating BAX/CASP3 and p53/p21/p16 pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Placenta is a kind of traditional Chinese medicine, known as "Ziheche", which has the function of tonifying qi and blood, nourishing liver and kidney. Placenta extract (PE) has been used for delaying organismal aging and treating various liver diseases. Cow placenta is a rich natural resource with large mass. Its composition is similar to that of human placenta, but it has not been effectively utilized. However, little is known about the effect of CPE on the liver of aging mice.

AIM OF THE STUDY

The aim of this study is to explore the protective effect and mechanism of CPE on the liver of d-galactose (D-gal) induced aging mice.

MATERIALS AND METHODS

Statistical methods were used to calculate mouse body weight and liver index. Hematoxylin-eosin (H&E) and transmission electron microscopy (TEM) were used to detect the morphological structure of the liver. Automatic biochemical analyzer was used to measure serum biochemical indicators. Three special staining methods were used to observe hepatocytes apoptosis, senescence and proliferation respectively. Relative kits were used to detect oxidative, inflammatory, and aging markers in the liver. Finally, real-time quantitative polymerase chain reaction and western-blot were used to detect aging related signaling pathways.

RESULTS

CPE significantly improved the morphological damage and dysfunction of liver, restored the activities of liver enzymes in serum, and alleviated liver oxidative stress and inflammatory response in D-gal induced aging mice. Furthermore, CPE inhibited hepatocyte apoptosis and senescence, and promoted hepatocyte proliferation by regulating BAX/CASP3 and p53/p21/p16 signaling pathways, ultimately reduced the effects of aging on the liver.

CONCLUSION

CPE effectively ameliorated the impact of aging on the liver by inhibiting free radical production or scavenging excessive free radicals, and its mechanism is associated to the regulation of apoptosis and proliferation-related factors.

Structural characterization, antioxidant and antibacterial activity of three pectin polysaccharides from blueberry

In this study, three pectin polysaccharides BP1, BP2 and BP3, were purified from blueberries. The weight-average molecular weight (Mw) of BP1, BP2, and BP3 were detected to be 9.027 × 104, 9.313 × 104, and 1.223 × 106 Da, respectively. The structures of the three pectin polysaccharides were characterized and compared based on the results of molecular weight, monosaccharide composition, GC-MS and NMR analysis. Structural characterization revealed that BP1, BP2, and BP3 all contain homogalacturonan (HG) and rhamnogalacturonan I (RG-I) domains, and the rhamnose residues in RG-I domains are substituted at C-4 with side chains such as araban and galactosan. BP2 had the highest degree of esterification and HG domain ratio, followed by BP3 and BP1. In addition, BP1, BP2 and BP3 showed great antioxidant and antibacterial activities, and could destroy the cell membrane of Staphylococcus aureus and Escherichia coli. Moreover, the better DPPH and ABTS free radical scavenging and antibacterial activities of BP1 and BP2 than BP3 might be related to their lower molecular weight. The results of this study will provide essential information for the structure-activity relationship of pectin polysaccharides and research basis for development and application of blueberry pectin polysaccharides.

Gastric acid-responsive deformable sodium alginate/Bletilla striata polysaccharide in situ gel for the protection and treatment of alcohol-induced peptic ulcers

First-line drugs for peptic ulcer (PU) treatment are typically limited by poor targeting and adverse effects associated with long-term use. Despite recent advancements in novel therapeutic approaches for PU, the development of sustained-release delivery systems tailored to specific pathological characteristics remains challenging. Persistent inflammation, particularly gastric inflammatory microenvironment imbalance, characterizes the PU. In this study, we prepared an in situ gel composed of sodium alginate, deacetylated gellan gum, calcium citrate, and Bletilla striata polysaccharide (BSP) to achieve sustained release of BSP. The BSP in situ gel demonstrated favorable fluidity in vitro and completed self-assembly in vivo in response to the acidic milieu at a pH of 1.5. Furthermore, the shear, extrusion, and deformation properties increased by 26.4 %, 103.7 %, and 46.3 %, respectively, with long-term gastric retention (4 h) and mucosal adaptation. Animal experiments confirmed that the BSP in situ gel could attenuate necrotic injury and inflammatory cell infiltration, maintain mucosal barrier integrity, regulate cytokine imbalance and inflammation-associated hyperapoptosis, thus effectively alleviate the inflammatory microenvironmental imbalance in PU without significant side effects. Overall, our findings demonstrated that the BSP in situ gel is a promising therapeutic strategy for PU and opens avenues for developing self-assembled formulations targeting the pathological features of PUs.

