Ginsenoside 20(S)-Rg3 targets HIF-1α to block hypoxia-induced epithelial-mesenchymal transition in ovarian cancer cells

A nanoscale natural drug delivery system for targeted drug delivery against ovarian cancer: action mechanism, application enlightenment and future potential

Ovarian cancer (OC) is one of the deadliest gynecological malignancies in the world and is the leading cause of cancer-related death in women. The complexity and difficult-to-treat nature of OC pose a huge challenge to the treatment of the disease, Therefore, it is critical to find green and sustainable drug treatment options. Natural drugs have wide sources, many targets, and high safety, and are currently recognized as ideal drugs for tumor treatment, has previously been found to have a good effect on controlling tumor progression and reducing the burden of metastasis. However, its clinical transformation is often hindered by structural stability, bioavailability, and bioactivity. Emerging technologies for the treatment of OC, such as photodynamic therapy, immunotherapy, targeted therapy, gene therapy, molecular therapy, and nanotherapy, are developing rapidly, particularly, nanotechnology can play a bridging role between different therapies, synergistically drive the complementary role of differentiated treatment schemes, and has a wide range of clinical application prospects. In this review, nanoscale natural drug delivery systems (NNDDS) for targeted drug delivery against OC were extensively explored. We reviewed the mechanism of action of natural drugs against OC, reviewed the morphological composition and delivery potential of drug nanocarriers based on the application of nanotechnology in the treatment of OC, and discussed the limitations of current NNDDS research. After elucidating these problems, it will provide a theoretical basis for future exploration of novel NNDDS for anti-OC therapy.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Targeting the key players of phenotypic plasticity in cancer cells by phytochemicals

Plasticity of phenotypic traits refers to an organism's ability to change in response to environmental stimuli. As a result, the response may alter an organism's physiological state, morphology, behavior, and phenotype. Phenotypic plasticity in cancer cells describes the considerable ability of cancer cells to transform phenotypes through non-genetic molecular signaling activities that promote therapy evasion and tumor metastasis via amplifying cancer heterogeneity. As a result of metastable phenotypic state transitions, cancer cells can tolerate chemotherapy or develop transient adaptive resistance. Therefore, new findings have paved the road in identifying factors and agents that inhibit or suppress phenotypic plasticity. It has also investigated novel multitargeted agents that may promise new effective strategies in cancer treatment. Despite the efficiency of conventional chemotherapeutic agents, drug toxicity, development of resistance, and high-cost limit their use in cancer therapy. Recent research has shown that small molecules derived from natural sources are capable of suppressing cancer by focusing on the plasticity of phenotypic responses. This systematic, comprehensive, and critical review analyzes the current state of knowledge regarding the ability of phytocompounds to target phenotypic plasticity at both preclinical and clinical levels. Current challenges/pitfalls, limitations, and future perspectives are also discussed.

From immune checkpoints to therapies: understanding immune checkpoint regulation and the influence of natural products and traditional medicine on immune checkpoint and immunotherapy in lung cancer

Lung cancer is a disease of global concern, and immunotherapy has brought lung cancer therapy to a new era. Besides promising effects in the clinical use of immune checkpoint inhibitors, immune-related adverse events (irAEs) and low response rates are problems unsolved. Natural products and traditional medicine with an immune-modulating nature have the property to influence immune checkpoint expression and can improve immunotherapy's effect with relatively low toxicity. This review summarizes currently approved immunotherapy and the current mechanisms known to regulate immune checkpoint expression in lung cancer. It lists natural products and traditional medicine capable of influencing immune checkpoints or synergizing with immunotherapy in lung cancer, exploring both their effects and underlying mechanisms. Future research on immune checkpoint modulation and immunotherapy combination applying natural products and traditional medicine will be based on a deeper understanding of their mechanisms regulating immune checkpoints. Continued exploration of natural products and traditional medicine holds the potential to enhance the efficacy and reduce the adverse reactions of immunotherapy.

Rare ginsenosides: A unique perspective of ginseng research

BACKGROUND

Rare ginsenosides (Rg3, Rh2, C-K, etc.) refer to a group of dammarane triterpenoids that exist in low natural abundance, mostly produced by deglycosylation or side chain modification via physicochemical processing or metabolic transformation in gut, and last but not least, exhibited potent biological activity comparing to the primary ginsenosides, which lead to a high concern in both the research and development of ginseng and ginsenoside-related nutraceutical and natural products. Nevertheless, a comprehensive review on these promising compounds is not available yet.

AIM OF REVIEW

In this review, recent advances of Rare ginsenosides (RGs) were summarized dealing with the structurally diverse characteristics, traditional usage, drug discovery situation, clinical application, pharmacological effects and the underlying mechanisms, structure-activity relationship, toxicity, the stereochemistry properties, and production strategies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

A total of 144 RGs with diverse skeletons and bioactivities were isolated from Panax species. RGs acted as natural ligands on some specific receptors, such as bile acid receptors, steroid hormone receptors, and adenosine diphosphate (ADP) receptors. The RGs showed promising bioactivities including immunoregulatory and adaptogen-like effect, anti-aging effect, anti-tumor effect, as well as their effects on cardiovascular and cerebrovascular system, central nervous system, obesity and diabetes, and interaction with gut microbiota. Clinical trials indicated the potential of RGs, while high quality data remains inadequate, and no obvious side effects was found. The stereochemistry properties induced by deglycosylation at C (20) were also addressed including pharmacodynamics behaviors, together with the state-of-art analytical strategies for the identification of saponin stereoisomers. Finally, the batch preparation of targeted RGs by designated strategies including heating or acid/ alkaline-assisted processes, and enzymatic biotransformation and biosynthesis were discussed. Hopefully, the present review can provide more clues for the extensive understanding and future in-depth research and development of RGs, originated from the worldwide well recognized ginseng plants.

Ginsenoside 20(S)-Rg3 reduces KIF20A expression and promotes CDC25A proteasomal degradation in epithelial ovarian cancer

Background

Ginsenoside 20(S)-Rg3 shows promising tumor-suppressive effects in ovarian cancer via inhibiting NF-κB signaling. This study aimed to explore the downstream tumor suppressive mechanisms of ginsenoside Rg3 via this signaling pathway.

Materials and methods

A systematical screening was applied to examine the expression profile of 41 kinesin family member genes in ovarian cancer. The regulatory effect of ginsenoside Rg3 on KIF20A expression was studied. In addition, we explored interacting proteins of KIF20A and their molecular regulations in ovarian cancer. RNA-seq data from The Cancer Genome Atlas (TCGA) was used for bioinformatic analysis. Epithelial ovarian cancer cell lines SKOV3 and A2780 were used as in vitro and in vivo cell models. Commercial human ovarian cancer tissue arrays were used for immunohistochemistry staining.

Results

KIF20A is a biomarker of poor prognosis among the kinesin genes. It promotes ovarian cancer cell growth in vitro and in vivo. Ginsenoside Rg3 can suppress the transcription of KIF20A. GST pull-down and co-immunoprecipitation (IP) assays confirmed that KIF20A physically interacts with BTRC (β-TrCP1), a substrate recognition subunit for SCFβ-TrCP E3 ubiquitin ligase. In vitro ubiquitination and cycloheximide (CHX) chase assays showed that via interacting with BTRC, KIF20A reduces BTRC-mediated CDC25A poly-ubiquitination and enhances its stability. Ginsenoside Rg3 treatment partly abrogates KIF20A overexpression-induced CDC25A upregulation.

Conclusion

This study revealed a novel anti-tumor mechanism of ginsenoside Rg3. It can inhibit KIF20A transcription and promote CDC25A proteasomal degradation in epithelial ovarian cancer.

Ginsenoside Rg3: A Review of its Anticancer Mechanisms and Potential Therapeutic Applications

BACKGROUND

Traditional Chinese Medicine (TCM) has a long history of treating various diseases and is increasingly being recognized as a complementary therapy for cancer. A promising natural compound extracted from the Chinese herb ginseng is ginsenoside Rg3, which has demonstrated significant anticancer effects. It has been tested in a variety of cancers and tumors and has proven to be effective in suppressing cancer.

