Moscatilin from the orchid Dendrobrium loddigesii is a potential anticancer agent

Novel bibenzyl compound 8Ae induces apoptosis and inhibits glycolysis by detaching hexokinase 2 from mitochondria in A549 cells

In this paper, we investigated the anticancer effect and the mechanism of our newly synthesized bibenzyl 8Ae against human lung cancer A549 cells. Compound 8Ae could induce apoptosis by inhibiting the glycolysis in A549 cells. Hexokinase 2 (HK2), the first key enzyme in glycolysis process, was significantly down-regulated by 8Ae. Besides, compound 8Ae induced HK2 dissociated from mitochondria to cytosol, which could be induced by inhibiting the phosphorylation of Akt. In addition, 8Ae could induce mitochondrial-mediated apoptosis, and mitochondrial membrane potential (MMP) was decreased. After 8Ae treatment, the Bax/Bcl-2 ratio was increased and cytochrome c (Cyt c) was release from mitochondria to cytosol. Molecular docking indicated that 8Ae have an interaction with HK2 by extending into acitve pockets of the protein to form stable hydrogen bonds. Additionally, 8Ae had significantly improved pharmacokinetic properties through the prediction, comparison, and analysis of the ADMET properties of 8Ae and moscatilin (MST). Taken together, 8Ae might inhibit glycolysis by stimulating the shedding of HK2 from mitochondria and promoting mitochondria-regulated apoptosis to inhibit the proliferation of A549 cells. This article provides a research basis for bibenzyl compounds as new small molecule drugs for lung cancer.

Multi-omics analyses and botanical perfumer hypothesis provide insights into the formation and maintenance of aromatic characteristics of Dendrobium loddigesii flowers

Dendrobium loddigesii, a member of the Orchidaceae family, is a valuable horticultural crop known for its aromatic qualities. However, the mechanisms responsible for the development of its aromatic characteristics remain poorly understood. To elucidate these underlying mechanisms, we assembled the first chromosome-level reference genome of D. loddigesii using PacBio HiFi-reads, Illumina short-reads, and Hi-C data. The assembly comprises 19 pseudochromosomes with N50 contig and N50 scaffold sizes of 55.15 and 89.94 Mb, respectively, estimating the genome size to be 1.68 Gb, larger than that of other sequenced Dendrobium species. During the flowering stages, we conducted a comprehensive analysis combining volatilomics and transcriptomics to understand the characteristics and biosynthetic mechanisms pathways of the floral scent. Our findings emphasize the significant contribution of aromatic terpenoids, especially monoterpenoids, in defining the floral aroma. Furthermore, we identified two crucial terpene synthase (TPS) genes that play a key role in maintaining the aroma during flowering. Through the integration volatilomics data with catalytic assays of DlTPSbs proteins, we identified specific compounds responsible for the aromatic characteristics of D. loddigesii. This integrated analysis of the genome, transcriptome, and volatilome, offers valuable insights into the development and preservation of D. loddigesii's aromatic characteristics, setting the stage for further exploration of the botanical perfumer hypothesis.

Novel bibenzyl compound Ae exhibits anti-agiogenic activity in HUVECs in vitro and zebrafish in vivo

The inhibition of angiogenesis has been considered as an attractive method for the discovery of potential anti-cancer drugs. Herein, we report our new synthesized bibenzyl compound Ae had potent anti-angiogenic activity(the lowest effective concentration is to 0.62-1.25 μM) in zebrafish in vivo and showed a concentration-dependent inhibition of inter-segmental blood vessels (ISVs) compared to control. Further, Ae exhibited the obvious inhibitory activity of proliferation, migration, invasion and tube formation in HUVEC cells in vitro. Moreover, qRT-PCR analysis revealed that the anti-angiogenic activity of compound Ae is connected with the ang-2, tek in ANGPT-TEK pathway and the kdr, kdrl signaling axle in VEGF-VEGFR pathway. Molecular docking studies revealed that compound Ae had an interaction with the angiopoietin-2 receptor(TEK) and VEGFR2. Additionally, analysis of the ADMET prediction data indicated that compound Ae possessed favorable physicochemical properties, drug-likeness, and synthetic accessibility. In conclusion, compound Ae had remarkable anti-angiogenic activity and could be served as an candidate for cancer therapy.

Moscatilin, a potential therapeutic agent for cancer treatment: insights into molecular mechanisms and clinical prospects

Moscatilin, a bibenzyl derivative from the Dendrobium genus, has been traditionally used in Chinese medicine. Recent studies suggest its potential as a powerful anticancer agent due to its diverse pharmacological properties.This review aims to consolidate current research on moscatilin's anticancer mechanisms, structure-activity relationships, and therapeutic potential to assess its viability for clinical use. A literature search was performed in PubMed/MedLine, Scopus, and Web of Science.The search focused on "cancer," "moscatilin," "anticancer," "bioactivity," "dendrobium," and "pharmacological properties." Relevant studies on molecular mechanisms, preclinical and clinical efficacy, and bioavailability were reviewed. Moscatilin exhibits significant anticancer effects in lung, breast, colorectal, and pancreatic cancers. It induces apoptosis via the JNK/SAPK pathway, inhibits cell proliferation, and suppresses metastasis. Structure-activity relationship studies reveal that phenolic groups and a two-carbon bridge are crucial for its efficacy. Additionally, moscatilin shows good bioavailability and a favorable safety profile, with low toxicity to healthy cells. Moscatilin demonstrates considerable potential as an anticancer agent, targeting multiple cancer progression pathways. Further clinical trials are essential to confirm its therapeutic efficacy and safety in humans.

