DcERF109 regulates shoot branching by participating in strigolactone signal transduction in Dendrobium catenatum.

Shoot branching fundamentally influences plant architecture and agricultural yield. However, research on shoot branching in Dendrobium catenatum, an endangered medicinal plant in China, remains limited. In this study, we identified a transcription factor DcERF109 as a key player in shoot branching by regulating the expression of strigolactone (SL) receptors DWARF 14 (D14)/ DECREASED APICAL DOMINANCE 2 (DAD2). The treatment of D. catenatum seedlings with GR24rac/TIS108 revealed that SL can significantly repress the shoot branching in D. catenatum. The expression of DcERF109 in multi-branched seedlings is significantly higher than that of single-branched seedlings. Ectopic expression in Arabidopsis thaliana demonstrated that overexpression of DcERF109 resulted in significant shoot branches increasing and dwarfing. Molecular and biochemical assays demonstrated that DcERF109 can directly bind to the promoters of AtD14 and DcDAD2.2 to inhibit their expression, thereby positively regulating shoot branching. Inhibition of DcERF109 by virus-induced gene silencing (VIGS) resulted in decreased shoot branching and improved DcDAD2.2 expression. Moreover, overexpression of DpERF109 in A. thaliana, the homologous gene of DcERF109 in Dendrobium primulinum, showed similar phenotypes to DcERF109 in shoot branch and plant height. Collectively, these findings shed new insights into the regulation of plant shoot branching and provide a theoretical basis for improving the yield of D. catenatum.

Structure characteristics, protective effect and mechanisms of ethanol-fractional polysaccharides from Dendrobium officinale on acute ethanol-induced gastritis.

Gastritis is a common disease characterized by gastric ulcers and severe bleeding. Excessive daily alcohol consumption can cause acute gastritis, impacting individuals' quality of life. This study aims to explore the protective effects of different ethanol-fractional polysaccharides of Dendrobium officinale (EPDO) on acute alcohol-induced gastric injury in vivo. Results showed that EPDO-80, identified as a ß-glucan, exhibited significant anti-inflammatory properties in pathology. It could reduce the area of gastric mucosal injury and cell infiltration. EPDO-80 had a dose-effect relationship in reducing the levels of malondialdehyde and cyclooxygenase-2 and decreasing the levels of inflammation mediators such as tumor necrosis factor α. More extensively, EPDO-80 could inhibit the activation of the TNFR/IκB/NF-κB signaling pathway, reducing the production of TNF-α mRNA and cell apoptosis in organs. Conversely, EPDO-80 could promote changes in the gut microbiota structure. These findings suggest that EPDO-80 could have great potential in limiting oxidative stress and inflammation mediated by inhibiting the NF-κB signaling pathway, which is highly related to its ß-glucan structure and functions in gut microbiota.

Effects of Ethanol Concentrations on Primary Structural and Bioactive Characteristics of Dendrobium officinale Polysaccharides.

Ethanol fractional precipitation can initially separate polysaccharides according to the structure, which exhibits strong correlation with the biological activities. This study aimed to investigate the impact of varying ethanol concentrations on the structural characteristics, and the antitumor and antioxidant activities of polysaccharides derived from Dendrobium officinale through ethanol fractional precipitation, as well as their internal relationships. The polysaccharides acquired by absolute alcohol additions at a final liquor-ethanol volume ratio of 1:1, 1:2, and 1:4 were named DOP-1, DOP-2, and DOP-4, and the supernatant was named DOP-S. The results of the structural analysis revealed that the increase in ethanol concentrations resulted in a reduction in the molecular weights and the acetylation degree of the polysaccharides, as well as a decrease in mannose content and an increase in glucose content. In vitro experiments demonstrated that DOP-S exhibited optimal antitumor and antioxidant activities. Animal experiments further confirmed that DOP-S suppressed the growth of solid tumors significantly, enhanced lymphocytes, mediated immune ability, and improved the activity of antioxidant enzymes. These findings would establish a theoretical foundation and provide technical support for further advances and applications of polysaccharides derived from D. officinale in the fields of food and medicine.

