Ginseng saponin metabolite suppresses phorbol ester-induced matrix metalloproteinase-9 expression through inhibition of activator protein-1 and mitogen-activated protein kinase signaling pathways in human astroglioma cells

Ginsenosides in cancer: Targeting cell cycle arrest and apoptosis

Despite the existence of extensive clinical research and novel therapeutic treatments, cancer remains undefeated and the significant cause of death worldwide. Cancer is a disease in which growth of cells goes out of control, being also able to invade other parts of the body. Cellular division is strictly controlled by multiple checkpoints like G1/S and G2/M which, when dysregulated, lead to uncontrollable cell division. The current remedies which are being utilized to combat cancer are monoclonal antibodies, chemotherapy, cryoablation, and bone marrow transplant etc. and these have also been greatly disheartening because of their serious adverse effects like hypotension, neuropathy, necrosis, leukemia relapse and many more. Bioactive compounds derived from natural products have marked the history of the development of novel drug therapies against cancer among which ginsenosides have no peer as they target several signaling pathways, which when abnormally regulated, lead to cancer. Substantial research has reported that ginsenosides like Rb1, Rb2, Rb3, Rc, Rd, Rg3, Rh2 etc. can prevent and treat cancer by targeting different pathways and molecules by induction of autophagy, neutralizing ROS, induction of cancerous cell death by controlling the p53 pathway, modulation of miRNAs by decreasing Smad2 expression, regulating Bcl-2 expression by normalizing the NF-Kb pathway, inhibition of inflammatory pathways by decreasing the production of cytokines like IL-8, causing cell cycle arrest by restricting cyclin E1 and CDC2, and induction of apoptosis during malignancy by decreasing β-catenin levels etc. In this review, we have analyzed the anti-cancer therapeutic potential of various ginsenoside compounds in order to consider their possible use in new strategies in the fight against cancer.

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.

Ginsenoside protopanaxadiol protects adult retinal pigment epithelial-19 cells from chloroquine by modulating autophagy and apoptosis

Chloroquine often causes serious eye and vision problems, which are mainly mediated by lysosomotropic alteration. In this study, we investigated whether the ginsenoside protopanaxadiol relieves chloroquine-induced retinopathy by restoring lysosomotropic abnormalities in human adult retinal pigment epithelial-19 cells. Cytotoxicity was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Morphological alterations in autophagosomes of adult retinal pigment epithelial-19 cells was detected using confocal microscopy. Apoptosis was examined using flow cytometry, whereas cellular reactive oxygen species levels were determined by measuring the fluorescence intensity of 5-(and-6)-carboxy-2'-7'-dichlorohydrofluorescein diacetate. Lysosomal function was assessed by measuring lysosomal pH and enzyme activity. Immunoprecipitation and western blotting analyses were performed. Adult retinal pigment epithelial-19 cells accumulated autophagosomes with fusion defects in lysosomes and reactive oxygen species formation following exposure to chloroquine. This effect trapped Beclin-1 and B-cell lymphoma 2 interfering with autophagy initiation and autophagosome development. Protopanaxadiol alleviated chloroquine-induced toxicity by modulating the interaction between Beclin-1 and Bcl-2, which was mediated by the AMP-activated protein kinase-mammalian target of rapamycin signal axis. Furthermore, autophagy and apoptosis were simultaneously controlled by protopanaxadiol via upregulation of autophagy flux and decreased reactive oxygen species formation and apoptotic protein expression. These findings suggest that protopanaxadiol is a promising treatment strategy for chloroquine-mediated retinopathy.

Effects of Korean red ginseng on three-dimensional trabecular bone microarchitecture and strength in growing rats: Comparison with changes due to jump exercise

Objectives

The preventive effects of Korean red ginseng (KRG) on bone loss and microarchitectural deterioration have been extensively studied in animal models. However, few results have been reported for the effects of KRG on the trabecular microarchitecture as compared to changes resulting from physiological stimuli such as exercise load. We compared the effects of KRG and jump exercise on improvements in trabecular microarchitecture and strength of the distal femoral metaphysis in rats.

Methods and materials

Eleven-week-old male Wistar rats were divided into sedentary (CON), KRG-administered (KRG), and jump-exercised (JUM) groups. Rats were orally administered KRG extract (200 mg/kg body weight/day) once a day for 6 weeks. The jump exercise protocol comprised 10 jumps/day, 5 days/week at a jump height of 40 cm. We used microcomputed tomography to assess the microarchitecture, volumetric bone mineral density (vBMD), and fracture load as predicted by finite element analysis at the right distal femoral metaphysis. The left femur was used for the quantitative bone histomorphometry measurements.

Results

Although KRG produced significantly higher trabecular bone volume (BV/TV) than CON, BV/TV was even higher in JUM than in KRG, and differences in vBMD and fracture load were only significant between JUM and CON. In terms of trabecular microarchitecture, KRG increased trabecular number and connectivity, whereas the JUM group showed increased trabecular thickness. Bone resorption showed significant decrease by JUM and KRG group. In contrast, bone formation showed significant increase by JUM group.

Conclusions

These data show that KRG has weak but significant positive effects on bone mass and suggest that the effects on trabecular microarchitecture differ from those of jump exercise. The effects of combined KRG and jump exercise on trabecular bone mass and strength should be investigated.

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.

The promising therapeutic potentials of ginsenosides mediated through p38 MAPK signaling inhibition

The p38 mitogen-activated protein kinases (p38 MAPK) is a 38kD polypeptide recognized as the target for many potential anti-inflammatory agents. Accumulating evidence indicates that p38 MAPK could perform many roles in human disease pathophysiology. Therefore, great therapeutic benefits can be attained from p38 MAPK inhibitors. Ginseng is an exceptionally valued medicinal plant of the family Araliaceae (Panax genus). Recently, several studies targeted the therapeutic effects of purified individual ginsenoside, the most significant active ingredient of ginseng, and studied its particular molecular mechanism(s) of action rather than whole-plant extracts. Interestingly, several ginsenosides: ginsenosides compound K, F1, Rb1, Rb3, Rc, Rd, Re, Rf, Rg1, Rg2, Rg3, Rg5, Rh1, Rh2, Ro, notoginsenoside R1, and protopanaxadiol have shown to possess great therapeutic potentials mediated by their ability to downregulate p38 MAPK signaling in different cell lines and experimental animal models. Our review compiles the research findings of various ginsenosides as potent anti-inflammatory agents, highlighting the crucial role of p38 MAPK suppression in their pharmacological actions. In addition, in silico studies were conducted to explore the probable binding of these ginsenosides to p38 MAPK. The results obtained proposed p38 MAPK involvement in the beneficial pharmacological activities of ginsenosides in different ailments.