Evaluation of the anticancer and antibacterial activities of moscatilin

Orchids (Dendrobium sp.) have been the subject of extensive research due to their ubiquitous pharmacological, antimicrobial, and anticancer properties. Moscatilin is a bibenzyl secondary metabolite enriched in orchids that exhibits anticancer and antimicrobial properties through mechanisms that have not yet been fully elucidated. The current study aimed to assess the in vitro anticancer and antibacterial potential of moscatilin. The in vitro anti-proliferative effects of moscatilin against breast cancer-MCF-7 and liver-HepG2 cells were assessed using the dimethylthiazol-diphenyltetrazolium bromide assay. Selected six pro-apoptotic (caspase-3, 8, 9, p53, p21 & Bax) and two anti-apoptotic (Bcl-xL & Bcl-2) gene markers were assessed via qPCR and tested antibacterial activity against various bacterial strains using disc diffusion and broth dilution methods. Moscatilin decreased the cellular viabilities of HepG2 and MCF-7 cancer cells, with anti-proliferation rates of 66 % (IC50 51 ± 5.18 μM) and 58 % (IC50 57 ± 4.18 μM), respectively. This effect was selectively observed in cancer cells, and the impact of moscatilin on non-cancerous MCF-12 cells was marginal. Moreover, moscatilin-treated cells exhibited higher mRNA levels of caspase-3,8, 9, Bax, p53, and p21, whereas lower levels of Bcl-2 and Bcl-xL, two anti-apoptotic markers, were observed. Furthermore, moscatilin exhibited varying degrees of antibacterial activity against the bacterial strains investigated. Notably, the highest antibacterial potentials were observed against Staphylococcus epidermidis and Klebsiella pneumonia, while the lowest inhibitory activity was observed in Escherichia coli and Pseudomonas aeruginosa. Overall, these findings demonstrated that moscatilin exerts potent anticancer effects via apoptosis and has antimicrobial properties against Gram-negative and Gram-positive bacteria that are clinically relevant. These findings highlight the potential of moscatilin as a natural therapeutic candidate for the treatment of cancer and clinically important bacterial pathogens.

Moscatilin Reverses EMT Progression and its Resulting Enhanced Invasion and Migration by Affecting the TGF-β Signaling Pathway in Bladder Cancer

BACKGROUND

Bladder cancer metastasis is an essential process in the progression of muscle-invasive bladder cancer. EMT plays a crucial role in facilitating the spread of cancer cells. Identifying compounds that can inhibit these abilities of cancer cells is a significant international endeavor.

OBJECTIVE

To explore the migration and invasion effect of Moscatilin on the bladder and clarify the mechanism of action Methods: The anti-bladder cancer effect of Moscatilin was observed by a cell proliferation experiment. The migration and invasion of bladder cancer cells inhibited by Moscatilin were detected by Transwell and Wound healing. The effects of Moscatilin on EMT-related proteins E-cadherin, N-cadherin, Snail1, Vimentin, and TGF-β signaling pathways were detected by Western blot, and nucleic acid levels were verified by qPCR.

RESULTS

Our study revealed that Moscatilin reduced the viability of bladder cancer cells in vitro and impeded their migration and invasion in experimental settings. Furthermore, we observed that Moscatilin decreased the activation levels of active proteins, specifically Smad3, Samd2, and MMP2. Additionally, we found that moscatilin significantly reduced the expression level of TGF-β and was also capable of reversing the overexpression effect of TGF-β. Treatment with Moscatilin also led to significant inhibition of interstitial cell markers Ncadherin and Snail1, which are associated with EMT.

CONCLUSION

These findings indicate that Moscatilin impedes the migration and invasion of bladder cancer cells by influencing cell survival, modulating TGF-β/Smad signaling, and inhibiting EMT.

Moscatilin suppresses the inflammation from macrophages and T cells

In this study, we aim to investigate moscatilin in alleviating symptoms of autoimmune liver disease (ALD) in a concanavalin A (ConA)-induced liver injury mouse model and elucidate the underlying mechanisms. ALD mouse models were constructed by intravenous injection of ConA (20 mg/kg) and the serum level of alanine aminotransferase (ALT) was measured using an enzyme-linked immunosorbent assay. Moscatilin in various doses was administered for two days starting from a day before the ConA injection. We showed that moscatilin dose-dependently decreased ALT levels in liver tissue of ALD mouse models. Ifng and Tnfa also showed significant downregulation in liver tissues. Macrophages only showed significant Tnfa downregulation and CD4⁺ T cells only showed significant Ifng downregulation at high moscatilin doses. In vivo administration of moscatilin induced interleukin-37 upregulation in hepatic tissues. In vitro, moscatilin also induced IL-37 upregulation in hepatic stellate cell line JS-1 rather than immune cells represented by RAW264.7 and CTLL-2 cell lines, suggesting that the hepatic stellate cell is majorly responsive to moscatilin treatment in terms of interleukin (IL)-37 upregulation. Our data indicate that moscatilin could alleviate liver injury in ConA-induced ALD mouse models through anti-inflammatory activities, warranting further development of moscatilin as a new drug in treating ALD.

