Inhibition of JAK1/STAT3 signaling mediates compound K-induced apoptosis in human multiple myeloma U266 cells

Synthesis and Biological Evaluation of 3-Amino-4,4-Dimethyl Lithocholic Acid Derivatives as Novel, Selective, and Cellularly Active Allosteric SHP1 Activators

Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP1), a non-receptor member of the protein tyrosine phosphatase (PTP) family, negatively regulates several signaling pathways that are responsible for pathological cell processes in cancers. In this study, we report a series of 3-amino-4,4-dimethyl lithocholic acid derivatives as SHP1 activators. The most potent compounds, 5az-ba, showed low micromolar activating effects (EC50: 1.54–2.10 μM) for SHP1, with 7.63–8.79-fold maximum activation and significant selectivity over the closest homologue Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP2) (>32-fold). 5az-ba showed potent anti-tumor effects with IC50 values of 1.65–5.51 μM against leukemia and lung cancer cells. A new allosteric mechanism of SHP1 activation, whereby small molecules bind to a central allosteric pocket and stabilize the active conformation of SHP1, was proposed. The activation mechanism was consistent with the structure–activity relationship (SAR) data. This study demonstrates that 3-amino-4,4-dimethyl lithocholic acid derivatives can be selective SHP1 activators with potent cellular efficacy.

Compound K: A systematic review of its anticancer properties and probable mechanisms

Panax ginseng is a common natural product, which is well-known to have a wide range of pharmacological activities in cancer. Its metabolite, compound K (CK), has been reported to have anticancer activity. We aimed to systematically review the literature for evidence of anticancer effects of CK. We conducted a systematic search in eight databases. We included all in vitro and in vivo studies investigating the anticancer effects of CK with no restrictions. Quality assessment was applied by ToxRTool. Fifty-four articles were included in our study. The purity of CK in our included studies was at least 95%. The in vitro studies reported that CK had a potential anticancer activity on several cell lines including human lung cancer cell lines (A549, PC-9), nasopharyngeal carcinoma cell line (Hk-1), liver cancer cell line (BEL 7402), and pediatric acute myeloid leukemia cell lines (Kasumi-1, MV4-11). The in vivo studies reported a significant decrease in tumor volume in mice treated with CK. CK is a potential supplementary treatment in cancer chemotherapies. The safety and further clinical trials of CK should be explored for future drug development.

Guggulsterone Induces Apoptosis in Multiple Myeloma Cells by Targeting High Mobility Group Box 1 via Janus Activated Kinase/Signal Transducer and Activator of Transcription Pathway

Multiple myeloma (MM) is a hematological disorder characterized by the abnormal expansion of plasma cells in the bone marrow. Despite great advances over the past three decades in discovering the efficacious therapies for MM, the disease remains incurable for most patients owing to emergence of drug-resistant cancerous cells. Guggulsterone (GS), a phytosteroid, extracted from the gum resin of guggul plant, has displayed various anticancer activities in vitro and in vivo; however, the molecular mechanisms of its anticancer activity have not been evaluated in MM cells. Therefore, in this study, we investigated the anticancer activity of GS in various MM cell lines (U266, MM.1S, and RPMI 8226) and the mechanisms involved. GS treatment of MM cells caused inhibition of cell proliferation and induction of apoptotic cell death as indicated by increased Bax protein expression, activation of caspases, and cleavage of poly (ADP-ribose) polymerase. This was associated with the downregulation of various proliferative and antiapoptotic gene products, including cyclin D, Bcl-2, Bcl-xL, and X-linked inhibitor of apoptosis protein. GS also suppressed the constitutive and interleukin 6-induced activation of STAT3. Interestingly, the inhibition of Janus activated kinase or STAT3 activity by the specific inhibitors or by siRNA knockdown of STAT3 resulted in the downregulation of HMGB1, suggesting an association between GS, STAT3, and HMGB1. Finally, GS potentiated the anticancer effects of bortezomib (BTZ) in MM cells. Herein, we demonstrated that GS could be a potential therapeutic agent for the treatment of MM, possibly alone or in combination with BTZ.