OBJECTIVES

This work covers various aspects of the role of ginsenoside Rg3 in cancer treatment, including its biological functions, key pathways, epigenetics, and potential for combination therapies, all of which have been extensively researched and elucidated. The study aims to provide a reference for future research on ginsenoside Rg3 as an anticancer agent and a support for the potential application of ginsenoside Rg3 in cancer treatment.

Advance in vasculogenic mimicry in ovarian cancer (Review)

Ovarian cancer (OC) is a common and highly prevalent malignant tumor in women, associated with a high mortality rate, easy recurrence and easy metastasis, which is predominantly at an advanced stage when detected in patients. This renders the cancer more difficult to treat, and consequently it is also associated with a low survival rate, being the malignancy with the highest mortality rate among the various gynecological tumors. As an important factor affecting the development and metastasis of OC, understanding the underlying mechanism(s) through which it is formed and developed is crucial in terms of its treatment. At present, the therapeutic methods of angiogenic mimicry for OC remain in the preliminary stages of exploration and have not been applied in actual clinical practice. In the present review, various signaling pathways and factors affecting angiogenic mimicry in OC were described, and the chemical synthetic drugs, natural compound extracts, small-molecule protein antibodies and their associated targets, and so on, that target angiogenic mimicry in the treatment of OC, were discussed. The purpose of this review was to provide new research ideas and potential theoretical support for the discovery of novel therapeutic targets for OC that may be applied in the clinic, with the aim of effectively reducing its metastasis and recurrence rates.

Perspectives of traditional Chinese medicine to patch up immune checkpoint blockers

In this era of cancer immunotherapy, the response rates of immune checkpoint blockers (ICBs) are still too low and the adverse events may also be significant. Of the ways of patching up such deficits, chemotherapy (ChT), especially if metronomic, seems promising, especially as immunity induced by immunogenic cell death (ICD) may be preserved. However, side effects, e.g., lymphocytopenia and interstitial pneumonitis cannot be ignored; eventually, resistance may also ensue. Vascular endothelial growth factors (VEGFs), being potent angiogenic factors, promote cancer cells’ purposeful angiogenesis rendering an extremely resistant tumor microenvironment (TME). This highly evasive and extremely resilient TME actually demands multi-agent, multi-target agents as currently in use through traditional Chinese medicine (TCM). With a good track record of 3,000 years, TCM is favored by mainland Chinese cancer patients. Although TCM had been criticized as unscientific and imprecise, recently, artificial intelligence (AI) technologies serve to elucidate the sound scientific basis and validity of TCM. Several TCM preparations having anti-VEGF actions are found; others suppress immune checkpoints. Especially, these herbs’ multi-prong approach appears to be more effective than Western medicine’s primarily monotherapy approach if one wishes to eradicate the very resistant TME. A “bonus” point is that some autoimmune-related adverse side effects of ICBs may also be reduced by TCM. Nevertheless, as the TCM experience is mostly anecdotal, robust clinical trials are mandatory. Moreover, other TCM problems, e.g., herbal batch variations and consistency and uniformity of herbal prescriptions are outstanding. Invariably, TCM prescriptions have daily variations as the practice of “syndrome differentiation” is hailed. Despite experienced TCM practitioners would refuse to give up their time-honored traditional practice, the multi-prong approach is still very attractive for the undue resilience of TME, let alone its good safety profile, ready availability, and eminent affordability. Although the passage is dark, light is now appearing at the end of the tunnel.

Regulating the Expression of HIF-1α or lncRNA: Potential Directions for Cancer Therapy

Previous studies have shown that tumors under a hypoxic environment can induce an important hypoxia-responsive element, hypoxia-induced factor-1α (HIF-1α), which can increase tumor migration, invasion, and metastatic ability by promoting epithelial-to-mesenchymal transition (EMT) in tumor cells. Currently, with the deeper knowledge of long noncoding RNAs (lncRNAs), more and more functions of lncRNAs have been discovered. HIF-1α can regulate hypoxia-responsive lncRNAs under hypoxic conditions, and changes in the expression level of lncRNAs can regulate the production of EMT transcription factors and signaling pathway transduction, thus promoting EMT progress. In conclusion, this review summarizes the regulation of the EMT process by HIF-1α and lncRNAs and discusses their relationship with tumorigenesis. Since HIF-1α plays an important role in tumor progression, we also summarize the current drugs that inhibit tumor progression by modulating HIF-1α.

Experimental Evidence for the Anti-Metastatic Action of Ginsenoside Rg3: A Systematic Review

Cancer metastasis is the leading cause of death in cancer patients. Due to the limitations of conventional cancer treatment, such as chemotherapy, there is a need for novel therapeutics to prevent metastasis. Ginsenoside Rg3, a major active component of Panax ginseng C.A. Meyer, inhibits tumor growth and has the potential to prevent tumor metastasis. Herein, we systematically reviewed the anti-metastatic effects of Rg3 from experimental studies. We searched for articles in three research databases, MEDLINE (PubMed), EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) through March 2022. In total, 14 studies (eight animal and six in vitro) provide data on the anti-metastatic effects of Rg3 and the relevant mechanisms. The major anti-metastatic mechanisms of Rg3 involve cancer stemness, epithelial mesenchymal transition (EMT) behavior, and angiogenesis. Taken together, Rg3 would be one of the herbal resources in anti-metastatic drug developments through further well-designed investigations and clinical studies. Our review provides valuable reference data for Rg3-derived studies targeting tumor metastasis.

Metabolic Reprogramming in Cancer Cells: Emerging Molecular Mechanisms and Novel Therapeutic Approaches

The constant changes in cancer cell bioenergetics are widely known as metabolic reprogramming. Reprogramming is a process mediated by multiple factors, including oncogenes, growth factors, hypoxia-induced factors, and the loss of suppressor gene function, which support malignant transformation and tumor development in addition to cell heterogeneity. Consequently, this hallmark promotes resistance to conventional anti-tumor therapies by adapting to the drastic changes in the nutrient microenvironment that these therapies entail. Therefore, it represents a revolutionary landscape during cancer progression that could be useful for developing new and improved therapeutic strategies targeting alterations in cancer cell metabolism, such as the deregulated mTOR and PI3K pathways. Understanding the complex interactions of the underlying mechanisms of metabolic reprogramming during cancer initiation and progression is an active study field. Recently, novel approaches are being used to effectively battle and eliminate malignant cells. These include biguanides, mTOR inhibitors, glutaminase inhibition, and ion channels as drug targets. This review aims to provide a general overview of metabolic reprogramming, summarise recent progress in this field, and emphasize its use as an effective therapeutic target against cancer.

HIF-1α Is a Rational Target for Future Ovarian Cancer Therapies

Ovarian cancer is the eighth most commonly diagnosed cancer among women worldwide. Even with the development of novel drugs, nearly one-half of the patients with ovarian cancer die within five years of diagnosis. These situations indicate the need for novel therapeutic agents for ovarian cancer. Increasing evidence has shown that hypoxia-inducible factor-1α(HIF-1α) plays an important role in promoting malignant cell chemoresistance, tumour metastasis, angiogenesis, immunosuppression and intercellular interactions. The unique microenvironment, crosstalk and/or interaction between cells and other characteristics of ovarian cancer can influence therapeutic efficiency or promote the disease progression. Inhibition of the expression or activity of HIF-1α can directly or indirectly enhance the therapeutic responsiveness of tumour cells. Therefore, it is reasonable to consider HIF-1α as a potential therapeutic target for ovarian cancer. In this paper, we summarize the latest research on the role of HIF-1α and molecules which can inhibit HIF-1α expression directly or indirectly in ovarian cancer, and drug clinical trials about the HIF-1α inhibitors in ovarian cancer or other solid malignant tumours.