Dendrobium nobile protects retinal cells from UV-induced oxidative stress damage via Nrf2/HO-1 and MAPK pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Excessive UV irradiation and ROS exposure are the main contributors of ocular pathologies. Pseudobulb of Dendrobium nobile Lindl. is one of the sources of Shihu and has long been used in traditional Chinese medicine as a tonic to nourish stomach, replenish body fluid, antipyretic and anti-inflammation.

AIM OF STUDY

This study aimed to investigate whether D. nobile could protect ocular cells against oxidative stress damage.

MATERIALS AND METHODS

Retinal-related cell lines, ARPE-19 and RGC-5 cells, were pretreated with D. nobile extracts before H₂O₂- and UV-treatment. Cell viability and the oxidative stress were monitored by sulforhodamine B (SRB) and SOD1 and CAT assay kits, respectively. The oxidative stress related proteins were measured by Western blotting.

RESULTS

Under activity-guided fractionation, a sesquiterpene-enriched fraction (DN-2) and a major component (1) could ameliorate H₂O₂- and UV-induced cytotoxicity and SOD1 and CAT activity, but not dendrobine, the chemical marker of D. nobile. Western blotting showed both DN-2 and compound 1 protected ARPE-19 cells against UV-induced oxidative stress damage by regulating MAPK and Nrf2/HO-1 signaling.

CONCLUSION

Our results suggest D. nobile extract protects retinal pigment epithelia cells from UV- and oxidative stress-damage, which may have a beneficial effect on eye diseases.

An Integrated Analysis of Metabolomics and Transcriptomics Reveals Significant Differences in Floral Scents and Related Gene Expression between Two Varieties of Dendrobium loddigesii

Flower fragrance is one of the traits that holds important economical values in flowering plants. Extensive attention has converged on fragrance preservation in flower cultivation and breeding. Dendrobium loddigesii is an important species for cultivating aromatic Dendrobium orchid varieties for the long term due to its fragrance. Few studies focus on exploring related genes responsible for the aroma components in D. loddigesii. We analyzed flowers from two aromatic D. loddigesii varieties using high-throughput RNA sequencing and gas chromatography-mass spectrometry (GC-MS). The metabolomics results showed that the main volatile compounds responsible for the aroma formation of D. loddigesii were terpenes, especially monoterpenes. The de novo transcriptome assembly comprised 175,089 unigenes, and 24,570 unigenes of the genes were identified as differential expressed genes (DEGs) between the two varieties. Among these DEGs, 525 genes were mapped into seven pathways that related to the floral scent synthesis. Seventeen key genes were significantly correlated with volatile aroma metabolites, including geraniol, α-pinene, eugenol, and (Z)-3-hexenal. These results provide references for understanding the aroma biosynthesis and perfume formulations of D. loddigesii.

In vitro bioproduction and enhancement of moscatilin from a threatened tropical epiphytic orchid, Dendrobium ovatum (Willd.) Kraenzl

Moscatilin, a bibenzyl derivative (stilbenoid), mostly found in one of the largest genera of Orchidaceae; Dendrobium has many therapeutic benefits. Its function as an anticancer agent has been widely demonstrated through many research investigations. However, the compound has not been produced in vitro to date. The present study highlights the development of cultures viz., seedling generation, callus induction and callus regeneration (transformation of callus into plantlets). These cultures were devised to conserve the threatened tropical epiphytic orchid species, Dendrobium ovatum and identify their potential towards moscatilin bioproduction in vitro. Among the three culture platforms, callus-derived plantlets could yield high moscatilin when treated with l-Phenylalanine as a precursor. Tissue differentiation was found to be indispensable for the high production of this polyphenol. These cultures also offer potential commercial benefits as they can serve as appropriate platforms to decode moscatilin biosynthesis and other significant bibenzyl derivatives. Elicitors, such as chitosan, salicylic acid, and methyl jasmonate, were found, causing an enhancement in moscatilin content in the cultures. The seedlings obtained can serve towards ecorestoration and preservation of the studied species. Callogenesis was useful in plantlet regeneration, as callus-derived plantlets could be utilized for the enrichment and commercial scale-up of moscatilin-like chemicals.

Cytotoxicity and radiosensitizing potency of Moscatilin in cancer cells at low radiation doses of X-ray and UV-C

Moscatilin (stilbenoid) is a plant-derived anticancer compound, and it has mostly been isolated from threatened wild Dendrobium species. The present study attempts to evaluate the cytotoxicity of Moscatilin on several cancer cell lines through MTT assay. Additionally, it also aims towards estimating and comparing the radiosensitivity, cell-cycle progression, and apoptotic/necrotic effect induced by Moscatilin on different cell lines. The effects of Moscatilin was compared with another significant stilbenoid anticancer agent, Resveratrol (a structural analog of Moscatilin), whose presence has also been reported in Dendrobiums. Considering the threatened nature of this genus, crude extracts of a tropical and epiphytic Dendrobium species, viz., Dendrobium ovatum, prepared from in vitro seedlings were also tested towards cytotoxicity and radiosensitization efficacy. Moscatilin functioned as an effective radiosensitizer at 5 µg/ml along with 1 Gy X-ray and 200 J/m² UV-C radiations. It was also able to perturb cell cycle both at replicative and post-replicative phases with the aforementioned combination. Moscatilin, in unison with radiation, triggered immunogenic death specifically on cancer cells starting from Pyroptosis, terminating in Necroptosis. Moscatilin, when used singly, could evoke immunogenic cell death. Analyses of Damage-Associated Molecular Patterns released during radiation and Moscatilin treatment would aid in ascertaining the mode of cell death. Moscatilin is a potential radiosensitizer and must be tested for preclinical and clinical trials to combat cancer.