The effects of Ginsenosides on PI3K/AKT signaling pathway

Ginsenosides belong to a group of steroid glycosides that are extracted from the plant genus Panax (ginseng). This plant has been used for a long time for the treatment of a variety of disorders in traditional medicine. Recent studies have assessed the biological impact of Ginsenosides in cell culture or animal models. Animal studies have shown their beneficial impacts in the remedy of pathological conditions in different tissues. The ameliorating effects of Ginsenosides in diverse pathogenic conditions can be attributed to their effects on the production of reactive oxygen species. These substances mainly affect the activity of AMPK/AKT and PI3K/AKT pathways. The beneficial effects of Ginsenosides have been appraised in diabetes-related complications, spinal cord injury, cerebral ischemia, myocardial ischemia, and other disorders which are associated with oxidative stress. Moreover, these substances have been shown to interfere with the pathologic conditions during carcinogenesis. In the current study, we explain these impacts in two distinct sections including non-neoplastic conditions and neoplastic conditions.

Active Components of Traditional Chinese Medicinal Material for Multiple Myeloma: Current Evidence and Future Directions

Multiple myeloma (MM) is a hematological malignancy characterized by clonal expansion of plasma cells in bone marrow, leading to the overproduction of monoclonal immunoglobulins. The clinical manifestations resulting from monoclonal proteins and malignant cells include signs of end-organ damage, such as hypercalcemia, renal failure, anemia, and bone lesions. Despite improvement in the survival of MM patients with use of myeloma-targeted and immunomodulatory therapies, MM remains an incurable disease. Moreover, patients with relapsed or refractory MM show poor survival outcomes. In recent years, there has been a growing interest in the use of traditional Chinese medicinal materials (TCMMs) for management of a wide spectrum of diseases. The bioactive ingredients derived from TCMMs hold great potential for the development of anticancer drugs. Here we summarize the evidence of the pharmacological effects of the active components in TCMMs on MM, including curcumin, resveratrol, baicalein, berberine, bufalin, cinobufagin, gambogic acid, ginsenoside, icariin, daidzin, formononetin, polysaccharides extracts from Hedyotis difus, and scutellarein. Available evidence indicates that the anti-MM effects of these bioactive ingredients are mediated via regulation of proliferation, apoptosis, autophagy, cell cycle, osteogenic differentiation, and drug resistance. In the future, the underlying mechanisms of the anti-MM effects of these components should be further investigated. Large-scale and well-designed clinical trials are also required to validate the efficacy of these bioactive constituents for MM.

Functional Mechanism of Ginsenoside Compound K on Tumor Growth and Metastasis

Ginsenosides, as the most important constituents of ginseng, have been extensively investigated in cancer chemoprevention and therapeutics. Among the ginsenosides, Compound K (CK), a rare protopanaxadiol type of ginsenoside, has been most broadly used for cancer treatment due to its high anticancer bioactivity. However, the functional mechanism of CK in cancer is not well known. This review describes the structure, transformation and pharmacological activity of CK and discusses the functional mechanisms of CK and its metabolites, which regulate signaling pathways related to tumor growth and metastasis. CK inhibits tumor growth by inducing tumor apoptosis and tumor cell differentiation, regulates the tumor microenvironment by suppressing tumor angiogenesis-related proteins, and downregulates the roles of immunosuppressive cells, such as myeloid-derived suppressor cells (MDSCs). There is currently much research on the potential development of CK as a new strategy when administered alone or in combination with other compounds.

Blocking the short isoform of augmenter of liver regeneration inhibits proliferation of human multiple myeloma U266 cells via the MAPK/STAT3/cell cycle signaling pathway

Multiple myeloma (MM) is the second most common haematological malignancy and remains an incurable disease, with most patients relapsing and requiring further treatment. Augmenter of liver regeneration (ALR) is a vital protein affecting fundamental processes such as energy transduction, cell survival and regeneration. Silencing ALR inhibits cell proliferation and triggers apoptosis in human MM U266 cells. However, little is known about the role of 15-kDa-ALR on MM. In the present study, the role of 15-kDa-ALR in human MM cells was investigated. Blocking extracellular 15-kDa-ALR with an anti-ALR monoclonal antibody (McAb) decreased the proliferation and viability of U266 cells. However, the results of flow cytometry revealed no changes in apoptosis, and the expression levels of Bax, Bcl-2, caspase-3 and cleaved caspase-3 were not affected. However, combined treatment with anti-ALR McAb and epirubicin increased the apoptosis of U266 cells. RNA sequencing results indicated that the ERK1/2, JNK-MAPK and STAT3 signaling pathways, as well as the cell cycle, were associated with the mechanism of action of the anti-ALR McAb, and PCR, western blotting and cell cycle analysis confirmed these results. The present findings suggested that blocking extracellular 15-kDa-ALR in U266 cells with an anti-ALR McAb decreased cell proliferation via the MAPK, STAT3 and cell cycle signaling pathways without increasing apoptosis. Thus, 15-kDa-ALR may be a new therapeutic target for myeloma.