Integrated component identification, network pharmacology, and experimental verification revealed mechanism of Dendrobium officinale Kimura et Migo against lung cancer.

BACKGROUND: Dendrobium officinale Kimura et Migo (DO), a valuable Chinese herbal medicine, has been reported to exhibit potential effects in the prevention and treatment of lung cancer. However, its material basis and mechanism of action have not been comprehensively analyzed. PURPOSE: The objective of this study was to preliminarily elucidate the active components and pharmacological mechanisms of DO in treating lung cancer, according to UPLC-Q/TOF-MS, HPAEC-PAD, network pharmacology, molecular docking, and experimental verification. METHODS: The chemical components of DO were identified via UPLC-Q/TOF-MS, while the monosaccharide composition of Dendrobium officinale polysaccharide (DOP) was determined by HPAEC-PAD. The prospective active constituents of DO as well as their respective targets were predicted in the combined database of Swiss ADME and Swiss Target Prediction. Relevant disease targets for lung cancer were searched in OMIM, TTD, and Genecards databases. Further, the active compounds and potential core targets of DO against lung cancer were found by the C-T-D network and the PPI network, respectively. The core targets were then subjected to enrichment analysis in the Metascape database. The main active compounds were molecularly docked to the core targets and visualized. Finally, the viability of A549 cells and the relative quantity of associated proteins within the major signaling pathway were detected. RESULTS: 249 ingredients were identified from DO, including 39 flavonoids, 39 bibenzyls, 50 organic acids, 8 phenanthrenes, 27 phenylpropanoids, 17 alkaloids, 17 amino acids and their derivatives, 7 monosaccharides, and 45 others. Here, 50 main active compounds with high degree values were attained through the C-T-D network, mainly consisting of bibenzyls and monosaccharides. Based on the PPI network analysis, 10 core targets were further predicted, including HSP90AA1, SRC, ESR1, CREBBP, MAPK3, AKT1, PIK3R1, PIK3CA, HIF1A, and HDAC1. The results of the enrichment analysis and molecular docking indicated a close association between the therapeutic mechanism of DO and the PI3K-Akt signaling pathway. It was confirmed that the bibenzyl extract and erianin could inhibit the multiplication of A549 cells in vitro. Furthermore, erianin was found to down-regulate the relative expressions of p-AKT and p-PI3K proteins within the PI3K-Akt signaling pathway. CONCLUSIONS: This study predicted that DO could treat lung cancer through various components, multiple targets, and diverse pathways. Bibenzyls from DO might exert anti-lung cancer activity by inhibiting cancer cell proliferation and modulating the PI3K-Akt signaling pathway. A fundamental reference for further studies and clinical therapy was given by the above data.

Drought Stress Induced Different Response Mechanisms in Three Dendrobium Species under Different Photosynthetic Pathways.

Many Dendrobium species, which hold a high status and value in traditional Chinese medicine, grow on barks and rocks in the wild, often encountering harsh environments and facing droughts. However, the molecular mechanisms underlying the shift in the photosynthetic pathway induced by drought remain unclear. To address this issue, three Dendrobium species with different photosynthetic pathways were selected for sequencing and transcriptome data analysis after drought treatment. The findings included 134.43 GB of sequencing data, with numerous Differentially Expressed Genes (DEGs) exhibiting different response mechanisms under drought stress. Gene Ontology (GO)-KEGG-based enrichment analysis of DEGs revealed that metabolic pathways contributed to drought tolerance and alterations in photosynthetic pathways. Phosphoenolpyruvate Carboxylase (PEPC) was subjected to phylogenetic tree construction, sequence alignment, and domain analysis. Under drought stress, variations were observed in the PEPC gene structure and expression among different Dendrobium species; the upregulation of Dc_gene2609 expression may be caused by dof-miR-384, which resulted in the shift from C3 photosynthesis to CAM, thereby improving drought tolerance in Dendrobium. This study revealed the expression patterns and roles of PEPC genes in enhancing plant drought tolerance and will provide an important basis for in-depth research on Dendrobium's adaptation mechanisms in arid environments.