Bibenzyls and bisbybenzyls of bryophytic origin as promising source of novel therapeutics: pharmacology, synthesis and structure-activity

BACKGROUND

The amphibian, non-vascular, gametophyte-dominant, bio-indicator class, bryophytes; with their wide ranges of habitat have attained importance due to their promising medicinal attributions and therapeutic role; mostly aided by presence of aromatic bibenzyl and bisbybenzyl class of compounds. Bibenzyls are steroidal ethane derivatives, resembling the structural moiety of bioactive dihydro-stilbenoids or iso-quinoline alkaloids. These stress triggered secondary metabolites are the by-products of the flavonoid biosynthetic pathway. Different classes of bryophytes (Bryophyta, Marchantiophyta and Anthocerotophyta) possess different subtypes of bibenzyls and dimeric bisbibenzyls. Among the liverwort, hornwort and mosses, former one is mostly enriched with bibenzyl type constituents as per the extensive study conducted for phytochemical deposit. Considering macrocyclic and acyclic group of bibenzyls and bisbybenzyls, generally marchantin type compounds are reported vividly for significant biological activity that includes neuro-nephro-cardio-protection besides anti-allergic, anti-microbial, anti-apoptotic and cytotoxic activities studied on in-vitro and in-vivo models or on cell lines.

RESULT

The critical analysis of reported chemical and pharmaceutical attributions of bibenzyls and bis-bibenzyls yielded detailed report on this compound class along with their application, mode of action, natural source, techniques of synthesis, extraction procedure, isolation and characterization. Further, the structure activity relationship studies and bioactivity of bibenzyls derived from non-bryophytic origin were also summarized.

CONCLUSION

This review encompasses prospective biological application of botanical reservoir of this primarily ignored, primeval land plant group where recent technical advances has paved the way for qualitative and quantitative isolation and estimation of novel compounds as well as marker components to study their impact on environment, as bio-control agents and as key leads in future drug designing. Graphical abstract.

Dactylorhiza hatagirea (D. Don) Soo: A Critically Endangered Perennial Orchid from the North-West Himalayas

Dactylorhiza hatagirea (Orchidaceae) is a perennial herb inhabiting sub-alpine to alpine regions, ranging at elevations between 2500 and 5000 m.a.s.l. With palmately lobed rhizome and lanceolate leaves having a sheathing leaf base, it bears pink flowers with purple-colored notches and a curved spur. It finds wide use in ayurveda, siddha, unani, and folk medicine in curing disorders of the circulatory, respiratory, nervous, digestive, skeletal, and reproductive systems, besides boosting the immune system to fight infectious diseases. Secondary metabolites such as dactylorhins A–E, dactyloses A–B, and others exhibit a wide spectrum of pharmacological activities (antioxidant, antimicrobial, antiseptic, anticancer, and immune enhancing activities). Its use as a dietary supplement was found to be beneficial in increasing testosterone levels, resulting in improved sexual desire and arousal. Incessant overexploitation of this medicinally important herb has resulted in the dwindling of its populations in the wild, which has resulted in its classification as a critically endangered plant species. Efforts involving mass reproduction through in vitro (through tissue culture) and in vivo (by vegetative propagation) means are currently being made to maintain the germplasm of this critically endangered orchid. Holding immense significance in clinical research and drug discovery, work on the genomic front (transcriptomics) has recently been carried out to discover the wealth of unexplored genetic information for this perennial herb. The present study is aimed at reviewing different aspects of the orchid to present collective (summarized) information on this medicinally important herb in the present, particularly its botany, ethnobotanical uses, phytochemistry, and pharmacognosy, along with the strategies that need to be adopted to prevent its overexploitation in natural habitats.

A Bibenzyl Component Moscatilin Mitigates Glycation-Mediated Damages in an SH-SY5Y Cell Model of Neurodegenerative Diseases through AMPK Activation and RAGE/NF-κB Pathway Suppression

Moscatilin can protect rat pheochromocytoma cells against methylglyoxal-induced damage. Elimination of the effect of advanced glycation end-products (AGEs) but activation of AMP-activated protein kinase (AMPK) are the potential therapeutic targets for the neurodegenerative diseases. Our study aimed to clarify AMPK signaling’s role in the beneficial effects of moscatilin on the diabetic/hyperglycemia-associated neurodegenerative disorders. AGEs-induced injury in SH-SY5Y cells was used as an in vitro neurodegenerative model. AGEs stimulation resulted in cellular viability loss and reactive oxygen species production, and mitochondrial membrane potential collapse. It was observed that the cleaved forms of caspase-9, caspase-3, and poly (ADP-ribose) polymerase increased in SH-SY5Y cells following AGEs exposure. AGEs decreased Bcl-2 but increased Bax and p53 expression and nuclear factor kappa-B activation in SH-SY5Y cells. AGEs also attenuated the phosphorylation level of AMPK. These AGEs-induced detrimental effects were ameliorated by moscatilin, which was similar to the actions of metformin. Compound C, an inhibitor of AMPK, abolished the beneficial effects of moscatilin on the regulation of SH-SY5Y cells’ function, indicating the involvement of AMPK. In conclusion, moscatilin offers a promising therapeutic strategy to reduce the neurotoxicity or AMPK dysfunction of AGEs. It provides a potential beneficial effect with AGEs-related neurodegenerative diseases.