In Vitro Validation of Network Pharmacology Predictions: Ginsenoside Rg3 Inhibits Hepatocellular Carcinoma Cell Proliferation via SIRT2

To elucidate the molecular mechanisms underlying the therapeutic activity of ginsenoside Rg3 (Gs-Rg3) in the context of hepatocellular carcinoma (HCC). Methods Relevant databases were searched to identify protein targets that were both dysregulated and implicated in HCC, as well as targeted by Gs-Rg3. Generation of a protein-protein interaction network facilitated the selection of connected nodes for the construction of a shared disease- and drug-target interaction network model, and topological analysis identified the most highly connected nodes. Targets were annotated with their associated Gene Ontology terms, followed by Kyoto Encyclopedia of Genes and Genomes biological pathway enrichment analysis. In vitro experiments using 2 hours CC cell lines (Bel-7402 and HCCLM3) were performed to investigate the impact of Gs-Rg3 on cell proliferation, viability, cell cycle, cyclin D1 and sirtuin 2 (SIRT2) levels, and global cellular histone acetylation (specifically H3K18ac and H4K16ac). Results Network pharmacology suggested that Gs-Rg3 synergistically targets multiple proteins and pathways relevant to HCC pathogenesis, including those involved in cell cycle and proliferation. In vitro experiments confirmed that Gs-Rg3 dose-dependently inhibits cell proliferation and viability; induces G1 phase cell cycle arrest; decreases cyclin D1, cyclin-dependent kinase 2 (CDK2), and SIRT2 levels; and enhances global H3K18ac and H4K16ac. Conclusions Hypotheses derived from the network analysis were confirmed in vitro. Gs-Rg3 induces G1 phase cell cycle arrest, concomitant with decreased cyclin D1 and CDK2 levels, suggesting a possible mechanism for inhibiting proliferation. In addition, Gs-Rg3 decreases SIRT2 levels, concomitant with enhanced global H3K18ac and H4K16ac. These findings provide a theoretical basis and a support for further preclinical study of the safety and antineoplastic molecular mechanisms of Gs-Rg3, with the goal of eventual clinical translation.

Pharmacological properties of ginsenosides in inflammation-derived cancers

Ginseng is commonly used as an herbal medicine for improvement of life quality. It is also used as a supplemental medication with anti-cancer drugs to enhance chemotherapy efficacy and shows some beneficial effects. Ginsenosides, also known as saponins, are the major active pharmacological compounds found in ginseng and have been extensively using in treatment of not only cancers but also the other inflammatory diseases such as atherosclerosis, diabetes, acute lung injury, cardiovascular, and infectious diseases. The anti-cancer activities of ginsengs and ginsenosides in different types of cancers have been well studied experimentally and clinically. The major anti-cancer mechanisms of ginseng compounds include inhibition of angiogenesis and metastasis as well as induction of cell cycle arrest and apoptosis. Herein, we review and summarize the current knowledge on the pharmacological effects of ginsengs and ginseng-derived compounds in the treatment of cancers. Moreover, the molecular and cellular mechanism(s) by which ginsengs and ginsenosides modulate the immune response in cancer diseases as well as ginsengs-drugs interaction are also discussed.

Ginsenoside Rh2 Improves the Cisplatin Anti-tumor Effect in Lung Adenocarcinoma A549 Cells via Superoxide and PD-L1

BACKGROUND

Ginsenoside Rh2 (Rh2) is a major biological component of ginseng that exerts antitumor activities in multiple cancers including Non-Small Cell Lung Cancers (NSCLCs). Rh2 also enhances the anti-tumor effects of various chemotherapy drugs including cisplatin at relatively low concentrations. Here, the mechanistic role of Rh2 in chemotherapy-treated NSCLCs will be investigated.

METHODS

In this study, FACS, western blot and siRNA addition were used to analyze the role of Rh2 in cisplatin- treated lung adenocarcinoma A549 and H1299 cells.

RESULTS

Subsequent observations indicated that Rh2 enhanced cisplatin-induced NSCLCs A549 and H1299 cells apoptosis. Cisplatin-induced productive autophagy was repressed by Rh2 in A549 cells. Rh2 also enhanced cisplatin cytotoxicity by elevating superoxide dismutase activity and repressing cisplatin-induced superoxide generation. Conversely, Rh2 was found to repress cisplatin-induced phosphorylation of epidermal growth factor receptor, phosphoinositide 3-kinase, protein kinase B, and autophagy. Cisplatin-induced Programmed Death- Ligand 1 (PD-L1) expression was repressed by Rh2 via the superoxide.

CONCLUSION

These findings suggest that Rh2 enhanced the function of cisplatin by repressing superoxide generation, PD-L1 expression, and autophagy in lung adenocarcinoma cells.

[Ginsenoside 20(S)-Rg3 upregulates tumor suppressor VHL gene expression by suppressing DNMT3A-mediated promoter methylation in ovarian cancer cells]

OBJECTIVE

To explore the mechanism by which ginsenoside 20(S)-Rg3 upregulates the expression of tumor suppressor von Hippel-Lindau (VHL) gene in ovarian cancer cells.

METHODS

Ovarian cancer cell line SKOV3 treated with 20(S)-Rg3 were examined for mRNA and protein levels of VHL, DNMT1, DNMT3A and DNMT3B by real-time PCR and Western blotting, respectively. The changes in VHL mRNA expression in SKOV3 cells in response to treatment with 5-Aza-CdR, a DNA methyltransferase inhibitor, were detected using real-time PCR. VHL gene promoter methylation was examined with methylation-specific PCR and VHL expression levels were determined with real-time PCR and Western blotting in non-treated or 20(S)-Rg3-treated SKOV3 cells and in 20(S)-Rg3-treated DNMT3A-overexpressing SKOV3 cells. VHL and DNMT3A protein levels were detected by immunohistochemistry in subcutaneous SKOV3 cell xenografts in nude mice.

RESULTS

Treatment of SKOV3 cells with 20(S)-Rg3 significantly upregulated VHL and downregulated DNMT3A expressions at both the mRNA and protein levels (P < 0.05) and upregulated DNMT3B expression only at the mRNA level, but did not cause significant changes in either the mRNA or protein level of DNMT1. Treatment of the cells with 2 and 5 μmol/L 5-Aza-CdR obviously increased VHL mRNA expression by by over 3 folds (P < 0.05). 20(S)-Rg3 significantly decreased the methylation level in the promoter region of VHL gene, and this effect was abrogated by DNMT3A overexpression in the cells (P < 0.05). Immunohistochemisty showed a significantly increased VHL expression but a lowered DNMT3A expression in subcutaneous SKOV3 cell xenografts in 20 (S)-Rg3-treated nude mice.

CONCLUSIONS

Ginsenoside 20(S)-Rg3 upregulates VHL expression in ovarian cancer cells by suppressing DNMT3A-mediated DNA methylation.

Adaptogenic effects of Panax ginseng on modulation of immune functions

Traditional medicinal practices have used natural products such as adaptogens to treat inflammatory, autoimmune, neurodegenerative, bacterial, and viral diseases since the early days of civilization. Panax ginseng Myer is a common herb used in East Asian countries for millennia, especially in Korea, China, and Japan. Numerous studies indicate that ginseng can modulate the immune system and thereby prevent diseases. Although the human immune system comprises many different types of cells, multiple studies suggest that each type of immune cell can be controlled or stimulated by ginseng or its derivatives. Provisional lists of ginseng's potential for use against viruses, bacteria, and other microorganisms suggest it may prove to be a valuable pharmaceutical resource, particularly if higher-quality evidence can be found. Here, we reviewed the role of ginseng as an immune-modulating agent in attempt to provide a valuable starting point for future studies on the herb and the human immune system.