Dendrobium officinale flowers' topical extracts improve skin oxidative stress and aging.

BACKGROUND: Dendrobium officinale flowers (DOF) have the effects of antiaging and nourishing yin, but it lacks pharmacological research on skin aging. OBJECTIVE: Confirming the role of DOF in delaying skin aging based on the "in vitro animal-human" model. METHODS: In this experiment, three kinds of free radical scavenging experiments in vitro, D-galactose-induced aging mouse model, and human antiaging efficacy test were used to test whether DOF can improve skin aging through anti-oxidation. RESULTS: In vitro experiment shows that DOF has certain scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical, hydroxyl free radical, and superoxide free radical, and its IC50 is 0.2090 µg/mL, 15.020, and 1.217 mg/mL respectively. DOF can enhance the activities of T-AOC, SOD, CAT, and GSH Px in the serum of aging mice, increase the content of GSH, and reduce the content of MDA when administered with DOF of 1.0, 2.0, and 4.0 g/kg for 6 weeks. In addition, it can enhance the activity of SOD in the skin of aging mice, increase the content of Hyp, and decrease the content of MDA, activated Keap1/Nrf2 pathway in the skin of aging mice. Applying DOF with a concentration of 0.2 g/mL on the face for 8 weeks can significantly improve the skin water score and elasticity value, reduce facial wrinkles, pores, acne, and UV spots, and improve the facial brown spots and roughness. CONCLUSION: DOF can significantly improve skin aging caused by oxidative stress, and its mechanism may be related to scavenging free radicals in the body and improving skin quality.

[Cloning and functional analysis of flavanone synthase â ¡ from Dendrobium huoshanense].

Flavonoid C-glycosides are a class of natural products that are widely involved in plant defense responses and have diverse pharmacological activities. They are also important active ingredients of Dendrobium huoshanense. Flavanone synthase Ⅱ has been proven to be a key enzyme in the synthesis pathway of flavonoid C-glycosides in plants, and their catalytic product 2-hydroxyflavanone is the precursor compound for the synthesis of various reported flavonoid C-glycosides. In this study, based on the reported amino acid sequence of flavanone synthase Ⅱ, a flavanone synthase Ⅱ gene(DhuFNSⅡ) was screened and verified from the constructed D. huoshanense genome localization database. Functional validation of the enzyme showed that it could in vitro catalyze naringenin and pinocembrin to produce apigenin and chrysin, respectively. The open reading frame(ORF) of DhuFNSⅡ was 1 644 bp in length, encoding 547 amino acids. Subcellular localization showed that the protein was localized on the endoplasmic reticulum. RT-qPCR results showed that DhuFNSⅡ had the highest expression in stems, followed by leaves and roots. The expression levels of DhuFNSⅡ and other target genes in various tissues of D. huoshanense were significantly up-regulated after four kinds of abiotic stresses commonly encountered in the growth process, but the extent of up-regulation varied among treatment groups, with drought and cold stress having more significant effects on gene expression levels. Through the identification and functional analysis of DhuFNSⅡ, this study is expected to contribute to the elucidation of the molecular mechanism of the formation of quality metabolites of D. huoshanense, flavonoid C-glycosides, and provide a reference for its quality formation and scientific cultivation.

Residue analysis and dietary risk assessment of picoxystrobin in potato (Solanum tuberosum), citrus fruit (Citrus reticulata Blanco), and Dendrobium officinale Kimura et Migo.