Vascular Epiphytic Medicinal Plants as Sources of Therapeutic Agents: Their Ethnopharmacological Uses, Chemical Composition, and Biological Activities

This is an extensive review on epiphytic plants that have been used traditionally as medicines. It provides information on 185 epiphytes and their traditional medicinal uses, regions where Indigenous people use the plants, parts of the plants used as medicines and their preparation, and their reported phytochemical properties and pharmacological properties aligned with their traditional uses. These epiphytic medicinal plants are able to produce a range of secondary metabolites, including alkaloids, and a total of 842 phytochemicals have been identified to date. As many as 71 epiphytic medicinal plants were studied for their biological activities, showing promising pharmacological activities, including as anti-inflammatory, antimicrobial, and anticancer agents. There are several species that were not investigated for their activities and are worthy of exploration. These epipythes have the potential to furnish drug lead compounds, especially for treating cancers, and thus warrant indepth investigations.

Design, synthesis and antitumour and anti-angiogenesis evaluation of 22 moscatilin derivatives

Two series of moscatilin derivatives were designed, synthesized and evaluated as anti-tumor and anti-angiogenesis agents. Most of these compounds showed moderate-to-obvious cytotoxicity against five cancer cell lines (A549, HepG2, MDA-MB-231, MKN-45, HCT116). Among these cell lines, compounds had obvious effects on HCT116. Especially for 8Ae, the IC₅₀ was low to 0.25 μM. 8Ae can inhibit the viability and induce the apoptosis of HCT116 cells but exhibit no cytotoxic activity in noncancerous NCM460 colon cells. 8Ae can also arrest the G2/M cell cycle in HCT116 cells by inhibiting the α-tubulin expression. Zebrafish bioassay-guided screen showed the 22 moscatilin derivatives had potent anti-angiogenic activities and compound 8Ae had better activities than positive compound. Molecular docking indicated 8Ae interacted with tubulin at the affinity of -7.2 Kcal/mol. In conclusion, compound 8Ae was a potential antitumor and anti-angiogenesis candidate for further development.

Dendrobium nobile Lindley and its bibenzyl component moscatilin are able to protect retinal cells from ischemia/hypoxia by dowregulating placental growth factor and upregulating Norrie disease protein

Background

Presumably, progression of developmental retinal vascular disorders is mainly driven by persistent ischemia/hypoxia. An investigation into vision-threatening retinal ischemia remains important. Our aim was to evaluate, in relation to retinal ischemia, protective effects and mechanisms of Dendrobium nobile Lindley (DNL) and its bibenzyl component moscatilin. The therapeutic mechanisms included evaluations of levels of placental growth factor (PLGF) and Norrie disease protein (NDP).

Methods

An oxygen glucose deprivation (OGD) model involved cells cultured in DMEM containing 1% O₂, 94% N₂ and 0 g/L glucose. High intraocular pressure (HIOP)-induced retinal ischemia was created by increasing IOP to 120 mmHg for 60 min in Wistar rats. The methods included electroretinogram (ERG), histopathology, MTT assay and biochemistry.

Results

When compared with cells cultured in DMEM containing DMSO (DMSO+DMEM), cells subjected to OGD and pre-administrated with DMSO (DMSO+OGD) showed a significant reduction in the cell viability and NDP expression. Moreover, cells that received OGD and 1 h pre-administration of 0.1 μM moscatilin (Pre-OGD Mos 0.1 μM) showed a significant counteraction of the OGD-induced decreased cell viability. Furthermore, compared with the DMSO+OGD group (44.54 ± 3.15%), there was significant elevated NDP levels in the Pre-OGD Mos 0.1 μM group (108.38 ± 29.33%). Additionally, there were significant ischemic alterations, namely reduced ERG b-wave, less numerous retinal ganglion cells, decreased inner retinal thickness, and reduced/enhanced amacrine’s ChAT/Müller’s GFAP or vimentin immunolabelings. Moreover, there were significantly increased protein levels of HIF-1α, VEGF, PKM2, RBP2 and, particularly, PLGF (pg/ml; Sham vs. Vehicle: 15.11 ± 1.58 vs. 39.53 ± 5.25). These ischemic effects were significantly altered when 1.0 g/Kg/day DNL (DNL1.0 + I/R or I/R+ DNL1.0) was applied before and/or after ischemia, but not vehicle (Vehicle+I/R). Of novelty and significance, the DNL1.0 action mechanism appears to be similar to that of the anti-PLGF Eylea [PLGF (pg/ml); DNL1.0 vs. Eylea+I/R: 19.93 ± 2.24 vs. 6.44 ± 0.60].

Conclusions

DNL and moscatilin are able to protect against retinal ischemic/hypoxic changes respectively by downregulating PLGF and upregulating NDP. Progression of developmental retinal vascular disorders such as Norrie disease due to persistent ischemia/hypoxia might be thus prevented.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2256-z) contains supplementary material, which is available to authorized users.