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p38 MAPK plays many roles in human disease pathophysiology. Therefore, great therapeutic benefits can be attained from p38 MAPK inhibitors.

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Several ginsenosides showed to possess great therapeutic potentials mediated by its ability to downregulate p38 MAPK signaling.

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in silico ​studies were conducted to explore the binding of these ginsenosides to p38 MAPK and evidenced the promising their inhibitory effect.

Saponins in Cancer Treatment: Current Progress and Future Prospects

Saponins are steroidal or triterpenoid glycoside that is distinguished by the soap-forming nature. Different saponins have been characterized and purified and are gaining attention in cancer chemotherapy. Saponins possess high structural diversity, which is linked to the anticancer activities. Several studies have reported the role of saponins in cancer and the mechanism of actions, including cell-cycle arrest, antioxidant activity, cellular invasion inhibition, induction of apoptosis and autophagy. Despite the extensive research and significant anticancer effects of saponins, there are currently no known FDA-approved saponin-based anticancer drugs. This can be attributed to a number of limitations, including toxicities and drug-likeness properties. Recent studies have explored options such as combination therapy and drug delivery systems to ensure increased efficacy and decreased toxicity in saponin. This review discusses the current knowledge on different saponins, their anticancer activity and mechanisms of action, as well as promising research within the last two decades and recommendations for future studies.

Anti-Metastatic and Anti-Inflammatory Effects of Matrix Metalloproteinase Inhibition by Ginsenosides

Matrix metalloproteinases (MMPs) are proteolytic enzymes which cleave extracellular matrix (ECM) and other substrates. They are deeply involved in both cancer metastasis and human chronic inflammatory diseases such as osteoarthritis and Crohn’s disease. Regulation of MMPs is closely associated with signaling molecules, especially mitogen-activated protein kinases (MAPKs), including three representative kinases, extracellular signal regulated kinases (ERK), p38 and c-Jun N-terminal kinases (JNK). Ginseng (Panax sp.) is a plant which has been traditionally used for medicinal applications. Ginsenosides are major metabolites which have potentials to treat various human diseases. In this review, the pharmacological effects of ginsenosides have been rigorously investigated; these include anti-metastatic and anti-inflammatory activities of ginsenosides associated with suppression of MMPs via regulation of various signaling pathways. This will highlight the importance of MMPs as therapeutic targets for anti-metastatic and anti-inflammatory drug development based on ginsenosides.

UPLC-QTOF-MS-guided isolation of anti-COPD ginsenosides from wild ginseng

Four previously undescribed ginsenosides, along with five known analogues were isolated from wild ginseng by a UPLC-QTOF-MS-guided fractionation procedure. Their structures were elucidated on the basis of spectroscopic and spectrometric data (1D and 2D NMR, HR-ESI-MS). The isolated compounds could significantly inhibit the cigarette smoke extract (CSE)-induced inflammatory reaction in A549 cells. The HDAC2 pathway might be involved in the protective effect against the CSE-mediated inflammatory response in A549 cells.

Ginsenoside Compound K Induces Ros-Mediated Apoptosis and Autophagic Inhibition in Human Neuroblastoma Cells In Vitro and In Vivo

Autophagy can result in cellular adaptation, as well as cell survival or cell death. Modulation of autophagy is increasingly regarded as a promising cancer therapeutic approach. Ginsenoside compound K (CK), an active metabolite of ginsenosides isolated from Panax ginseng C.A. Meyer, has been identified to inhibit growth of cancer cell lines. However, the molecular mechanisms of CK effects on autophagy and neuroblastoma cell death have not yet been investigated. In the present study, CK inhibited neuroblastoma cell proliferation in vitro and in vivo. Treatment by CK also induced the accumulation of sub-G1 population, and caspase-dependent apoptosis in neuroblastoma cells. In addition, CK promotes autophagosome accumulation by inducing early-stage autophagy but inhibits autophagic flux by blocking of autophagosome and lysosome fusion, the step of late-stage autophagy. This effect of CK appears to be mediated through the induction of intracellular reactive oxygen species (ROS) and mitochondria membrane potential loss. Moreover, chloroquine, an autophagy flux inhibitor, further promoted CK-induced apoptosis, mitochondrial ROS induction, and mitochondria damage. Interestingly, those promoted phenomena were rescued by co-treatment with a ROS scavenging agent and an autophagy inducer. Taken together, our findings suggest that ginsenoside CK induced ROS-mediated apoptosis and autophagic flux inhibition, and the combination of CK with chloroquine, a pharmacological inhibitor of autophagy, may be a novel therapeutic potential for the treatment of neuroblastoma.

Effects of ginseng supplementation on selected markers of inflammation: A systematic review and meta-analysis

The present meta-analysis was performed to evaluate the efficacy of ginseng administration on serum level of inflammatory biomarkers. We performed a systematic search of all available randomized controlled trials (RCTs) conducted up to June 2018 in the following electronic databases: PubMed, Scopus, Cochrane, and Google Scholar. RCTs that investigated the effect ginseng supplementation on high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were included for final analysis. A total of seven RCTs were included in the meta-analysis. Results indicated significant reduction in IL-6 (mean difference [MD]: -0.265 pg/ml, 95% CI [-0.396, -0.135], p < .001) and TNF-α (MD: -2.471 pg/ml, 95% CI [-2.904, -2.039], p < .001) and no significant change in hs-CRP (MD: -0.125 mg/L, 95% CI [-0.597, 0.347], p = .604). Although there was publication bias across studies, trim and fill analysis showed that results from unpublished studies could not change the results for CRP. However, removing one study in sensitivity analysis did reveal a significant reduction in CRP. We conclude that ginseng supplementation significantly lowered IL-6 and TNF-α but did not significantly lower CRP. However, these findings were not robust, because they showed sensitivity for CRP and IL-6, and future long-term well-designed dose-escalating trials are required.