Evolution of the adaptogenic concept from traditional use to medical systems: Pharmacology of stress- and aging-related diseases

Adaptogens comprise a category of herbal medicinal and nutritional products promoting adaptability, resilience, and survival of living organisms in stress. The aim of this review was to summarize the growing knowledge about common adaptogenic plants used in various traditional medical systems (TMS) and conventional medicine and to provide a modern rationale for their use in the treatment of stress-induced and aging-related disorders. Adaptogens have pharmacologically pleiotropic effects on the neuroendocrine-immune system, which explain their traditional use for the treatment of a wide range of conditions. They exhibit a biphasic dose-effect response: at low doses they function as mild stress-mimetics, which activate the adaptive stress-response signaling pathways to cope with severe stress. That is in line with their traditional use for preventing premature aging and to maintain good health and vitality. However, the potential of adaptogens remains poorly explored. Treatment of stress and aging-related diseases require novel approaches. Some combinations of adaptogenic plants provide unique effects due to their synergistic interactions in organisms not obtainable by any ingredient independently. Further progress in this field needs to focus on discovering new combinations of adaptogens based on traditional medical concepts. Robust and rigorous approaches including network pharmacology and systems pharmacology could help in analyzing potential synergistic effects and, more broadly, future uses of adaptogens. In conclusion, the evolution of the adaptogenic concept has led back to basics of TMS and a new level of understanding of holistic approach. It provides a rationale for their use in stress-induced and aging-related diseases.

Ginsenoside Compound K Regulates HIF-1α-Mediated Glycolysis Through Bclaf1 to Inhibit the Proliferation of Human Liver Cancer Cells

This study aimed to demonstrate that ginsenoside compound K (20 (S)-ginsenoside CK; CK) downregulates Bcl-2-associated transcription factor 1 (Bclaf1), which inhibits the hypoxia-inducible factor-1α (HIF-1α)-mediated glycolysis pathway to inhibit the proliferation of liver cancer cells. Treatment of hepatoma cells (Bel-7404 and Huh7) under hypoxic conditions with different concentrations of CK showed that CK inhibited the proliferation of hepatoma cells in a time- and concentration-dependent manner; furthermore, the ability of the cells to form colonies was reduced, and cell growth was blocked in the G0/G1 phase. CK promoted the degradation of HIF-1α ubiquitination in liver cancer cells by regulating the expression of HIF-1α and related ubiquitination proteins; moreover, it reduced the activity of key enzymes involved in glycolysis, the pressure of cellular glycolysis, and the rate of real-time ATP production, thereby inhibiting the glycolysis pathway. It also decreased the expression of Bclaf1 in hypoxic liver cancer cells and thus reduced the ability of Bclaf1 to bind to HIF-1α. CK treatment of Bel-7404 and Huh7 cells with CRISPR/Cas9-engineered knock out of Bclaf1 gene under hypoxic conditions further suppressed the expression of HIF-1α, promoted HIF-1α ubiquitination, and inhibited the glycolysis pathway. In a rat model of primary liver cancer induced by diethylnitrosamine, positron emission tomography and computed tomography scans showed that after CK administration, tumor tissue volumes were reduced and glucose uptake capacity decreased. Increased Bclaf1 and HIF-1α expression promoted the ubiquitination of HIF-1α and inhibited the glycolysis pathway, thereby inhibiting the proliferation of liver cancer cells. In summary, this study confirmed by in vitro and in vivo experiments that in hypoxic liver cancer cells CK downregulates the expression of Bclaf1, inhibits the HIF-1α-mediated glycolysis pathway, and inhibits cell proliferation, suggesting that the CK-mediated effects on Bclaf1 may represent a novel therapeutic approach for the treatment of liver cancer patients.

The Zn(S-pr-thiosal)2 complex attenuates murine breast cancer growth by inducing apoptosis and G1/S cell cycle arrest

Aim: We investigated the antitumor effects of zinc(II) complex with S-propyl thiosalicylic acid [Zn(S-pr-thiosal)₂] in 4T1 murine breast cancer model. Results: The Zn(S-pr-thiosal)₂ complex reduced primary tumor growth in vivo and induced tumor cell apoptosis. The Zn(S-pr-thiosal)₂ complex disrupted the balance between pro- and antiapoptotic Bcl-2 family members in 4T1 cells and induced G1/S cell cycle arrest. The Zn(S-pr-thiosal)₂ complex increased the percentage of p16, p21 and p27 positive 4T1 cells. There was a significantly decrease in expression of STAT3 and its targets c-Myc and cyclin D3 in 4T1 cells treated with the Zn(S-pr-thiosal)₂ complex thus contributing to G1/S cell cycle arrest and/or apoptosis. Conclusion: Our data suggest that the Zn(S-pr-thiosal)₂ complex restricted tumor growth through induction of mitochondrial-driven apoptosis and suppression of cell cycle progression.