Dendrobium chrysanthum ethanolic extract induces apoptosis via p53 up-regulation in HeLa cells and inhibits tumor progression in mice

Background Dendrobium is one of the diverse genus of orchid plants. It possesses a number of pharmacological activities and has long been used in traditional system of medicine. The goal of this study was to investigate the apoptosis inducing property of the ethanolic extract from the leaves of Dendrobium chrysanthum, a species of Dendrobium whose anticancer role has not been ascertained yet. Methods To evaluate the anticancer activity of the ethanolic extract of D. chrysanthum in vitro in HeLa (human cervical cancer) cells, cytotoxic activity, generation of reactive oxygen species (ROS), induction of apoptosis and effect on cell cycle were determined. The in vivo study was carried out in Dalton's lymphoma (DL) bearing mice to assess the tumor growth delay. Results Our study demonstrated that the ethanolic extract showed dose-dependent cytotoxicity against HeLa cells. The extract exhibited dose-dependent increase in ROS production as well as apoptotic cell death which was further confirmed through presence of DNA fragmentation. Cell cycle analysis by flow cytometry suggests that the ethanolic extract perturbed cell cycle progression and leads to the delay of the cells in S phase. Further, the real-time PCR studies also showed up-regulation of apoptotic genes p53 and Bax. The in vivo antitumor activity exhibited significant increase in the life span of DL bearing mice as compared to control with significant decrease in abdominal size along with reduced tumor ascites. Conclusions These observations demonstrate the anticancer potential of the D. chrysanthum ethanolic extract mediated through p53-dependent apoptosis.

Eulophia macrobulbon - an orchid with significant anti-inflammatory and antioxidant effect and anticancerogenic potential exerted by its root extract

BACKGROUND

The Orchidaceae family is one of the largest families of flowering plants. Orchids are widely used for the traditional herbal medicine, acting as aphrodisiac, antisepic, antimicrobial, anti-cancer agent, etc.

PURPOSE

This study was designed to elucidate the anti-inflammatory, antioxidant and cytotoxic potential of a 50% ethanolic extract of Eulophia macrobulbon roots (EME) in vitro, an orchid growing in Southern Asia. Furthermore, the main active compounds were isolated, and the bioactivity of the single constituents was determined.

METHODS

The anti-inflammatory activity of EME and its compounds was evaluated by the secretion of pro- and anti-inflammatory cytokines and by the expression of inducible nitric oxide synthase (iNOS) in a lipopolysaccharide (LPS)-stimulated macrophage model, as determined by an enzyme linked immunosorbent assay (ELISA) and Western blot. Antioxidant activity was assessed using a DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) photometric assay. Cytotoxic effects were determined using a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-assay.

RESULTS

EME and its compounds significantly reduced the production of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α), the expression of iNOS and subsequently increased the production of the anti-inflammatory cytokine interleukin 10 (IL-10) in LPS-stimulated macrophages. Additionally it could be demonstrated that EME is rich in radical scavengers. Furthermore, EME and its components showed notable cytotoxic effects on the human cervical adenocarcinoma cell line HeLa, the human colorectal adenocarcinoma cell line CaCo-2 and the human breast adenocarcinoma cell line MCF-7. The most active constituents were identified as 4-methoxy-9,10-dihydro-2,7-phenanthrenediol (8), 4-methoxy-2,7-phenanthrenediol (9), 1,5-dimethoxy-2,7-phenanthrenediol (10), 1,5,7-trimethoxy-2,6-phenanthrenediol (11), 1-(4-hydroxybenzyl)-4,8-dimethoxy-2,7-phenanthrenediol (15).

CONCLUSION

Based on this data, EME provides various beneficial anti-inflammatory, antioxidant and cytotoxic attributes and may be used as herbal remedy in the pharmaceutical or food industries.

Gigantol Inhibits Epithelial to Mesenchymal Process in Human Lung Cancer Cells

Lung cancer remains a leading public health problem as evidenced by its increasing death rate. The main cause of death in lung cancer patients is cancer metastasis. The metastatic behavior of lung cancer cells becomes enhanced when cancer cells undergo epithelial to mesenchymal transition (EMT). Gigantol, a bibenzyl compound extracted from the Thai orchid, Dendrobium draconis, has been shown to have promising therapeutic potential against cancer cells, which leads to the hypothesis that gigantol may be able to inhibit the fundamental EMT process in cancer cells. This study has demonstrated for the first time that gigantol possesses the ability to suppress EMT in non-small cell lung cancer H460 cells. Western blot analysis has revealed that gigantol attenuates the activity of ATP-dependent tyrosine kinase (AKT), thereby inhibiting the expression of the major EMT transcription factor, Slug, by both decreasing its transcription and increasing its degradation. The inhibitory effects of gigantol on EMT result in a decrease in the level of migration in H460 lung cancer cells. The results of this study emphasize the potential of gigantol for further development against lung cancer metastasis.

Moscatilin inhibits epithelial-to-mesenchymal transition and sensitizes anoikis in human lung cancer H460 cells

Metastasis in lung cancer has been recognized as an important cause of high mortality. Resistance to anoikis and the epithelial-to-mesenchymal transition (EMT) are critical factors for the successful spread of cancer cells. Compounds that suppress these features of cancer cells should be potentially active for anti-metastasis approaches. We have demonstrated for the first time that moscatilin, at its non-toxic concentrations to lung cancer cells and human normal keratinocytes, significantly decreases lung cancer cell survival in the detached condition, and suppresses the formation of tumors in an anchorage-independent growth assay. Furthermore, we found that moscatilin significantly decreased the activated level of survival proteins, namely ERK and Akt. In addition, moscatilin down-regulated cavelolin-1 (Cav-1), leading to a reduction in anti-apoptotic Mcl-1 protein. In terms of EMT, treatment of the cells with moscatilin significantly suppressed mesenchymal cell markers, namely vimentin, Slug, and Snail. These results indicate that moscatilin inhibited anoikis resistance in lung cancer cells via survival suppression, Cav-1 down-regulation, and inhibition of EMT. The compound could therefore be beneficial for the treatment and prevention of lung cancer metastasis.