HIF-1α is a Potential Molecular Target for Herbal Medicine to Treat Diseases

HIF-1α is an important factor regulating oxygen balance in mammals, and its expression is closely related to various physiological and pathological conditions of the body. Because HIF-1α plays an important role in the occurrence and development of cancer and other diseases, it has become an enduring research hotspot. At the same time, natural medicines and traditional Chinese medicine compounds have amazing curative effects in various diseases related to HIF-1 subtype due to their unique pharmacological effects and more effective ingredients. Therefore, in this article, we first outline the structure of HIF-1α and the regulation related to its expression, then introduce various diseases closely related to HIF-1α, and finally focus on the regulation of natural medicines and compound Chinese medicines through various pathways. This will help us understand HIF-1α systematically, and use HIF-1α as a target to discover more natural medicines and traditional Chinese medicines that can treat related diseases.

Antitumor effects and molecular mechanisms of action of natural products in ovarian cancer

Ovarian cancer is a common malignancy and the second leading cause of mortality among females with genital tract cancer. At present, postoperative platinum drugs and paclitaxel-based chemotherapy is the gold standard treatment for ovarian cancer. However, patients who receive this chemotherapy often develop cumulative toxic effects and are prone to chemotherapy resistance. Therefore, it is necessary to determine more effective treatment options that would be better tolerated by patients. Recent studies have reported the therapeutic effects of numerous natural products in patients with ovarian cancer. Notably, these natural ingredients do not induce adverse effects in healthy cells and tissues, suggesting that natural products may serve as a safe alternative treatment for ovarian cancer. The antitumor effects of natural products are attributed to suppression of cell proliferation and metastasis, stimulation of autophagy, improved chemotherapy sensitivity, and induction of apoptosis. The present review focused on the antitumor effects of several natural products, including curcumin, resveratrol, ginsenosides, (-)-epigallocatechin-3-gallate and quercetin, which are increasingly being investigated as therapeutic options in ovarian cancer, and discussed the molecular mechanisms involved in cell proliferation, apoptosis, autophagy, metastasis and sensitization.

Ginsenoside 20(S)-Rg3 upregulates HIF-1α-targeting miR-519a-5p to inhibit the Warburg effect in ovarian cancer cells

The Warburg effect, one of the metabolic hallmarks of cancer, is responsible for rapid energy production through a high rate of aerobic glycolysis. Ginsenoside 20(S)-Rg3 antagonizes the Warburg effect in ovarian cancer cells by upregulating some microRNAs, including miR-519a-5p, that target key enzymes involved in aerobic glycolysis. How 20(S)-Rg3-upregulated miR-519a-5p influences the Warburg effect in ovarian cancer cells remains poorly defined, however. Here we report that while overexpression of miR-519a-5p in ovarian cancer cells inhibited the Warburg effect, inhibition of miR-519a-5p negated the suppressive action of 20(S)-Rg3 against the Warburg effect as evidenced by a decrease in glucose consumption, lactate production and HK2 expression. We identified HIF-1α as a direct target of miR-519a-5p via luciferase reporter assays and demonstrated the counteraction by overexpressed HIF-1α of 20(S)-Rg3-suppressed Warburg effect. Further, 20(S)-Rg3 decreased DNMT3A-mediated DNA methylation in the promoter region of its precursor gene, leading to an increase in the level of miR-519a-5p. In conclusion, 20(S)-Rg3 upregulates miR-519a-5p via reducing DNMT3A-mediated DNA methylation to inhibit HIF-1α-stimulated Warburg effect in ovarian cancer.

Standardized Saponin Extract from Baiye No.1 Tea (Camellia sinensis) Flowers Induced S Phase Cell Cycle Arrest and Apoptosis via AKT-MDM2-p53 Signaling Pathway in Ovarian Cancer Cells

Ovarian cancer is considered to be one of the most serious malignant tumors in women. Natural compounds have been considered as important sources in the search for new anti-cancer agents. Saponins are characteristic components of tea (Camellia sinensis) flower and have various biological activities, including anti-tumor effects. In this study, a high purity standardized saponin extract, namely Baiye No.1 tea flower saponin (BTFS), which contained Floratheasaponin A and Floratheasaponin D, were isolated from tea (Camellia sinensis cv. Baiye 1) flowers by macroporous resin and preparative liquid chromatography. Then, the component and purity were detected by UPLC-Q-TOF/MS/MS. This high purity BTFS inhibited the proliferation of A2780/CP70 cancer cells dose-dependently, which is evidenced by the inhibition of cell viability, reduction of colony formation ability, and suppression of PCNA protein expression. Further research found BTFS induced S phase cell cycle arrest by up-regulating p21 proteins expression and down-regulating Cyclin A2, CDK2, and Cdc25A protein expression. Furthermore, BTFS caused DNA damage and activated the ATM-Chk2 signaling pathway to block cell cycle progression. Moreover, BTFS trigged both extrinsic and intrinsic apoptosis—BTFS up-regulated the expression of death receptor pathway-related proteins DR5, Fas, and FADD and increased the ratio of pro-apoptotic/anti-apoptotic proteins of the Bcl-2 family. BTFS-induced apoptosis seems to be related to the AKT-MDM2-p53 signaling pathway. In summary, our results demonstrate that BTFS has the potential to be used as a nutraceutical for the prevention and treatment of ovarian cancer.

A steroidal saponin form Paris vietnamensis (Takht.) reverses temozolomide resistance in glioblastoma cells via inducing apoptosis through ROS/PI3K/Akt pathway

Glioblastoma is one of the most difficult cancers to treat with a 5-year overall survival rate less than 5%. Temozolomide (TMZ) is an effective drug for prolonging the overall survival time of patients, while drug-resistance is an important clinical problem at present. Pennogenin-3-α-L-rhamnopyranosyl-(1→4)-[α-Lrhamno-pyranosyl-(1→2)]- β-D-glucopyranoside (N45), a steroidal saponin, was isolated from the rhizomes of Paris vietnamensis (Takht.), which is used as a Traditional Chinese Medicine and has been reported to possess preclinical anticancer efficacy in various cancer types. However, the mechanism of the inhibition of N45 on glioblastoma cells and its possible application in the treatment of chemotherapy-resistant glioblastoma cells are still unknown. In this study, we use cellular methodological experiments including cell counting kit-8 (CCK-8) assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining assay, flow cytometry assay, transmission electron microscopy (TEM) and Western blot. The results show that N45 significantly suppresses the proliferation of glioblastoma cells and TMZ-resistant glioblastoma cells (U87R) by inducing mitochondrial apoptosis through reactive oxygen species (ROS)/phosphoinositide 3-kinase (PI3K)/Akt signal pathway, and the N-acetyl-L-cysteine (NAC) combined with N45 effectively reduced N45-mediated apoptosis and reversed the inhibition of PI3K/Akt signal pathway. In addition, N45 decreased the drug-resistance by down-regulation of nuclear factor kappa-B p65 (NF-κB p65) to attenuate O⁶-methylguanine-DNA methyltransferase (MGMT) in TMZ-resistant glioblastoma cells (U87R). Our findings proved that N45 might be a potential therapeutic agent against glioblastoma and TMZ-resistant glioblastoma, promising to be a potential agent to reduce drug resistance.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Mechanisms of Vasculogenic Mimicry in Ovarian Cancer

Solid tumors carry out the formation of new vessels providing blood supply for growth, tumor maintenance, and metastasis. Several processes take place during tumor vascularization. In angiogenesis, new vessels are derived from endothelial cells of pre-existing vessels; while in vasculogenesis, new vessels are formed de novo from endothelial progenitor cells, creating an abnormal, immature, and disorganized vascular network. Moreover, highly aggressive tumor cells form structures similar to vessels, providing a pathway for perfusion; this process is named vasculogenic mimicry (VM), where vessel-like channels mimic the function of vessels and transport plasma and blood cells. VM is developed by numerous types of aggressive tumors, including ovarian carcinoma which is the second most common cause of death among gynecological cancers. VM has been associated with poor patient outcome and survival in ovarian cancer, although the involved mechanisms are still under investigation. Several signaling molecules have an important role in VM in ovarian cancer, by regulating the expression of genes related to vascular, embryogenic, and hypoxic signaling pathways. In this review, we provide an overview of the current knowledge of the signaling molecules involved in the promotion and regulation of VM in ovarian cancer. The clinical implications and the potential benefit of identification and targeting of VM related molecules for ovarian cancer treatment are also discussed.