Effects of ginseng on C-reactive protein level: A systematic review and meta-analysis of clinical trials

OBJECTIVE

The aim of this meta-analysis was to assess effects of ginseng supplementation on CRP/hs-CRP levels in clinical trial studies.

DESIGN

A systematic literature search was carried out for clinical trials published in ISI web of Science, Scopus, PubMed and Cochrane Library databases from the beginning to 16th February 2018. Of 83 articles found in the first step of the systematic search, seven studies with nine arms included in this meta-analysis.

RESULTS

Results of pooled random-effect size analysis of nine trials showed non-significant decreasing effects of ginseng supplementation on CRP level (WMD: -0.1 mg/l, 95% CI, -0.26, 0.1; P = 0.27) with significant heterogeneity shown within the studies. The subgroup analysis showed that ginseng supplementation could significantly reduce CRP level by 0.51 (95% CI: -0.68, -0.34; P < 0001, test for heterogeneity: P = 0.44, I² = 0.0%) in patients with a baseline serum CRP level of greater than 3 mg/dl. Trial duration and dose of ginseng supplementation included no significant effects on CRP level in this meta-analysis.

CONCLUSION

Results of the current meta-analysis study have shown that ginseng supplementation can decrease significantly serum CRP/hsCRP levels in patients with elevated serum level of this inflammatory marker.

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.

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.

Targeting VEGF/VEGFRs Pathway in the Antiangiogenic Treatment of Human Cancers by Traditional Chinese Medicine

Bearing in mind the doctrine of tumor angiogenesis hypothesized by Folkman several decades ago, the fundamental strategy for alleviating numerous cancer indications may be the strengthening application of notable antiangiogenic therapies to inhibit metastasis-related tumor growth. Under physiological conditions, vascular sprouting is a relatively infrequent event unless when specifically stimulated by pathogenic factors that contribute to the accumulation of angiogenic activators such as the vascular endothelial growth factor (VEGF) family and basic fibroblast growth factor (bFGF). Since VEGFs have been identified as the principal cytokine to initiate angiogenesis in tumor growth, synthetic VEGF-targeting medicines containing bevacizumab and sorafenib have been extensively used, but prominent side effects have concomitantly emerged. Traditional Chinese medicines (TCM)–derived agents with distinctive safety profiles have shown their multitarget curative potential by impairing angiogenic stimulatory signaling pathways directly or eliciting synergistically therapeutic effects with anti-angiogenic drugs mainly targeting VEGF-dependent pathways. This review aims to summarize (a) the up-to-date understanding of the role of VEGF/VEGFR in correlation with proangiogenic mechanisms in various tissues and cells; (b) the elaboration of antitumor angiogenesis mechanisms of 4 representative TCMs, including Salvia miltiorrhiza, Curcuma longa, ginsenosides, and Scutellaria baicalensis; and (c) circumstantial clarification of TCM-driven therapeutic actions of suppressing tumor angiogenesis by targeting VEGF/VEGFRs pathway in recent years, based on network pharmacology.

Dammarane-type triterpene ginsenoside-Rg18 inhibits human non-small cell lung cancer A549 cell proliferation via G1 phase arrest

A previous study reported that a novel dammarane-type triterpene saponin, ginsenoside-Rg18, derived from the root of Panax ginseng, displayed hydroxyl radical scavenging, anti-bacterial and cytotoxic activities. However, the underlying molecular mechanisms of its anti-proliferative effect on non-small cell lung cancer (NSCLC) A549 cells remains unclear. In the present study, it was determined that Rg18 inhibited the proliferation of A549 cells with a half-maximal inhibitory concentration of 150 µM. Flow cytometry analysis indicated that cell cycle progression was blocked by Rg18 at G₁ phase in A549 cells, which was accompanied by downregulation of cyclin-dependent kinase 2 (CDK2), CDK4, CDK6, cyclin D1, cyclin D2, cyclin E and phosphorylated retinoblastoma protein expression at the protein level. In addition, the CDK inhibitors (CDKNs), CDKN1A and CDKN1B, were upregulated following Rg18 treatment. Furthermore, Rg18 treatment resulted in the intracellular accumulation of reactive oxygen species (ROS), and a dose-dependent inhibition of p38 mitogen activated protein kinase (p38), c-Jun N-terminal kinase (JNK) and nuclear factor-κB (NF-κB)/p65 phosphorylation. Taken together, Rg18-mediated G₁ phase arrest was closely associated with the generation of intracellular ROS, and p38, JNK and NF-κB/p65 inhibition in A549 human NSCLC cells.

Emerging signals modulating potential of ginseng and its active compounds focusing on neurodegenerative diseases

Common features of neurodegenerative diseases (NDDs) include progressive dysfunctions and neuronal injuries leading to deterioration in normal brain functions. At present, ginseng is one of the most frequently used natural products. Its use has a long history as a cure for various diseases because its extracts and active compounds exhibit several pharmacological properties against several disorders. However, the pathophysiology of NDDs is not fully clear, but researchers have found that various ion channels and specific signaling pathways might have contributed to the disease pathogenesis. Apart from the different pharmacological potentials, ginseng and its active compounds modulate various ion channels and specific molecular signaling pathways related to the nervous system. Here, we discuss the signal modulating potential of ginseng and its active compounds mainly focusing on those relevant to NDDs.