Cytotoxic and Antimigratory Activities of Phenolic Compounds from Dendrobium brymerianum

Chromatographic separation of a methanol extract prepared from the whole plant of Dendrobium brymerianum led to the isolation of eight phenolic compounds. Among the isolated compounds (1-8), moscatilin (1), gigantol (3), lusianthridin (4), and dendroflorin (6) showed appreciable cytotoxicity against human lung cancer cell lines with IC50 values of 196.7, 23.4, 65.0, and 125.8 μg/mL, respectively, and exhibited antimigratory property at nontoxic concentrations. This study is the first report on the biological activities of this plant.

Antitumor activity of ethanolic extract of Dendrobium formosum in T-cell lymphoma: an in vitro and in vivo study

Dendrobium, a genus of orchid, was found to possess useful therapeutic activities like anticancer, hypoglycaemic, antimicrobial, immunomodulatory, hepatoprotective, antioxidant, and neuroprotective activities. The study was aimed to evaluate the anticancer property of the ethanolic extract of Dendrobium formosum on Dalton's lymphoma. In vitro cytotoxicity was determined by MTT assay, apoptosis was determined by fluorescence microscopy, and cell cycle progression was analysed using flow cytometry; in vivo antitumor activity was performed in Dalton's lymphoma bearing mice. The IC₅₀ value of ethanolic extract was obtained at 350 μg/mL in Dalton's lymphoma cells. Fluorescence microscopy analysis showed significant increase in apoptotic cell death in dose- and time-dependent manner which was further confirmed through the resulting DNA fragmentation. Further, flow cytometry analysis showed that the ethanolic extract arrests the cells in G₂/M phase of the cell cycle. The in vivo anticancer activity study illustrates significant increase in the survival time of Dalton's lymphoma bearing mice on treatment with ethanolic extract when compared to control. These results substantiate the antitumor properties of ethanolic extract of Dendrobium formosum and suggest an alternative in treatment of cancer. Further studies are required regarding the isolation and characterization of bioactive components along with the analysis of molecular mechanism involved.

Moscatilin induces apoptosis and mitotic catastrophe in human esophageal cancer cells

Moscatilin, a bibenzyl derivative from the orchid Dendrobium loddigesii, has been shown to possess anticancer activity. We examined the effect of moscatilin on human esophageal cancer cells, including squamous cell carcinoma (SCC) and adenocarcinoma (ADC) cells and its possible mechanisms. Moscatilin suppressed the growth of both the histological cell lines in a dose- and time-dependent manner. Morphological changes indicative of apoptosis and mitotic catastrophe were observed following moscatilin treatment. The population of cells in the sub-G1 phase and polyploidy phase significantly increased after treatment. Immunofluorescence revealed multipolar mitosis and subsequent multinucleation in moscatilin-treated cells, indicating the development of mitotic catastrophe. Western blot showed a marked increase in expressions of polo-like kinase 1 and cyclin B1 after exposure to moscatilin. In conclusion, moscatilin inhibits growth and induces apoptosis and mitotic catastrophe in human esophageal SCC- and ADC-derived cell lines, indicating that moscatilin has broad potential against esophageal cancer.

Moscatilin inhibits lung cancer cell motility and invasion via suppression of endogenous reactive oxygen species

Lung cancer is the leading cause of death among cancer patients worldwide, and most of them have died from metastasis. Migration and invasion are prerequisite processes associated with high metastasis potential in cancers. Moscatilin, a bibenzyl derivative isolated from the Thai orchid Dendrobium pulchellum, has been shown to have anticancer effect against numerous cancer cell lines. However, little is known regarding the effect of moscatilin on cancer cell migration and invasion. The present study demonstrates that nontoxic concentrations of moscatilin were able to inhibit human nonsmall cell lung cancer H23 cell migration and invasion. The inhibitory effect of moscatilin was associated with an attenuation of endogenous reactive oxygen species (ROS), in which hydroxyl radical (OH^∙) was identified as a dominant species in the suppression of filopodia formation. Western blot analysis also revealed that moscatilin downregulated activated focal adhesion kinase (phosphorylated FAK, Tyr 397) and activated ATP-dependent tyrosine kinase (phosphorylated Akt, Ser 473), whereas their parental counterparts were not detectable changed. In conclusion, our results indicate the novel molecular basis of moscalitin-inhibiting lung cancer cell motility and invasion and demonstrate a promising antimetastatic potential of such an agent for lung cancer therapy.

Anti-metastatic Activities of Bibenzyls from Dendrobium pulchellum

Our investigation of the stem of Dendrobium pulchellum resulted in the isolation of four known bibenzyls, chrysotobibenzyl (1), chrysotoxine (2), crepidatin (3) and moscatilin (4). The present study reveals for the first time the ability of these four compounds to facilitate anoikis and inhibit the growth of lung cancer cells in anchorage-independent condition. The preliminary data obtained disclose the inhibitory effect on cancer cell metastasis of the isolated compounds, and provide an important new approach for cancer drug development.

