Variations in Cold Resistance and Contents of Bioactive Compounds among Dendrobium officinale Kimura et Migo Strains

Dendrobium officinale is a valuable traditional Chinese herbal plant that is both medicinal and edible. However, the yield of wild Dendrobium officinale is limited. Adverse stress affects the growth, development, and yield of plants, among which low temperature is the primary limiting factor for introducing Dendrobium officinale to high-latitude areas and expanding the planting area. Therefore, this study aims to explore the variations in growth ability, cold resistance, and contents of bioactive compounds among different Dendrobium officinale strains. Four strains of Dendrobium officinale were selected as experimental materials and were subjected to low-temperature stress (4 °C). The agronomic traits, physiological indices, as well as the expressions of cold resistance-related genes (HSP70, DcPP2C5, DoCDPK1, and DoCDPK6) in the roots and leaves of Dendrobium officinale, were determined. The contents of bioactive compounds, including polysaccharides, flavonoids, and phenols were also measured. Compared with the other strains, Xianju had the highest seed germination and transplantation-related survival rates. Under low-temperature stress, Xianju exhibited the strongest cold resistance ability, as revealed by the changes in water contents, chlorophyll levels, electrical conductivities, enzyme activities, and expressions of the cold resistance-related genes. Additionally, the polysaccharide content of Xianju increased the most, while the stem flavonoid and leaf phenol contents were elevated in all four strains under cold treatment. Therefore, selecting excellent performing strains is expected to expand the planting area, improve the yield, and increase the economic benefits of Dendrobium officinale in high latitude areas with lower temperatures.

Structural characterization and high-efficiency prebiotic activity of the polysaccharide from Tremella aurantialba endophytic bacteria

Herein, the low-molecular-weight heteropolysaccharide (designated as TABP), with a weight-average Mw of 5408 Da, was produced by the endophytic bacterium Bacillus sp. TAB, which was initially isolated from the fruiting bodies of the wild Tremella aurantialba. A relatively high TABP accumulation was obtained and enhanced to 6.94 g/L in 5 L fed-batch fermentation by high-density cultivation. Monosaccharide composition analysis showed that the TABP comprised arabinose, glucosamine, galactose, glucose, and mannose with a molar ratio of 0.073: 0.145: 0.406: 0.182: 0.195, respectively. Methylation and NMR analyses indicated that TABP contained 1,4-linked β-d-Galp and 1,4-linked β-d-Manp pyranosyl backbone, extensively substituted at the side chains to form a complex structure. Prebiotic potential analysis exhibited significant growth-promoting effects for various lactic acid bacteria by more than 90 %. Overall, this study initially provides valuable insights into the endophytic exopolysaccharides from T. aurantialba and their biological activity, which provides prospective sources of prebiotics for functional foods and aids in understanding the endophytes symbiosis mechanism in edible mushrooms.

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.

Structure, Health Benefits, Mechanisms, and Gut Microbiota of Dendrobium officinale Polysaccharides: A Review

Dendrobium officinale polysaccharides (DOPs) are important active polysaccharides found in Dendrobium officinale, which is commonly used as a conventional food or herbal medicine and is well known in China. DOPs can influence the composition of the gut microbiota and the degradation capacity of these symbiotic bacteria, which in turn may determine the efficacy of dietary interventions. However, the necessary analysis of the relationship between DOPs and the gut microbiota is lacking. In this review, we summarize the extraction, structure, health benefits, and related mechanisms of DOPs, construct the DOPs-host axis, and propose that DOPs are potential prebiotics, mainly composed of 1,4-β-D-mannose, 1,4-β-D-glucose, and O-acetate groups, which induce an increase in the abundance of gut microbiota such as Lactobacillus, Bifidobacterium, Akkermansia, Bacteroides, and Prevotella. In addition, we found that when exposed to DOPs with different structural properties, the gut microbiota may exhibit different diversity and composition and provide health benefits, such as metabolism regulations, inflammation modulation, immunity moderation, and cancer intervention. This may contribute to facilitating the development of functional foods and health products to improve human health.

Dendrocandin U from Dendrobium officinale Kimura et Migo Inhibits M1 Polarization in Alveolar Macrophage by Suppressing NF-κB Signaling Pathway

Dendrobium officinale Kimura et Migo is a valuable and homologous medicine and food traditional Chinese medicine. Currently there are few studies on the anti-inflammatory activity of lipophilic components. The aim of this study was to explore the anti-inflammatory effect and mechanism of the lipophilic compounds in Dendrobium officinale. Six compounds were isolated and identified, including three bibenzyl compounds, dendrocandin U, dendronbibisline B, erianin, and three lignans, (-)-syringaresinol, (+)-syringaresinol-O-β-D-glucopyranoside, 5-methoxy-(+)-isolariciresinol. Among them, dendronbibisline B and 5-methoxy-(+)-isolariciresinol were isolated from Dendrobium officinale for the first time. Besides, we found dendrocandin U, dendronbibisline B and (-)-syringaresinol exhibited the anti-inflammation to inhibit nitric oxide secretion induced by lipopolysaccharide (LPS)/interferon (IFN-γ) in MH-S cells. Furthermore, dendrocandin U could inhibit the expression of tumor necrosis factor-α (TNF-α), Cluster of Differentiation 86 (CD86), and reduce inflammatory morphological changes of macrophages. Meanwhile, we confirmed that the anti-inflammation mechanism of dendrocandin U was to inhibit M1 polarization by suppressing toll-like receptor 4 (TLR4)/recombinant myeloid differentiation factor 88 (MyD88)/nuclear factor kappa B (NF-κB) signaling pathway. In this paper, dendrocandin U with significant anti-inflammatory activity was found from Dendrobium officinale, which could provide a basis for the study of its anti-inflammatory drugs.

The Mechanisms of Polysaccharides from Tonic Chinese Herbal Medicine on the Enhancement Immune Function: A Review

Tonic Chinese herbal medicine is a type of traditional Chinese medicine, and its primary function is to restore the body's lost nutrients, improve activity levels, increase disease resistance, and alleviate physical exhaustion. The body's immunity can be strengthened by its polysaccharide components, which also have a potent immune-system-protecting effect. Several studies have demonstrated that tonic Chinese herbal medicine polysaccharides can improve the body's immune response to tumor cells, viruses, bacteria, and other harmful substances. However, the regulatory mechanisms by which various polysaccharides used in tonic Chinese herbal medicine enhance immune function vary. This study examines the regulatory effects of different tonic Chinese herbal medicine polysaccharides on immune organs, immune cells, and immune-related cytokines. It explores the immune response mechanism to understand the similarities and differences in the effects of tonic Chinese herbal medicine polysaccharides on immune function and to lay the foundation for the future development of tonic Chinese herbal medicine polysaccharide products.