Impact of Natural Dietary Agents on Multiple Myeloma Prevention and Treatment: Molecular Insights and Potential for Clinical Translation

Chemoprevention is based on the use of non-toxic, pharmacologically active agents to prevent tumor progression. In this regard, natural dietary agents have been described by the most recent literature as promising tools for controlling onset and progression of malignancies. Extensive research has been so far performed to shed light on the effects of natural products on tumor growth and survival, disclosing the most relevant signal transduction pathways targeted by such compounds. Overall, anti-inflammatory, anti-oxidant and cytotoxic effects of dietary agents on tumor cells are supported either by results from epidemiological or animal studies and even by clinical trials. Multiple myeloma is a hematologic malignancy characterized by abnormal proliferation of bone marrow plasma cells and subsequent hypercalcemia, renal dysfunction, anemia, or bone disease, which remains incurable despite novel emerging therapeutic strategies. Notably, increasing evidence supports the capability of dietary natural compounds to antagonize multiple myeloma growth in preclinical models of the disease, underscoring their potential as candidate anti-cancer agents. In this review, we aim at summarizing findings on the anti-tumor activity of dietary natural products, focusing on their molecular mechanisms, which include inhibition of oncogenic signal transduction pathways and/or epigenetic modulating effects, along with their potential clinical applications against multiple myeloma and its related bone disease.

Insights into gastrointestinal microbiota-generated ginsenoside metabolites and their bioactivities

The gastrointestinal microbiota and host co-evolve into a complex 'super-organism,' and this relationship plays a vital role in many physiological processes, such as drug metabolism. Ginseng is an important medicinal resource and the main ingredients are ginsenosides, which are less polar, difficult to absorb, and have low bioavailability. However, studies have shown that the biological activity of ginsenosides such as compound K (CK), ginsenoside Rg3 (Rg3), ginsenoside Rh2 (Rh2), 20(S)-protopanaxatriol (20(S)-PPT), and 20(S)-protopanaxadiol (20(S)-PPD) is closely related to the gastrointestinal microbiota. In this paper, the metabolic pathway of gastrointestinal microbiota-generated ginsenosides and the main pharmacological effects of these metabolites are discussed. Furthermore, our study provides a new insight into the discovery of novel drugs. Specifically, in new drug screening process, candidates with low biological activity and bioavailability should not be excluded. Because their metabolites may exhibit good pharmacological effects due to the involvement of the gastrointestinal microbiota. In addition, in further research studies to develop probiotics, a combination of agents could exert greater efficacy than single agents. Moreover, differences in lifestyle and diet lead to differences in the gastrointestinal microbiota in the human body. Therefore, administration of the same drug dose to different individuals could elicit different therapeutic effects, owing to the involvement of the gastrointestinal microbiota. Thus, treatment accuracy could be achieved by detecting the gastrointestinal microbiota before drug treatment.HighlightsGastrointestinal microbiota plays a decisive role in bioactivities of ginsenosides.The metabolic pathway and main pharmacological effects of ginsenoside metabolites are discussed.It provides new insights into novel drug discovery and further research to find probiotic, combinations to exert greater efficacy.Differences in lifestyle and diet, varies the gastrointestinal microbiota in the human body. However, the same dose of a drug producing different therapeutic effects may involve gastrointestinal microbiota.

Anticancer Activity and Underlying Mechanism of Phytochemicals against Multiple Myeloma

Multiple myeloma (MM)-a common hematologic malignancy of plasma cells-accounts for substantial mortality and morbidity rates. Due to the advent of novel therapies such as immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs), and monoclonal antibodies (mAbs), response rates were increased and free survival and overall survival have been elevated. However, adverse events including toxicity, neuropathy or continuous relapse are still problems. Thus, development of novel drugs which have less side effects and more effective is needed. This review aims to recapitulate the pharmacologic anti-MM mechanisms of various phytochemicals, elucidating their molecular targets. Keywords related to MM and natural products were searched in PUBMED/MEDLINE. Phytochemicals have been reported to display a variety of anti-MM activities, including apoptosis, cell cycle arrest, antiangiogenesis, and miRNA modulation. Some phytochemicals sensitize the conventional therapies such as dexamethasone. Also, there are clinical trials with phytochemicals such as agaricus, curcumin, and Neovastat regarding MM treatment. Taken together, this review elucidated and categorized the evidences that natural products and their bioactive compounds could be potent drugs in treating MM.