Ginsenoside Rg3 Reduces Epithelial-Mesenchymal Transition Induced by Transforming Growth Factor-β1 by Inactivation of AKT in HMrSV5 Peritoneal Mesothelial Cells

Background

Ginsenosides, including ginsenoside Rg3, are components of Panax ginseng C.A. Meyer (Araliaceae) used in traditional Chinese medicine. Long-term peritoneal dialysis induces peritoneal fibrosis that impairs ultrafiltration and is associated with epithelial-mesenchymal transition (EMT) of peritoneal cells. This study aimed to investigate the effects of ginsenoside Rg3 on EMT induced by transforming growth factor-β1 (TGF-β1) in HMrSV5 human peritoneal mesothelial cells.

Material/Methods

The cell counting kit-8 (CCK-8) assay measured HMrSV5 cell viability. The expression of EMT markers, E-cadherin, vimentin, and α-smooth muscle actin (α-SMA) were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The wound-healing assay determined cell migration. The S-phase of the cell cycle was assessed by 5-ethynyl-2′-deoxyuridine (EdU) labeling, and expression of phosphorylated AKT was measured by Western blot. The effect of ginsenoside Rg3 and the AKT activator SC79 on the TGF-β1-induced EMT of HMrSV5 cells were evaluated.

Results

Low concentration of ginsenoside Rg3 did not effect cell viability of HMrSV5 cells. TGF-β1 treatment decreased the expression of E-cadherin, and increased the expression of vimentin and α-SMA and promoted cell migration of HMrSV5 cells. However, co-treatment of ginsenoside Rg3 and TGF-β1 significantly reduced TGF-β1-induced EMT in HMrSV5 cells. TGF-β1 increased the phosphorylation of AKT and increased the expression of Smurf2. Ginsenoside Rg3 reduced TGF-β1-induced activation of AKT and Smurf2. SC79 reversed the effects of ginsenoside Rg3 on TGF-β1-induced EMT in HMrSV5 cells.

Conclusions

Ginsenoside Rg3 inhibited EMT induced by TGF-β1 in HMrSV5 human peritoneal mesothelial cells by inhibiting the activation of AKT.

Protopanaxadiol inhibits epithelial-mesenchymal transition of hepatocellular carcinoma by targeting STAT3 pathway

Diol-type ginsenosides, such as protopanaxadiol (PPD), exhibit antioxidation, anti-inflammation, and antitumor effects. However, the antitumor effect of these ginsenosides and the mechanism of PPD remain unclear. In this work, the antitumor effects of several derivatives, including PPD, Rg5, Rg3, Rh2, and Rh3, were evaluated in five different cancer cell lines. PPD demonstrated the best inhibitory effects on the proliferation and migration of the five cancer cell lines, especially the hepatocellular carcinoma (HCC) cell lines. Therefore, the mechanism of action of PPD in HCC cells was elucidated. PPD inhibited the proliferation, migration, and invasion ability of HepG2 and PLC/PRF/5 cells in a dose-dependent manner. Western blot and immunofluorescence assay showed that PPD can alter the expression of epithelial–mesenchymal transition markers, increase E-cadherin expression, and decrease vimentin expression. Docking and biacore experiments revealed that STAT3 is the target protein of PPD, which formed hydrogen bonds with Gly583/Leu608/Tyr674 at the SH2 domain of STAT3. PPD inhibited the phosphorylation of STAT3 and its translocation from the cytosol to the nucleus, thereby inhibiting the expression of Twist1. PPD also inhibited tumor volume and tumor lung metastasis in PLC/PRF/5 xenograft model. In conclusion, PPD can inhibit the proliferation and metastasis of HCC cells through the STAT3/Twist1 pathway.

Stereoselective Anti-Cancer Activities of Ginsenoside Rg3 on Triple Negative Breast Cancer Cell Models

Ginsenoside Rg3 (Rg3) has two epimers, 20(S)-ginsenoside Rg3 (SRg3) and 20(R)-ginsenoside Rg3 (RRg3), and while Rg3 itself has been reported to have anti-cancer properties, few studies have been reported on the anti-cancer effects of the different epimers. The aim was to investigate the stereoselective effects of the Rg3 epimers on triple negative breast cancer (TNBC) cell lines, tested using cell-based assays for proliferation, apoptosis, cell cycle arrest, migration and invasion. Molecular docking showed that Rg3 interacted with the aquaporin 1 (AQP1) water channel (binding score -9.4 kJ mol-1). The Xenopus laevis oocyte expression system was used to study the effect of Rg3 epimers on the AQP1 water permeability. The AQP1 expression in TNBC cell lines was compared with quantitative-polymerase chain reaction (PCR). The results showed that only SRg3 inhibited the AQP1 water flux and inhibited the proliferation of MDA-MB-231 (100 μM), due to cell cycle arrest at G0/G1. SRg3 inhibited the chemoattractant-induced migration of MDA-MB-231. The AQP1 expression in MDA-MB-231 was higher than in HCC1143 or DU4475 cell lines. These results suggest a role for AQP1 in the proliferation and chemoattractant-induced migration of this cell line. Compared to SRg3, RRg3 had more potency and efficacy, inhibiting the migration and invasion of MDA-MB-231. Rg3 has stereoselective anti-cancer effects in the AQP1 high-expressing cell line MDA-MB-231.

Effects of ginsenoside Rg3 on epigenetic modification in ovarian cancer cells

Epigenetic modifications are closely related to oncogene activation and tumor suppressor gene inactivation. The aim of this study was to determine the effects of ginsenoside Rg3 on epigenetic modification in ovarian cancer cells. Cell proliferation, metastasis, invasion and apoptosis were respectively determined using Cell Counting Kit‑8 (CCK‑8), wound healing, Transwell and flow cytometric assays. Methylation levels were determined using methylation specific PCR (MSP). Related‑factor expression was detected by conducting real‑time‑qPCR (RT‑qPCR) and western blotting. The results revealed that cell proliferation was inhibited by ginsenoside Rg3 (0, 25, 50, 100 and 200 µg/ml) in a time‑dependent manner (12, 24 and 48 h). Ginsenoside Rg3 (50, 100 and 200 µg/ml) was selected to treat cells in various experiments. When ovarian cells were treated with ginsenoside Rg3, cell apoptosis was observed to be promoted, while cell metastasis and invasion were inhibited at 48 h. The results of the present study revealed that in the promoter regions of p53, p16 and hMLH1, the methylation levels decreased, while the mRNA and protein levels significantly increased. The activities of DNMTs and mRNA as well as protein levels of DNMT1, DNMT3a and DNMT3b were decreased by Rg3. The data also demonstrated that the mRNA and protein levels of acetyl‑H3 K14/K9 and acetyl‑H4 K12/K5/K16 were increased by Rg3. Hence, ginsenoside Rg3 inhibited ovarian cancer cell viability, migration and invasion as well as promoted cell apoptosis.

Restoring E-cadherin Expression by Natural Compounds for Anticancer Therapies in Genital and Urinary Cancers

E-cadherin plays a pivotal role in cancer progression, including the epithelial-mesenchymal transition (EMT) process and tumor metastasis. Loss of E-cadherin contributes to enhanced invasion and metastasis in human cancers. Therefore, restoring E-cadherin could be a potential approach for cancer therapy. Multiple natural compounds have been shown to possess anti-tumor activities through the regulation of key molecules in signaling pathways, including E-cadherin. In this review, we describe the numerous compounds that restore the expression of E-cadherin in genital and urinary malignancies. We further discuss the potential anti-tumor molecular mechanisms of these agents as the activators of E-cadherin in genital and urinary cancers. Although these compounds exhibit their potential to inhibit the development and progression of cancers, there are several challenges to developing them as therapeutic drugs for cancer patients. Poor bioavailability in vivo is the main disadvantage of these compounds. Modification of compound structures has produced actual improvements in bioavailability. Nanoparticle-based delivery systems could be useful to deliver the agents to targeted organs. These compounds could be new promising therapeutic agents for the treatment of human genital and urinary cancers. Further investigations are required to determine the safety and side effects of natural compounds using animal models prior to clinical trials.