Chemical Constituents, Bioactivities, and Pharmacological Mechanisms of Dendrobium officinale: A Review of the Past Decade

Dendrobium officinale, a plant in the Orchidaceae family, has been used in traditional Chinese medicine for thousands of years. Sweet and slightly cold in nature, it can invigorate the stomach, promote fluid production, nourish Yin, and dissipate heat. Over the past decade, more than 60 compounds have been derived from D. officinale, including flavonoids, bibenzyl, and phenanthrene. Various studies have explored the underlying pharmacological mechanisms of these compounds, which have shown antitumor, hypoglycemic, hypertensive, gastrointestinal-regulatory, visceral organ protection, antiaging, and neurorestorative effects. This paper presents a systematic review of the structural classification, biological activity, and pharmacological mechanisms of different chemical components obtained from D. officinale over the past decade. This review aims to provide a reference for future study and establish a foundation for clinical applications. Furthermore, this review identifies potential shortcomings in current research as well as potential directions and methodologies in future plant research.

Effect of Dendrobium officinale polysaccharides on central nervous system disease: Based on gut microbiota

Dendrobium officinale has anti-inflammatory effects and is one of the well-known functional foods. Dendrobium officinale polysaccharide (DOP) can reduce intestinal barrier disruption and excessive inflammatory response by regulating intestinal bacterial homeostasis as well as short-chain fatty acid levels. It can also inhibit the activation of astrocytes and microglia, further realizing the protective effect on neuronal apoptosis and apoptosis, thus exerting a significant alleviating effect on neurological diseases. There is now evidence that bidirectional communication between the central nervous system and the gastrointestinal tract may influence human neurology, cognition and behavior via the gut-brain axis. In this review, we review the structural characterization, bioactivity and possible bioactive mechanisms of DOP, so as to elucidate the advantages of DOP's action on CNS diseases, with the aim of providing new perspectives for its drug and functional food development as well as clinical applications.

Modern interpretation of the traditional application of Shihu - A comprehensive review on phytochemistry and pharmacology progress of Dendrobium officinale

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) "Shihu" has a long history of medicinal use in China from some species of Dendrobium. D. officinale is a major source of "Shihu" and is widely cultivated in south of China and listed separately as "Tiepi Shihu" by the Chinese Pharmacopoeia in now time. Traditionally, D. officinale has been widely used in daily health care and the treatment of diabetes and gastrointestinal diseases.

AIM OF THIS REVIEW

In order to better develop and utilize D. officinale, we conducted this systematic review of previous studies, showed clear structure of all isolates from D. officinale together with pharmacological progress, hoping to provide references for further research and utilization. In addition, specific display of the chemical components and the research progress of related activities can help to better understand the traditional records and modern pharmaceutical applications of the plant medicine.

MATERIALS AND METHODS

Information on phytochemistry and pharmacological studies of D. officinale was collected from various scientific databases including Web of Science, SciFinder, ACS, Springer, Scopus, PubMed, ScienceDirect, Google Scholar and CNKI.

RESULTS

More than 180 compounds isolated from D. officinale, including bibenzyls, phenols, phenylpropanoids, lignans, flavonoids and polysaccharides are listed in this review. Furthermore, modern pharmacological researches such as hypoglycemia, immune regulation, antioxidant, cardiovascular regulation and gastrointestinal protection are summarized.

CONCLUSION

Based on the summary of the research work of D. officinale, we systematically show the chemical composition of the plant, and concluded the relationship of those composition with plant habitat together with the relationship between the structure of chemical components and pharmacological activity. Moreover, we suggest that some of small molecule compounds could also be quality control of D. officinale besides polysaccharides.

Polysaccharides from Chinese materia medica: Perspective towards cancer management

Cancer has always been a focus of global attention, and the difficulty of treatment and poor prognosis have always plagued humanity. Conventional chemotherapeutics and treatment with synthetic disciplines will cause adverse side effects and drug resistance. Therefore, searching for a safe, valid, and clinically effective drug is necessary. At present, some natural compounds have proved to have the potential to fight cancer. Polysaccharides obtained from Chinese materia medica are good anti-cancer ingredients. Polysaccharides are macromolecular compounds of equal or distinct monosaccharides with an α- or β-glycosidic bonds. The anti-cancer activity has been fully demonstrated in vivo and in vitro. However, Chinese materia medica polysaccharides are only used as adjuvant therapy for cancer-related diseases. Hence, this review mainly discusses the chemical composition, biological activity, absorption in vivo, and clinical application of Chinese materia medica polysaccharides. Also, we discussed the anti-cancer mechanism. We also discussed the current research's limitations on treating cancer with Chinese materia medica polysaccharides and insights into future research.

Glucomannan in Dendrobium catenatum: Bioactivities, Biosynthesis and Perspective

Dendrobium catenatum is a classical and precious dual-use plant for both medicine and food in China. It was first recorded in Shen Nong's Herbal Classic, and has the traditional functions of nourishing yin, antipyresis, tonifying the stomach, and promoting fluid production. The stem is its medicinal part and is rich in active polysaccharide glucomannan. As an excellent dietary fiber, glucomannan has been experimentally confirmed to be involved in anti-cancer, enhancing immunity, lowering blood sugar and blood lipids, etc. Here, the status quo of the D. catenatum industry, the structure, bioactivities, biosynthesis pathway and key genes of glucomannan are systematically described to provide a crucial foundation and theoretical basis for understanding the value of D. catenatum and the potential application of glucomannan in crop biofortification.

Bioactivities and Mechanism of Actions of Dendrobium officinale: A Comprehensive Review

Dendrobium officinale has a long history of being consumed as a functional food and medicinal herb for preventing and managing diseases. The phytochemical studies revealed that Dendrobium officinale contained abundant bioactive compounds, such as bibenzyls, polysaccharides, flavonoids, and alkaloids. The experimental studies showed that Dendrobium officinale and its bioactive compounds exerted multiple biological properties like antioxidant, anti-inflammatory, and immune-regulatory activities and showed various health benefits like anticancer, antidiabetes, cardiovascular protective, gastrointestinal modulatory, hepatoprotective, lung protective, and neuroprotective effects. In this review, we summarize the phytochemical studies, bioactivities, and the mechanism of actions of Dendrobium officinale, and the safety and current challenges are also discussed, which might provide new perspectives for its development of drug and functional food as well as clinical applications.

