A bibenzyl from Dendrobium ellipsophyllum induces apoptosis in human 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.

Dendrobium and its active ingredients: Emerging role in liver protection

Dendrobium is a traditional medicinal plant, which has a variety of clinical applications in China. It has been reported that Dendrobium contains various bioactive components, mainly including polysaccharides and alkaloids. Previous studies have shown that Dendrobium has pharmacological activities including antiviral, anti-inflammatory, and antioxidant effects, as well as immune regulation. Particularly, the anti-aging functions and neuroprotective effects of Dendrobium have been well characterized in a wide array of cell and animal models. In recent years, the effect of Dendrobium on the liver has emerged as a new direction to explore its therapeutic benefits and has received more and more attention. This review is focused on the beneficial effects of Dendrobium on liver toxicity and various liver disorders, which presumably are attributed to a consequence of an array of modes of action due to its multiple bioactive components, and largely lack mechanistic and pharmacokinetic characterization. A particular emphasis is placed on the potential action mechanisms related to Dendrobium's liver protection. Research perspectives in regard to the potential therapeutic application for Dendrobium are also discussed in this review.

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.

Potential Anti-allergic Effects of Bibenzyl Derivatives from Liverworts, Radula perrottetii

The liverwort Radula perrottetii contains various bibenzyl derivatives which are known to possess various biological activities, such as anti-inflammatory effects. Mast cells (MC) play crucial roles in allergic and inflammatory diseases; thus, inhibition of MC activation is pivotal for the treatment of allergic and inflammatory disorders. We investigated the effects of perrottetin D (perD), isolated from Radula perrottetii, and perD diacetate (Ac-perD) on antigen-induced activation of MCs. Bone marrow-derived MCs (BMMCs) were generated from C57BL/6 mice. The degranulation ratio, histamine release, and the interleukin (IL)-4 and leukotriene B₄ productions on antigen-triggered BMMC were investigated. Additionally, the effects of the bibenzyls on binding of IgE to FcεRI were observed by flow cytometry, and signal transduction proteins was examined by Western blot. Furthermore, binding of the bibenzyls to the Fyn kinase domain was calculated. At 10 µM, perD decreased the degranulation ratio (p < 0.01), whereas 10 µM Ac-perD down-regulated IL-4 production (p < 0.05) in addition to decreasing the degranulation ratio (p < 0.01). Both compounds tended to decrease histamine release at a concentration of 10 µM. Although 10 µM perD reduced only Syk phosphorylation, 10 µM Ac-perD diminished phosphorylation of Syk, Gab2, PLC-γ, and p38. PerD appeared to selectively bind Fyn, whereas Ac-perD appeared to act as a weak but broad-spectrum inhibitor of kinases, including Fyn. In conclusion, perD and Ac-perD suppressed the phosphorylation of signal transduction molecules downstream of the FcεRI and consequently inhibited degranulation, and/or IL-4 production. These may be beneficial potential lead compounds for the development of novel anti-allergic and anti-inflammatory drugs.

Untapped Pharmaceutical Potential of 4,5,4'-Trihydroxy-3,3'-dimethoxybibenzyl for Regulating Obesity: A Cell-Based Study with a Focus on Terminal Differentiation in Adipogenesis

Obesity and its global prevalence has become a threat to human health, while its pharmacotherapy via the application of natural products is still underdeveloped. Here, we probed how 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl (TDB) derived from an orchid (Dendrobium ellipsophyllum) could exert its roles on the differentiation and function of murine (3T3-L1) and human (PCS-210-010) pre-adipocytes and offer some implications to modulate obesity. Cytotoxic effects of TDB on adipocytes were 2-fold lower than those detected with pre-adipocytes, and no significant difference was detected in cytotoxic profiles between both cell lineages. TDB in a dose-dependent manner decreased cellular lipid accumulation and enhanced lipolysis of both cell lines assessed at early differentiation and during maturation. Underlining molecular mechanisms proved that TBD paused the cell cycle progression by regulating inducers and inhibitors in mitotic clonal expansion, leading to growth arrest of pre-adipocytes at the G0/G1 phase. The compound also governed adipocyte differentiation by repressing expressions of crucial adipogenic regulators and effectors through deactivating the AKT/GSK-3β signaling pathway and activating the AMPK-ACC pathway. To this end, TDB has shown its pharmaceutical potential for modulating adipocyte development and function, and it would be a promising candidate for further assessments as a therapeutic agent to defeat obesity.

Natural therapeutics and nutraceuticals for lung diseases: Traditional significance, phytochemistry, and pharmacology

BACKGROUND

Lung diseases including chronic obstructive pulmonary disease (COPD), infections like influenza, acute respiratory distress syndrome (ARDS), asthma and pneumonia lung cancer (LC) are common causes of sickness and death worldwide due to their remoteness, cold and harsh climatic conditions, and inaccessible health care facilities.