Black Ginseng and Its Saponins: Preparation, Phytochemistry and Pharmacological Effects

Black ginseng is a type of processed ginseng that is prepared from white or red ginseng by steaming and drying several times. This process causes extensive changes in types and amounts of secondary metabolites. The chief secondary metabolites in ginseng are ginsenosides (dammarane-type triterpene saponins), which transform into less polar ginsenosides in black ginseng by steaming. In addition, apparent changes happen to other secondary metabolites such as the increase in the contents of phenolic compounds, reducing sugars and acidic polysaccharides in addition to the decrease in concentrations of free amino acids and total polysaccharides. Furthermore, the presence of some Maillard reaction products like maltol was also engaged. These obvious chemical changes were associated with a noticeable superiority for black ginseng over white and red ginseng in most of the comparative biological studies. This review article is an attempt to illustrate different methods of preparation of black ginseng, major chemical changes of saponins and other constituents after steaming as well as the reported biological activities of black ginseng, its major saponins and other metabolites.

Antitumor activity of ginsenoside Rg3 in melanoma through downregulation of the ERK and Akt pathways

Advanced metastatic melanoma is a malignant tumor for which there is currently no effective treatment due to resistance development. Ginsenoside Rg3, a saponin component extracted from ginseng roots, has been shown to reduce melanoma cell proliferation by decreasing histone deacetylase 3 and increasing p53 acetylation. The availability of data on the role of Rg3 in melanoma is currently extremely limited. The aim of the present study was to further investigate the effects of Rg3 on B16 melanoma cells and the underlying molecular events. The findings demonstrated that Rg3 suppressed the proliferation and DNA synthesis of B16 cells. Rg3 exposure induced tumor cell cycle arrest at the S phase and reduced the expression of proliferating cell nuclear antigen (PCNA). Rg3 treatment also decreased metastasis of B16 cells in vitro and in vivo. The results indicated that this reduction was due to downregulation of matrix metalloproteinase (MMP)-2 and MMP-9. Moreover, Rg3 inhibited melanoma-induced angiogenesis, most likely by downregulating vascular endothelial growth factor (VEGF) in B16 cells. Rg3 exposure decreased the expression of VEGF in B16 cells and the VEGF downregulation further suppressed angiogenesis by attenuating the proliferation and migration of vascular endothelial cells. Finally, the western blotting data demonstrated that Rg3 reduced the expression of extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) in vitro and in vivo. This result indicated that the antimelanoma effects of Rg3 may be mediated through suppression of ERK and Akt signaling. Further research is required to assess the value of Rg3 as a novel therapeutic strategy for melanoma in the clinical setting.

Ginsenoside Rg3 Inhibits Migration and Invasion of Nasopharyngeal Carcinoma Cells and Suppresses Epithelial Mesenchymal Transition

Nasopharyngeal carcinoma (NPC) is a highly invasive and metastatic head and neck cancer. Distant metastasis becomes the predominant mode of treatment failure in NPC patients. Ginsenoside Rg3 (Rg3), an active pharmaceutical component extracted from traditional Chinese medicine ginseng, shows antitumor effects in various cancers. In this study, we aimed to determine whether Rg3 inhibits the migration and invasion activity of NPC cells and to explore the possible mechanisms. Our results revealed that Rg3 hampers cell migration and invasion in both HNE1 and CNE2 cell lines. A reduced level of matrix metalloproteinase-2 (MMP-2) and MMP-9 was induced by Rg3 treatment. In addition, Rg3 significantly altered the expression of epithelial mesenchymal transition (EMT) markers with increased E-cadherin but decreased Vimentin and N-cadherin expression. Transforming growth factor β- (TGF-β-) induced morphological transition and marker proteins change of EMT were reversed by Rg3. What is more, Rg3 suppressed the expression of EMT-related transcription factors, especially the Zinc Finger E-Box Binding Homeobox 1 (ZEB1). In summary, our data suggested that Rg3 could inhibit migration and invasion of NPC cells. This effect of Rg3 might be mediated through regulating MMP-2 and MMP-9 expressions and suppressing EMT. Thus, Rg3 may be a potentially effective agent for the treatment of NPC.

Ginsenoside Rg3: Potential Molecular Targets and Therapeutic Indication in Metastatic Breast Cancer

Breast cancer is still one of the most prevalent cancers and a leading cause of cancer death worldwide. The key challenge with cancer treatment is the choice of the best therapeutic agents with the least possible toxicities on the patient. Recently, attention has been drawn to herbal compounds, in particular ginsenosides, extracted from the root of the Ginseng plant. In various studies, significant anti-cancer properties of ginsenosides have been reported in different cancers. The mode of action of ginsenoside Rg3 (Rg3) in in vitro and in vivo breast cancer models and its value as an anti-cancer treatment for breast cancer will be reviewed.

Ginsenoside Rg3 Decreases NHE1 Expression via Inhibiting EGF-EGFR-ERK1/2-HIF-1 α Pathway in Hepatocellular Carcinoma: A Novel Antitumor Mechanism

Na + /H + exchanger 1 (NHE1) plays a vital role in the oncogenesis and development of hepatocellular carcinoma (HCC) and has been regarded as a promising target for the treatment of HCC. Ginsenoside Rg3 (Rg3), a bioactive ginseng compound, is suggested to possess pleiotropic antitumor effects on HCC. However, the underlying mechanisms of Rg3 suppressing HCC remain unclear. In the present study, we uncovered a novel antitumor mechanism of Rg3 on HCC by decreasing NHE1 expression through in vivo and in vitro studies. Mechanistically, we demonstrated that epidermal growth factor (EGF) could dramatically upregulate NHE1 expression, while increasing the phosphorylated extracellular signal-regulated protein kinase (ERK1/2) level and hypoxia-inducible factor 1 alpha (HIF-1 α) expression. In the presence of ERK1/2-specific inhibitor PD98059, EGF stimulated HIF-1 α and NHE1 expression was obviously blocked in addition, the presence of HIF-1 α -specific inhibitor 2-methoxyestradiol (2-MeOE2) blocked EGF stimulated NHE1 expression. Moreover, results from in vivo and in vitro studies indicate that Rg3 treatment markedly decreased the expression of EGF, EGF receptor (EGFR), phosphorylated ERK1/2 and HIF-1 α . Conclusively, these findings suggested that NHE1 was stimulated by EGF, and Rg3 could decrease NHE1 expression by integrally inhibiting EGF-EGFR-ERK1/2-HIF- α signal axis in HCC. Together, our evidence indicated that Rg3 was an effective multi-targets antitumor agent for the treatment of HCC.

Pharmacological effect of prohibited combination pair Panax ginseng and Veratrum nigrum on colorectal metastasis in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

The pharmacological effect derived from herb-herb interaction is important to constitute the prescription especially in traditional oriental medicine. The relationship of two medicinal herbs is called "couplet medicinals" which is used in pair for the purpose of enhancing the therapeutic effect, reducing the toxic effect or the adverse effect. The "Eighteen Incompatible Medicaments" constitute one of the contents in the incompatibility of traditional oriental drugs in a prescription. Among the "Eighteen Incompatible Medicaments", the roots and rhizomes of Veratrum nigrum (VN), is incompatible with the roots and rhizomes of Panax ginseng (PG). However, definite evidences of adverse effect by these combinations has yet to be reported.