Refined polysaccharide from Dendrobium devonianum resists H1N1 influenza viral infection in mice by activating immunity through the TLR4/MyD88/NF-κB pathway

Dendrobium polysaccharide exhibits multiple biological activities, such as immune regulation, antioxidation, and antitumor. However, its resistance to viral infection by stimulating immunity is rarely reported. In this study, we explored the effect and mechanism of DVP-1, a novel polysaccharide from Dendrobium devonianum, in the activation of immunity. After being activated by DVP-1, the ability of mice to prevent H1N1 influenza virus infection was investigated. Results of immune regulation showed that DVP-1 significantly improved the immune organ index, lymphocyte proliferation, and mRNA expression level of cytokines, such as IL-1β, IL-4, IL-6, and TNF-α in the spleen. Immunohistochemical results showed that DVP-1 obviously promoted the mucosal immunity in the jejunum tissue. In addition, the expression levels of TLR4, MyD88, and TRAF6 and the phosphorylation levels of TAK1, Erk, JNK, and NF-κB in the spleen were upregulated by DVP-1. The virus infection results showed that the weight loss of mice slowed down, the survival rate increased, the organ index of the lung reduced, and the virus content in the lung decreased after DVP-1 activated immunity. By activating immunity with DVP-1, the production of inflammatory cells and inflammatory factors in BALF, and alveolar as well as peribronchiolar inflammation could be prevented. The results manifested that DVP-1 could resist H1N1 influenza virus infection by activating immunity through the TLR4/MyD88/NF-κB pathway.

Importance of Dendrobium officinale in improving the adverse effects of high-fat diet on mice associated with intestinal contents microbiota

A growing body of evidence suggests that the disturbance of intestinal microbiota induced by high-fat diet is the main factor causing many diseases. Dendrobium officinale (DO), a medicinal and edible homologous Chinese herbal medicine, plays essential role in regulating intestinal microbiota. However, the extent of DO on the intestinal contents microbiota in mice fed with a high-fat diet still remains unclear. Therefore, this study explored the role of intestinal contents microbiota in the regulation of adverse effects caused by high-fat diet by DO from the perspective of intestinal microecology. Twenty-four mice were randomly distributed into the normal saline-treated basal diet (bcn), normal saline-treated high-fat diet (bmn), 2.37 g kg⁻¹ days⁻¹ DO traditional decoction-treated high-fat diet (bdn) and 1.19 g kg⁻¹ days⁻¹ lipid-lowering decoction-treated high-fat diet (bjn) groups for 40 days. Subsequently, we assessed the changes in body weight, serum total cholesterol (TC), total triacylglycerol (TG), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C) levels, and the characteristics of intestinal contents microbiota. Results demonstrated that DO exerted the modulating effect on the changes in body weight, TG, TC, LDL-C, and HDL-C levels. Besides, DO decreased the richness and diversity of intestinal contents microbiota, and altered the structure as a whole. Dominant bacteria, Ruminococcus and Oscillospira, varied significantly and statistically. Moreover, DO influenced the carbohydrate, amino acid, and energy metabolic functions. Furthermore, Ruminococcus and Oscillospira presented varying degrees of inhibition/promotion of TG, TC, LDL-C, and HDL-C. Consequently, we hypothesized that Ruminococcus and Oscillospira, as dominant bacteria, played key roles in the treatment of diseases associated with a high-fat diet DO.

Research progress on extraction, purification, structure and biological activity of Dendrobium officinale polysaccharides

Dendrobium officinale Kimura et Migo (D. officinale) is a traditional medicinal and food homologous plant that has been used for thousands of years in folk medicine and nutritious food. Recent studies have shown that polysaccharide is one of the main biologically active components in D. officinale. D. officinale polysaccharides possess several biological activities, such as anti-oxidant, heptatoprotective, immunomodulatory, gastrointestinal protection, hypoglycemic, and anti-tumor activities. In the past decade, polysaccharides have been isolated from D. officinale by physical and enzymatic methods and have been subjected to structural characterization and activity studies. Progress in extraction, purification, structural characterization, bioactivity, structure-activity relationship, and possible bioactivity mechanism of polysaccharides D. officinale were reviewed. In order to provide reference for the in-depth study of D. officinale polysaccharides and the application in functional food and biomedical research.

Identification of Dendrobiums in situ by Raman spectroscopy and micro-computed tomography imaging

Background

Dendrobium candidum/officinale (Dendrobium candidum Wall.ex Lindl.; Dendrobium officinale Kimura et Migo) is an expensive medicinal plant used mainly as a tonic in China. Tie-pi-feng-dou is the common name of the processed medicinal Dendrobium candidum/officinale. The market prices of Dendrobium sources vary significantly and it is difficult to identify different types of Dendrobiums due to their similar appearances. The use of counterfeit Dendrobium candidum/officinale is ubiquitous and problematic. Therefore, it is important to be able to discriminate between the wide range of available Dendrobium.

Methods

In an effort to better distinguish between the varieties of Dendrobium, Raman spectroscopy was used to detect specific Dendrobiums relative to their source. Transport channel imaging of the microstructural sites by micro-computed tomography (micro-CT) was used to identify the unique constitution and enrichment status of dendrobines, which was determined mainly by the geographical source of the Dendrobium. This implies that exclusive spectral traits may be unique to different regions. The presence or absence of these traits differ among the geographical origins.

Results

We can identify several spectral traits for various Dendrobiums. An intense peak at 1,525 cm−1 was only found in Dendrobium candidum/officinale (Zhe-jiang/Yun-nan/An-hui), while the characteristic Dendrobium candidum/officinale bands were near 742 cm−1, 1,326 cm−1 and 1,330 cm−1. A systematic method for distinguishing between four geographical locations of Dendrobium (Zhe-jiang/Yun-nan/An-hui/Gui-zhou) were established. This reveals that the origin of an unknown Dendrobium may be identified by Raman spectroscopy and micro-CT imaging. This method was shown to be efficacious, fast, and non-destructive.