Crystal structure and physical stability of ginsenoside compound-K solvates

Through systematic investigation on the structure of and thermal/hygroscopic experiments on GCK solvates, superior physical stabilities of the hemihydrate and monohydrate are demonstrated.

Ginsenosides, catechins, quercetin and gut microbiota: Current evidence of challenging interactions

Recent studies have shown the role of gut microbiota in favoring the absorption of herbal products and the transformation of their active principles into metabolites endowed with biological activity. This review focuses on the evidence supporting the changes occurring, after metabolic reactions by specific bacteria that colonize the human gut, to ginseng-derived ginsenosides, green tea-derived catechins, and quercetin, this latter being a flavonoid aglycon bound to sugars and abundant in some vegetables and roots. Furthermore, the results of several studies demonstrating the potential beneficial effects of the active metabolites generated by these biotransformations on ginsenosides, catechins and quercetin will be reported.

Functional mechanism of Ginsenosides on tumor growth and metastasis

Ginsengs, has long been used as one medicinal herb in China for more than two thousand years. Many studies have shown that ginsengs have preventive and therapeutic roles for cancer, and play a good complementary role in cancer treatment. Ginsenosides, as most important constituents of ginseng, have been extensively investigated and emphasized in cancer chemoprevention and therapeutics. However, the functional mechanism of Ginsenosides on cancer is not well known. This review will focus on introducing the functional mechanisms of ginsenosides and their metabolites, which regulate signaling pathways related with tumor growth and metastasis. Ginsenosides inhibit tumor growth via upregulating tumor apoptosis, inducing tumor cell differentiation and targeting cancer stem cells. In addition, Ginsenosides regulate tumor microenvironment via suppressing tumor angiogenesis-related proteins and pathways. Structural modification of ginsenosides and their administration alone or combinations with other Chinese medicines or chemical medicines have recently been developed to be a new therapeutic strategy for cancer.

Compound K Induces Endoplasmic Reticulum Stress and Apoptosis in Human Liver Cancer Cells by Regulating STAT3

The ginsenoside compound K (20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol; CK) is an intestinal bacterial metabolite of ginseng protopanaxadiol saponin that has been reported to induce apoptosis in many cancer cells; however, the precise mechanisms of its activity in human hepatocellular carcinoma (HCC) cells remain unclear. Herein, we demonstrated that CK inhibited the growth and colony formation of HepG2 and SMMC-7721 cells, phenotypes that were mediated by inducing apoptosis. Meanwhile, CK showed lower toxicity in normal hepatoma cells. After treating HepG2 and SMMC-7721 cells with CK, p-STAT3 levels decreased, the three branches of the unfolded protein response were activated, and levels of endoplasmic reticulum stress (ERS)-related proteins were increased. We also revealed that CK decreased the DNA-binding capacity of STAT3. Moreover, silencing STAT3 with CRISPR/Cas9 technology enhanced CK-induced ERS and apoptosis. Finally, we showed that CK inhibited the growth of liver cancer xenografts with little toxicity. Mice bearing human HCC xenografts that were treated with CK showed increased GRP78 expression and decreased p-STAT3 levels. Taken together, these data showed that CK induced ERS and apoptosis by inhibiting p-STAT3 in human liver cancer cells; thus, CK might be a potential therapeutic candidate for human HCC.

Kinase inhibitors as potential agents in the treatment of multiple myeloma

Recent years have witnessed a dramatic increase in the number of therapeutic options available for the treatment of multiple myeloma (MM) - from immunomodulating agents to proteasome inhibitors to histone deacetylase (HDAC) inhibitors and, most recently, monoclonal antibodies. Used in conjunction with autologous hematopoietic stem cell transplantation, these modalities have nearly doubled the disease's five-year survival rate over the last three decades to about 50%. In spite of these advances, MM still is considered incurable as resistance and relapse are common. While small molecule protein kinase inhibitors have made inroads in the therapy of a number of cancers, to date their application to MM has been less than successful. Focusing on MM, this review examines the roles played by a number of kinases in driving the malignant state and the rationale for target development in the design of a number of kinase inhibitors that have demonstrated anti-myeloma activity in both in vitro and in vivo xenograph models, as well as those that have entered clinical trials. Among the targets and their inhibitors examined are receptor and non-receptor tyrosine kinases, cell cycle control kinases, the PI3K/AKT/mTOR pathway kinases, protein kinase C, mitogen-activated protein kinase, glycogen synthase kinase, casein kinase, integrin-linked kinase, sphingosine kinase, and kinases involved in the unfolded protein response.

