Nudol, a phenanthrene derivative from Dendrobium nobile, induces cell cycle arrest and apoptosis and inhibits migration in osteosarcoma cells

Dendrobium nobile active ingredient Dendrobin A against hepatocellular carcinoma via inhibiting nuclear factor kappa-B signaling

OBJECTIVE

Dendrobin A, a typical active ingredient of the traditional Chinese medicine Dendrobium nobile, has potential clinical application in cancer treatment; however, its effect and mechanism in anti-hepatocellular carcinoma (HCC) remain unsolved.

METHOD

The effects of Dendrobin A on the viability, migration, invasion, cycle, apoptosis, and epithelial-mesenchymal transition of HepG2 and SK-HEP-1 cells were verified by in vitro experiments. mRNA sequencing was performed to screen the differentially expressed genes (DEGs) of HCC cells before and after Dendrobin A treatment, following GO enrichment and KEGG signaling pathway analyses. Mechanistically, molecular docking was used to evaluate the binding of Dendrobin A with proteins p65 and p50, before further verifying the activation of nuclear factor kappa-B (NF-κB) signaling. Finally, the antiproliferative effect of Dendrobin A on HCC cells was explored through animal experiments.

RESULTS

Dendrobin A arrested cell cycle, induced apoptosis, and inhibited proliferation, migration, invasion, and blocked epithelial-mesenchymal transition in HepG2 and SK-HEP-1 cells. mRNA sequencing identified 830 DEGs, involving various biological processes. KEGG analysis highlighted NF-κB signaling. Molecular docking revealed strong binding of Dendrobin A with p65 and p50 proteins, and western blotting confirmed reduced levels of p-p65 and p-p50 in HCC cells post Dendrobin A treatment. NF-κB agonist PMA reversed Dendrobin A-inhibited cell proliferation migration and invasion. In vivo experiments showed that Dendrobin A inhibited HCC cell growth.

CONCLUSION

Our findings suggest that Dendrobin A exhibits anti-HCC properties by inhibiting the activation of the NF-κB pathway. These results provide a scientific basis for utilizing Dendrobium nobile in anti-HCC therapies.

Three new anti-inflammatory stilbenoids and a diphenyl ether derivative from Cajanus cajan

Three new stilbenoids, namely two rare plant-derived phenanthrenes denominated Cajananthrenes A and B (1, 2) and one bibenzyl named Cajanbenzyl (3), together with a diphenyl ether derivative designated Cajanether (4), as well as five other known compounds (5-9) were isolated from the ethanolic extract of the leaves of Cajanus cajan. Their structures were determined through extensive spectroscopic analysis including UV, IR, NMR (1D and 2D) and HRESIMS as well. A plausible biogenesis pathway was proposed for the biosynthesis of compounds 1-3. Compounds 1 and 2 displayed moderate anti-inflammatory activity as evident from the inhibitory effect on NO production in LPS-stimulated RAW 264.7 macrophages with IC50 values of 73.6 and 44.6 μM respectively.

1,5,6-Trimethoxy-2,7-dihydroxyphenanthrene from Dendrobium officinale Exhibited Antitumor Activities for HeLa Cells

Natural products are irreplaceable reservoirs for cancer treatments. In this study, 12 phenanthrene compounds were extracted and isolated from Dendrobium officinale. Each chemical structure was identified using comprehensive NMR analysis. All compounds were evaluated for their cytotoxic activities against five tumor cell lines, i.e., HeLa, MCF-7, SK-N-AS, Capan-2 and Hep G2. Compound 5, 1,5,6-trimethoxy-2,7-dihydroxyphenanthrene, displayed the most significant cytotoxic effect against HeLa and Hep G2 cells, with an IC50 of 0.42 and 0.20 μM. For Hela cells, further experiments demonstrated that compound 5 could obviously inhibit cell migration, block cell cycle in the G0/G1 phase and induce apoptosis. Expression measurements for p53 indicated that knock down of p53 by siRNA could mitigate the apoptosis induced by compound 5. Therefore, the compound 5 is a potential candidate drug for HeLa cells in cervical cancer.

Molecular mechanisms underlying the anticancer property of Dendrobium in various systems of the human body: A review

Dendrobium, which belongs to the family of Orchidaceae, is a highly valuable traditional Chinese medicine commonly used in China. It exerts pharmacological activities such as antitumor and hypoglycemia effects, and its main components are alkaloids, polysaccharides, and terpenoids, among others. In recent years, research on the clinical application of Dendrobium in antitumor therapy has gained increasing attention. Accumulating evidence suggests that the active components of Dendrobium possess significant inhibitory effects on the viability of cancer cells as evident from in vivo and in vitro experiments, which indicates that Dendrobium exerts significant anticancer effect in treating and preventing cancer development, inhibiting the underlying potential molecular mechanisms, including suppression of cancer cell growth and proliferation, epithelial-mesenchymal transition (EMT), apoptosis induction, tumor angiogenesis, and reinforcement of cisplatin (DDP) -induced apoptosis. We herein present a review that summarizes the research progress of the application of Dendrobium in cancer therapy and its molecular mechanisms. This review describes the positive aspects of the active ingredients of Dendrobium in the treatment of cancers in various systems of the human body, their inhibitory effects on tumor survival and tumor microenvironment, and their potential mechanisms. Additionally, this review proposes future application prospects of Dendrobium in cancer therapy to promote further research and future extensive clinical applications of Dendrobium in cancer therapy.