Structural characterization of a mannoglucan polysaccharide from Dendrobium huoshanense and evaluation of its osteogenesis promotion activities

Dendrobium huoshanense, a valuable traditional Chinese herb, is widely used to prolong life in China. Our study aims to characterize the structure and osteogenesis-promotion effects of a heteropolysaccharide component isolated from Dendrobium huoshanense (DHPW1). The structure of DHPW1 was characterized using gas chromatography-mass spectrometry and nuclear magnetic resonance, while its osteogenic activity was evaluated using MG-63 cells and zebrafish skulls. The results showed that the molecular weight of DHPW1 was 230 kDa and it was mainly composed of mannose and glucose. In addition, the DHPW1 backbone consisted of (1 → 4)-linked-β-D-Mannopyranosyl and (1 → 4)-linked-β-d-Glucopyranosyl. Furthermore, DHPW1 significantly increased ALP activity and mineralized nodule formation in MG-63 cells. DHPW1 in zebrafish skull models significantly enhanced the relative fluorescence intensity of bone mass and increased the degree of bone mineralization. These results suggested that the DHPW1 component in D. huoshanense has potential to promote osteogenesis.

Effect of Polysaccharides From Enteromorpha intestinalis on Intestinal Function in Sprague Dawley Rats

This study aims to determine the effect of polysaccharides extracted from Enteromorpha intestinalis (EI) on the intestinal function of Sprague Dawley (SD) rats. The polysaccharides were extracted from the green alga using water and alkaline solution, where these extracts were named WPEI and APEI, respectively. The dried powder of EI was labeled as DPEI. Proximate compositions, minerals, and amino acids of the DPEI, WPEI, and APEI were determined. The growth-promoting effect of the polysaccharides on selected intestinal microflora was determined based on the plate count method. In contrast, the in vivo effect of DPEI and its polysaccharides on the intestinal function of the SD rats was determined. These rats were fed with 1% WPEI, APEI, and DPEI. The result showed that APEI had lower total sugars and total proteins content than the WPEI. WPEI did not contain arabinose. The WPEI and APEI also had a better ability to promote microbial growth than the DPEI. The in vivo study showed that WPEI improved intestinal peristalsis and other intestinal functions compared with the other rat groups. The average final body weight of the experimental rats treated with DPEI was also lower than the other groups. The pH value of the feces of all treated rats was lower than the control rats, and the moisture content of the fecal samples of these experimental groups was higher than the control group. Also, the intestinal activated carbon propulsion of the WPEI, APEI, and DPEI fed rats increased. Among the short-chain fatty acids content determined in the fecal samples, the propionic acid content of the WPEI group was significantly highest. Therefore, WPEI had the best effect in improving intestinal digestion.

Dendrobium officinale polysaccharide ameliorates polycystic ovary syndrome via regulating butyrate dependent gut-brain-ovary axis mechanism

Research has shown that dendrobium officinale polysaccharide (DOP) can promote follicular development and inhibit the apoptosis of ovarian granular cells in PCOS rats. However, DOP cannot be absorbed directly by the stomach and small intestine but is degraded into short-chain fatty acids by gut microbiota in the large intestine and regulates the composition of gut microbiota. How DOP improved ovarian function in PCOS rats through the blood-brain barrier is unclear. In this study, we generated letrozole-induced PCOS rat models and studied the therapeutic effect and mechanism of DOP. 16S rRNA amplicon sequencing analysis, GC-MS short-chain fatty acid detection, and Gene Expression Omnibus database searching were conducted to screen the significantly changed pathways, and a series of experiments, such as enzyme-linked immunosorbent assay, RT-qPCR, Western blot, and immunohistochemistry, were performed. We found that DOP treatment could improve ovarian morphology and endocrine disorders, restore the normal estrus cycle, increase gut microbiota α diversity, and alter β diversity and enrichment of butyrate-producing bacterium in PCOS rats. In addition, compared with PCOS rats, those treated with DOP exhibited higher butyrate and polypeptide YY levels, possibly due to the regulation of G protein-coupled receptor 41 expression. These results indicated that DOP relieved the symptoms of PCOS rats which may be related to the mechanism of butyrate dependent gut-brain-ovary axis protection.

Structural characterization and immunoregulatory activity of polysaccharides from Dendrobium officinale leaves

In this study, two kinds of polysaccharides from leaves of Dendrobium officinale, namely DLP-1 and DLP-2, were obtained by hot water extraction, ethanol sedimentation, and chromatographic separation using DEAE-52 cellulose and Sephadex G-100 columns. They were composed of different monosaccharides and the content of monosaccharides varied significantly while DLP-1 (M_w 1.38 × 10⁶  Da) was mainly composed of mannose (71.69%) and glucose (22.89%), and DLP-2 (M_w 1.93 × 10⁶  Da) was constituted by rhamnose (35.05%), arabinose (24.12%), and galactose (25.65%). A triple-helical conformation was exhibited by both of them. The scanning electron microscope image of DLP-1 showed an irregular and large lamellar shape, as well as a smooth surface and a porous interior, illustrating they had an amorphous structure. In contrast, DLP-2 revealed a rough, loose, and uneven surface consisting of large sponge-like particles. Nuclear magnetic resonance analysis showed that (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and (1→4)-2-O-acetyl-β-D-Manp were the main linkage types of DLP-1, whereas DLP-2 was constituted by a large amount of (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and other residues. Besides, DLP-1 and DLP-2 stimulated the proliferation and phagocytic capacities of RAW 264.7 cells and improved the production of nitric oxide, interleukin-6, TNF-α, and IL-1β. These results proved that both DLP-1 and DLP-2 possessed excellent immunoregulatory bioactivities and could be functional food or adjuvant drug. PRACTICAL APPLICATIONS: The leaf of Dendrobium officinale is a by-product with huge biomass. The lack of systematic research on its chemical composition and pharmacologic effect, leading to a great waste of resources. In order to maximize the value of D. officinale, this study aimed to investigate the structural characteristics and immunologic effects of two polysaccharide fractions (DLP-1 and DLP-2) from D. officinale leaves, showing that DLP-1 and DLP-2 in D. officinale leaves could be used as anti-inflammatory agents to avoid wasting.

Erianin, the main active ingredient of Dendrobium chrysotoxum Lindl, inhibits precancerous lesions of gastric cancer (PLGC) through suppression of the HRAS-PI3K-AKT signaling pathway as revealed by network pharmacology and in vitro experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium chrysotoxum Lindl, a well-known traditional Chinese medicinal herb used in the treatment of gastric disease, is distinguished as the first of the "nine immortal grasses". Dendrobium chrysotoxum Lindl and the traditional Chinese medicine prescriptions containing Dendrobium chrysotoxum Lindl are often prescribed clinically to treat chronic gastritis and precancerous lesions of gastric cancer (PLGC), showing favorable clinical effects and medicinal value in the prevention of gastric cancer. However, the effective ingredients and pharmacological mechanisms through which Dendrobium chrysotoxum Lindl prevents and treats PLGC have not been adequately identified or interpreted.

