Traditional uses, chemical compositions and pharmacological activities of Dendrobium: A review

Octahydroindolizine alkaloid Homocrepidine A from Dendrobium crepidatum attenuate P. acnes-induced inflammatory in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium crepidatum Lindl. ex Paxton is a perennial epiphyte of Dendrobium genus, distributed in southern China, and utilized as the traditional Chinese medicine "Shihu" in Yunnan Province. Due to its heat-clearing and detoxicating properties, it is formulated as the "XiaoCuoWan" as recorded in the China Pharmacopoeia, and specially used to treat chronic skin inflammatory diseases, such as acne.

AIM OF THE STUDY

This research aimed to estimate impact of the octahydroindoline alkaloid Homocrepidine A (HCA), isolated from D. crepidatum, on acne inflammation using both human THP-1 cells and mouse models. Furthermore, the potential anti-inflammatory mechanism of HCA has been analyzed through molecular biology methods and computer simulation.

MATERIALS AND METHODS

THP-1 cells and mouse models induced by live Propionibacterium acnes (P. acnes) were employed to evaluate the anti-inflammatory properties of crude extract of D. crepidatum (DCE) and HCA. ELISA was utilized to detect the release of inflammatory cytokines in both cellular and murine ear tissues. RNAseq was used to screen the pathways associated with HCA-mediated inflammatory inhibition, while Western blot, RT-qPCR, and immunofluorescence were utilized to detect the expression of relevant proteins. Additionally, molecular docking simulations and cellular thermal shift assays were employed to confirm the target of HCA.

RESULTS

Our research shows that DCE and HCA can effectively alleviate acne inflammation. HCA inhibits TLR2 expression by interacting with amino acid residues in the TIR domain of hTLR2, including Pro-681, Asn-688, Trp-684, and Ile-685. Moreover, HCA disrupts inflammatory signal transduction mediated by MAPK and NF-κB pathways through MyD88-dependent pathway. Additionally, HCA treatment facilitates Nrf2 nuclear translocation and upregulates HO-1 expression, thereby inhibiting NLRP3 inflammasomes activation. In vivo experiments further revealed that HCA markedly attenuated erythema and swelling caused by P. acnes in mice ears, while also decreasing the expression of pro-inflammatory cytokines IL-1β and IL-8.

CONCLUSIONS

Our research highlights the protective effects of D. crepidatum and its bioactive compound HCA against acne inflammation, marking the first exploration of its potential in this context. The discoveries indicate that HCA treatment may represent a promising functional approach for acne therapy.

Acylated anthocyanins from Dendrobium officinale Kimura & Migo: Structural characteristics, antioxidant and hypoglycemic activities

Dendrobium officinale Kimura & Migo (D. officinale) has been widely used as Chinese medicine and functional food. In present study, the structural characteristics of anthocyanins in D. officinale were investigated by ultra-performance liquid chromatography with diode array detector (UPLC-DAD) and ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS/MS). Totally, 14 anthocyanins were detected and identified, and 13 of them were first reported in D. officinale. Results showed that the vast majority of anthocyanins had multi-glycosylated cyanidin core, with variable acylation pattern mainly comprising phenolic acids. The composition and content of anthocyanins in D. officinale stems with different cultivation modes and years have been compared. The anthocyanins showed potent antioxidant activity in terms of radicals scavenging capacity and reducing power, as well as superior α-amylase and α-glucosidase inhibitory activity. The results provided a complete profile of anthocyanins in D. officinale and laid a foundation for further utilizing them as functional foods.

Quantitative analysis of six sesquiterpene glycosides from Dendrobium nobile Lindl. under different growth conditions by high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry in MRM mode

INTRODUCTION

The sesquiterpene glycosides (SGs) from Dendrobium nobile Lindl. have immunomodulatory effects. However, there are no studies on the growth conditions affecting its contents and quantitative analysis methods.

OBJECTIVE

In the present study, a quantitative analysis method for six SGs from D. nobile was established. We explored which growth conditions could affect the contents of SGs, providing a basis for the cultivation and clinical application of D. nobile.

METHODS

Firstly, based on the optimization of mass spectrometry parameters and extraction conditions for six SGs in D. nobile, a method for the determination of the contents of six SGs was established using high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (HPLC-QqQ-MS/MS) in multiple reaction monitoring (MRM) mode. Then, the methodology of the established method was validated. Secondly, the established method was applied to determine the contents of six SGs from 78 samples of D. nobile grown under different growth conditions. Finally, chemometrics analysis was employed to analyze the results and select optimal growth conditions for D. nobile.

RESULTS

The results indicated significant variations in the contents of SGs from D. nobile grown under different growth conditions. The primary factors influencing SG contents included age, geographical origin, altitude, and epiphytic pattern.

CONCLUSION

Therefore, the established method for determining SG contents from D. nobile is stable. In particular, the SG contents were relatively high in samples of 3-year-old D. nobile grown at an altitude of approximately 500 m on Danxia rocks in Chishui, Guizhou.