MATERIALS AND METHODS

The aim of the present study was to investigate the effects of ethanol extracts of PG, VN, and their combination (P + V) on the metastatic ability of colorectal cancer (CRC) cells using WST assay, flow cytometry, western blot analysis, real-time RT-PCR, immunofluorescence, migration assay, invasion assay, zymography, and an in vivo experiment with a lung-metastasis mouse model.

RESULTS

The PG extract decreased cell proliferation by inducing cell cycle arrest and apoptosis of CRC cells. In addition, PG inhibited metastatic abilities of CRC cells including Epithelial-Mesenchymal Transition, migration, and invasion. Additionally, the PG extract suppressed lung metastasis of the CRC cells in the mouse model. However, the P + V extract exhibited weaker anti-proliferative and anti-metastatic effects than PG alone.

CONCLUSION

Based on these results, the P + V couplet medicinal attenuates the anti-metastatic effects of PG, both in vitro and in vivo.

Pseudo-Ginsenoside Rh2 induces A549 cells apoptosis via the Ras/Raf/ERK/p53 pathway

Ginsenoside Rh2, a major effective constituent of ginseng, has been suggested to have a pro-apoptotic effect in a variety of cancer cells. Pseudo-Ginsenside-Rh2 (pseudo-G-Rh2) is a novel derivative of ginsenoside Rh2. The aim of the present study was to evaluate the effect of pseudo-G-Rh2 on the apoptosis of lung adenocarcinoma A549 cells. The cytotoxicity of pseudo-G-Rh2 on A549 cells was evaluated using an MTT assay. Apoptosis was detected using DAPI staining and flow cytometry. The expression of apoptosis associated proteins was identified by western blot analysis. The results demonstrated that pseudo-G-Rh2 inhibits the proliferation of A549 cells in a dose-dependent manner. DAPI staining revealed topical morphological changes in apoptotic bodies following pseudo-G-Rh2 treatment. Flow cytometric analysis revealed that the percentage of Annexin V-fluorescein isothiocyanate-positive cells, which are apoptotic, increased with pseudo-G-Rh2 treatment in a dose-dependent manner. Furthermore, treatment with pseudo-G-Rh2 increased the level of reactive oxygen species in A549 cells as well as the activation of caspase-9, caspase-3 and poly ADP-ribose polymerase. Pseudo-G-Rh2 treatment was observed to induce mitochondrial membrane potential loss. Furthermore, the results of western blotting revealed that B-cell lymphoma 2 (Bcl-2) expression was significantly decreased while Bcl-2-associated X protein expression was significantly upregulated in A549 cells with pseudo-G-Rh2 treatment. Pseudo-G-Rh2-induced apoptosis was accompanied by sustained phosphorylation of Ras, Raf, extracellular signal-regulated kinase (ERK) and p53. In conclusion, the results of the present study suggest that pseudo-G-Rh2 induces mitochondrial apoptosis in A549 cells and is responsible for excessive activation of the Ras/Raf/ERK/p53 pathway.

Treatment with 20(S)-ginsenoside Rg3 reverses multidrug resistance in A549/DDP xenograft tumors

Multidrug resistance (MDR) is an obstacle for cancer chemotherapy. It was reported that 20(S)-ginsenoside Rg3 (hereafter Rg3) was able to regulate MDR in mouse leukemia cells. The present study investigated the effect of Rg3 on the MDR of A549 lung cancer cells. A cell viability assay revealed that Rg3 treatment increased cisplatin (DDP) cytotoxicity in DDP resistant A549 cells (A549/DDP). Furthermore, Rg3 increases the antitumor effect of DDP on A549/DDP xenograft mice. The expression of MDR-mediated proteins, including P-glycoprotein (P-gp), multidrug resistance-associated protein (MPR1) and lung resistance protein 1 (LPR1), was detected in tumor tissue of A549/DDP xenograft mice. The results revealed that Rg3 treatment inhibited the expression of these MDR-associated proteins. Additionally, technetium-99m labeled hexakis-2-methoxyisobutylisonitrile (^99mTc-MIBI) single-photon emission computed tomography was used to monitor the effect of Rg3 on cisplatin sensitivity of A549/DDP xenograft tumors. It was observed that uptake of ^99mTc-MIBI was increased by Rg3 treatment, which indicated that Rg3 is able to effectively enhance chemotherapy sensitivity of A549/DDP xenograft tumors. Taken together, these results revealed that Rg3 may be able to reverse MDR of lung cancer via the downregulation of P-gp, MPR1 and LPR1.

Phosphoproteomic analysis of the antitumor effects of ginsenoside Rg3 in human breast cancer cells

The incidence of breast cancer has been increasing in China and the age of breast cancer onset is earlier compared with Western countries. Compounds commonly used in Traditional Chinese Medicine (TCM) are an important source of anticancer drugs. Ginseng is one of the most common medicines used in TCM. Ginsenosides, which are saponins found in the ginseng plant, are the major active components responsible for the chemopreventive effects of ginseng in cancer. However, the mechanisms by which ginsenosides exert their anticancer effects remain elusive. The current study combined tandem mass tag (TMT)-based quantification with titanium dioxide-based phosphopeptide enrichment to quantitatively analyze the changes in phosphoproteomes in breast cancer MDA-MB-231 cells that occur following treatment with the ginsenoside Rg3. A total of 5,140 phosphorylation sites on 2,041 phosphoproteins were quantified and it was demonstrated that the phosphorylation status of 13 sites were altered in MDA-MB-231 cells following treatment with Rg3. The perturbed phosphoproteins were: Cleavage and polyadenylation specificity factor subunit 7, elongation factor 2 (EEF2), HIRA-interacting protein 3, melanoma-associated antigen D2, myosin phosphatase Rho-interacting protein, probable E3 ubiquitin-protein ligase MYCBP2, PRKC apoptosis WT1 regulator protein, protein phosphatase 1 regulatory subunit 12A, E3 SUMO-protein ligase RanBP2, Septin-9, thymopoietin, and E3 UFM1-protein ligase 1. Western blotting confirmed that Rg3 increased the phosphorylation of EEF2 on Thr57 but did not alter the protein expression of EEF2 in MDA-MB-231 and HCC1143 cells. These ginsenoside Rg3-regulated proteins are involved in various biological processes, including protein synthesis, cell division and the inhibition of nuclear factor-κB signaling. The results of the present study revealed that Rg3 exerts its anticancer effects via a combination of different signaling pathways.

Inhibitory Effects of Total Triterpenoid Saponins Isolated from the Seeds of the Tea Plant (Camellia sinensis) on Human Ovarian Cancer Cells

Ovarian cancer is regarded as one of the most severe malignancies for women in the world. Death rates have remained steady over the past five decades, due to the undeniable inefficiency of the current treatment in preventing its recurrence and death. The development of new effective alternative agents for ovarian cancer treatment is becoming increasingly critical. Tea saponins (TS) are triterpenoidsaponins composed of sapogenins, glycosides, and organic acids, which possess a variety of pharmacological activities, and have shown promise in the anti-cancer field. Through cell CellTiter 96^® Aqueous One Solution Cell Proliferation assay (MTS) assay, colony formation, Hoechst 33342 staining assay, caspase-3/7 activities, flow cytometry for apoptosis analysis, and Western blot, we observed that TS isolated from the seeds of tea plants, Camellia sinensis, exhibited strong anti-proliferation inhibitory effects on OVCAR-3 and A2780/CP70 ovarian cancer cell lines. Our results indicate that TS may selectivity inhibit human ovarian cancer cells by mediating apoptosis through the extrinsic pathway, and initiating anti-angiogenesis via decreased VEGF protein levels in a HIF-1α-dependent pathway. Our data suggests that, in the future, TS could be incorporated into a potential therapeutic agent against human ovarian cancer.