AIM OF THE STUDY

The present study aimed to evaluate the effective ingredients and pharmacological mechanisms of Dendrobium chrysotoxum Lindl in the prevention and treatment of PLGC using network pharmacology. In addition, in vitro verification was performed to evaluate the mechanism of action of Erianin, the main active ingredient in Dendrobium chrysotoxum Lindl, providing experimental evidence for the clinical use of Dendrobium chrysotoxum Lindl in the treatment of PLGC.

MATERIALS AND METHODS

Using network pharmacology methods, the main ingredients in Dendrobium chrysotoxum Lindl were screened from the ETCM, BATMAN-TCM, and TCMID databases, and their potential targets were predicted using the Swiss Target Prediction platform. The targets related to PLGC were retrieved through the GeneCard database, and the targets common to the main ingredients of Dendrobium chrysotoxum Lindl and PLGC were analyzed. The protein-protein interaction (PPI) network was obtained via the STRING database and analyzed visually using Cytoscape 3.7.2. The underlying mechanisms of the common targets identified through gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were analyzed using DAVID online. The "component-target-pathway" networks of Dendrobium chrysotoxum Lindl and Erianin were visually constructed by Cytoscape 3.7.2. The biological activity evaluation of Erianin's effect on PLGC was carried out using MC cell lines, the PLGC cell model established using MNNG to induce damage in normal gastric mucosal epithelial cell (GES-1). After the intervention of different concentrations of Erianin, MC cell viability was explored using the MTT assays, cell migration was determined by wound healing assays, the cell cycle and apoptosis were analyzed using flow cytometry, and the expression levels of related proteins and their phosphorylation in the HRAS-PI3K-AKT signaling pathway were detected by Western blot.

RESULTS

The "component-target-pathway" network constructed in this study showed 37 active ingredients from Dendrobium chrysotoxum Lindl and 142 overlapping targets related to both Dendrobium chrysotoxum Lindl and PLGC. The targets were associated with a variety of cancer-related signaling pathways, including Pathways in cancer, PI3K-Akt signaling pathway, Rap1 signaling pathway, Focal adhesion, Ras signaling pathway, and MAPK signaling pathway. Notably, the network showed that Erianin, the primary active ingredient from Dendrobium chrysotoxum Lindl and the component associated with the most targets, could regulate Pathways in cancer, PI3K-AKT signaling pathway, Focal adhesion, Rap1 signaling pathway, cell cycle, and RAS signaling pathway in the treatment of PLGC. Verification through in vitro experiments found that Erianin can significantly inhibit MC cell viability, inhibit cell migration, block the cell cycle in the G2/M phase, and induce cell apoptosis in a dose-dependent manner. The results of the Western blot experiment further showed that Erianin can significantly decrease the protein expression levels of HRAS, AKT, p-AKT, MDM2, Cyclin D1, and p-Gsk3β, and increase the protein expression level of p21, which suggests that Erianin can treat PLGC by regulating the HRAS-PI3K-AKT signaling pathway.

CONCLUSION

This study explained the positive characteristics of multi-component, multi-target, and multi-approach intervention with Dendrobium chrysotoxum Lindl in the treatment of PLGC. Our results suggest that Erianin may be a promising candidate in the development of prevention and treatment methods for PLGC. This study provided experimental evidence for the clinical use of Dendrobium chrysotoxum Lindl to treat PLGC and prevent gastric cancer.

Supplementation of Alhagi honey polysaccharides contributes to the improvement of the intestinal immunity regulating the structure of intestinal flora in mice

Alhagi honey polysaccharides (AH), a main active component of Alhagi honey, are known to possess excellent pharmacological activities and have been widely used as dietary supplements in traditional Chinese medicine for thousands of years. This study is aimed to investigate the heath effect of AH on murine intestinal mucosal immune function and composition of the gut microbiome. ICR mice received daily intragastric administration of AH (three dosages, 200 mg kg^-1, 400 mg kg^-1, and 800 mg kg^-1) or saline for 7 consecutive days. Results indicated an improvement in the intestinal barrier function through increases in secretory immunoglobulin A (sIgA) and β-defensins. Simultaneously, AH also significantly stimulated IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α cytokine secretion as compared to the control samples. Moreover, hematoxylin and eosin staining showed that AH enhanced the number of intraepithelial lymphocytes (IELs) in the small intestine. An obvious increase in the ratio of IgA⁺ cells of AH-treatment samples in the lamina propria was also detected by immunohistochemical staining. In addition, the CD3⁺, CD4⁺ and CD8⁺ T-cell ratio in mesenteric lymph nodes and Peyer's patches in the AH-treatment was significantly higher than that in the control group. Furthermore, 16S rDNA gene sequencing was used to monitor the dynamic changes in the gut microbiota. The result revealed that AH significantly increased the indexes of Shannon and obviously decreased the indexes of Simpson, suggesting the enhancement of the diversity and richness of the intestinal microbiome. Moreover, AH modulated the gut microbiome via increasing the abundance of probiotics and decreasing the levels of pathogenic bacteria. In summary, these results indicated that AH could be used as a prebiotic to enhance murine intestinal mucosal immunity and to modulate the gut microbiome.

Isolation, structural properties, bioactivities of polysaccharides from Dendrobium officinale Kimura et. Migo: A review

Dendrobium officinale Kimura et Migo (D. officinale) is used as herbal medicine and new food resource in China, which is nontoxic and harmless, and can be used as common food. Polysaccharide as one of the main bioactive components in D. officinale, mainly composed of glucose and mannose (Manp: Glcp = 2.01:1.00-8.82:1.00), along with galactose, xylose, arabinose, and rhamnose in different molar ratios and types of glycosidic bonds. Polysaccharides of D. officinale exhibit a variety of biological effects, including immunomodulatory, anti-tumor, gastro-protective, hypoglycemic, anti-inflammatory, hepatoprotective, and vasodilating effects. This paper presents the extraction, purification, structural characteristics, bioactivities, structure-activity relationships and analyzes gaps in the current research on D. officinale polysaccharides. In addition, based on in vitro and in vivo experiments, the possible mechanisms of bioactivities of D. officinale polysaccharides were summarized. We hope that this work may provide helpful references and promising directions for further study and development of D. officinale polysaccharides.