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.

Metabolites rapid-annotation in mice by comprehensive method of virtual polygons and Kendric mass loss filtering: A case study of Dendrobium nobile Lindl

With significant advancements in high-resolution mass spectrometry, there has been a substantial increase in the amount of chemical component data acquired from natural products. Therefore, the rapid and efficient extraction of valuable mass spectral information from large volumes of high-resolution mass spectrometry data holds crucial significance. This study illustrates a targeted annotation of the metabolic products of alkaloid and sesquiterpene components from Dendrobium nobile (D. nobile) aqueous extract in mice serum through the integration of an in-houses database, R programming, a virtual metabolic product library, polygonal mass defect filtering, and Kendrick mass defect strategies. The research process involved initially establishing a library of alkaloids and sesquiterpenes components and simulating 71 potential metabolic reactions within the organism using R programming, thus creating a virtual metabolic product database. Subsequently, employing the virtual metabolic product library allowed for polygonal mass defect filtering, rapidly screening 1705 potential metabolites of alkaloids and 3044 potential metabolites of sesquiterpenes in the serum. Furthermore, based on the chemical composition database of D. nobile and online mass spectrometry databases, 95 compounds, including alkaloids, sesquiterpenes, and endogenous components, were characterized. Finally, utilizing Kendrick mass defect analysis in conjunction with known alkaloids and sesquiterpenes targeted screening of 209 demethylation, methylation, and oxidation products in phase I metabolism, and 146 glucuronidation and glutathione conjugation products in phase II metabolism. This study provides valuable insights for the rapid and accurate annotation of chemical components and their metabolites in vivo within natural products.

Dendrobium nobile Polysaccharide Attenuates Blue Light-Induced Injury in Retinal Cells and In Vivo in Drosophila

Blue light is the higher-energy region of the visible spectrum. Excessive exposure to blue light is known to induce oxidative stress and is harmful to the eyes. The stems of Dendrobium nobile Lindl. (Orchidaceae), named Jinchaishihu, have long been used in traditional Chinese medicine (TCM) for nourishing yin, clearing heat, and brightening the eyes. The polysaccharide is one of the major components in D. nobile. However, the effect on ocular cells remains unclear. This study aimed to investigate whether the polysaccharide from D. nobile can protect the eyes from blue light-induced injury. A crude (DN-P) and a partially purified polysaccharide (DN-PP) from D. nobile were evaluated for their protective effects on blue light-induced damage in ARPE-19 and 661W cells. The in vivo study investigated the electroretinographic response and the expression of phototransduction-related genes in the retinas of a Drosophila model. The results showed that DN-P and DN-PP could improve blue light-induced damage in ARPE-19 and 661W cells, including cell viability, antioxidant activity, reactive oxygen species (ROS)/superoxide production, and reverse opsin 3 protein expression in a concentration-dependent manner. The in vivo study indicated that DN-P could alleviate eye damage and reverse the expression of phototransduction-related genes, including ninaE, norpA, Gαq, Gβ76C, Gγ30A, TRP, and TRPL, in a dose-dependent manner in blue light-exposed Drosophila. In conclusion, this is the first report demonstrating that D. nobile polysaccharide pretreatment can protect retinal cells and retinal photoreceptors from blue light-induced damage. These results provide supporting evidence for the beneficial potential of D. nobile in preventing blue light-induced eye damage and improving eyesight.

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.

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.

Two new sesquiterpene glycosides from Dendrobium findleyanum

One new ylangene-type sesquiterpene glycoside, findlayanoside C (1), and one new picrotoxane-type sesquiterpene glycoside, findlayanoside D (3), together with five known sesquiterpene glycosides, dendrofindlayanoside C (2), dendronobiloside B (4), dendronobiloside A (5), dendroside F (6) and dendromoniliside D (7), have been isolated from the stems of Dendrobium findleyanum. The structures of compounds 1 and 3 were elucidated by means of extensive spectroscopic analyses, and their absolute configuration were confirmed by electronic circular dichroism (ECD) calculations. Cytotoxic activity assays against SMMC-7721, A-549 and MCF-7 human cancer cell lines revealed IC50 values of 10.12, 12.32 and 14.13 μM for compound 1, and of 9.25, 13.16 and 16.26 μM for compound 2. This study enriches the anti-tumour sesquiterpenoids composition of D. findleyanum.