Anticancer Activities of Protopanaxadiol- and Protopanaxatriol-Type Ginsenosides and Their Metabolites

Recently, most anticancer drugs are derived from natural resources such as marine, microbial, and botanical sources, but the low success rates of chemotherapies and the development of multidrug resistance emphasize the importance of discovering new compounds that are both safe and effective against cancer. Ginseng types, including Asian ginseng, American ginseng, and notoginseng, have been used traditionally to treat various diseases, due to their immunomodulatory, neuroprotective, antioxidative, and antitumor activities. Accumulating reports have shown that ginsenosides, the major active component of ginseng, were helpful for tumor treatment. 20(S)-Protopanaxadiol (PDS) and 20(S)-protopanaxatriol saponins (PTS) are two characteristic types of triterpenoid saponins in ginsenosides. PTS holds capacity to interfere with crucial metabolism, while PDS could affect cell cycle distribution and prodeath signaling. This review aims at providing an overview of PTS and PDS, as well as their metabolites, regarding their different anticancer effects with the proposal that these compounds might be potent additions to the current chemotherapeutic strategy against cancer.

Ginseng Metabolites on Cancer Chemoprevention: An Angiogenesis Link?

Cancer is a leading cause of death in the United States. Angiogenesis inhibitors have been introduced for the treatment of cancer. Based on the fact that many anticancer agents have been developed from botanical sources, there is a significant untapped resource to be found in natural products. American ginseng is a commonly used herbal medicine in the U.S., which possesses antioxidant properties. After oral ingestion, natural ginseng saponins are biotransformed to their metabolites by the enteric microbiome before being absorbed. The major metabolites, ginsenoside Rg3 and compound K, showed significant potent anticancer activity compared to that of their parent ginsenosides Rb1, Rc, and Rd. In this review, the molecular mechanisms of ginseng metabolites on cancer chemoprevention, especially apoptosis and angiogenic inhibition, are discussed. Ginseng gut microbiome metabolites showed significant anti-angiogenic effects on pulmonary, gastric and ovarian cancers. This review suggests that in addition to the chemopreventive effects of ginseng compounds, as angiogenic inhibitors, ginsenoside metabolites could be used in combination with other cancer chemotherapeutic agents in cancer management.

Logic-Based and Cellular Pharmacodynamic Modeling of Bortezomib Responses in U266 Human Myeloma Cells

Systems models of biological networks show promise for informing drug target selection/qualification, identifying lead compounds and factors regulating disease progression, rationalizing combinatorial regimens, and explaining sources of intersubject variability and adverse drug reactions. However, most models of biological systems are qualitative and are not easily coupled with dynamical models of drug exposure-response relationships. In this proof-of-concept study, logic-based modeling of signal transduction pathways in U266 multiple myeloma (MM) cells is used to guide the development of a simple dynamical model linking bortezomib exposure to cellular outcomes. Bortezomib is a commonly used first-line agent in MM treatment; however, knowledge of the signal transduction pathways regulating bortezomib-mediated cell cytotoxicity is incomplete. A Boolean network model of 66 nodes was constructed that includes major survival and apoptotic pathways and was updated using responses to several chemical probes. Simulated responses to bortezomib were in good agreement with experimental data, and a reduction algorithm was used to identify key signaling proteins. Bortezomib-mediated apoptosis was not associated with suppression of nuclear factor κB (NFκB) protein inhibition in this cell line, which contradicts a major hypothesis of bortezomib pharmacodynamics. A pharmacodynamic model was developed that included three critical proteins (phospho-NFκB, BclxL, and cleaved poly (ADP ribose) polymerase). Model-fitted protein dynamics and cell proliferation profiles agreed with experimental data, and the model-predicted IC50 (3.5 nM) is comparable to the experimental value (1.5 nM). The cell-based pharmacodynamic model successfully links bortezomib exposure to MM cellular proliferation via protein dynamics, and this model may show utility in exploring bortezomib-based combination regimens.