Therapeutic potential of the chemical composition of Dendrobium nobile Lindl

Dendrobium nobile Lindl. belongs to the genus Dendrobium of the orchid family and is a valuable herbal medicinal material. The information in this paper has been collected from the scientific literature databases including PubMed, Google Scholar, Web of Science, SciFinder, China National Knowledge Infrastructure, published books, Ph.D., and M.S. dissertations systematically in recent 20 years. "Dendrobium nobile Lindl.," "chemical composition," "pharmacological activities," and "diseases" were used as search terms to screen the literature. The collected chemical compositions are classified and summarized according to their different chemical structures, and the clinical disease treatment effects of Dendrobium nobile Lindl. are classified and summarized based on their pharmacological activities and different experimental disease models. Recent studies have revealed that Dendrobium nobile Lindl. contains chemical components such as alkaloids, bibenzyls, sesquiterpenes, phenanthrenes, and polysaccharides, and that its pharmacological activities are closely related to the chemical components, with pharmacological activities such as anti-tumor, anti-aging, immune enhancement, hypoglycemic, and anti-cataract. Currently, researchers are conducting extensive and detailed studies on Dendrobium nobile Lindl. and research experiments on its chemical constituents in the treatment of various clinical diseases. Therefore, the purpose of this paper is to review the chemical composition of Dendrobium nobile Lindl. and its experimental studies in the treatment of diseases and to provide a scientific reference for the future application of Dendrobium nobile Lindl. in the treatment of diseases.

Exogenous and Endophytic Fungal Communities of Dendrobium nobile Lindl. across Different Habitats and Their Enhancement of Host Plants' Dendrobine Content and Biomass Accumulation

Both the biosynthesis and array of bioactive and medicinal compounds in plants can be influenced by interactions with endophytic and exogenous fungi. However, the composition of endophytic and exogenous fungal communities associated with many medicinal plants is unknown, and the mechanism by which these fungi stimulate the secondary metabolism of host plants is unclear. In this study, we conducted a correlative analysis between endophytic and exogenous fungi and dendrobine and biomass accumulation in Dendrobium nobile across five Chinese habitats: wild Danxia rock, greenhouse-associated large Danxia stone, broken Danxia stone, broken coarse sandstone, and wood spile. Across habitats, fungal communities exhibited significant differences. The abundances of Phyllosticta, Trichoderma, and Hydropus were higher in wild habitats than in greenhouse habitats. Wild habitats were host to a higher diversity and richness of exogenous fungi than were greenhouse habitats. However, there was no significant difference in endophytic fungal diversity between habitats. The differences between the fungal communities' effects on the dendrobine content and biomass of D. nobile were attributable to the composition of endophytic and exogenous fungi. Exogenous fungi had a greater impact than endophytic fungi on the accumulation of fresh weight (FW) and dendrobine in D. nobile. Furthermore, D. nobile samples with higher exogenous fungal richness and diversity exhibited higher dendrobine content and FW. Phyllosticta was the only genus to be significantly positively correlated with both FW and dendrobine content. A total of 86 strains of endophytic fungi were isolated from the roots, stems, and leaves of D. nobile, of which 8 strains were found to be symbiotic with D. nobile tissue-cultured seedlings. The strain DN14 (Phyllosticta fallopiae) was found to promote not only biomass accumulation (11.44%) but also dendrobine content (33.80%) in D. nobile tissue-cultured seedlings. The results of this study will aid in the development of strategies to increase the production of dendrobine in D. nobile. This work could also facilitate the screening of beneficial endophytic and exogenous fungal probiotics for use as biofertilizers in D. nobile.

Active Compounds with Medicinal Potential Found in Maxillariinae Benth. (Orchidaceae Juss.) Representatives-A Review

Orchids are widely used in traditional medicine for the treatment of a whole range of different health conditions, and representatives of the Neotropical subtribe Maxillariinae are not an exception. They are utilized, for instance, for their spasmolytic and anti-inflammatory activities. In this work, we analyze the literature concerning the chemical composition of the plant extracts and secretions of this subtribe's representatives published between 1991 and 2022. Maxillariinae is one of the biggest taxa within the orchid family; however, to date, only 19 species have been investigated in this regard and, as we report, they produce 62 semiochemicals of medical potential. The presented review is the first summary of biologically active compounds found in Maxillariinae.