Hypoglycemic Effects and Quality Marker Screening of Dendrobium nobile Lindl. at Different Growth Years

(1) Background: The effect of Dendrobium nobile Lindl. (D. nobile) on hyperglycemic syndrome has only been recently known for several years. Materials of D. nobile were always collected from the plants cultivated in various growth ages. However, regarding the efficacy of D. nobile on hyperglycemic syndrome, it was still unknown as to which cultivation age would be selected. On the other hand, with the lack of quality markers, it is difficult to control the quality of D. nobile to treat hyperglycemic syndrome. (2) Methods: The effects of D. nobile cultivated at year 1 and year 3 were checked on alloxan-induced diabetic mice while their body weight, diet, water intake, and urinary output were monitored. Moreover, levels of glycosylated serum protein and insulin were measured using Elisa kits. The constituents of D. nobile were identified and analyzed by using UPLC-Q/trap. Quality markers were screened out by integrating the data from UPLC-Q/trap into a network pharmacology model. (3) Results: The D. nobile cultivated at both year 1 and year 3 showed a significant effect on hyperglycemic syndrome at the high dosage level; however, regarding the significant level, D. nobile from year 1 showed the better effect. In D. nobile, most of the metabolites were identified as alkaloids and sesquiterpene glycosides. Alkaloids, represented by dendrobine, were enriched in D. nobile from year 1, while sesquiterpene glycosides were enriched in D. nobile from year 3. Twenty one metabolites were differentially expressed between D. nobile from year 1 and year 3. The aforementioned 21 metabolites were enriched to 34 therapeutic targets directly related to diabetes. (4) Conclusions: Regarding the therapy for hyperglycemic syndrome, D. nobile cultivated at year 1 was more recommended than that at year 3. Alkaloids were recommended to be used as markers to control the quality of D. nobile for hyperglycemic syndrome treatment.

Polysaccharides derived from natural edible and medicinal sources as agents targeting exercise-induced fatigue: A review

Exercise-induced fatigue (EF) is a common occurrence during prolonged endurance and excessive exercise and is mainly caused by energy depletion, harmful metabolite accumulation, oxidative stress, and inflammation. EF usually leads to a reduction in initiating or maintaining spontaneous activities and muscle performance and ultimately results in a decrease in the quality of life of people who engage in physical work. Therefore, the interest in investigating EF-targeting agents with minimal side effects and good long-term efficacy has substantially increased. Natural edible and medicinal polysaccharides have shown positive anti-EF effects, but the relevant reviews are rare. This review comprehensively summarizes studies on natural polysaccharides from edible and medicinal sources that can relieve EF and improve physical performance from the past decade, focusing on their sources, monosaccharide compositions, anti-EF effects, and possible molecular mechanisms. Most of these anti-EF polysaccharides are heteropolysaccharides and are mainly composed of glucose, arabinose, galactose, rhamnose, xylose, and mannose. In EF animal models, the polysaccharides exert positive EF-alleviating effects through energy supply, metabolic regulation, antioxidation, anti-inflammation, and gut microbiota remodeling. However, further studies are still needed to clarify the anti-EF effects of these polysaccharides on human beings. In summary, the present review expects to provide scientific data for the future research and development of natural polysaccharide-based anti-EF drugs, dietary supplements, and health-care products for specific fatigue groups.

A Comparative Analysis of Chemical Constituents and Antioxidant Effects of Dendrobium fimbriatum Hook Fractions with Different Polarities

The aim of this study was to investigate the chemical composition and antioxidant capacity of various polar fractions obtained from Dendrobium fimbriatum Hook (DH). First, a 90% ethanol-aqueous extract of DH (CF) was subjected to sequential fractionation using different organic solvents, resulting in the isolation of a methylene chloride fraction (DF), an ethyl acetate fraction (EF), an n-butanol fraction (BF), and a remaining water fraction (WF) after condensation. Additionally, the CF was also subjected to column chromatography via a D101 macroreticular resin column, eluted with ethanol-aqueous solution to yield six fractions (0%, 20%, 40%, 60%, 80%, and 100%). UPLC-Q-Exactive Orbitrap-MS/MS analysis identified a total of 47 chemical compounds from these polar fractions, including fatty acids, amino acids, phenolic acids, flavonoids, organic heterocyclic molecules, and aromatic compounds. Moreover, DF, EF, and the 60%, 80%, and 100% ethanol-aqueous fractions had higher total phenol content (TPC) and total flavonoid content (TFC) values and greater 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS-) and 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging abilities. In H2O2-induced HepG2 cells, the aforementioned fractions could increase the activities of antioxidative enzymes NAD(P)H: quinone oxidoreductase 1 (NQO1), superoxide dismutase (SOD), heme oxygenase-1 (HO-1) and catalase (CAT), stimulate glutathione (GSH) synthesis by increasing the activities of glutamic acid cysteine ligase (GCL) and glutathione synthetase (GS), regulate GSH metabolism by increasing glutathione peroxidase (GSH-Px) and glutathione reductase (GR) activities, and reduce levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Furthermore, the antioxidative stress effect of the DH fractions was found to be positively correlated with the activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) protein and the presence of antioxidative chemical constituents. In conclusion, this study highlights the efficacy of both liquid-liquid extraction and macroporous resin purification techniques in the enrichment of bioactive compounds from natural food resources. The comprehensive analysis of chemical constituents and antioxidant effects of different polar fractions from Dendrobium fimbriatum Hook contributes to the understanding of its potential application in functional foods and nutraceuticals.