Dual properties of pharmacological activities and preparation excipient: Bletilla striata polysaccharides

Bletilla striata has been used for thousands of years and shows the functions of stopping bleeding, reducing swelling, and promoting healing in traditional applications. For Bletilla striata, Bletilla striata polysaccharides (BSP) is the main active ingredient, exhibiting biological functions of anti-inflammatory, anti-oxidant, anti-fibrotic, immune modulation, anti-glycation, and so on. In addition, BSP has exhibited the characteristics of excipient such as bio-adhesion, bio-degradability, and bio-safety and has been prepared into a series of preparations such as nanoparticles, microspheres, microneedles, hydrogels, etc. BSP, as both a drug and an excipient, has already aroused more and more attention. In this review, publications in recent years related to the extraction and identification, biological activities, and excipient application of BSP are reviewed. Specifically, we focused on the advances in the application of BSP as a formulation excipient. We hold opinion that BSP not only needed more researches in the mechanisms, but also the development into hydrogels, nano-formulations, tissue engineering, and so on. And we believe that this paper provides a beneficial reference for further BSP innovation and in-depth research and promotes the use of these natural products in pharmaceutical applications.

Preclinical pharmacokinetics-related pharmacological effects of orally administered polysaccharides from traditional Chinese medicines: A review

Polysaccharides (TCMPs) derived from traditional Chinese medicines (TCMs), such as Ganoderma lucidum, Astragalus membranaceus, Lycium barbarum, and Panax ginseng, are considered to be the main active constituents in TCMs. However, the significant pharmacological effects of orally administered TCMPs do not align well with their poor pharmacokinetics. This article aims to review the literature published mainly from 2010 to 2022, focusing on the relationship between pharmacokinetics and pharmacological effects. It has been found that unabsorbed TCMPs can exert local pharmacological effects in the gut, including anti-inflammation, anti-oxidation, regulation of intestinal flora, modulation of intestinal immunity, and maintenance of intestinal barrier integrity. Unabsorbed TCMPs can also produce systemic pharmacological effects, such as anti-tumor activity and immune system modulation, by regulating intestinal flora and immunity. Conversely, some TCMPs can be absorbed and distributed to various tissues, especially the liver, where they exhibit tissue-protecting effects against inflammation and oxidative stress-induced damage and improve glucose and lipid metabolism. In future studies, it is important to improve quality control and experimental design. Furthermore, research on enhancing the oral bioavailability of TCMPs, exploring the activity of TCMP metabolites, investigating pharmacokinetic interactions between TCMPs and oral drugs, and developing oral drug delivery systems using TCMPs holds great significance.

A Gellan Gum/Sodium Alginate-based gastric-protective hydrogel loaded with a combined herbal extract consisting of Panax notoginseng, Bletilla striata and Dendrobium officinale

One Chinese herbal combination consisting of Panax notoginseng, Bletilla striata and Dendrobium officinale (PBD) is an effective Traditional Chinese Medicine (TCM) prescription and is widely used in clinics to treat gastric ulcers due to their safety and effectiveness compared with chemical agents, such as aspirin and omeprazole. Herein, an in situ forming gel (ISFG) based on Gellan Gum (GG) and Sodium Alginate (SA) was designed to deliver extracts of PBD prescription (EPBDP). The central composite design optimized prescription dosage was 0.1 % w/v of GG and 0.5 % w/v of SA. Gels prepared with this formulation demonstrated outstanding fluidity and instantaneous gel formation. In vitro release data showed that sustained drug release occurred in the gel, and the gel was pH-sensitive. The rheological tests confirmed the formation of stable gel, which exhibited strong viscosity and elasticity. In vitro adhesion assays revealed that the gel had strong gastric mucosal adhesion, while in vivo residual rate experiments of active ingredients revealed that the gel might greatly improve the gastric retention of active ingredients. Animal studies demonstrated that the gel was effective in treating gastric ulcers. Hence, the results of the study show that EPBDP-ISFG, a highly pH-sensitive sustained-release system, is effective.

