A bibenzyl from Dendrobium ellipsophyllum inhibits migration in lung cancer cells

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.

Stemness-Suppressive Effect of Bibenzyl from Dendrobium ellipsophyllum in Human Lung Cancer Stem-Like Cells

Cancer stem-like cells (CSCs) are key mediators driving tumor initiation, metastasis, therapeutic failure, and subsequent cancer relapse. Thus, targeting CSCs has recently emerged as a potential strategy to improve chemotherapy. In this study, the anticancer activity and stemness-regulating capacity of 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl (TDB), a bibenzyl extracted from Dendrobium ellipsophyllum, are revealed in CSCs of various human lung cancer cells. Culture with TDB (5-10 μM) strongly abolished tumor-initiating cells in lung cancer H460, H23, and A549 cells in both anchorage-dependent and anchorage-independent colony formation assays. Through the 3D single-spheroid formation model, attenuation of self-renewal capacity was observed in CSC-enriched populations treated with 1-10 μM TDB for 7 days. Flow cytometry analysis confirmed the attenuation of %cell overexpressing CD133, a CSC biomarker, in TDB-treated lung cancer spheroids. TDB at 5-10 μM remarkably suppressed regulatory signals of p-Akt/Akt, p-GSK3β/GSK3β, and β-catenin corresponding to the downregulated mRNA level of stemness transcription factors including Nanog, Oct4, and Sox2. Moreover, the antiapoptosis Bcl-2 and Mcl-1 proteins, which are downstream molecules of Akt signaling, were evidently decreased in CSC-enriched spheroids after culture with TDB (1-10 μM) for 24 h. Interestingly, the diminution of Akt expression by specific siAkt effectively reversed suppressive activity of TDB targeting on the CSC phenotype in human lung cancer cells. These findings provide promising evidence of the inhibitory effect of TDB against lung CSCs via suppression of Akt/GSK3β/β-catenin cascade and related proteins, which would facilitate the development of this bibenzyl natural compound as a novel CSC-targeted therapeutic approach for lung cancer treatment.

Targeting the PI3K/AKT/mTOR Signaling Pathway in Lung Cancer: An Update Regarding Potential Drugs and Natural Products

Lung cancer is one of the most common cancers and has a high mortality rate. Due to its high incidence, the clinical management of the disease remains a major challenge. Several reports have documented a relationship between the phosphatidylinositol-3-kinase (PI3K)/ protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway and lung cancer. The recognition of this pathway as a notable therapeutic target in lung cancer is mainly due to its central involvement in the initiation and progression of the disease. Interest in using natural and synthetic medications to target these signaling pathways has increased in recent years, with promising results in vitro, in vivo, and in clinical trials. In this review, we focus on the current understanding of PI3K/AKT/mTOR signaling in tumor development. In addition to the signaling pathway, we highlighted the therapeutic potential of recently developed PI3K/AKT/mTOR inhibitors based on preclinical and clinical trials.

A narrative review of the migration and invasion features of non-small cell lung cancer cells upon xenobiotic exposure: insights from in vitro studies

Lung cancer (LC) is the leading cause of cancer deaths worldwide, being non-small lung cancer (NSCLC) sub-types the most prevalent. Since most LC cases are only detected during the last stage of the disease the high mortality rate is strongly associated with metastases. For this reason, the migratory and invasive capacity of these cancer cells as well as the mechanisms involved have long been studied to uncover novel strategies to prevent metastases and improve the patients’ prognosis. This narrative review provides an overview of the main in vitro migration and invasion assays employed in NSCLC research. While several methods have been developed, experiments using conventional cell culture models prevailed, specifically the wound-healing and the transwell migration and invasion assays. Moreover, it is provided herewith a summary of the available information concerning chemical contaminants that may promote the migratory/invasive properties of NSCLC cells in vitro, shedding some light on possible LC risk factors. Most of the reported agents with pro-migration/invasion effects derive from cigarette smoking [e.g., Benzo(a)pyrene and cadmium] and air pollution. This review further presents several studies in which different dietary/plant-derived compounds demonstrated to impair migration/invasion processes in NSCLC cells in vitro. These chemicals that have been proposed as anti-migratory consisted mainly of natural bioactive substances, including polyphenols non-flavonoids, flavonoids, bibenzyls, terpenes, alkaloids, and steroids. Some of these compounds may eventually represent novel therapeutic strategies to be considered in the future to prevent metastasis formation in LC, which highlights the need for additional in vitro methodologies that more closely resemble the in vivo tumor microenvironment and cancer cell interactions. These studies along with adequate in vivo models should be further explored as proof of concept for the most promising compounds.

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.

The role of Rho GTPases' substrates Rac and Cdc42 in osteoclastogenesis and relevant natural medicinal products study

Recently, Rho GTPases substrates include Rac (Rac1 and Rac2) and Cdc42 that have been reported to exert multiple cellular functions in osteoclasts, the most prominent of which includes regulating the dynamic actin cytoskeleton rearrangements. In addition, natural products and their molecular frameworks have a long tradition as valuable starting points for medicinal chemistry and drug discovery. Although currently, there are reports about the natural product, which could play a therapeutic role in bone loss diseases (osteoporosis and osteolysis) through the regulation of Rac1/2 and Cdc42 during osteoclasts cytoskeletal structuring. There have been several excellent studies for exploring the therapeutic potentials of various natural products for their role in inhibiting cancer cells migration and function via regulating the Rac1/2 and Cdc42. Herein in this review, we try to focus on recent advancement studies for extensively understanding the role of Rho GTPases substrates Rac1, Rac2 and Cdc42 in osteoclastogenesis, as well as therapeutic potentials of natural medicinal products for their properties on the regulation of Rac1, and/or Rac2 and Cdc42, which is in order to inspire drug discovery in regulating osteoclastogenesis.