Therapeutic orchids: traditional uses and recent advances--an overview

Orchids have been used as a source of medicine for millennia to treat different diseases and ailments including tuberculosis, paralysis, stomach disorders, chest pain, arthritis, syphilis, jaundice, cholera, acidity, eczema, tumour, piles, boils, inflammations, menstrual disorder, spermatorrhea, leucoderma, diahorrhea, muscular pain, blood dysentery, hepatitis, dyspepsia, bone fractures, rheumatism, asthma, malaria, earache, sexually transmitted diseases, wounds and sores. Besides, many orchidaceous preparations are used as emetic, purgative, aphrodisiac, vermifuge, bronchodilator, sex stimulator, contraceptive, cooling agent and remedies in scorpion sting and snake bite. Some of the preparations are supposed to have miraculous curative properties but rare scientific demonstration available which is a primary requirement for clinical implementations. Incredible diversity, high alkaloids and glycosides content, research on orchids is full of potential. Meanwhile, some novel compounds and drugs, both in phytochemical and pharmacological point of view have been reported from orchids. Linking of the indigenous knowledge to the modern research activities will help to discover new drugs much more effective than contemporary synthetic medicines. The present study reviews the traditional therapeutic uses of orchids with its recent advances in pharmacological investigations that would be a useful reference for plant drug researches, especially in orchids.

Targeting tumor proteasome with traditional Chinese medicine

The proteasome is a multicatalytic protease complex whose activity is required for the growth of normal or tumor cells. It has been shown that human cancer cells are more sensitive to proteasome inhibition than normal cells, indicating that the proteasome could be a target of chemotherapy. Studies suggest that traditional Chinese medicine (TCM) is an effective approach for cancer treatment. Here we reviewed several TCMs for their potential in treatment of cancer. This short review focuses mainly on the TCMs that potentially target the tumor cellular proteasome and NF-kappaB pathway whose activation is dependent on the proteasome activity.

Moscatilin repressed lipopolysaccharide-induced HIF-1alpha accumulation and NF-kappaB activation in murine RAW264.7 cells

In the present study, we investigated the signaling pathways involved in the inhibition of cyclooxygenase 2 (COX-2) and iNOS by moscatilin under LPS challenge in murine macrophage-derived cell line RAW264.7. The results showed that moscatilin (10-100 microM) had a significant inhibition in a concentration-dependent manner on proinflammatory enzymes (COX-2 and iNOS) expression and macrophage activation under LPS (100 ng/mL) treatment. Hypoxia-inducible factor 1 (HIF-1)alpha was reported to initiate inflammation under cytokine stimulation or hypoxic conditions. In addition, the increase in transcriptional activity and translation process of HIF-1alpha under LPS stimulation resulted in HIF-1alpha accumulation. Moscatilin, a purified compound from Chinese herbs, had a dominant repression on HIF-1alpha expression via down regulating HIF-1alpha mRNA without inhibition of cell viability, translation machinery, or proteasome-mediated degradation of HIF-1alpha. Moreover, the results showed that moscatilin suppressed nuclear translocation of nuclear factor (NF)-kappaB subunits, p65 and p50, and NF-kappaB activity by inhibiting phosphorylation of inhibitor of kappaBalpha. Taken together, we demonstrated that moscatilin inhibited both COX-2 and iNOS expressions after LPS treatment in RAW264.7. Furthermore, the inhibition of moscatilin seemed to be dependent on the repression of HIF-1alpha accumulation and NF-kappaB activation.

Moscatilin induces apoptosis in human colorectal cancer cells: a crucial role of c-Jun NH2-terminal protein kinase activation caused by tubulin depolymerization and DNA damage

PURPOSE

To study the effect of moscatilin (purified from the stem of orchid Dendrobrium loddigesii) on the proliferation of human colorectal cancer HCT-116 cells in vitro and in vivo.

EXPERIMENTAL DESIGN

The growth inhibition of moscatilin was screened on several human cancer cell lines. The effect of moscatilin on tubulin was detected in vitro. Following moscatilin treatment on HCT-116 cells, c-Jun NH(2)-terminal protein kinase (JNK) and caspase activation was studied by Western blot analysis, and DNA damage was done by Comet assay. Specific JNK inhibitor SP600125 was cotreated to reverse moscatilin-induced apoptosis. Tumor growth inhibition of moscatilin was done on HCT-116 xenograft models.

RESULTS

Moscatilin induced a time-dependent arrest of the cell cycle at G(2)-M, with an increase of cells at sub-G(1). Moscatilin inhibited tubulin polymerization, suggesting that it might bind to tubulins. Moscatilin also induced the phosphorylation of JNK1/2. SP600125 significantly inhibited the activation of caspase-9 and caspase-3 and the subsequent moscatilin-induced apoptosis. The data suggest that JNK activation may contribute to moscatilin-mediated apoptosis signaling. A parallel experiment showed that SP600125 significantly inhibits Taxol- and vincristine-induced HCT-116 cell apoptosis. This suggests that the JNK activation may be a common mechanism for tubulin-binding agents. Moreover, moscatilin induces DNA damage, phosphorylation of H2AX and p53, and up-regulation of p21. Our HCT-116 xenograft models show the in vivo efficacy of moscatilin.

CONCLUSIONS

In summary, our results suggest that moscatilin induces apoptosis of colorectal HCT-116 cells via tubulin depolymerization and DNA damage stress and that this leads to the activation of JNK and mitochondria-involved intrinsic apoptosis pathway.