Extraction, structural-activity relationships, bioactivities, and application prospects of Bletilla striata polysaccharides as ingredients for functional products: A review

Bletilla striata is a well-known medicinal plant with high pharmaceutical and ornamental values. Polysaccharide is the most important bioactive ingredient in B. striata and has various health benefits. Recently, B. striata polysaccharides (BSPs) have attracted much attention from industries and researchers due to their remarkable immunomodulatory, antioxidant, anti-cancer, hemostatic, anti-inflammatory, anti-microbial, gastroprotective, and liver protective effects. Despite the successful isolation and characterization of B. striata polysaccharides (BSPs), there is still limited knowledge regarding their structure-activity relationships (SARs), safety concerns, and applications, which hinders their full utilization and development. Herein, we provided an overview of the extraction, purification, and structural features, as well as the effects of different influencing factors on the components and structures of BSPs. We also highlighted and summarized the diversity of chemistry and structure, specificity of biological activity, and SARs of BSP. The challenges and opportunities of BSPs in the food, pharmaceutical, and cosmeceutical fields are discussed, and the potential development and future study direction are scrutinized. This article provides comprehensive knowledge and underpinnings for further research and application of BSPs as therapeutic agents and multifunctional biomaterials.

Polysaccharides-Naturally Occurring Immune Modulators

The prevention of disease and infection requires immune systems that operate effectively. This is accomplished by the elimination of infections and abnormal cells. Immune or biological therapy treats disease by either stimulating or inhibiting the immune system, dependent upon the circumstances. In plants, animals, and microbes, polysaccharides are abundant biomacromolecules. Due to the intricacy of their structure, polysaccharides may interact with and impact the immune response; hence, they play a crucial role in the treatment of several human illnesses. There is an urgent need for the identification of natural biomolecules that may prevent infection and treat chronic disease. This article addresses some of the naturally occurring polysaccharides of known therapeutic potential that have already been identified. This article also discusses extraction methods and immunological modulatory capabilities.

Untargeted serum and liver metabolomics analyses reveal the gastroprotective effect of polysaccharide from Evodiae fructus on ethanol-induced gastric ulcer in mice

This study aimed at investigating the gastroprotective effect of Evodiae fructus polysaccharide (EFP) against ethanol-induced gastric ulcer in mice. Biochemical indexes along with untargeted serum and liver metabolomics were determined. Results showed that pre-treatment of EFP alleviated ethanol-induced gastric ulcer in mice. EFP lessened oxidative stress and inflammation levels of stomachs, showing as increments of SOD and GSH-Px activities, GSH content and IL-10 level, and reductions of MDA and IL-6 levels. Meanwhile, EFP activated the Keap1/Nrf2/HO-1 signaling pathway through increasing Nrf2 and HO-1 protein expressions, and decreasing Keap1 protein expression. Serum and liver metabolomics analyses indicated that 10 metabolic potential biomarkers were identified among normal control, ulcer control and 200 mg/kg·bw of EFP groups, which were related to 5 enriched metabolic pathways including vitamin B6 metabolism, nicotinate and nicotinamide metabolism, pentose phosphate pathway, bile secretion and ascorbate and aldarate metabolism. Further pearson's correlation analysis indicated that there were some positive and negative correlations between the biomarkers and the biochemical indexes. It could be concluded that the gastroprotection of EFP might be related to anti-oxidative stress, anti-inflammation, activation of Keap1/Nrf2/HO-1 signaling pathway and alteration of metabolic pathways. This study supports the potential application of EFP in preventing ethanol-induced gastric ulcer.

Polysaccharides from Bletilla striata protect against mercury-induced gastrointestinal toxicology in adult Drosophila melanogaster via modulation of sestrin

Oxidative stress was one of the major causes of heavy metal-induced toxicity in organisms. The polysaccharide from Bletilla striata (Orchidaceae) (BSP) has been recently recognized as a novel player in the management of oxidative stress response in organisms. Here, we took the midgut of adult Drosophila melanogaster (Diptera: Drosophilidae) (D. melanogaster), a functional equivalent to the mammalian intestine and stomach, as a model to evaluate the protective effects of BSP (50 μg/mL) on mercuric chloride-induced gastrointestinal toxicology in insects. As a result, BSP exposure significantly improved the survival rates and climbing ability of adult flies exposed to mercury. Further study demonstrated that BSP significantly alleviated the mercury-induced oxidative injury to midgut epithelium, at least partly, through increasing antioxidant enzyme activity (glutathione-S-transferase and superoxide dismutase), decreasing reactive oxidative species production, inhibiting cell death, restoring intestinal epithelial barrier and regulating intestinal stem cell-mediated tissue regeneration. Additionally, sestrin, an oxidative-stress gene, was required in mediating the protection of BSP against mercury-induced oxidative damage to midgut. This study suggested that BSP has great potential for future application in the treatment and prevention of heavy metal-induced gastrointestinal adversities in mammals.