Picoxystrobin is a systemic fungicide widely used on potato, citrus fruit, and Dendrobium officinale. To provide information for the risk assessment of potato, citrus, and Dendrobium officinale, field experiments combined with QuEChERS and HPLC-MS/MS were performed to detect picoxystrobin. Picoxystrobin had good linearity (R2 > 0.99), the average recovery rate was 75 - 102%, and the relative standard deviation was 1 - 11%. Picoxystrobin was utilized as the test agent in field experiments, and samples were evaluated and analyzed at various times after the final application utilizing random sampling. The results showed that picoxystrobin residuals in potato and citrus (orange meat) were ˂ 0.01 mg kg-1, whereas those in citrus whole fruit, D. officinale (fresh), and D. officinale (dried) were < 0.05 - 0.084, 0.16 - 3.82, and 0.34 - 9.05 mg kg-1, respectively. Based on these results, both the acute risk quotient (2.77%) and chronic risk quotient (8.7%) were ˂100%, and the dietary risk assessment indicated that the intake of picoxystrobin residues in potato, citrus fruit, and D. officinale did not pose a health risk. This study can guide the reasonable use of picoxystrobin in potato, citrus fruit, and D. officinale.

Critical review on the research of chemical structure, bioactivities, and mechanism of actions of Dendrobium officinale polysaccharide.

Dendrobium officinale (Tie-Pi-Shi-Hu) is a precious traditional Chinese medicine (TCM). The principal active components are polysaccharides (DOP), which have a high potency in therapeutic applications. However, limitations in structure analysis and underlying mechanism investigation impede its further research. This review systemically and critically summarises current understanding in both areas, and points out the influence of starch impurities and the role of gut microbiota in DOP research. As challenges faced in studying natural polysaccharide investigations are common, this review contributes to a broader understanding of polysaccharides beyond DOP.

Diverse modulatory effects of bibenzyls from Dendrobium species on human immune cell responses under inflammatory conditions.

Dendrobium plants are widely used in traditional Chinese medicine. Their secondary metabolites such as bibenzyls and phenanthrenes show various pharmacological benefits such as immunomodulation and inhibitory effects on cancer cell growth. However, our previous study also showed that some of these promising compounds (i.e., gigantol and cypripedin) also induced the expression of inflammatory cytokines including TNF in human monocytes, and thus raising concerns about the use of these compounds in clinical application. Furthermore, the effects of these compounds on other immune cell populations, apart from monocytes, remain to be investigated. In this study, we evaluated immunomodulatory effects of seven known bibenzyl compounds purified from Dendrobium species in human peripheral blood mononuclear cells (PBMCs) that were stimulated with lipopolysaccharide (LPS). Firstly, using flow cytometry, moscatilin (3) and crepidatin (4) showed the most promising dose-dependent immunomodulatory effects among all seven bibenzyls, determined by significant reduction of TNF expression in LPS-stimulated CD14+ monocytes. Only crepidatin at the concentration of 20 µM showed a significant cytotoxicity, i.e., an increased cell death in late apoptotic state. In addition, deep immune profiling using high-dimensional single-cell mass cytometry (CyTOF) revealed broad effects of Dendrobium compounds on diverse immune cell types. Our findings suggest that to precisely evaluate therapeutic as well as adverse effects of active natural compounds, a multi-parameter immune profiling targeting diverse immune cell population is required.

Dendrobium officinale Polysaccharides as a Natural Functional Component for Acetic-Acid-Induced Gastric Ulcers in Rats.

Dendrobium officinale is an important edible and medicinal plant, with the Dendrobium officinale polysaccharide (DOP) being its primary active constituent, known for its diverse biological activities. In this study, DOP was extracted and characterized for its structural properties. The potential of DOP to ameliorate gastric ulcers (GUs) was investigated using an acetic-acid-induced GU model in rats. The results demonstrated that DOP exerted a multifaceted protective effect against GU, mitigating the deleterious impact on food intake and body weight in rats. DOP exhibited its protective action by attenuating cellular damage attributed to oxidative stress and inflammatory reactions mediated by enhanced activities of SOD, GSH, and GSH-PX, coupled with a downregulation in the expression of pro-inflammatory cytokines, including IL-1ß, IL-6, and TNF-α. Furthermore, DOP effectively inhibited apoptosis in gastric mucosa cells of acetic-acid-induced GU rat models and facilitated the self-repair of damaged tissues. Remarkably, the DOP-200 and DOP-400 groups outperformed omeprazole in reducing the expression of IL-6 and malondialdehyde (MDA) in tissues, as well as IL-1ß, IL-6, and TNF-α in serum. These groups also exhibited an improved expression of SOD in tissues and SOD, GSH, and GSH-PX in serum. A Western blot analysis of gastric mucosa demonstrated that the DOP-200 and DOP-400 groups significantly reduced the expression of NF-κBp65, phosphorylated NF-κBp65, FoxO3a, and Bim. The observed antagonism to GU appeared to be associated with the NF-κB cell pathway. Additionally, qRT-PCR results indicate that DOP reduced the mRNA transcription levels of IL-6, and TNF-α, which shows that the healing of GU is related to the reduction in the inflammatory reaction by DOP. However, the expression of EGF and VEGF decreased, suggesting that the mechanism of DOP inhibiting GU may not be directly related to EGF and VEGF, or there is an uncertain competitive relationship between them, so further research is needed.