Green synthesis of gold nanoparticles from Dendrobium officinale and its anticancer effect on liver cancer

A novel gold nanoparticle (Do-AuNP) was successfully synthesized from water extracts of traditional Chinese medicine Dendrobium officinale (DO) without using any extra chemicals regents. The physicochemical properties of Do-AuNPs were analyzed by transmission electron microscopy, dynamic light scattering, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and atomic force microscopy. The amount of DO extract on the AuNPs was about 13%. In order to evaluate the anti-tumor efficiency and biosafety, the inhibitory rate of HepG2 cells and survival rate of L02 cells were performed in vitro, and the immunohistochemical analysis of H&E, Ki-67, and TUNEL staining were conducted in vivo. Our results demonstrated that Do-AuNP had better anti-tumor efficiency compared with DO extraction alone without increasing toxicity in vivo and in vitro. The present study provides useful information for Do-AuNP as a new nanomedicine for liver cancer.

Current advances of Dendrobium officinale polysaccharides in dermatology: a literature review

Context

Dendrobium officinale Kimura et Migo (Orchidaceae) is a naturally occurring precious traditional Chinese medicine (TCM) originally used in treating yin-deficiency diseases. The main active substances of Dendrobium officinale are polysaccharides (DOP). Recent findings highlighted the potential of DOP as a promising natural material for medical use with a diversity of pharmaceutical effects.

Objective

In this review, we provide a systematic discussion of the current development and potential pharmacological effects of Dendrobium officinale polysaccharides in dermatology.

Methods

English and Chinese literature from 1987 to 2019 indexed in databases including PubMed, PubMed Central, Web of Science, ISI, Scopus and CNKI (Chinese) was used. Dendrobium officinale, Dendrobium officinale polysaccharides, phytochemistry, chemical constituents, biological activities, and pharmacological activities were used as the key words.

Results

Dendrobium officinale polysaccharides have been found to possess hair growth promoting, skin moisturising and antioxidant effects, which are highly valued by doctors and cosmetic engineers. We highlighted advances in moisturising and antioxidant properties from in vivo and in vitro studies. Dendrobium officinale polysaccharides exhibited strong antioxidant effects by decreasing free radicals, enhancing antioxidant system, inhibiting nuclear factor-kappa B and down-regulating inflammatory response.

Conclusions

Our review is a foundation to inspire further research to facilitate the application of Dendrobium officinale polysaccharides in dermatology and promote active research of the use of TCM in dermatology.

Structural characteristics and immunostimulatory activities of a new polysaccharide from Dendrobium fimbriatum Hook

A new polysaccharide (cDFP-W1) with high immunostimulatory activities was isolated from the stems of Dendrobium fimbriatum Hook. The analysis of the physicochemical properties showed that cDFP-W1 consisted of mannose and glucose in a molar ratio of 1 : 3.84, and its relative molecular weight was 4.0 × 10⁴ Da. Structural analysis implied that the linear backbone of cDFP-W1 was composed of α-1,4-d-Glcp, β-1,4-d-Manp, 3-O-acetyl-α-1,4-d-Glcp and α-1,4,6-d-Glcp, and its branches were the terminal β-d-Manp that was attached to the C-6 position of α-1,4,6-d-Glcp. An in vivo immunostimulatory assay exhibited that cDFP-W1 at 200 mg kg^-1 could significantly increase the proportions of CD4⁺ T-cell subpopulations, B cells, natural killer cells and dendritic cells, decrease the proportion of CD8⁺ T-cell subpopulations, and upregulate the percentage of activated macrophages (p < 0.01) in the spleen of mice. An in vitro immunostimulatory assay revealed that cDFP-W1 could effectively promote the proliferation of spleen lymphocytes, enhance the proliferation and phagocytosis of macrophage RAW264.7 cells, and stimulate the mRNA expression and extracellular release of NO, TNF-α and IL-1β of RAW264.7 cells. The western blot experiment suggested that the immunostimulatory activities of cDFP-W1 were closely related to the activation of MAPKs, NF-κB and PI3K/Akt signaling pathways.

Wheat germ glycoprotein regionally modulates immunosuppressed mouse intestinal immunity function from early life to adulthood

Wheat germ glycoprotein (WGP) is widely used due to its nutritional benefits and biological activity. This study evaluated the effects of WGP on intestinal-immunosuppressed mice from early life to adulthood and detected the underlying mechanism. The results revealed that WGP demonstrated no clinical side effects on the body index, serum total IgA level, protein expression and the morphology of intestine in newborn mice. In the phase of life, compared with the cyclophosphamide-treated group (CG), WGP clearly promoted the secretion of sIgA and effectively regulated the cytokine gene (IL-2, IFN-γ, TNF-α, IL-4, IL-6, IL-5, IL-17, and TGF-β1) expression in the intestine. Furthermore, WGP promoted the expression of CD40L and CD40, phosphorylation of IKKα/β and transcription of NF-κB-p65. The data as reported in this present analysis suggest that WGP can improve the intestinal immunity of newborn mice to adulthood via the CD40L-CD40-IKKα/β-NF-κB p65 signaling pathway.

A review of isolation methods, structure features and bioactivities of polysaccharides from Dendrobium species

Dendrobium, orchid, is a traditional Chinese herb medicine applied extensively as tonic and precious food for thou-sands of years recorded in ancient Chinese medical book "Shen Nong's Materia Medica". It's well known that bioactivities are usually related to the ingredients' basis. Based on the previous research, Dendrobium species contain amino acid, sesquiterpenoids, alkaloids and polysaccharides. As the bioactive substances, carbohydrate shows extensive activities in antitumor, antiglycation, immune-enhancing, antivirus, antioxidant, antitumor and etc. Therefore, as the main biologically active substance, the exact structures and latent activities of polysaccharides from Dendrobium species are widely focused on. In this review, we focus on the advancements of extraction methods and diversity of structures and bioactivities of polysaccharides obtained from Dendrobium species.

Comparative metabolomic analyses of Dendrobium officinale Kimura et Migo responding to UV-B radiation reveal variations in the metabolisms associated with its bioactive ingredients

Background

Dendrobium officinale Kimura et Migo, a member of the genus Dendrobium, is a traditional Chinese medicine with high commercial value. The positive roles of UV-B radiation on active ingredient metabolism in various medicinal plants have been studied. However, the metabolic responses of D. officinale stems to UV-B treatment is largely unknown.