Structural characteristics of a novel Bletilla striata polysaccharide and its activities for the alleviation of liver fibrosis

Liver fibrosis has proven to be the main predisposing factor for liver cirrhosis and liver cancer; however, an effective treatment remains elusive. Polysaccharides, with low toxicity and a wide range of bioactivities, are strong potential candidates for anti-hepatic fibrosis applications. For this study, a new low molecular weight neutral polysaccharide (B. striata glucomannan (BSP)) was extracted and purified from Bletilla striata. The structure of BSP was characterized and its activities for alleviating liver fibrosis in vivo were further evaluated. The results revealed that the structural unit of BSP was likely →4)-β-D-Glcp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-2ace-Manp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Glcp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-Manp-(1 → 4)-β-D-3ace-Manp-(1→, with a molecular weight of only 58.5 kDa. Additionally, BSP was observed to attenuate the passive impacts of liver fibrosis in a manner closely related to TLR2/TLR4-MyD88-NF-κB signaling pathway conduction. In summary, the results of this study provide theoretical foundations for the potential applications of BSP as an anti-liver fibrosis platform.

Gastroprotective polysaccharide from natural sources: Review on structure, mechanism, and structure–activity relationship

Polysaccharides from natural sources have the potentials in being used as substitutes of chemosynthetic drugs for gastroprotection because of its safety and efficacy. For giving a better understanding of gastroprotective polysaccharides, the research progress on preparation, structure, bioactivity, and their action mechanism is comprehensively summarized in this review. Moreover, the structure–activity relationship of gastroprotective polysaccharides is discussed. Accumulating evidence has indicated that natural polysaccharides, which were widely prepared by water extraction and column chromatography purifications, exhibited gastroprotective effects in vitro and in vivo. The action mechanism might be related to gastric secretions, promotion of gastric defensive factor releases, antioxidation, anti‐inflammatory, antiapoptosis, and facilitation of proliferation. Phenolic compounds, molecular weight and conformation, monosaccharide composition, backbone structure and side chain, and functional group have great influences on the gastroprotective activities of polysaccharides. This review gives comprehensive guidance to the exploitation and application of natural polysaccharides in food and other industries for gastroprotection.

Structural Characterization of an Alcohol-Soluble Polysaccharide from Bletilla striata and Antitumor Activities in Vivo and in Vitro

In general, Bletilla striata polysaccharides were mostly water-soluble. However, the structural property, immunomodulatory effects and antitumor activities of alcohol-soluble Bletilla striata polysaccharide were rarely reported. In this study, an alcohol-soluble Bletilla striata polysaccharide was firstly extracted, investigated the structural property and evaluated the antitumor activity in vivo and in vitro. Results showed that BSAP was a low molecular weight polysaccharide (2.29×10⁴  Da) and consisted of glucose, xylose and mannose (molar ratio: 2.39 : 1.00 : 0.21). Animal experiments results suggested that BSAP could effectively inhibit the expansion of H22 solid tumors, protect thymus and spleen, improve macrophages, lymphocytes and NK cells activities and enhance lymphocyte subsets proportion, presenting a better immunological enhancement effect in vivo. Additionally, the results of cell experiments showed that BSAP had obvious antitumor effect in vitro, including inhibiting the proliferation of H22 cells and inducing the apoptosis of tumor cells. These results would provide theoretical basis and new ideas for the further development and utilization of BSAP in the biomedical field.