PURPOSE

Many drugs have already been proposed for the treatment of lung diseases. Few of them are in clinical trials and have the potential to cure infectious diseases. Plant extracts or herbal products have been extensively used as Traditional Chinese Medicine (TCM) and Indian Ayurveda. Moreover, it has been involved in the inhibition of certain genes/protiens effects to promote regulation of signaling pathways. Natural remedies have been scientifically proven with remarkable bioactivities and are considered a cheap and safe source for lung disease.

METHODS

This comprehensive review highlighted the literature about traditional plants and their metabolites with their applications for the treatment of lung diseases through experimental models in humans. Natural drugs information and mode of mechanism have been studied through the literature retrieved by Google Scholar, ScienceDirect, SciFinder, Scopus and Medline PubMed resources against lung diseases.

RESULTS

In vitro, in vivo and computational studies have been explained for natural metabolites derived from plants (like flavonoids, alkaloids, and terpenoids) against different types of lung diseases. Probiotics have also been biologically active therapeutics against cancer, anti-inflammation, antiplatelet, antiviral, and antioxidants associated with lung diseases.

CONCLUSION

The results of the mentioned natural metabolites repurposed for different lung diseases especially for SARS-CoV-2 should be evaluated more by advance computational applications, experimental models in the biological system, also need to be validated by clinical trials so that we may be able to retrieve potential drugs for most challenging lung diseases especially SARS-CoV-2.

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.

Erianin regulates programmed cell death ligand 1 expression and enhances cytotoxic T lymphocyte activity

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium chrysotoxum Lindl is a cultivation of Dendrobium which belongs to the family of Orchidaceae. D. chrysotoxum Lindl is a traditional Chinese medicine with a wide range of clinical applications including tonic, astringent, analgesic and anti-inflammatory properties as early as the 28th century B.C. Erianin is a representative index component for the quality control of the D. chrysotoxum Lindl, which is included in the Pharmacopoeia of the People's Republic of China (2020 version).

AIM OF THE STUDY

To clarify the anti-tumour mechanisms of erianin in vitro and in vivo.

MATERIALS AND METHODS

We detected the anti-tumour activity of erianin using in vitro HeLa cell models and in vivo cervical cancer xenograft models. We performed MTT, western blot, RT-PCR, homology modeling, flow cytometry, and immunoprecipitation assays to study the proteins, genes, and pathways related to erianin's anti-tumour activity. LysoTracker Red staining was performed to detect lysosome function. Transwell, wound healing, tube formation, colony formation and EdU labelling assays were performed to determine cell proliferation, migration and invasion abilities, respectively. Cytotoxic T lymphocytes ability was confirmed using HeLa/T-cell co-culture model.

RESULTS

Experimental data demonstrated that erianin inhibited PD-L1 expression and induced the lysosomal degradation of PD-L1. Erianin suppressed HIF-1α synthesis through mTOR/p70S6K/4EBP1 pathway, and inhibited RAS/Raf/MEK/MAPK-ERK pathway. Immunoprecipitation experiments demonstrated that erianin reduced the interaction between RAS and HIF-1α. Experiments using a co-cultivation system of T cells and HeLa cells confirmed that erianin restored cytotoxic T lymphocytes ability to kill tumour cells. Erianin inhibited PD-L1-mediated angiogenesis, proliferation, invasion and migration. The anti-proliferative effects of erianin were supported using in vivo xenotransplantation experiments.

CONCLUSIONS

Collectively, these results revealed previously unknown properties of erianin and provided a new basis for improving the efficacy of immunotherapy against cervical cancer and other malignant tumours through PD-L1.

Curcumin suppresses LGR5(+) colorectal cancer stem cells by inducing autophagy and via repressing TFAP2A-mediated ECM pathway

Abstract

Colorectal cancer stem cells (CSCs) have the potential for self-renewal, proliferation, and differentiation. And LGR5 is a stem cell marker gene of colorectal cancer. Curcumin can suppress oncogenicity of many cancer cells, yet the effect and mechanism of curcumin in LGR5(+) colorectal cancer stem cells (CSCs) have not been studied. In this study, we studied the effect of curcumin on LGR5(+) colorectal CSCs using the experiments of tumorsphere formation, cell viability and cell apoptosis. Then autophagy analysis, RNA-Seq, and real-time PCR were used to identify the mechanism responsible for the inhibition of LGR5(+) colorectal CSCs. Our results showed that curcumin inhibited tumorsphere formation, decreased cell viability in a dose-dependent manner, and also promoted apoptosis of LGR5(+) colorectal CSCs. Next, we found curcumin induced autophagy of LGR5(+) colorectal CSCs. When LGR5(+) colorectal CSCs were co-treated with curcumin and the autophagy inhibitor (hydroxychloroquine), curcumin-induced cell proliferation inhibition decreased. In addition, we also found that curcumin inhibited the extracellular matrix (ECM)-receptor interaction pathway via the downregulation of the following genes: GP1BB, COL9A3, COMP, AGRN, ITGB4, LAMA5, COL2A1, ITGB6, ITGA1, and TNC. Further, these genes were transcriptionally regulated by TFAP2A, and the high expression of TFAP2A was associated with poor prognosis in colorectal cancer. In conclusion, curcumin suppressed LGR5(+) colorectal CSCs, potentially by inducing autophagy and repressing the oncogenic TFAP2A-mediated ECM pathway.