Deguelin Impairs Cell Adhesion, Migration and Invasion of Human Lung Cancer Cells through the NF-[Formula: see text]B Signaling Pathways

Deguelin, a rotenoid, is isolated from a natural plant species, and has biological activities including antitumor function. In the present study, we investigated the effect of deguelin on the cell adhesion, migration and invasion of NCI-H292 human lung cancer cells in vitro. Cell viability was analyzed by using flow cytometer. Cell adhesion was determined by using the cell-matrix adhesion assay. Wound healing assay was used to examine cell migration. Cell migration and invasion were investigated using a Boyden chamber assay. The protein expression was measured by Western blotting and confocal laser microscopy. The electrophoretic mobility shift assay was used to measure NF-[Formula: see text]B p65 binding to DNA.We selected the concentrations of deguelin at 0, 0.5, 1.0, 1.5, 2.0 and 2.5[Formula: see text][Formula: see text]M and we found that those concentrations of deguelin did not induce significant cytotoxic effects on NCI-H292 cells. Thus, we selected those concentrations of deguelin for metastasis assay. We found that deguelin inhibited cell adhesion, migration and invasion in dose-dependent manners that was assayed by wound healing and transwell methods, respectively. Deguelin decreased the expression of MMP-2/-9, SOS 1, Rho A, p-AKT (Thr308), p-ERK1/2, p-p38, p-JNK, NF-[Formula: see text]B (p65) and uPA in NCI-H292 cells. Deguelin suppressed the expression of PI3K, SOS 1, NF-[Formula: see text]B (p65), but did not significantly affect PKC and Ras in the nuclei of NCI-H292 cells that were confirmed by confocal laser microscopy. We suggest that deguelin may be used as a novel anticancer metastasis of lung cancer in the future.

A bibenzyl from Dendrobium ellipsophyllum induces apoptosis in human lung cancer cells

Failure of current chemotherapeutic drugs leads to the recurrence of tumor pathology and mortality in lung cancer patients. This study aimed to evaluate the anticancer activity and related mechanisms of 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl (TDB), a bibenzyl extracted from Dendrobium ellipsophyllum Tang and Wang, in human lung cancer cells. Cytotoxicity of TDB (0-300 µM) in different types of human lung cancer cells (H460, H292 and H23) and human dermal papilla cells (DPCs) was evaluated via MTT viability assay. Selective anticancer activity of TDB against human lung cancer cells was demonstrated with a high IC₅₀ (approximately > 300 µM) in DPCs, while IC₅₀ in human lung cancer H460, H292 and H23 cells was approximately 100 ± 5.18, 100 ± 8.73 and 188.89 ± 8.30 µM, respectively. After treatment with 50 µM of TDB for 24 h, flow cytometry analysis revealed the significant increase of early and late apoptosis with absence of necrosis cell death in human lung cancer cells. The up-regulation of p53, a tumor-suppressor protein, was elucidated in human lung cancer cells treated with 10-50 µM of TDB. Alteration to down-stream signaling of p53 including activation of pro-apoptosis protein (Bcl-2-associated X protein; Bax), reduction of anti-apoptosis (B cell lymphoma 2; Bcl-2 and myeloid cell leukemia 1; Mcl-1) and suppression on protein kinase B (Akt) survival pathway were notified in TDB-treated lung cancer cells. The information obtained from this study strengthens the potential development of TDB as an anticancer compound with a favorable human safety profile and high efficacy.

Dendrobium: Sources of Active Ingredients to Treat Age-Related Pathologies

Dendrobium represents one of the most important orchid genera, ornamentally and medicinally. Dendrobiums are sympodial epiphytic plants, which is a name they are worthy of, the name coming from Greek origin: "dendros", tree, and "bios", life. Dendrobium species have been used for a thousand years as first-rate herbs in traditional Chinese medicine (TCM). They are source of tonic, astringent, analgesic, antipyretic, and anti-inflammatory substances, and have been traditionally used as medicinal herbs in the treatment of a variety of disorders, such as, nourishing the stomach, enhancing production of body fluids or nourishing Yin. The Chinese consider Dendrobium as one of the fifty fundamental herbs used to treat all kinds of ailments and use Dendrobium tonic for longevity. This review is focused on main research conducted during the last decade (2006-2016) on Dendrobium plants and their constituents, which have been subjected to investigations of their pharmacological effects involving anticancer, anti-diabetic, neuroprotective and immunomodulating activities, to report their undeniable potential for treating age-related pathologies.

The medicinal and pharmaceutical importance of Dendrobium species

Plants of the Dendrobium genus, one of the largest in the Orchidaceae, manifest a diversity of medicinal effects encompassing antiangiogenic, immunomodulating, antidiabetic, cataractogenesis-inhibiting, neuroprotective, hepatoprotective, anti-inflammatory, antiplatelet aggregation, antifungal, antibacterial, antiherpetic, antimalarial, aquaporin-5 stimulating, and hemagglutininating activities and also exert beneficial actions on colonic health and alleviate symptoms of hyperthyroidism. The active principles include a wide range of proteinaceous and non-proteinaceous molecules. This mini-review discusses the latest advances in what is known about the medicinal and pharmaceutical properties of members of the Dendrobium genus and explores how biotechnology can serve as a conduit to mass propagate valuable germplasm for sustainable exploration for the pharmaceutical industry.