Immunoenhancement activity of Bletilla striata polysaccharide through MAPK and NF-κB signalling pathways in vivo and in vitro

Bletilla striata (Thunb.) Reichb.f., is a traditional Chinese medicine, and the Bletilla striata polysaccharide (BSP) is one of the principal components extracted from Bletilla striata with various biological activities. Previous studies have shown that many natural polysaccharides have significant immunomodulatory activities. However, as a plant polysaccharide, the research of BSP on immunomodulatory activities is limited. In this study, we aim to investigate the immunomodulatory effect of BSP in vivo and further explore its underlying mechanism in vitro. In vivo, a cyclophosphamide (CTX)-induced immunosuppression mice mode was established by intraperitoneal injection of CTX, and the immune-enhancing effect of BSP (25, 50 and 100 mg/kg) on immunosuppressed mice were evaluated. The result indicated that BSP could significantly improve the immune organ index and the content of immunoglobulin, TNF-α and IL-4 in serum. It was also found that BSP could clearly ameliorate the spleen damage induced by CTX. Meanwhile, the result showed that BSP could not only improve the proliferation of splenocytes, but also activate the lactate dehydrogenase (LDH) and acid phosphatase (ACP) in mouse spleen tissue. In vitro, potential mechanism was further revealed in macrophages. The result supported that BSP could activate macrophages with high phagocytic ability, and induce macrophages to secrete cytokines. Finally, it revealed that activation of NF-κB and MAPK signalling pathway should be the underlying mechanism of the immunoenhancment of BSP.

Bioactive Bibenzyl Enantiomers From the Tubers of Bletilla striata

Six new bibenzyls (three pairs of enantiomers), bletstrins D-F (1-3), were isolated from the ethyl acetate-soluble (EtOAc) extract of tubers of Bletilla striata (Thunb.) Rchb f. Their structures, including absolute configurations, were determined by 1D/2D NMR spectroscopy, optical rotation value, and experimental electronic circular dichroism (ECD) data analyses, respectively. Compounds 1-3 possess a hydroxyl-substituted chiral center on the aliphatic bibenzyl bridge, which represented the first examples of natural bibenzyl enantiomers from the genus of Bletilla. The antibacterial, antitumor necrosis factor (anti-TNF-α), and neuroprotective effects of the isolates have been evaluated. Compounds 3a and 3b were effective against three Gram-positive bacteria with minimum inhibitory concentrations (MICs) of 52-105 μg/ml. Compounds 2a and 2b exhibited significant inhibitory effects on TNF-α-mediated cytotoxicity in L929 cells with IC₅₀ values of 25.7 ± 2.3 μM and 21.7 ± 1.7 μM, respectively. Subsequently, the possible anti-TNF-α mechanism of 2 was investigated by molecular docking simulation. Furthermore, the neuroprotective activities were tested on the H₂O₂-induced PC12 cell injury model, and compounds 2b, 3a, and 3b (10 μM) could obviously protect the cells with the cell viabilities of 57.86 ± 2.08%, 64.82 ± 2.84%, and 64.11 ± 2.52%, respectively.

Review on Modification of Glucomannan as an Excipient in Solid Dosage Forms

Glucomannan (GM)-a polysaccharide generally extracted from the tuber of Amorphophallus konjac-has great potential as a filler-binder in direct compression, disintegrant in tablets, or gelling agent due to its strong hydrophilicity and extremely high viscosity. However, it has poor water resistance and low mechanical strength when used as an excipient in solid form. Several physical and chemical modifications have been carried out to improve these drawbacks. Chemical modification affects the characteristics of GM based on the DS. Carboxymethylation improves GM functionality by modifying its solubility and viscosity, which in turn allows it to bind water more efficiently and thus improve its elongation and gel homogeneity. Meanwhile, physical modification enhances functionality through combination with other excipients to improve mechanical properties and modify swelling ability and drug release from the matrix. This review discusses extraction of GM and its modification to enhance its applicability as an excipient in solid form. Modified GM is a novel excipient applicable in the pharmaceutical industry for direct compression, as a tablet disintegrant, a film-forming agent, and for encapsulation of macromolecular compounds or drug carriers for controlled release.

Structural characterization and preventive effect on non-alcoholic fatty liver disease of oligosaccharides from Bletilla striata

In this study, Bletilla striata polysaccharides were degraded into oligosaccharides. The structural features were analyzed by HPLC, HPLC-MS, FT-IR, and NMR spectroscopy. The results indicated that Bletilla striata oligosaccharides (BOs) were composed of mannose and glucose with a molar ratio of 5.2 : 1, and the main backbones of BOs contained (1→4)-linked-α-D-Man, (1→2)-linked-α-D-Man, and (1→2)-linked-α-D-Glc. By using a high-fat diet (HFD)-induced mouse model, we demonstrated that BOs had an improving effect on non-alcoholic fatty liver disease (NAFLD). Using the metabolomics assay, we found that BOs significantly regulated the hepatic metabolism of fatty acids, arachidonic acid, and other related metabolites in HFD-fed mice, accompanied by the reduction of lipid accumulation and fibrosis in liver tissues. In summary, BOs displayed high potential for the treatment of NAFLD as a functional food.