Chinese medicines induce cell death: the molecular and cellular mechanisms for cancer therapy

Chinese medicines have long history in treating cancer. With the growing scientific evidence of biomedical researches and clinical trials in cancer therapy, they are increasingly accepted as a complementary and alternative treatment. One of the mechanisms is to induce cancer cell death. Aim. To comprehensively review the publications concerning cancer cell death induced by Chinese medicines in recent years and provide insights on anticancer drug discovery from Chinese medicines. Materials and Methods. Chinese medicines (including Chinese medicinal herbs, animal parts, and minerals) were used in the study. The key words including “cancer”, “cell death”, “apoptosis”, “autophagy,” “necrosis,” and “Chinese medicine” were used in retrieval of related information from PubMed and other databases. Results. The cell death induced by Chinese medicines is described as apoptotic, autophagic, or necrotic cell death and other types with an emphasis on their mechanisms of anticancer action. The relationship among different types of cell death induced by Chinese medicines is critically reviewed and discussed. Conclusions. This review summarizes that CMs treatment could induce multiple pathways leading to cancer cell death, in which apoptosis is the dominant type. To apply these preclinical researches to clinic application will be a key issue in the future.

The ginsenoside 20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol induces autophagy and apoptosis in human melanoma via AMPK/JNK phosphorylation

Studies have shown that a major metabolite of the red ginseng ginsenoside Rb1, called 20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol (GPD), exhibits anticancer properties. However, the chemotherapeutic effects and molecular mechanisms behind GPD action in human melanoma have not been previously investigated. Here we report the anticancer activity of GPD and its mechanism of action in melanoma cells. GPD, but not its parent compound Rb1, inhibited melanoma cell proliferation in a dose-dependent manner. Further investigation revealed that GPD treatment achieved this inhibition through the induction of autophagy and apoptosis, while Rb1 failed to show significant effect at the same concentrations. The inhibitory effect of GPD appears to be mediated through the induction of AMPK and the subsequent attenuation of mTOR phosphorylation. In addition, GPD activated c-Jun by inducing JNK phosphorylation. Our findings suggest that GPD suppresses melanoma growth by inducing autophagic cell death and apoptosis via AMPK/JNK pathway activation. GPD therefore has the potential to be developed as a chemotherapeutic agent for the treatment of human melanoma.

Red ginseng extract ameliorates autoimmune arthritis via regulation of STAT3 pathway, Th17/Treg balance, and osteoclastogenesis in mice and human

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic joint inflammation. Red ginseng is a steamed and dried Panax ginseng C.A. Meyer, which has been used as alternative medicine for thousands of years. This study was undertaken to investigate the effects of red ginseng extracts (RGE) on autoimmune arthritis in mice and humans and to delineate the underlying mechanism. RGE was orally administered three times a week to mice with arthritis. Oral administration of RGE markedly ameliorated clinical arthritis score and histologically assessed joint inflammation in mice with CIA. A significant reduction in STAT3 phosphorylation and a decrease in the number of Th17 cells were observed with RGE treatment. There was also a marked reduction in RANKL-induced osteoclastogenesis with treatment of RGE. The inhibitory effect of RGE on Th17 differentiation and osteoclastogenesis observed in mice was also confirmed in the subsequent experiments performed using human peripheral blood mononuclear cells. Our findings provide the first evidence that RGE can regulate Th17 and reciprocally promote Treg cells by inhibiting the phosphorylation of STAT3. Therefore, RGE can ameliorate arthritis in mice with CIA by targeting pathogenic Th17 and osteoclast differentiation, suggesting a novel therapy for treatment of RA.

Biochemical basis of cancer chemoprevention and/or chemotherapy with ginsenosides (Review)

Cancer still imposes a global threat to public health. After decades of research on cancer biology and enormous efforts in developing anticancer therapies, we now understand that the majority of cancers can be prevented. Bioactive phytochemicals present in edible plants have been shown to reduce the risk of various types of cancer. Ginseng (Panax ginseng C.A. Meyer), which contains a wide variety of saponins, known as ginsenosides, is an age-old remedy for human ailments, including cancer. Numerous laboratory-based studies have revealed the anticancer properties of ginsenosides, which compel tumor cells to commit suicide, arrest the proliferation of cancer cells in culture and inhibit experimentally-induced tumor formation in laboratory animals. Ginsenosides have been reported to inhibit tumor angiogenesis, as well as the invasion and metastasis of various types of cancer cells. Moreover, ginsenosides as combination therapy enhance the sensitivity of chemoresistant tumors to clinically used chemotherapeutic agents. This review sheds light on the molecular mechanisms underlying the cancer chemopreventive and/or chemotherapeutic activity of ginsenosides and their intestinal metabolites with particular focus on the modulation of cell signaling pathways associated with oxidative stress, inflammation, cell proliferation, apoptosis, angiogenesis and the metastasis of cancer cells.