Dendrobium huoshanense in the treatment of ulcerative colitis: Network pharmacology and experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: Dendrobium huoshanense C. Z. Tang et S. J. Cheng (DH) is a traditional medicinal herb with a long history of medicinal use. DH has been recorded as protecting the gastrointestinal function. Modern pharmacology research shows that DH regulates intestinal flora, intestinal mucosal immunity, gastrointestinal peristalsis and secretion of digestive juices. At the same time, some studies have shown that DH has a good therapeutic effect on ulcerative colitis, but its mechanism of action has not been fully elucidated. AIMS OF THIS STUDY: To investigate the mechanism and effect of Dendrobium huoshanense C. Z. Tang et S. J. Cheng (DH) in the treatment of ulcerative colitis (UC) by combining network pharmacology and in vivo experimental validation. METHODS: A network pharmacology approach was used to perform component screening, target prediction, PPI network interaction analysis, GO and KEGG enrichment analysis to initially predict the mechanism of DH treatment for UC. Then, the mechanism was validated with the UC mouse model induced by 3% DSS. RESULTS: Based on the network pharmacological analysis, a comprehensive of 101 active components were identified, with 19 of them potentially serving as the crucial elements in DH's effectiveness against UC treatment. Additionally, the study revealed 314 potential core therapeutic targets along with the top 5 key targets: SRC, STAT3, AKT1, HSP90AA1, and PIK3CA. In experiments conducted on live mice with UC, DH was found to decrease the levels of IL-6 and TNF-α in the blood, while increasing the levels of IL-10 and TGF-ß. This led to notable improvements in colon length, injury severity, and an up-regulation of SRC, STAT3, HSP90AA1, PIK3CA, p-AKT1 and PI3K/AKT signaling pathway expression in the colon tissue. CONCLUSIONS: In this study, the active components and main targets of DH for UC treatment were initially forecasted, and the potential mechanism was investigated through network pharmacology. These findings offer an experimental foundation for the clinical utilization of DH.

Wild imitating vs greenhouse cultivated Dendrobium huoshanense: Chemical quality differences.

Dendrobium huoshanense (D. huoshanense) has been used as functional food supplements and herbal medicines for preventing and managing diseases with a long history in China. Due to its endangered natural resources and huge demand, people tend to cultivate D. huoshanense to protect this species. However, the quality of wild and cultivated herbs of the same species may change. This work quantified and compared the main quality traits and chemical components of wild imitating and greenhouse cultivated D. huoshanense with different growth years. As a result, wild and cultivated D. huoshanense had similar chemical composition, but there are significant differences in the content of many ingredients (polysaccharides, flavonoids, nucleosides, bibenzyls, lignans and volatile compounds). And the contents of many of these components increased with growing years. In addition, multivariate statistical analyses have been applied to classify and evaluate samples from different cultivation modes according to these components. In conclusion, our results demonstrated that the overall quality of greenhouse cultivated D. huoshanense was not as good as wild-grown, but this mode can be a promising and sustainable way of producing D. huoshanense.