Recent Research Progress on Natural Stilbenes in Dendrobium Species

Dendrobium is the second biggest genus in the Orchidaceae family, and many of them have been utilized as a traditional Chinese medicine (TCM) for thousands of years in China. In the last few decades, constituents with great chemical diversity were isolated from Dendrobium, and a wide range of biological activities were detected, either for crude extracts or for pure compounds. Stilbene compound is one of the primary active constituents in the genus Dendrobium. At present, 267 stilbene compounds with clarified molecular structures have been extracted and isolated from 52 species of Dendrobium, including 124 phenanthrenes and 143 bibenzyls. At the same time, activity studies have indicated that 157 compounds have pharmaceutical activity. Among them, most of the compounds showed antitumor activity, followed by antioxidant, anti-inflammatory and anti-α-glucosidase inhibitory activities. Additionally, 54 compounds have multiple pharmacological activities, such as confusarin (14), 2,4,7-trihydroxy-9,10-dihydro-phenanthrene (43), moscatilin (148), gigantol (150) and batatasin III (151). This review summarizes current knowledge about the chemical composition of stilbene, bioactivities and pharmacologic effects in 52 species of Dendrobium. We also expect to provide a reference for further research, development and utilization of stilbene constituents in the Dendrobium genus.

Orchidaceae-Derived Anticancer Agents: A Review

Simple Summary

Orchids are commonly used in folk medicine for the treatment of infections and tumors but little is known about the actual chemical composition of these plants and their anticancer properties. In this paper, the most recent literature on orchid-derived bioactive substances with anticancer properties is reviewed. According to the published data, numerous species of orchids contain potential antitumor chemicals. Still, a relatively insignificant number of species of orchids have been tested for their bioactive properties and most of those studies were on Asian taxa. Broader research, ’including American and African species, as well as the correct identification of samples, is essential for evaluating the usefulness of orchids as a plant family with huge anticancer potential.

Abstract

Species of orchids, which belong to the largest family of flowering plants, are commonly used in folk medicine for the treatment of infections and tumors. However, little is known about the actual chemical composition of these plants and their anticancer properties. In this paper, the most recent literature on orchid-derived bioactive substances with anticancer properties is reviewed. For the assessment, previous papers on the anticancer activity of Orchidaceae published since 2015 were considered. The papers were found by exploring electronic databases. According to the available data, many species of orchids contain potential antitumor chemicals. The bioactive substances in a relatively insignificant number of orchids are identified, and most studies are on Asian taxa. Broader research on American and African species and the correct identification of samples included in the experiments are essential for evaluating the usefulness of orchids as a plant family with vast anticancer potential.

As a novel anticancer candidate, ether extract of Dendrobium nobile overstimulates cellular protein biosynthesis to induce cell stress and autophagy

Increasing data has confirmed the potential anticancer properties of Dendrobium, a traditional Chinese herb. However, most anticancer compositions from the plant of Dendrobium were usually extracted by high polar solvent, while weak polar compositions with excellent anticancer activity remained largely unexplored. In this study, the differences between ether extract and ethanol extract of Dendrobium nobile Lindl. on chemical components and anticancer activities were investigated, as well as the anticancer mechanisms among different extracts. The results demonstrated that the ether extract exhibited a stronger anticancer effect than ethanol extract, and its anticancer effect was mainly due to weak polar compounds rather than polysaccharides and alkaloids. Quantitative proteomics suggested that the ether extract significantly stimulated the over-expression of immature proteins, the endoplasmic reticulum stress and unfolded protein response were subsequently induced, the intracellular reactive oxygen species level was seriously elevated, and oxidative stress occurred in the meanwhile. Eventually, autophagy and apoptosis were activated to cause cell death. Our findings demonstrate that the ether extract of D. nobile is a potential candidate for anticancer drug development, and that future research on anticancer drugs derived from medicinal plants should also concentrate on weak polar compounds.

Dihydrophenanthrenes from a Sicilian Accession of Himantoglossum robertianum (Loisel.) P. Delforge Showed Antioxidant, Antimicrobial, and Antiproliferative Activities

The peculiar aspect that emerges from the study of Orchidaceae is the presence of various molecules, which are particularly interesting for pharmaceutical chemistry due to their wide range of biological resources. The aim of our study was to investigate the properties of two dihydrophenanthrenes, isolated, for the first time, from Himantoglossum robertianum (Loisel.) P. Delforge (Orchidaceae) bulbs and roots. Chemical and spectroscopic study of the bulbs and roots of Himantoglossumrobertianum (Loisel.) P. Delforge resulted in the isolation of two known dihydrophenanthrenes-loroglossol and hircinol-never isolated from this plant species. The structures were evaluated based on ¹H-NMR, ¹³C-NMR, and two-dimensional spectra, and by comparison with the literature. These two molecules have been tested for their possible antioxidant, antimicrobial, antiproliferative, and proapoptotic activities. In particular, it has been shown that these molecules cause an increase in the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) in polymorphonuclear leukocytes (PMN); show antimicrobial activity against Escherichia coli and Staphylococcus aureus, and have anti-proliferative effects on gastric cancer cell lines, inducing apoptosis effects. Therefore, these two molecules could be considered promising candidates for pharmaceutical and nutraceutical preparations.