Synthesis of esters of ginsenoside metabolite M1 and their cytotoxicity on MGC80-3 cells

Monoesters of ginsenoside metabolite M1 at the 3-OH, 4-OH and 6-OH positions of the glucose moiety at M1 were synthesized via the reaction of M1 with acyl chloride, or acid-N,N'-diisopropylcarbodiimide in the presence of DMAP. Their structures were fully characterized by spectral methods. The cytotoxicity of these compounds against then MGC80-3 human gastric cancer cell line was also assessed. High inhibitory effects were found at a concentration of 100 μg/mL.

Icariside II induces apoptosis in U937 acute myeloid leukemia cells: role of inactivation of STAT3-related signaling

Background

The aim of this study is to determine anti-cancer effect of Icariside II purified from the root of Epimedium koreanum Nakai on human acute myeloid leukemia (AML) cell line U937.

Methodology/Principal Findings

Icariside II blocked the growth U937 cells in a dose- and time-dependent manner. In this anti-proliferation process, this herb compound rendered the cells susceptible to apoptosis, manifested by enhanced accumulation of sub-G1 cell population and increased the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells. Icariside II was able to activate caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP) in a time-dependent manner. Concurrently, the anti-apoptotic proteins, such as bcl-x_L and survivin in U937 cells, were downregulated by Icariside II. In addition, Icariside II could inhibit STAT3 phosphorylation and function and subsequently suppress the activation of Janus activated kinase 2 (JAK2), the upstream activators of STAT3, in a dose- and time-dependent manner. Icariside II also enhanced the expression of protein tyrosine phosphatase (PTP) SH2 domain-containing phosphatase (SHP)-1, and the addition of sodium pervanadate (a PTP inhibitor) prevented Icariside II-induced apoptosis as well as STAT3 inactivation in STAT3 positive U937 cells. Furthermore, silencing SHP-1 using its specific siRNA significantly blocked STAT3 inactivation and apoptosis induced by Icariside II in U937 cells.

Conclusions/Significance

Our results demonstrated that via targeting STAT3-related signaling, Icariside II sensitizes U937 cells to apoptosis and perhaps serves as a potent chemotherapeutic agent for AML.

Melatonin synergistically enhances cisplatin-induced apoptosis via the dephosphorylation of ERK/p90 ribosomal S6 kinase/heat shock protein 27 in SK-OV-3 cells

To evaluate melatonin's ability to enhance ovarian cancer cells to cisplatin treatment for ovarian cancer, this study was performed. Melatonin by itself had no significant cytotoxicity against SK-OV-3 cells, while cisplatin suppressed the cell viability in a dose-dependent manner. Combined treatment with cisplatin and melatonin synergistically inhibited the viability of SK-OV-3 cells with the synergism between two drugs (1 > combination index). In contrast, melatonin revealed the protective effect against cisplatin-induced cytotoxicity in OSEN normal ovarian epithelial cells. Cotreatment with cisplatin and melatonin increased the sub-G1 DNA contents and TdT-mediated dUTP nick end-labeling (TUNEL)-positive cells compared with cisplatin control in SK-OV-3 cells, suggesting that melatonin augments cisplatin-induced apoptosis. Consistently, combined treatment of cisplatin and melatonin increased the cleavage of caspase-3 and poly-(ADP-ribose) polymerase (PARP). Importantly, melatonin synergistically inhibited the phosphorylation of extracellular signal-regulated kinase (ERK) along with dephosphorylation of 90-kDa ribosomal S6 kinase (p90RSK) and heat shock protein 27 (HSP27) induced by cisplatin. Furthermore, melatonin remarkably blocked the expression and colocalization of p90RSK and HSP27 by combination treatment with cisplatin. Taken together, our findings demonstrate that melatonin enhances cisplatin-induced apoptosis via the inactivation of ERK/p90RSK/HSP27 cascade in SK-OV-3 cells as a potent synergist to cisplatin treatment.

Bioactivity enhancement of herbal supplements by intestinal microbiota focusing on ginsenosides

Intestinal microbiota contribute to diverse mammalian processes including the metabolic functions of drugs. It is a potential new territory for drug targeting, especially for dietary herbal products. Because most herbal medicines are orally administered, the chemical profile and corresponding bioactivities of herbal medicines may be altered by intestinal microbiota. Ginseng is one of the most commonly used herbs and it is an attractive natural product to study its effect in the body. In this review, after briefly introducing the interactions of herbal products and gut microbiota, we discuss the microbiota-mediated metabolism of ginsenosides in ginseng and red ginseng. In particular, the major metabolite compound K and its pharmacological advances are described including anticancer, antidiabetic and anti-inflammatory effects. In summary, the intestinal microbiota may play an important role in mediating the metabolism bioactivity of herbal medicines.