Methods

An untargeted metabolomics method was used to investigate the metabolic variations in D. officinale stems between the control and UV-B treatments.

Results

In total, 3,655 annotated metabolites, including 640 up- and 783 down-regulated metabolites, were identified and grouped into various primary metabolic categories. Then, a number of metabolites involved in the polysaccharide, alkaloid and flavonoid biosynthesis pathways were identified. For polysaccharide biosynthesis, several intermediate products, such as pyruvate, secologanate, tryptophan and secologanin, were significantly up-regulated by the UV-B treatment. For polysaccharide biosynthesis, many key fundamental building blocks, from the glycolysis, starch and sucrose metabolism, and fructose and mannose metabolism pathways, were induced by the UV-B treatment. For flavonoid metabolism, accumulations of several intermediate products of chalcone synthase, chalcone isomerase and flavanone 3-hydroxylase were affected by the UV-B treatment, indicating an involvement of UV-B in flavonoid biosynthesis. The UV-B induced accumulation of polysaccharides, alkaloids and flavonoids was confirmed by HPLC analysis. Our study will help to understand the effects of UV-B on the accumulation of active ingredients in D. officinale.

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.

A comparative study on the structures of Grifola frondosa polysaccharides obtained by different decolourization methods and their in vitro antioxidant activities

Decolourization of polysaccharides is one of the crucial procedures that affects their structure, which is closely related to their bioactivity. Here, Grifola frondosa polysaccharide (GFP) was decolourized with H2O2 and AB-8 macroporous resin. Then, two main fractions, named DGFP and SGFP, were obtained by purification with Sepharose CL-4B. The molecular weights of these two polysaccharides were determined to be 6.306 × 106 (±0.410%) Da and 1.174 × 107 (±0.299%) Da by HPSEC. Monosaccharide analysis indicated that DGFP was composed of glucose, mannose, and galactose (32.20 : 1.00 : 1.75), while SGFP consisted entirely of glucose. Despite a backbone →4)-α-Glcp-(1→ in two polysaccharides, reducing ends Rα →3)-α-Glcp and Rβ →4)-β-Glcp were observed in DGFP by 1D/2D NMR. The results suggested that decolourization with low concentrations of H2O2 might alter the structure of GFP and generate new reducing ends. In vitro antioxidant results implied that DGFP exhibited a higher ability to scavenge DPPH and hydroxyl radicals and reduced the over-generated ROS levels in a concentration-dependent manner. These results suggested that the antioxidant effects of GFP could be activated by decolourization with H2O2. Therefore, DGFP might be a more promising natural antioxidant than SGFP.

Intestinal microbes derived butyrate is related to the immunomodulatory activities of Dendrobium officinale polysaccharide

Although immunomodulatory activities of Dendrobium officinale polysaccharide has been investigated for many years, yet the potential contribution of its metabolite derived from intestinal microbes on immunoregulation effect has not been reported. In this study, polysaccharide DOW-5B with average molecular weight of 39.4 kDa was isolated from the stem of Dendrobium officinale Kimura et Migo. The carbohydrate content was 91.97% and no protein was detected. The monosaccharide analysis showed this polysaccharide was composed of glucuronic acid and glucose at a molar ratio (M/G) of 1.2:19.4. Animal test indicated DOW-5B increased the diversity of gut microbiota on mice. Beneficial microbes such as Ruminococcus, Eubacterium, Clostridium, Bifidobacterium, Parabacteroides and Akkermansiamuciniphila increased while harmful bacteria in Proteobacteria decreased. Surprisingly, DOW-5B promoted gut microbes to generate more butyrate and mainly produced by Parabacteroides_sp_HGS0025. Further, we found the health of large intestine as well as immunity response of mice was improved. In addition, Parabacteroides_sp_HGS0025 positively correlated with butyrate, IgM, IL-10, and TNF-α products in intestine and mice blood, respectively. The data suggested that Dendrobium officinale polysaccharide has function on immunity may be mediated by butyrate. It adds new evidence to support the basis of how herbal polysaccharides affect immunity.

Dendrobium sonia polysaccharide regulates immunity and restores the dysbiosis of the gut microbiota of the cyclophosphamide-induced immunosuppressed mice

To recognize the potential medicinal value of the Dendrobium sonia, polysaccharide (DSP) was extracted, purified, and investigated for its immunomodulatory activity. In vitro, DSP was shown to enhance the viability (MTT assay) and phagocytosis of macrophages. In cyclophosphamide-induced immunosuppressed mice, DSP increased serum levels of TNF-α, IL-6 and IFN-γ (enzyme-linked immunosorbent assay, ELISA), and ameliorated the imbalance of the community of gut microbiota as detected by 16S ribosomal RNA gene sequencing. These results suggest that DSP might be beneficial for patients under immunosuppressed conditions.

A novel polysaccharide from Dendrobium devonianum serves as a TLR4 agonist for activating macrophages

Dendrobium devonianum has been used as herbal medicines and nutraceutical products since ancient time in China. However, its chemical composition and pharmacological mechanisms are not fully known. In present studies, by chemical purification and characteristic identification, we discovered a novel polysaccharide from D. devonianum, which was designated as DvP-1 with molecular weights of 9.52 × 10⁴ Da. DvP-1 is a homogeneous heteropolysaccharide consisting of D-mannose and d-glucose in the molar ration of 10.11: 1. The main glycosidic linkages were β-1, 4-Manp, which were substituted with acetyl groups at the O-2, O-3 and/or O-6 positions. DvP-1 was found to directly stimulate the activation of macrophages in vitro, as evidenced by inducing morphologic change, thereby promoting the production of cytokines TNF-α, IL-6 and NO, and enhancing the pinocytic activity of macrophages. By establishing a zebrafish model, we also found that DvP-1 could alleviate vinorelbine-induced decrease of macrophages in vivo. Further findings indicated that DvP-1 activated macrophages through several toll-like receptors (TLRs), but mainly through TLR4. DvP-1 served as a TLR4 agonist and induced ERK, JNK, p38, and IκB-α phosphorylation, suggesting the activation of MAPK and NFκB signaling pathways downstream of TLR4. These findings could help us further understand the immunomodulating effects of D. devonianum in Chinese medicines or health foods for immunocompromised persons. They also show the medicinal value of DvP-1 for the treatment of cancer and infectious diseases caused by TLR4 dysfunction.