Genome-wide identification of the alkaloid synthesis gene family CYP450, gives new insights into alkaloid resource utilization in medicinal Dendrobium.

The medicinal Dendrobium species of Orchidaceae possess significant pharmaceutical value, and modern pharmacological research has shown that Dendrobium contains many important active ingredients. Alkaloids, the crucial components of medicinal Dendrobium, demonstrate beneficial healing properties in cardiovascular, cataract, gastrointestinal, and respiratory diseases. Members of the cytochrome P450 monooxygenase (CYP) gene family play essential roles in alkaloid synthesis, participating in alkaloid terpene skeleton construction and subsequent modifications. Although studies of the CYP family have been conducted in some species, genome-wide characterization and systematic analysis of the CYP family in medicinal Dendrobium remain underexplored. In this study, we identified CYP gene family members in the genomes of four medicinal Dendrobium species recorded in the Pharmacopoeia: D. nobile, D. chrysotoxum, D. catenatum, and D. huoshanense. Further, we analyzed the motif composition, gene replication events, and selection pressure of this family. Syntenic analysis revealed that members of the clan 710 were present on chromosome 18 in three medicinal Dendrobium species, except for D. nobile, indicating a loss of clan 710 occurring in D. nobile. We also conducted an initial screening of the CYP genes involved in alkaloid synthesis through transcriptome sequencing. Quantitative real-time reverse transcription PCR showed that the expression of DnoNew43 and DnoNew50, homologs of secologanin synthase involved in the alkaloid synthesis pathway, was significantly higher in the stems than in the leaves. This result coincided with the distribution of dendrobine content in Dendrobium stems and leaves, indicating that these two genes might be involved in the dendrobine synthesis pathway. Our results give insights into the CYP gene family evolution analysis in four medicinal Dendrobium species for the first time and identify two related genes that may be involved in alkaloid synthesis, providing a valuable resource for further investigations into alkaloid synthesis pathway in Dendrobium and other medicinal plants.

Sesquiterpenoids and bibenzyl derivative from Dendrobium hercoglossum.

Three new sesquiterpenoids, dendrohercoglin A - C (1-3), and one new bibenzyl derivative, dendronbiline D (4), together with nine known sesquiterpenoids (5-13) were isolated from Dendrobium hercoglossum. The structures of the new compounds were elucidated by extensive spectroscopic analysis as well as NMR and ECD calculations. All the compounds were evaluated for their neuroprotective and anti-inflammatory activities. Compounds 2 and 3 increased the H2O2-damaged SH-SY5Y cell viabilities from 43.3% to 58.6% and 68.4%, respectively. Compound 4 exhibited pronounced anti-inflammatory activity with IC50 value of 9.5 ± 0.45 µM which was superior to the reference compound quercetin (IC50: 15.7 ± 0.89 µM).

Detection of the Adulteration of Dendrobium Huoshanense with Dendrobium Henanense by UV-Vis-Shortwave Near-Infrared Diffuse Reflectance Spectroscopy Combined with Chemometrics.

BACKGROUND: Dendrobium huoshanense (DHS) is a classic traditional Chinese medicine (TCM) with distinctive medicinal benefits and great economic worth; nevertheless, because of similar tastes and looks, it is simple to adulterate with less expensive substitutes (such as Dendrobium henanense [DHN]). OBJECTIVE: This work aimed to develop a reliable tool to detect and quantify the adulteration of DHS with DHN by using UV-Vis-shortwave near-infrared diffuse reflectance spectroscopy (UV-Vis-SWNIR DRS) combined with chemometrics. METHODS: Adulterated samples prepared in varying concentrations (0-100%, w/w) were analyzed with UV-Vis-SWNIR DRS methods. Partial least-square-discriminant analysis (PLS-DA) and partial least-squares (PLS) regression techniques were used for the differentiation of adulterated DHN from pure DHS and the prediction of adulteration levels. RESULTS: The PLS-DA classification models successfully differentiated adulterated and nonadulterated DHS with an over 100% correct classification rate. UV-Vis-SWNIR DRS data were also successfully used to predict adulteration levels with a high coefficient of determination for calibration (0.9924) and prediction (0.9906) models and low error values for calibration (3.863%) and prediction (5.067%). CONCLUSION: UV-Vis-SWNIR DRS, as a fast and environmentally friendly tool, has great potential for both the identification and quantification of adulteration practices involving herbal medicines and foods. HIGHLIGHTS: UV-Vis-SWNIR DRS combined with chemometrics can be applied to identify and quantify the adulteration of herbal medicines and foods.