Korean Ginseng Berry Fermented by Mycotoxin Non-producing Aspergillus niger and Aspergillus oryzae: Ginsenoside Analyses and Anti-proliferative Activities

To transform ginsenosides, Korean ginseng berry (KGB) was fermented by mycotoxin non-producing Aspergillus niger and Aspergillus oryzae. Changes of ginsenoside profile and anti-proliferative activities were observed. Results showed that A. niger tended to efficiently transform protopanaxadiol (PPD) type ginsenosides such as Rb1, Rb2, Rd to compound K while A. oryzae tended to efficiently transform protopanaxatriol (PPT) type ginsenoside Re to Rh1 via Rg1. Butanol extracts of fermented KGB showed high cytotoxicity on human adenocarcinoma HT-29 cell line and hepatocellular carcinoma HepG2 cell line while that of unfermented KGB showed little. The minimum effective concentration of niger-fermented KGB was less than 2.5 µg/mL while that of oryzae-fermented KGB was about 5 µg/mL. As A. niger is more inclined to transform PPD type ginsenosides, niger-fermented KGB showed stronger anti-proliferative activity than oryzae-fermented KGB.

Anti‑wrinkle effect of fermented black ginseng on human fibroblasts

Fermented black ginseng (FBG) is processed by the repeated steaming and drying of fresh ginseng followed by fermentation with Saccharomyces cerevisiae. It is known to possess anti‑oxidative effects. Skin wrinkle formation is associated with oxidative stress and inflammatory reactions. The aim of this study was to determine whether FBG possesses anti‑wrinkle activity using human fibroblasts (HS68). According to the Korea Ministry of Food and Drug Safety (MFDS) guidelines for the evaluation of the efficacy of functional anti‑wrinkle cosmetics, we attempted to elucidate the effects of FBG on type I procollagen, matrix metalloproteinase (MMP)‑1, MMP‑2, MMP‑9 and tissue inhibitor of metalloproteinase‑2 (TIMP‑2). In addition, the eye irritation potential of FBG was examined using the EpiOcular‑EIT kit. Our results revealed that FBG was not cytotoxic at concentrations <10 µg/ml. It was considered as safe for the eyes at concentrations of up to 100 µg/ml. Treatment with FBG at concentrations from 0.3 to 10 µg/ml significantly (P<0.05) increased the type I procollagen expression levels from 117.61±1.51 to 129.95±4.47% in the human fibroblasts. By contrast, FBG significantly (P<0.05) decreased the MMP‑1 expression level from 18.41±4.95 to 27.41±3.96%. FBG at 3 µg/ml also increased the expression of TIMP‑2 up to 154.55%. However, FBG at 10 µg/ml decreased the expression levels of MMP‑2 and MMP‑9 to 45.15 and 66.65%, respectively. These results suggest that FBG has potential anti‑wrinkle effects as a potential ingredient in cosmetics.

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.

Antimelanogenesis Activity of Hydrolyzed Ginseng Extract (GINST) via Inhibition of JNK Mitogen-activated Protein Kinase in B16F10 Cells

GINST is a hydrolyzed ginseng extract produced by an in vitro process that imitates the metabolic function of bacteria in the human digestive track and has approved by the Ministry of Food and Drug Safety of Korea for the management of postprandial hyperglycemia. Additionally, GINST has been reported to have other physiological functions including anti-aging and antioxidant effects. The objectives of this study are to compare the antimelanogenic effects of fresh ginseng extract (FGE) and GINST extract and to elucidate the functional mechanism. The concentration of total ginsenosides in FGE and GINST was measured using ultraperformance liquid chromatography with a C18 column. B16F10 cells were treated with FGE and GINST for 72 h to assess melanin content, tyrosinase activity, and protein levels of microphthalmia-associated transcription factor (MITF) and tyrosinase-related protein-1 (TRP-1). The activity of kinases involved in mitogen-activated protein kinase (MAPK) signaling, such as extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and p38 mitogen-activated protein kinases (p38), were measured using western blots. While neither FGE nor GINST inhibited the activity of mushroom tyrosinase directly, GINST decreased melanogenesis and tyrosinase activity markedly. Furthermore, our results indicate that GINST downregulated the levels of MITF and TRP-1 possibly by suppressing JNK signaling. We concluded that, when compared to FGE, GINST has a superior antimelanogenic effect mediated by the downregulation of MITF, TRP-1, and intracellular tyrosinase activity via the JNK signaling pathway. Thus, we suggest that GINST has the potential to be used as a novel skin whitening agent.

Exogenous C2 Ceramide Suppresses Matrix Metalloproteinase Gene Expression by Inhibiting ROS Production and MAPK Signaling Pathways in PMA-Stimulated Human Astroglioma Cells

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases, which play a pivotal role in invasion, migration, and angiogenesis of glioma. Therefore, controlling MMPs is potentially an important therapeutic strategy for glioma. In the present study, we found that exogenous cell-permeable short-chain C2 ceramide inhibits phorbol myristate acetate (PMA)-induced MMP-1, -3, and -9 gene expressions in U87MG and U373MG human astroglioma cells. In addition, C2 ceramide inhibited the protein secretion and enzymatic activities of MMP-1, -3, and -9. The Matrigel invasion assay and wound healing assay showed that C2 ceramide suppresses the in vitro invasion and migration of glioma cells, which appears to be involved in strong inhibition of MMPs by C2 ceramide. Subsequent mechanistic studies revealed that C2 ceramide inhibits PMA-induced mitogen-activated protein kinase (MAPK) phosphorylation and nuclear factor (NF)-κB/activator protein (AP)-1 DNA binding activities. Furthermore, C2 ceramide significantly inhibited PMA-induced reactive oxygen species (ROS) production and NADPH oxidase 4 (NOX4) expression, and inhibition of ROS by diphenylene iodonium (DPI, NADPH oxidase inhibitor) mimicked the effects of C2 ceramide on MMP expression and NF-κB/AP-1 via inhibition of p38 MAPK. The results suggest C2 ceramide inhibits MMP expression and glioma invasion, at least partly, by modulating ROS-p38 MAPK signaling axis and other MAPK signaling pathways.

Compound K attenuates stromal cell-derived growth factor 1 (SDF-1)-induced migration of C6 glioma cells

BACKGROUND/OBJECTIVES

Stromal cell-derived growth factor 1 (SDF-1), also known as chemokine ligand 12, and chemokine receptor type 4 are involved in cancer cell migration. Compound K (CK), a metabolite of protopanaxadiol-type ginsenoside by gut microbiota, is reported to have therapeutic potential in cancer therapy. However, the inhibitory effect of CK on SDF-1 pathway-induced migration of glioma has not yet been established.