Human amniotic epithelial cells inhibit growth of epithelial ovarian cancer cells via TGF‑β1-mediated cell cycle arrest

It is reported that human amniotic epithelial cells (hAECs) endow intrinsic antitumor effects on certain kinds of cancer. This research was designed to evaluate whether hAECs endowed potential anticancer properties on epithelial ovarian cancer (EOC) cells in vivo and in vitro, which has not been reported before. In this study, we established a xenografted BALB/c nude mouse model by subcutaneously co-injecting ovarian cancer cell line, SK-OV-3, and hAECs for 28 days. In ex vivo experiments, CCK‑8 cell viability assay, real-time PCR, cell counting assay, cell cycle analysis and immunohistochemistry (IHC) assay were used to detect the effects of hAEC‑secreted factors on the proliferation and cell cycle progression of EOC cells. A cytokine array was conducted to detect anticancer-related cytokines released from hAECs. Human recombinant TGF‑β1 and TGF‑β1 antibody were used to treat EOC cells and analyzed whether TGF‑β1 contributed to the cell cycle arrest. Results from in vivo and ex vivo experiments showed that hAEC-secreted factors and rhTGF‑β1 decreased proliferation of EOC cells and induced G0/G1 cell cycle arrest in cancer cells, which could be partially reversed by excess TGF‑β1 antibody. These data indicate that hAECs endow potential anticancer properties on epithelial ovarian cancer in vivo and in vitro which is partially mediated by hAEC‑secreted TGF‑β1-induced cell cycle arrest. This study suggests a potential application of hAEC‑based therapy against epithelial ovarian cancer.

Ginsenoside Rb1 inhibits hypoxia-induced epithelial-mesenchymal transition in ovarian cancer cells by regulating microRNA-25

Metastasis frequently occurs in advanced ovarian cancer, which not only leads to substantial mortality but also becomes a major challenge to effective treatment. Epithelial-mesenchymal transition (EMT) is a key mechanism facilitating cancer metastasis. Targeting the EMT process with more efficacious and less toxic agents to prevent metastasis is of significant therapeutic value for ovarian cancer treatment. The anti-EMT function and mechanism of ginsenoside Rb1, a monomer composition extracted from the traditional Chinese herb Panax ginseng or P. notoginseng, was investigated in the present study. Western blotting demonstrated that treatment with ginsenoside Rb1 antagonized hypoxia-induced E-cadherin downregulation and vimentin upregulation in SKOV3 and 3AO human ovarian cancer cells. Wound healing assays and in vitro migration assays indicated that ginsenoside Rb1 weakened hypoxia-enhanced cell migration ability. Furthermore, it was demonstrated that microRNA (miR)-25 is upregulated by hypoxia in ovarian cancer cells, which was attenuated by ginsenoside Rb1 treatment. Additionally, forced expression of miR-25 in ovarian cancer cells was identified to not only trigger EMT, but also block the suppressive effects of ginsenoside Rb1 on hypoxia-induced EMT by negatively targeting the E-cadherin transactivator, EP300. In conclusion, ginsenoside Rb1 may reverse hypoxia-induced EMT by abrogating the suppression of miR-25 on EP300 and E-cadherin, which suggests that ginsenoside Rb1 may be a potential therapeutic candidate for the treatment of ovarian cancer.

Hypoxia-inducible factor-1 alpha Correlates with Tumor-Associated Macrophages Infiltration, Influences Survival of Gastric Cancer Patients

Background: Hypoxia was a common feature for accelerating tumor metastasis by both inducting epithelial-mesenchymal transition (EMT) of tumor cells and polarization of tumor-associated macrophages (TAMs). The association and roles between hypoxia, EMT and TAMs in the biological behavior of gastric cancer (GC) for the time being recurrence is unclear. Material and methods: hypoixa by expression of hypoxia-inducible factor-1 alpha (HIF-1α), polarized functional status of infiltrated TAMs by immunohistochemical staining of CD68 and CD163, and the expression of E-cadherin as EMT property had been evaluated in 236 patients consecutive with histologically confirmed GC. Clinical significance was assessed for all these patients. Results: High expression of HIF-1α was found in patients with aggressive features, especially for recurrent patients. High infiltration of TAMs and abnormal expression of EMT-marker were also related to aggressive characteristics and predicted poor prognosis in GC. Meanwwhile, there existed a significant correlation among expression of HIF-1α, infiltration of TAMs and EMT marker in GC tissues. Multivariate Cox analysis revealed that high expression of HIF-1α combined TAMs infiltration were independent prognostic factors for disease-specific survival rate. Conclusion: HIF-1α is an unfavorable indicator for prognosis, may promote tumor progression through the induction of EMT and establishment of a pro-tumor immunosuppressive microenvironment. Further investigation into the therapeutic effects of blocking hypoxia is possible a potential strategy for GC treatment.

20(S)-Rg3 blocked epithelial-mesenchymal transition through DNMT3A/miR-145/FSCN1 in ovarian cancer

Epithelial-mesenchymal transition (EMT) is one of the key mechanisms mediating cancer progression. MicroRNAs (miRs) are essential regulators of gene expression by suppressing translation or causing degradation of target mRNA. Growing evidence illustrates the crucial roles of miRs dysregulation in cancer development and progression. Here, we have found for the first time that the ginsenoside 20(S)-Rg3, a pharmacologically active component of Panax ginseng, potently increases miR-145 expression by downregulating methyltransferase DNMT3A to attenuate the hypermethylation of the promoter region in the miR-145 precursor gene. Restoration of DNMT3A reverses the inhibitory effect of 20(S)-Rg3 on EMT. FSCN1 is verified as the target of miR-145 to suppress EMT in human ovarian cancer cells. The results from nude mouse xenograft models further demonstrate the suppressive effect of miR-145 on malignant progression of ovarian cancer. Taken together, our results show that 20(S)-Rg3 blocks EMT by targeting DNMT3A/miR-145/FSCN1 pathway in ovarian cancer cells, highlighting the potentiality of 20(S)-Rg3 to be used as a therapeutic agent for ovarian cancer.

Ginsenoside 20(S)-Rg3 suppresses ovarian cancer migration via hypoxia-inducible factor 1 alpha and nuclear factor-kappa B signals

Hypoxia-inducible factor 1 is believed to play a prominent role in the survival and developing progress of cancers. As a result, inhibiting α subunit of hypoxia-inducible factor 1 represents an attractive strategy against tumor. Although hypoxia-inducible factor 1α is a hypoxia-regulated subunit, increasing evidence indicates that hypoxia-inducible factor 1α could stable expression under normoxic conditions, regulated by non-hypoxia-mediated mechanisms. However, there are few strategies to target hypoxia-inducible factor 1α under normoxic conditions. Here, we report that ginsenoside 20(S)-Rg3, one of the main active ingredients in red ginseng, restrains hypoxia-inducible factor 1α expression under normal oxygen levels in human ovarian cancer cell lines, SKOV3 and 3AO, which leads to potently inhibits migration of ovarian cancer in vitro and in vivo. 20(S)-Rg3 could decrease the expression of hypoxia-inducible factor 1α by upregulation of prolyl hydroxylase domain protein 1 to promoting hypoxia-inducible factor 1α ubiquitin-proteasome degradation under normal oxygen levels. Furthermore, 20(S)-Rg3 could attenuate the expression of nuclear factor-κ B, which may be another possible mechanism for 20(S)-Rg3 to block ovarian cancer migration. Taken together, our study suggests that 20(S)-Rg3 is a strong inhibitor of hypoxia-inducible factor 1α, which may provide a novel agent for future treatments for ovarian cancer.

Functional role of ginseng-derived compounds in cancer

Ginseng is a natural product best known for its curative properties in diverse physiological processes such as cancer, neurodegenerative disorders, hypertension, and maintenance of hemostasis in the immune system. In previous decades, there have been some promising studies into the pharmacology and chemistry of ginseng components and the relationship between their structure and function. The emerging use of modified ginseng and development of new compounds from ginseng for clinical studies have been topics of study for many researchers. The present review deals with the anticancer, anti-inflammatory, antioxidant, and chemopreventive effects, and recent advances in microRNA technology related to red ginseng. The review also summarizes the current knowledge on the effect of ginsenosides in the treatment of cancer.