Phytochemical Profile of Alkaloid Extract from Dendrobium huoshanense and Inhibitory Effects against Oxidative Stress in H2 O2 -Induced PC12 Cells.

This study aimed to explore the alkaloid profile of Dendrobium huoshanense and determine the potential protective effect against oxidative damage. The crude D. huoshanense alkaloid extract (DHAE) was obtained by 70 % ethanol extraction and liquid-liquid partition. DHAE contained specific alkaloid components with abundant 6-hydroxynobiline (58.15 %) and trace dendrobine (3.23 %) in the preliminary HPLC fingerprint and GC-MS analysis, which was distinguished from D. officinale or D. nobile. Subsequently, six alkaloids including 6-hydroxynobiline, 2-hydroxy dendrobine, nobilonine, dendrobine, Findlayines D and trans-dendrochrysanine were identified in the purified DHAE (namely DHSAE-3, DHSAE-3') via further solid phase extraction coupled with UPLC-MS/MS analysis. Meanwhile, pretreatment with DHAE or DHSAE (0.5, 5 µg/mL) increased cell viability by 14.0-57.4 % compared to that of H2 O2 -induced PC12 Model cells. Among them, 5 µg/mL DHSAE-3-treated cells displayed a pronounced reversion than the positive vitamin E (p<0.01). Furthermore, a clear cellular morphological restoration and 38.4 % reduction in intracellular reactive oxidative species level were achieved. Our findings suggest that D. huoshanense has a characteristic alkaloid profile represented by abundant 6-hydroxynobiline, and DHAEs exhibit obvious protection against oxidative neuronal damage. Overall, this study indicates that DHAEs might be used to inhibit oxidative stress and provide a source to develop novel neuroprotective drugs.

Dendrobium nobile Lindl ameliorates learning and memory deficits in scopolamine-treated mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Dendrobium nobile Lindl (DNL), a valued time-honored herb, possesses immune-boosting and age-delaying properties, has been widely used to treat hyperglycemia and neurological diseases, and is probably a potential drug for improving learning and memory. Scopolamine (Scop), an antagonist for muscarinic receptors, potentially impairing intelligence and memory. AIM OF THE STUDY: This investigation aimed to assess the efficacy of DNL in alleviating scopolamine-induced cognitive deficits in mice and its mechanisms. MATERIALS AND METHODS: We utilized the open-field test, novel object recognition test (NOR), and Morris water maze test (MWM) to assess the potential of DNL in ameliorating learning and memory dysfunction caused by scopolamine in mice. Enzyme-linked immunosorbent assay (ELISA) was employed to measure Choline acetyltransferase (ChAT) content and Acetylcholinesterase (AChE) activities in the brain, and oxidative stress-related factors in the serum, including Malondialdehyde (MDA), Superoxide dismutase (SOD), and glutathione (GSH) content. RESULTS: Scopolamine injection significantly reduced the discrimination index of mice in the NOR test and impaired their performance in the MWM test, as demonstrated by longer escape latency, fewer target crossings, and less time spent in the target quadrant in the MWM. After 25 days of administration, DNL increased the discrimination index of the scopolamine-treated mice in the NOR test. DNL reduced the escape latency in the MWM test in the model mice. DNL increased the target crossing number and the percentage of time spent in the target quadrant in the MWM test. ELISA experiments indicated that DNL decreased the AChE activities, increased the ChAT activities, and modulated oxidative stress makers (GSH, SOD, and MDA) in scopolamine-induced mice. CONCLUSIONS: DNL may improve the learning and memory in mice treated with scopolamine, possibly by modulating oxidative stress and impaired cholinergic function.