MATERIALS/METHODS

Cytotoxicity of CK in C6 glioma cells was determined using an EZ-Cytox cell viability assay kit. Cell migration was tested using the wound healing and Boyden chamber assay. Phosphorylation levels of protein kinase C (PKC)α and extracellular signal-regulated kinase (ERK) were measured by western blot assay, and matrix metallopeptidases (MMP) were measured by gelatin-zymography analysis.

RESULTS

CK significantly reduced the phosphorylation of PKCα and ERK1/2, expression of MMP9 and MMP2, and inhibited the migration of C6 glioma cells under SDF-1-stimulated conditions.

CONCLUSIONS

CK is a cell migration inhibitor that inhibits C6 glioma cell migration by regulating its downstream signaling molecules including PKCα, ERK1/2, and MMPs.

Effects of Korean red ginseng (Panax ginseng) on obesity and adipose inflammation in ovariectomized mice

ETHNOPHARMACOLOGICAL RELEVANCE

Korean red ginseng (ginseng, Panax ginseng C.A. Meyer) is a famous traditional drug used in Korea for the treatment and prevention of obesity, type 2 diabetes, cancer, and liver and cardiovascular diseases. Menopause is strongly associated with many of the aforementioned metabolic diseases and increased visceral obesity. The aims of this study were to investigate whether ginseng inhibits obesity and related disorders in ovariectomized (OVX) C57BL/6J mice, which is a mouse model of postmenopausal women, and to determine the mechanism of action involved in this process.

MATERIALS AND METHODS

After OVX mice were treated with 5% (w/w) ginseng for 15 weeks, we determined the effects of ginseng on obesity and adipose inflammation, angiogenesis, metalloproteinase (MMP) activity and metabolic parameters.

RESULTS

OVX mice had higher body weight, adipose tissue mass and adipocyte size when fed a high fat diet (HFD) compared with HFD-fed sham-operated mice. All of these parameters were significantly reduced in OVX mice fed a HFD supplemented with ginseng. Ginseng treatment also decreased blood vessel density, MMP activity, and mRNA levels of angiogenic factors (e.g., VEGF-A and FGF-2) and MMPs (e.g., MMP-2 and MMP-9) in adipose tissues of OVX mice. Infiltrating inflammatory cells and expression of inflammatory cytokines (e.g., CD68, TNFα and MCP-1) in adipose tissue were reduced by ginseng. Ginseng not only reduced the circulating levels of free fatty acids and triglycerides, but also normalized hyperinsulinemia and hyperglycemia in OVX mice. Hepatic lipid droplets were almost completely abolished by ginseng.

CONCLUSIONS

These results suggest that ginseng inhibited ovariectomy-induced obesity, adiposity, and adipocyte hypertrophy by modulating angiogenesis and MMP activity. Ginseng also suppressed adipose inflammation, insulin resistance, and hepatic steatosis in OVX mice. Thus, it is likely that ginseng may be a promising drug for the prevention and treatment of obesity and related disorders in obese postmenopausal women.

Recent advances in ginseng as cancer therapeutics: a functional and mechanistic overview

Cancer is one of the leading causes of death worldwide. Ginseng, a key ingredient in traditional Chinese medicine, shows great promise as a new treatment option. As listed by the U.S. National Institutes of Health as a complementary and alternative medicine, its anti-cancer functions are being increasingly recognized. This review covers the mechanisms of action of ginsenosides and their metabolites, which can modulate signaling pathways associated with inflammation, oxidative stress, angiogenesis, metastasis, and stem/progenitor-like properties of cancer cells. The emerging use of structurally modified ginsenosides and recent clinical studies on the use of ginseng either alone or in combination with other herbs or Western medicines which are exploited as novel therapeutic strategies will also be explored.

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.

Inhibitory mechanism of Korean Red Ginseng on GM-CSF expression in UVB-irradiated keratinocytes

Background

UV-irradiated keratinocytes secrete various proinflammatory cytokines. UV-induced skin damage is mediated by growth factors and proinflammatory cytokines such as granulocyte macrophage colony stimulating factor (GM-CSF). In a previous study, we found that the saponin of Korean Red Ginseng (SKRG) decreased the expression of GM-CSF in UVB-irradiated SP-1 keratinocytes. In this study, we attempted to find the inhibitory mechanism of SKRG on UVB-induced GM-CSF expression in SP-1 keratinocytes.

Methods

We investigated the inhibitory mechanism of SKRG and ginsenosides from Panax ginseng on UVB-induced GM-CSF expression in SP-1 keratinocytes.

Results

Treatment with SKRG decreased the expression of GM-CSF mRNA and protein induced by irradiation of UVB in SP-1 keratinocytes. The phosphorylation of ERK was induced by UVB at 10 min, and decreased with SKRG treatment in SP-1 keratinocytes. In addition, treatment with SKRG inhibited the UVB-induced phosphorylation of epidermal growth factor receptor (EGFR), which is known to be an upstream signal of ERK. From these results, we found that the inhibition of GM-CSF expression by SKRG was derived from the decreased phosphorylation of EGFR. To identify the specific compound composing SKRG, we tested fifteen kinds of ginsenosides. Among these compounds, ginsenoside-Rh3 decreased the expression of GM-CSF protein and mRNA in SP-1 keratinocytes.

Conclusion

Taken together, we found that treatment with SKRG decreased the phosphorylation of EGFR and ERK in UVB-irradiated SP-1 keratinocytes and subsequently inhibited the expression of GM-CSF. Furthermore, we identified ginsenoside-Rh3 as the active saponin in Korean Red Ginseng.

Hepatoprotective effect of fermented ginseng and its major constituent compound K in a rat model of paracetamol (acetaminophen)-induced liver injury

Objectives

This work aimed at evaluating the effect of fermented ginseng (FG) and fermented red ginseng (FRG) against rat liver injury caused by paracetamol (acetaminophen (APAP)).