Structural characterization of a low molecular weight Bletilla striata polysaccharide and antitumor activity on H22 tumor-bearing mice

In this study, a novel low molecular weight polysaccharide (named LMW-BSP) was extracted from Bletilla striata at 4 °C. The results of structural characteristics analysis showed that LMW-BSP was a 23 kDa neutral polysaccharide contained glucose and mannose at a molar ratio of 1.00:1.26. Structural investigations of the periodate oxidation studies, Smith-degradation as well as methylation were performed, and combined with 1D and 2D NMR spectroscopy, the main chain residues sequence of LMW-BSP was concluded to be: α-D-Manp-(1 → 3)-β-D-Manp-(1 → [4)-β-D-Glcp-(1]₂ → 4)-β-D-Manp-(1 → 3)-β-D-Manp-(1→. Moreover, the antitumor activity of LMW-BSP was evaluated in H22 tumor-bearing mice. And the results suggested that LMW-BSP could effectively improve immune cells activities and lymphocytes subsets proportions dose-dependently in tumor-bearing mice, leading to the apoptosis of H22 cells via G1 phase arrested. LMW-BSP inhibited tumor growth and exhibited antitumor effects in vivo. And it supported considering the novel polysaccharide as a potential drug component in hepatocellular carcinoma treatment.

The medicinal uses of the genus Bletilla in traditional Chinese medicine: A phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Different orchids are important in traditional medicine, and species belonging to the genus Bletilla are important. Bletilla species have been used for thousands of years in Traditional Chinese Medicine (TCM) for the treatment of several health disorders, such as gastrointestinal disorders, peptic ulcer, lung disorders, and traumatic bleeding etc. AIM OF THIS REVIEW: This review aims to provide a systematic overview and objective analysis of Bletilla species and to find the probable relationship between their traditional use, chemical constituents, and pharmacological activities, while assessing their therapeutic potential in treatment of different human diseases.

MATERIALS AND METHODS

Relevant literatures on Bletilla species have been collected using the keywords "Bletilla", "phytochemistry", and "pharmacology" in scientific databases, such as "PubMed", "Scifinder", "The Plant List", "Elsevier", "China Knowledge Resource Integrated databases (CNKI)", "Google Scholar", "Baidu Scholar", and other literature sources, etc. RESULTS: This review indicates the isolation and identification of over 261 compounds from this genus, till December 2020. These chemical isolates belong to the stilbenes (bibenzyls and phenanthrenes), flavonoids, triterpenoids, steroids, simple phenolics, and glucosyloxybenzyl 2-isobutylmalates classes of compounds. These compounds have been reported to be characteristically distributed in Bletilla striata (Thunb.) Rchb. f. (BS), Bletilla ochracea Schltr. (BO), and Bletilla formosana (Hayata) Schltr. (BF). The crude extracts and pure compounds derived from the three Bletilla species have reportedly exhibited a wide spectrum of in vitro and in vivo pharmacological effects, such as hemostatic, anti-inflammatory, anti-tumor, and anti-microbial activities. As a Traditional Chinese Medicine (TCM), Bletilla species or preparations containing Bletilla species have been used for the treatment of epistaxis, gastrointestinal bleeding, cough and hemoptysis, gastric and duodenal ulcer, and traumatic injuries. Thus, Bletilla species have proven potential both in traditional uses and scientific studies.

CONCLUSIONS

Pharmacological studies have validated the use of Bletilla species in the traditional medicine, especially hemorrhagic diseases. Polysaccharides and stilbenes are the major bioactive chemical constituents of Bletilla genus according to the literatures. However, the mechanism of action of these molecules is yet to be studied. In addition, a detailed comparative analysis of the phytochemistry and biological activities of the three Bletilla species (BS, BO and BF) is highly recommended for understanding their ethnopharmacological uses and applications in clinics. Clinical toxicity tests on BS have been found to be negative, but it can't be used with Aconitum carmichaeli in traditional uses. Furthermore, not many reports are present in the literature regarding the conservation of Bletilla species.