Discrimination of Different Species of Dendrobium with an Electronic Nose Using Aggregated Conformal Predictor

A method using electronic nose to discriminate 10 different species of dendrobium, which is a kind of precious herb with medicinal application, was developed with high efficiency and low cost. A framework named aggregated conformal prediction was applied to make predictions with accuracy and reliability for E-nose detection. This method achieved a classification accuracy close to 80% with an average improvement of 6.2% when compared with the results obtained by using traditional inductive conformal prediction. It also provided reliability assessment to show more comprehensive information for each prediction. Meanwhile, two main indicators of conformal predictor, validity and efficiency, were also compared and discussed in this work. The result shows that the approach integrating electronic nose with aggregated conformal prediction to classify the species of dendrobium with reliability and validity is promising.

Physicochemical properties of polysaccharides from Dendrobium officinale by fractional precipitation and their preliminary antioxidant and anti-HepG2 cells activities in vitro

Background

Dendrobium officinale as a precious traditional Chinese herb is widely used in medicines and health supplements. Thus the extraction, purification and biological activities of polysaccharides from the stem of Dendrobium officinale have significant meaning on theory and application value.

Methods

The crude Dendrobium officinale polysaccharide (DOP) was obtained by hot water extraction- ethanol precipitation method, and four new polysaccharide fractions (DOP-40, DOP-50, DOP-60, and DOP-70) were further obtained from the crude DOP by fractional precipitation with ethanol method, then four fractions were further purified by Toyopearl-H65F gel resin. The molecular weight and monosaccharide composition of four purified fractions were determined by high performance anion exchange chromatography and high performance liquid chromatography. The antioxidant activities of them were evaluated by the reducing power assay, and the superoxide anion, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and hydroxyl free radicals scavenging assays, respectively. Finally, the anticancer activities of them were investigated via the MTT assay and the western blot analysis using HepG2 cells.

Results

Among these four purified fractions were mainly composed of d-mannose and d-glucose with different molar ratios, and their average molecular weights were 999, 657, 243 and 50.3 kDa, respectively. What’s more, DOP-70 always exhibited the strongest antioxidant and anticancer activities, while DOP-40 and DOP-60 showed very close antioxidant and anticancer activities which were better than that of DOP-50. The western blotting analysis also showed that DOP-40, DOP-60, and DOP-70 induced apoptosis in HepG2 human liver cancer cells through the Bcl-2 and Bax-dependent pathway.

Conclusions

Fractional precipitation with ethanol could successfully apply to extract four new polysaccharide fractions from Dendrobium officinale stems, and the polysaccharide fractions possessed efficient antioxidant and anticancer activities, especially DOP-70.

Dendrobium polysaccharides attenuate cognitive impairment in senescence-accelerated mouse prone 8 mice via modulation of microglial activation

Dendrobium is one of the most important traditional Chinese medicinal foods used to treat age-related disorders. However, it remains unclear whether Dendrobium affects the progression of Alzheimer's disease (AD). In the present study, we investigated the effects of Dendrobium officinale polysaccharides (DOP) on the BV2 microglial cell line and the senescence-accelerated mouse prone 8 (SAMP8) mouse strain. In vitro experiments showed that DOP pretreatment contributed to BV2 cells shifting from proinflammatory to anti-inflammatory phenotypes with enhanced Aβ clearance in response to Aβ insults. For the in vivo study, mice were chronically treated with DOP in drinking water from 4 to 7 months of age. The results showed that DOP remarkably attenuated cognitive decline in SAMP8 mice. DOP also inhibited the increased hippocampal microglial activation in SAMP8 mice with downregulation of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), while interleukin-10 (IL-10), neprilysin (NEP) and insulin-degrading enzyme (IDE) were upregulated. The accumulation of hippocampal Aβ42 and phosphated Tau proteins in SAMP8 mice was also reduced. Taken together, our data suggest that Dendrobium has the potential to provide neuroprotection against AD-related cognitive impairment via modulation of microglial activation.

Differential Accumulation of Anthocyanins in Dendrobium officinale Stems with Red and Green Peels

Dendrobium officinale stems, including red and green stems, are widely used as a dietary supplement to develop nutraceutical beverages and food products. However, there is no detailed information on pigment composition of red and green stems. Here, we investigated the content and composition of pigments in red and green stems by Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry and assessed the differential accumulation of anthocyanins at the molecular level. The color of peels in red stems was caused by the presence of anthocyanins in epidermal cells unlike the peels of green stems. The glucoside derivatives delphinidin and cyanidin are responsible for the red color. Within the D. officinale anthocyanidin biosynthetic pathway, DoANS and DoUFGT, coding for anthocyanidin synthase and UDP-glucose flavonoid-3-O-glucosyltransferase, respectively, are critical regulatory genes related to the differential accumulation of anthocyanidin. These findings provide a more complete profile of pigments, especially anthocyanin, in D. officinale stems, and lay a foundation for producing functional foods.

Characterization and anti-tumor activity of a polysaccharide isolated from Dendrobium officinale grown in the Huoshan County

Background

Polysaccharides are carbohydrate chains composed of linked monosaccharide units. Accumulating studies report that polysaccharides isolated from Dendrobium officinale have a variety of functions. However, the composition and anti-tumor activity of D. officinale grown in the Huoshan area are largely unknown.

Methods

A polysaccharide (DOPA-1) was isolated from D. officinale by hot water extraction and ethanol precipitation, followed by purification via DEAE-cellulose and Sephadex G-100 chromatography. DOPA-1 was analyzed by infrared and nuclear magnetic resonance and then characterized by periodate oxidation and Smith degradation. The anti-tumor activity of DOPA-1 was then tested in HepG-2 cells.

Results

Our results show that DOPA-1 is mainly comprised of mannose, glucose, and galactose at a molar ratio of 1:0.42:0.27 and has an average molecular weight of 2.29 × 10⁵ Da. Additionally, DOPA-1 inhibited HepG-2 cell growth in a dose-dependent manner. DOPA-1-treated HepG-2 cells also had increased reactive oxygen species (ROS) levels and decreased mitochondrial membrane potential. Furthermore, apoptosis was observed in DOPA-1-treated HepG-2 cells along with Bcl-2 downregulation and Bax upregulation at the protein level.

Conclusions

Our findings suggest that DOPA-1 induces apoptosis in tumor cells via altered mitochondrial function, ROS production, and altered apoptosis-related protein expression. This bioactive polysaccharide could, therefore, potentially be further developed as an anti-tumor adjuvant drug.