Chemical and Biological Profiles of Dendrobium in Two Different Species, Their Hybrid, and Gamma-Irradiated Mutant Lines of the Hybrid Based on LC-QToF MS and Cytotoxicity Analysis

The Dendrobium species (Orchidaceae) has been cultivated as an ornamental plant as well as used in traditional medicines. In this study, the chemical profiles of Dendrobii Herba, used as herbal medicine, Dendrobium in two different species, their hybrid, and the gamma-irradiated mutant lines of the hybrid, were systematically investigated via ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QToF MS). Among the numerous peaks detected, 17 peaks were unambiguously identified. Gigantol (1), (1R,2R)-1,7-hydroxy-2,8-methoxy-2,3-dihydrophenanthrene-4(1H)-one (2), tristin (3), (−)-syringaresinol (4), lusianthridin (5), 2,7-dihydroxy-phenanthrene-1,4-dione (6), densiflorol B (7), denthyrsinin (8), moscatilin (9), lusianthridin dimer (10), batatasin III (11), ephemeranthol A (12), thunalbene (13), dehydroorchinol (14), dendrobine (15), shihunine (16), and 1,5,7-trimethoxy-2-phenanthrenol (17), were detected in Dendrobii Herba, while 1, 2, and 16 were detected in D. candidum, 1, 11, and 16 in D. nobile, and 1, 2, and 16 in the hybrid, D. nobile × candidum. The methanol extract taken of them was also examined for cytotoxicity against FaDu human hypopharynx squamous carcinoma cells, where Dendrobii Herba showed the greatest cytotoxicity. In the untargeted metabolite analysis of 436 mutant lines of the hybrid, using UPLC-QToF MS and cytotoxicity measurements combined with multivariate analysis, two tentative flavonoids (M1 and M2) were evaluated as key markers among the analyzed metabolites, contributing to the distinction between active and inactive mutant lines.

Juncaceae Species as Promising Sources of Phenanthrenes: Antiproliferative Compounds from Juncus maritimus Lam

Juncaceae family represents an abundant source of phenanthrenes. In continuation of our work aiming at the isolation of biologically active compounds from Juncaceae species, Juncus maritimus Lam. was subjected to phytochemical and pharmacological investigations. The isolation process was carried out by using combined extraction and chromatographic methods. The structures of the obtained chemical compounds were elucidated by spectroscopic analysis, including HRESIMS, 1D (¹H, ¹³C-JMOD), and 2D (¹H-¹H-COSY, HSQC, HMBC, NOESY) NMR spectra. Four new [maritins A–D (1–4)] and seven known phenanthrenes (5–11) were isolated from the plant, of which two (4 and 11) are phenanthrene dimers composed of effusol monomers. Maritin C (3) has an unusual 4,5-ethanophenanthrene skeleton most likely produced by biosynthetic incorporation of a vinyl group into a cyclohexadiene ring. Compounds 1–11 were tested for their antiproliferative activity on seven human tumor cell lines (HeLa, HTM-26, T-47D, A2780, A2780cis, MCF-7, KCR) and one normal cell line (MRC-5) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The dimeric phenanthrenes showed strong antiproliferative activity against T-47D cells with IC₅₀ values of 9.1 and 6.2 µM, respectively.

Arthpyrone L, a New Pyridone Alkaloid from a Deep-Sea Arthrinium sp., Inhibits Proliferation of MG63 Osteosarcoma Cells by Inducing G0/G1 Arrest and Apoptosis

Fractionation of the ethanol extract of a marine fungus, Arthrinium sp., afforded a new pyridone alkaloid (arthpyrone L (1)), the structure with absolute configuration of which was established by comprehensive spectroscopic analyses. In vitro cell viability assays revealed that compound 1 showed antiproliferative effects toward human A549 (lung), MG63, U2OS (bone), MCF-7 and MDA-MB-231 (breast) cancer cells. MG63 cell lines were chosen for further biological evaluations and presented apoptosis and cell cycle arrest (G0/G1 phase) upon treatment of 1. Subsequent mechanism studies demonstrated that the growth inhibition of 1 against MG63 cells was via activation of caspase-modulated apoptotic pathway and inhibition of PI3K/Akt pathway.