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

ETHNOPHARMACOLOGICAL RELEVANCE: Dendrobium officinale Kimura & Migo (DEN) is a traditional medicine in China since Han dynasty. Decoction of its stem is often used in the treatment of Type-II diabetes (T2D), which is a typical metabolic disease accompanied with the impaired metabolic function of blood glucose and lipid. AIM OF THE STUDY: Our study aimed to investigate the role of gut microbiota in differentiating DEN from different sources and its related pathway in the alleviation of metabolic syndromes induced by T2D. MATERIALS AND METHODS: The aqueous extracts of four commercially available Dendrobium (DEN-1∼4) were prepared and screened through an in-vitro fermentation system. Based on their alterations in monosaccharide composition and short chain fatty acids (SCFA) formation during fermentation with db/db faecal fluid, one DEN extract was selected for further in vivo verification. The selected Dendrobium (DEN-4) was orally administered to db/db mice for 16 days once daily at the dosage of 200 mg/kg followed by evaluating its effect on blood glucose level, liver function and intestinal microenvironment including alterations of intestinal integrity and gut microbiota composition. In addition, liver metabolomics analysis was employed to reveal the related metabolic pathways. RESULTS: Different extent of SCFA formation and utilization of monosaccharides were observed for the extracts of four DEN from different sources with a negative correlation between SCFA level and the ratio of Utilized glucose/Utilized mannose observed in the in-vitro fermentation system with db/db faecal fluid. DEN-4 with the highest SCFA formation during the in-vitro fermentation was selected and exhibited significantly hypoglycaemic effect in db/db mice with the alleviation of hepatic steatosis and impaired lipid homeostasis. Further mechanistic studies revealed that orally administered DEN-4 could improve the intestinal integrity of db/db mice via elevating their tight junction protein (ZO-1 and Occludin) expression in the colon and improve the diversity of gut microbiota with enhanced formation of SCFA. Moreover, metabolomics and KEGG pathway analysis of liver tissues suggested that the alleviated metabolic syndrome in db/db mice by DEN-4 might possibly be achieved through activation of PPAR pathway. CONCLUSION: Our current study not only revealed the potential of gut microbiota in differentiating DEN from different sources, but also demonstrated that DEN exhibited its beneficial effect on the T2D induced metabolic syndrome possibly through enhancement of intestinal integrity and activation of PPAR pathway via gut-liver axis in db/db mice.

Dendrobium officinale polysaccharides-chemical properties and pharmacodynamic effects on the airways in experimental conditions.

The study aimed to analyze the effects of Dendrobium polysaccharides on the cough and airway reactivity and compare them with the effects of clinically used antitussives (codeine phosphate and butamirate citrate) and bronchodilators (salbutamol), using the guinea pig test system. Dendrobium officinale polysaccharides contained proteins (4.0 wt%) and phenolic compounds (1.7 wt%) with a molecular weight of 25,000 g/mol. The sugar analysis revealed a dominance of glucose (93.7 wt%) and a lesser amount of mannose (5.1 wt%) while other sugar quantities were negligible. Methylation analysis indicated the presence of highly branched polysaccharides. Glucose was found mainly as terminal, 1,4- and 1,6-linked. Furthermore, some 1,4- and 1,6-linked glucose units were found branched at O2, O3, and O6/O4. Mannose was terminal and 1,4-linked. NMR spectra signals indicate the presence of the (1→4)-linked α-d-glucan, (1→4)-linked ß-d-glucan branched at position O6, (1→6)-linked ß-d-glucan branched at position O3 and (1→4)-linked glucomannan. Pharmacological studies showed statistically significant antitussive activity of Dendrobium polysaccharides, exceeding the effect of clinically used antitussives, which may be partially associated with confirmed bronchodilation and the ability of polysaccharides to increase the threshold of cough receptor activation. Dendrobium polysaccharides may increase the possibility of symptomatic treatment of cough, especially in asthmatics.