Structural characterization of a pure polysaccharide from Bletilla striata tubers and its protective effect against H2O2-induced injury fibroblast cells

The present study investigated the structural characteristics and its protective effect against H₂O₂-induced injury fibroblast cells of Bletilla striata tuber polysaccharide. The polysaccharides were gently extracted by water and recovered using the method of alcohol precipitation, and after further purification by DEAE-Sepharose Fast Flow gel column, a pure polysaccharide (pBSP) was finally obtained. The structural characterization of pBSP were investigated by using periodate oxidation studies, Smith-degradation, FT-IR spectroscopy, 1D and 2D NMR spectroscopy. The antioxidant effect of pBSP was evaluated by inhibiting the production of reactive oxygen species (ROS) in human fibroblast model cells induced by H₂O₂. It was firstly reported that pBSP was composed of d-glucose and D-mannose in a molar ratio of 1.00:1.34 with a molecular weight of 327.6 kDa. The repeating units of pBSP contained (1 → 4)-linked-β-D-Manp, (1 → 4)-linked-α-D-Glcp and (1 → 3)-linked-β-D-Manp, and there was no branched chain. pBSP exhibited no toxic effect on fibroblasts cells and could protect them against H₂O₂-induced injuries. After pretreatment with pBSP for 24 h, the content of ROS in fibroblasts decreased significantly. These results not only confirm the availability B. striata, but also indicate that pBSP have potential antioxidant capacity. Our observations can provide foundation for further development of pBSP-based cosmetics.

Gastroprotective Effect of Ethanol Extracts from Bark of Magnolia officinalis on Ethanol-Induced Gastric Mucosal Damage in Rats

Background. Magnolia officinalis Rehd. and Wils. is widely used in Asian countries because of its multiple pharmacological effects. This study investigated the gastroprotective effect and mechanisms of the ethanol extracts from the bark of Magnolia officinalis (MOE) against ethanol-induced gastric mucosal damage in rats. Methods. MOE was prepared by reflux extraction with 70% ethanol, and its main compounds were analyzed by UPLC-Q-Exactive Orbitrap-MS. DPPH, ABTS, and FRAP methods were used to evaluate the antioxidant capacity of MOE in vitro. The gastroprotective effects of MOE were evaluated by the area of gastric injury, H&E (hematoxylin-eosin), and PAS (periodic acid-Schiff). The mechanism was explored by measuring the levels of cytokines and protein in the NF-κB signaling pathway. Results. 30 compounds were identified from MOE, mainly including lignans and alkaloids. MOE presented a high antioxidant activity in several oxidant in vitro systems. Gastric ulcer index and histological examination showed that MOE reduced ethanol-induced gastric mucosal injury in a dose-dependent manner. MOE pretreatment significantly restored the depleted activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) enzymes, reduced malondialdehyde (MDA), and prostaglandin E2 (PGE2) levels in the gastric tissue in rats. In addition, MOE also inhibited the activation of nuclear factor kappa B (NF-κB) pathway and decreased the production of proinflammatory cytokines. Conclusions. The gastroprotective effect of MOE was attributed to the inhibition of oxidative stress and the NF-κB inflammatory pathway. The results provided substantial evidence that MOE could be a promising phytomedicine for gastric ulcer prevention.

Optimization of Extraction and Purification of Polysaccharides from Veronicastrum axillare, and Evaluation of Their Biological Activities

Veronicastrum axillare polysaccharides (VAP) were isolated by cellulase-assisted digestion. The optimum conditions (2 % cellulase, 47 °C for 2.5 h, then, 95 °C for 2.5 h, pH 4.1, solid/liquid ratio 1 : 7.6) were identified by a combination of single factor optimization and response surface DOE (design of experiment) methods, and achieved a yield of 4.7 %. Treatment with 1 % TCA for 10 min, then, 2 % DEAE-cellulose removed protein and colored impurities. Purified VAP retained most of the radical-scavenging activities and GES-1 cell protection capability in vitro, indicating VAP were the key active components of V. axillare. Some molecular features were identified by FT-IR and NMR analyses. The molecular weight was estimated from DOSY NMR experiments to be around 21 kDa. There were 6.3 % uronic acid residues in the VAP. The constituent sugars after TFA hydrolysis were identified by HPLC to include glucose, arabinose, rhamnose, galactose, and xylose in a molar ratio of 405 : 259 : 82 : 42 : 1.