Methods

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum and histopathological changes in the liver were analysed to determine the degree of liver injury. Deoxyribonucleic acid (DNA) microarray analysis was performed to compare gene expression levels altered in the rat livers. Phosphorylated Jun-N-terminal kinase (JNK) in human hepatocellular carcinoma (HepG2) cells were detected using western blot analysis to investigate the anti-inflammatory activity of compound K.

Key findings

Pretreatment with FG, containing compound K at high concentration, attenuated AST as well as ALT levels in rats, while no obvious effect was observed in the group that received FRG, whose content of compound K was lower than that of FG. In addition, the results of our histopathological analysis were consistent with changes in the serum biochemical analysis. DNA microarray analysis indicated that JNK- and glutathione S-transferase (GST)-related genes were involved in the hepatotoxicity. Notably, compound K, a major ginsenoside in FG, inhibited the phosphorylation of JNK in HepG2 cells.

Conclusions

FG was shown to possess hepatoprotective activity against paracetamol (APAP)-induced liver injury better than FRG. Compound K might play an important role for an anti-inflammatory activity of FG by inhibiting JNK signalling in the liver.

Therapeutic potential of Panax ginseng and ginsenosides in the treatment of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a major global health burden and will become the third largest cause of death in the world by 2030. It is currently believed that an exaggerated inflammatory response to inhaled irritants, in particular cigarette smoke, cause progressive airflow limitation. This inflammation, where macrophages, neutrophils and lymphocytes are prominent, leads to oxidative stress, emphysema, airways fibrosis and mucus hypersecretion. COPD responds poorly to current anti-inflammatory treatments including corticosteroids, which produce little or no benefit. Panax ginseng has a long history of use in Chinese medicine for respiratory conditions, including asthma and COPD.

OBJECTIVES

In this perspective we consider the therapeutic potential of Panax ginseng for the treatment of COPD.

RESULTS

Panax ginseng and its compounds, ginsenosides, have reported effects through multiple mechanisms but primarily have anti-inflammatory and anti-oxidative effects. Ginsenosides are functional ligands of glucocorticoid receptors and appear to inhibit kinase phosphorylation including MAPK and ERK1/2, NF-κB transcription factor induction/translocation, and DNA binding. They also inhibit pro-inflammatory mediators, TNF-α, IL-6, IL-8, ROS, and proteases such as MMP-9. Panax ginseng protects against oxidative stress by increasing anti-oxidative enzymes and reducing the production of oxidants.

CONCLUSION

Given that Panax ginseng and ginsenosides appear to inhibit processes related to COPD pathogenesis, they represent an attractive therapeutic target for the treatment of COPD.

Exogenous endothelin-1 induces cell migration and matrix metalloproteinase expression in U251 human glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common and lethal type of primary brain tumor characterized by its rapid infiltration to surrounding tissues during the early stages. The fast spreading of GBM obscures the initiation of the tumor mass making the treatment outcome undesirable. Endothelin-1 is known as a secretory protein presented in various types of brain cells, which has been indicated as a factor for cancer pathology. The aim of the present study was to investigate the molecular mechanism of cell migration in GBM. We found that various malignant glioma cells expressed higher amounts of endothelin-1, ETA, and ETB receptors than nonmalignant human astrocytes. The application of endothelin-1 enhanced the migratory activity in human U251 glioma cells corresponding to increased expression of matrix metalloproteinase (MMP)-9 and MMP-13. The endothelin-1-induced cell migration was attenuated by MMP-9 and MMP-13 inhibitors and inhibitors of mitogen-activated protein (MAP) kinase and PI3 kinase/Akt. Furthermore, the elevated levels of phosphate c-Jun accumulation in the nucleus and activator protein-1 (AP-1)-DNA binding activity were also found in endothelin-1 treated glioma cells. In migration-prone sublines, cells with greater migration ability showed higher endothelin-1, ETB receptor, and MMP expressions. These results indicate that endothelin-1 activates MAP kinase and AP-1 signaling, resulting in enhanced MMP-9 and MMP-13 expressions and cell migration in GBM.

AMP-activated protein kinase determines apoptotic sensitivity of cancer cells to ginsenoside-Rh2

Ginseng saponins exert various important pharmacological effects with regard to the control of many diseases, including cancer. In this study, the anticancer effect of ginsenosides on human cancer cells was investigated and compared. Among the tested compounds, ginsenoside-Rh2 displays the highest inhibitory effect on cell viability in HepG2 cells. Ginsenoside-Rh2, a ginseng saponin isolated from the root of Panax ginseng, has been suggested to have potential as an anticancer agent, but the underlying mechanisms remain elusive. In the present study, we have shown that cancer cells have differential sensitivity to ginsenoside-Rh2-induced apoptosis, raising questions regarding the specific mechanisms responsible for the discrepant sensitivity to ginsenoside-Rh2. In this study, we demonstrate that AMP-activated protein kinase (AMPK) is a survival factor under ginsenoside-Rh2 treatment in cancer cells. Cancer cells with acute responsiveness of AMPK display a relative resistance to ginsenoside-Rh2, but cotreatment with AMPK inhibitor resulted in a marked increase of ginsenoside-Rh2-induced apoptosis. We also observed that p38 MAPK (mitogen-activated protein kinase) acts as another survival factor under ginsenoside-Rh2 treatment, but there was no signaling crosstalk between AMPK and p38 MAPK, suggesting that combination with inhibitor of AMPK or p38 MAPK can augment the anticancer potential of ginsenoside Rh2.

Anti-Cancer Effect of Ginsenoside F2 against Glioblastoma Multiforme in Xenograft Model in SD Rats

The glioblastoma multiforme (GBM) is the most common malignant brain tumor in adults. Despite combination treatments of radiation and chemotherapy, the survival periods are very short. Therefore, this study was conducted to assess the potential of ginsenoside F₂ (F2) to treat GBM. In in vitro experiments with glioblastoma cells U373MG, F2 showed the cytotoxic effect with IC₅₀ of 50 μg/mL through apoptosis, confirmed by DNA condensation and fragmentation. The cell population of cell cycle sub-G1 as indicative of apoptosis was also increased. In xenograft model in SD rats, F2 at dosage of 35 mg/kg weight was intravenously injected every two days. This reduced the tumor growth in magnetic resonance imaging images. The immunohistochemistry revealed that the anticancer activity might be mediated through inhibition of proliferation judged by Ki67 and apoptosis induced by activation of caspase-3 and -8. And the lowered expression of CD31 showed the reduction in blood vessel densities. The expression of matrix metalloproteinase-9 for invasion of cancer was also inhibited. The cell populations with cancer stem cell markers of CD133 and nestin were reduced. The results of this study suggested that F2 could be a new potential chemotherapeutic drug for GBM treatment by inhibiting the growth and invasion of cancer.