Graphic abstract

Emerging role of phytochemicals in targeting predictive, prognostic, and diagnostic biomarkers of lung cancer

Lung-cancer is the foremost cause of cancer in humans worldwide, of which 80-85% cases are composed of non-small cell lung carcinoma. All treatment decisions depend on the pattern of biomarkers selection to enhance the response to the targeted therapies. Although advanced treatments are available for lung-cancer, the disease treatment remains not adequate. There are several synthetic chemotherapeutic agents available for the treatment of lung cancer. However, due to their toxic effect, survival rate is still 15-18%. Besides, medicinal plants are a huge reservoir of natural products that provide protective effects against lung cancer. Likewise, successful studies of potential phytochemicals in targeting lung-cancer biomarkers have created a novel paradigm for the discovery of potent drugs against lung-cancer. Hence, to defeat severe toxicity and resistance towards the synthetic drugs, detailed studies are required regarding the available phytochemicals and targets responsible for the treatment of lung-cancer. The present review provides a comprehensive information about the lung-cancer biomarkers under the classification of predictive, prognostic, and diagnostic type. Moreover, it discusses and enlists the phytochemicals with mode of action against different biomarkers, effective doses in in vitro, in vivo, and clinical studies, the limitations associated with usage of phytochemicals as a drug to prevent/cure lung-cancer and the latest techniques employed to overcome such issues.

Discrimination of Different Species of Dendrobium with an Electronic Nose Using Aggregated Conformal Predictor

A method using electronic nose to discriminate 10 different species of dendrobium, which is a kind of precious herb with medicinal application, was developed with high efficiency and low cost. A framework named aggregated conformal prediction was applied to make predictions with accuracy and reliability for E-nose detection. This method achieved a classification accuracy close to 80% with an average improvement of 6.2% when compared with the results obtained by using traditional inductive conformal prediction. It also provided reliability assessment to show more comprehensive information for each prediction. Meanwhile, two main indicators of conformal predictor, validity and efficiency, were also compared and discussed in this work. The result shows that the approach integrating electronic nose with aggregated conformal prediction to classify the species of dendrobium with reliability and validity is promising.

Review of Hair Follicle Dermal Papilla cells as in vitro screening model for hair growth

Hair disorders such as hair loss (alopecia) and androgen dependent, excessive hair growth (hirsutism, hypertrichosis) may impact the social and psychological well-being of an individual. Recent advances in understanding the biology of hair have accelerated the research and development of novel therapeutic and cosmetic hair growth agents. Preclinical models aid in dermocosmetic efficacy testing and claim substantiation of hair growth modulators. The in vitro models to investigate hair growth utilize the hair follicle Dermal Papilla cells (DPCs), specialized mesenchymal cells located at the base of hair follicle that play essential roles in hair follicular morphogenesis and postnatal hair growth cycles. In this review, we have compiled and discussed the extensively reported literature citing DPCs as in vitro model to study hair growth promoting and inhibitory effects. A variety of agents such as herbal and natural extracts, growth factors and cytokines, platelet-rich plasma, placental extract, stem cells and conditioned medium, peptides, hormones, lipid-nanocarrier, light, electrical and electromagnetic field stimulation, androgens and their analogs, stress-serum and chemotherapeutic agents etc. have been examined for their hair growth modulating effects in DPCs. Effects on DPCs' activity were determined from untreated (basal) or stress induced levels. Cell proliferation, apoptosis and secretion of growth factors were included as primary end-point markers. Effects on a wide range of biomolecules and mechanistic pathways that play key role in the biology of hair growth were also investigated. This consolidated and comprehensive review summarizes the up-to-date information and understanding regarding DPCs based screening models for hair growth and may be helpful for researchers to select the appropriate assay system and biomarkers. This review highlights the pivotal role of DPCs in the forefront of hair research as screening platforms by providing insights into mechanistic action at cellular level, which may further direct the development of novel hair growth modulators.