Protopanaxatriol ginsenoside Rh1 inhibits the expression of matrix metalloproteinases and the in vitro invasion/migration of human astroglioma cells

Malignant gliomas are the most common and fatal brain tumors in adults. In particular, the strong invasiveness of glioma cells into the normal brain tissue makes eradication of glioma very difficult. Matrix metalloproteinases (MMPs) play a pivotal role in glioma invasion, and thus controlling MMP expression has been suggested as an important therapeutic target for brain tumors. In the present study, we investigated the effect of protopanaxatriol ginsenoside Rh1 on MMP expressions in human astroglioma U87MG and U373MG cells. RT-PCR analysis showed that Rh1 inhibits the mRNA expressions of MMP-1, -3, and -9 in PMA-stimulated U87MG and U373MG cells. Rh1 also suppressed the promoter activities of MMP-1, -3 and -9. The ELISA, Western blot, and zymographic analyses revealed that Rh1 inhibits the protein expression and/or enzymatic activity of MMP-1, -3 and -9. In accordance with the strong inhibitory effects of Rh1 on MMPs, Rh1 efficiently inhibited the invasion and migration of U87MG and U373MG glioma cells as demonstrated by Matrigel invasion assay and wound healing assay. Further mechanistic studies revealed that Rh1 inhibits MAPK and PI3K/Akt signaling pathways and downstream transcription factors such as NF-κB and AP-1, which play an important role in MMP gene expressions. The data collectively suggest that ginsenoside Rh1 may have a therapeutic potential for malignant gliomas.

Ginseng saponin metabolite 20(S)-protopanaxadiol inhibits tumor growth by targeting multiple cancer signaling pathways

Plant-derived active constituents and their semi-synthetic or synthetic analogs have served as major sources of anticancer drugs. 20(S)-protopanaxadiol (PPD) is a metabolite of ginseng saponin of both American ginseng (Panax quinquefolius L.) and Asian ginseng (Panax ginseng C.A. Meyer). We previously demonstrated that ginsenoside Rg3, a glucoside precursor of PPD, exhibits anti-proliferative effects on HCT116 cells and reduces tumor size in a xenograft model. Our subsequent study indicated that PPD has more potent antitumor activity than that of Rg3 in vitro although the mechanism underlying the anticancer activity of PPD remains to be defined. Here, we investigated the mechanism underlying the anticancer activity of PPD in human cancer cells in vitro and in vivo. PPD was shown to inhibit growth and induce cell cycle arrest in HCT116 cells. The in vivo studies indicate that PPD inhibits xenograft tumor growth in athymic nude mice bearing HCT116 cells. The xenograft tumor size was significantly reduced when the animals were treated with PPD (30 mg/kg body weight) for 3 weeks. When the expression of previously identified Rg3 targets, A kinase (PRKA) anchor protein 8 (AKAP8L) and phosphatidylinositol transfer protein α (PITPNA), was analyzed, PPD was shown to inhibit the expression of PITPNA while upregulating AKAP8L expression in HCT116 cells. Pathway-specific reporter assays indicated that PPD effectively suppressed the NF-κB, JNK and MAPK/ERK signaling pathways. Taken together, our results suggest that the anticancer activity of PPD in colon cancer cells may be mediated through targeting NF-κB, JNK and MAPK/ERK signaling pathways, although the detailed mechanisms underlying the anticancer mode of PPD action need to be fully elucidated.

Intestinal bacterial transformation - a nonnegligible part of Chinese medicine research

Intestinal bacteria play an essential part in the metabolism of the constituents of herbal drugs, and a lot of investigations have been done to unveil their functions and mechanisms in modification of these constituents and their effect. This review provides a progressive description of intestinal bacterial transformation with respect to properties, reactions, correlation with the effect of herbal drugs, research interests, and methodology. In addition, the problems encountered during the investigation are addressed and perspectives are proposed.

Compound K, a Ginsenoside Metabolite, Inhibits Colon Cancer Growth via Multiple Pathways Including p53-p21 Interactions

Compound K (20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol, CK), an intestinal bacterial metabolite of ginseng protopanaxadiol saponins, has been shown to inhibit cell growth in a variety of cancers. However, the mechanisms are not completely understood, especially in colorectal cancer (CRC). A xenograft tumor model was used first to examine the anti-CRC effect of CK in vivo. Then, multiple in vitro assays were applied to investigate the anticancer effects of CK including antiproliferation, apoptosis and cell cycle distribution. In addition, a qPCR array and western blot analysis were executed to screen and validate the molecules and pathways involved. We observed that CK significantly inhibited the growth of HCT-116 tumors in an athymic nude mouse xenograft model. CK significantly inhibited the proliferation of human CRC cell lines HCT-116, SW-480, and HT-29 in a dose- and time-dependent manner. We also observed that CK induced cell apoptosis and arrested the cell cycle in the G1 phase in HCT-116 cells. The processes were related to the upregulation of p53/p21, FoxO3a-p27/p15 and Smad3, and downregulation of cdc25A, CDK4/6 and cyclin D1/3. The major regulated targets of CK were cyclin dependent inhibitors, including p21, p27, and p15. These results indicate that CK inhibits transcriptional activation of multiple tumor-promoting pathways in CRC, suggesting that CK could be an active compound in the prevention or treatment of CRC.

Panax ginseng in randomised controlled trials: a systematic review

Panax ginseng C.A. Meyer is a common herb with many purported health benefits. However, there is no conclusive evidence supporting its use in the treatment of any particular disease. We conducted a systematic review to evaluate randomised controlled trials. Four English databases were searched with no publication date restriction. Included studies evaluated P. ginseng in patients with any type of disease or in healthy individuals. We assessed the quality of studies using the Cochrane risk of bias tool. Of the 475 potentially relevant studies, 65 met the inclusion criteria. These studies examined P. ginseng's effects on psychomotor performance (17 studies), physical performance (ten), circulatory system (eight), glucose metabolism (six), the respiratory system (five), erectile dysfunction (four), immunomodulation (four), quality of life/mood (four), antioxidant function (two), cancer (two), menopausal symptoms (two) and dry mouth (one). The risk of bias was unclear in most studies. Authors evaluated adverse events in 40 studies, with 135 minor events and no serious adverse events reported. P. ginseng shows promising results for improving glucose metabolism and moderating the immune response. This may have implications for several diseases including type 2 diabetes and chronic respiratory conditions. Further studies are needed to explore P. ginseng's potential as an effective treatment for these and other health conditions.

Metabolism of ginseng and its interactions with drugs

Ginseng is an herbal medicine used worldwide. It is reported to have a wide range of pharmacological activities because of a diversified group of steroidal saponins called ginsenosides. Compared to extensive pharmacological studies of ginseng, the pharmacokinetics, especially the metabolism of this herb, has received less attention. In this article we review the known pharmacokinetic data on ginseng. Understanding ginseng's pharmacokinetics may reduce the potential for interactions in patients who use both ginseng and prescription medications. In addition, bioavailability after taking ginseng orally is low, and the metabolites of ginsenosides produced by gut microbiota may be biologically active. One ginseng metabolite, Compound K, and its potential for cancer chemoprevention is also discussed. An active ginseng metabolite may differ in distribution and clearance from its parent compound, and the parent compound and its metabolite may be bioactive by similar or different mechanisms. Thus, further investigation of ginseng metabolites is needed for predicting the therapeutic outcome with ginseng.

Intestinal metabolite compound K of panaxoside inhibits the growth of gastric carcinoma by augmenting apoptosis via Bid-mediated mitochondrial pathway

Compound K (20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol, CK), an intestinal bacterial metabolite of panaxoside, has been shown to inhibit tumour growth in a variety of tumours. However, the mechanisms involved are largely unknown. We use human gastric carcinoma cell lines BGC823, SGC7901 and human gastric carcinoma xenograft in nude mice as models to study the mechanisms of CK in gastric cancers. We found that CK significantly inhibits the viabilities of BGC823 and SGC7901 cells in dose- and time-dependent manners. CK-induced BGC823 and SGC7901 cells apoptosis and cell cycle arrest in G2 phase by up-regulation of p21 and down-regulation of cdc2 and cyclin B1. Further studies show that CK induces apoptosis in BGC823 and SGC7901 cells mainly through mitochondria-mediated internal pathway, and that CK induces the translocation of nuclear Bid to mitochondria. Finally, we found that CK effectively inhibited the tumour formation of SGC7901 cells in nude mice. Our studies show that CK can inhibit the viabilities and induce apoptosis of human gastric carcinoma cells via Bid-mediated mitochondrial pathway.

Selective inhibition of MMP-9 gene expression by mangiferin in PMA-stimulated human astroglioma cells: involvement of PI3K/Akt and MAPK signaling pathways

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases which play a key role in invasion, migration, and angiogenesis of astrogliomas and other malignant tumors. Thus, controlling MMPs has been considered an important therapeutic strategy for prevention and/or treatment of gliomas. However, most MMP inhibitors developed so far are broad spectrum inhibitors; thus, it is necessary to develop a selective MMP inhibitor to minimize potential side effects. In the present study, we found that mangiferin, a glucosylxanthone isolated from Anemarrhena asphodeloides, specifically inhibited MMP-9 gene expression in phorbol myristate acetate (PMA)-stimulated human astroglioma U87MG, U373MG, and CRT-MG cells. However, it did not affect other MMPs, such as MMP-1, -2, -3, and -14. Mangiferin suppressed MMP-9 expression at the promoter, mRNA, and protein levels and additionally inhibited MMP-9 enzymatic activity. The Matrigel-invasion assay showed that mangiferin suppresses the in vitro invasiveness of glioma cells, which appears to be correlated with mangiferin-mediated MMP-9 inhibition. Further mechanistic studies demonstrated that mangiferin inhibits the binding of NF-κB and AP-1 to the MMP-9 promoter and suppresses the PMA-induced phosphorylation of Akt and MAP kinases, which are upstream signaling molecules in MMP-9 expression. Thus, the specific inhibition of MMP-9 by mangiferin may provide a valuable pharmacological tool for treatment of gliomas.

Ginsenosides as Anticancer Agents: In vitro and in vivo Activities, Structure-Activity Relationships, and Molecular Mechanisms of Action

Conventional chemotherapeutic agents are often toxic not only to tumor cells but also to normal cells, limiting their therapeutic use in the clinic. Novel natural product anticancer compounds present an attractive alternative to synthetic compounds, based on their favorable safety and efficacy profiles. Several pre-clinical and clinical studies have demonstrated the anticancer potential of Panax ginseng, a widely used traditional Chinese medicine. The anti-tumor efficacy of ginseng is attributed mainly to the presence of saponins, known as ginsenosides. In this review, we focus on how ginsenosides exert their anticancer effects by modulation of diverse signaling pathways, including regulation of cell proliferation mediators (CDKs and cyclins), growth factors (c-myc, EGFR, and vascular endothelial growth factor), tumor suppressors (p53 and p21), oncogenes (MDM2), cell death mediators (Bcl-2, Bcl-xL, XIAP, caspases, and death receptors), inflammatory response molecules (NF-κB and COX-2), and protein kinases (JNK, Akt, and AMP-activated protein kinase). We also discuss the structure–activity relationship of various ginsenosides and their potentials in the treatment of various human cancers. In summary, recent advances in the discovery and evaluation of ginsenosides as cancer therapeutic agents support further pre-clinical and clinical development of these agents for the treatment of primary and metastatic tumors.

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.