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

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.

Ginseng extract and ginsenosides improve neurological function and promote antioxidant effects in rats with spinal cord injury: A meta-analysis and systematic review

Spinal cord injury (SCI) is defined as damage to the spinal cord that temporarily or permanently changes its function. There is no definite treatment established for neurological complete injury patients. This study investigated the effect of ginseng extract and ginsenosides on neurological recovery and antioxidant efficacies in rat models following SCI and explore the appropriate dosage. Searches were done on PubMed, Embase, and Chinese databases, and animal studies matches the inclusion criteria were selected. Pair-wise meta-analysis and subgroup analysis were performed. Ten studies were included, and the overall methodological qualities were low quality. The result showed ginseng extract and ginsenosides significantly improve neurological function, through the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale (pooled MD = 4.40; 95% CI = 3.92 to 4.88; p < 0.00001), significantly decrease malondialdehyde (MDA) (n = 290; pooled MD = −2.19; 95% CI = −3.16 to −1.22; p < 0.0001) and increase superoxide dismutase (SOD) levels (n = 290; pooled MD = 2.14; 95% CI = 1.45 to 2.83; p < 0.00001). Both low (<25 mg/kg) and high dosage (≥25 mg/kg) showed significant improvement in the motor function recovery in SCI rats. Collectively, this review suggests ginseng extract and ginsenosides has a protective effect on SCI, with good safety and a clear mechanism of action and may be suitable for future clinical trials and applications.

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.

•

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

•

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

•

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

Ginsenoside Rh2 stimulates the production of mitochondrial reactive oxygen species and induces apoptosis of cervical cancer cells by inhibiting mitochondrial electron transfer chain complex

Ginsenoside Rh2 (G-Rh2) is a monomeric compound that extracted from ginseng and possesses anti-cancer activities both in vitro and in vivo. Previously, we reported that G-Rh2 induces apoptosis in HeLa cervical cancer cells and that the process was related to reactive oxygen species (ROS) accumulation and mitochondrial dysfunction. However, the upstream mechanisms of G-Rh2, along with its cellular targets, remain to be elucidated. In the present study, the Cell Counting Kit-8 assay, flow cytometry and Hoechst staining revealed that G-Rh2 significantly inhibited cell viability and induced apoptosis of cervical cancer cells. However, G-Rh2 was demonstrated to be non-toxic to End1/e6e7 cells. JC-1, rhodamine 123 staining, oxidative phosphorylation and glycolysis capacity assays demonstrated that G-Rh2 exposure caused an immediate decrease in mitochondrial transmembrane potential due to its inhibition of mitochondrial oxidative phosphorylation, as well as glycolysis, both of which reduced cellular ATP production. Western blotting and electron transport chain (ETC) activity assays revealed that G-Rh2 significantly inhibited the activity of ETC complexes I, III and V. Overexpression of ETC complex III partially significantly restored mitochondrial ROS and inhibited the apoptosis of cervical cancer cells induced by G-Rh2. The predicted results of binding energy in molecular docking, confirmed that G-Rh2 was highly likely to induce mitochondrial ROS production and promote cell apoptosis by targeting the ETC complex, especially for ETC complex III. Taken together, the present results revealed the potential anti-cervical cancer activity of G-Rh2 and provide direct evidence for the contribution of impaired ETC complex activity to cervical cancer cell death.

Anticancer Effects of Ginsenoside Rh2: A Systematic Review

BACKGROUND

As one of the effective pharmacological constituents of Ginseng Radix et Rhizoma, ginsenoside Rh2 (Rh2) exerts a remarkable anticancer effect on various cancer cell lines in vitro and strongly inhibits tumor growth in vivo without severe toxicity.

OBJECTIVE

This article reviewed existing evidence supporting the anticancer effects of Rh2 to classify and conclude previous and current knowledge on the mechanisms and therapeutic effects of Rh2, as well as to promote the clinical application of this natural product.

CONCLUSION

This article reviewed the anticancer efficacies and mechanisms of Rh2, including the induction of cell cycle arrest and programmed cell death, repression of metastasis, alleviation of drug resistance, and regulation of the immune system. Finally, this paper discussed the research and application prospects of Rh2.

PEI-assisted boronate affinity magnetic nanoparticle-based SELEX for efficient in vitro evolution of saponin-binding aptamers

Branched polyethyleneimine assisted boronate affinity magnetic nanoparticle-based aptamer evolution platform.

Anticancer property of ginsenoside Rh2 from ginseng

Ginseng has been used as a well-known traditional Chinese medicine since ancient times. Ginsenosides as its main active constituents possess a broad scope of pharmacological properties including stimulating immune function, enhancing cardiovascular health, increasing resistance to stress, improving memory and learning, developing social functioning and mental health in normal persons, and chemotherapy. Ginsenoside Rh2 (Rh2) is one of the major bioactive ginsenosides from Panax ginseng. When applied to cancer treatment, Rh2 not only exhibits the anti-proliferation, anti-invasion, anti-metastasis, induction of cell cycle arrest, promotion of differentiation, and reversal of multi-drug resistance activities against multiple tumor cells, but also alleviates the side effects after chemotherapy or radiotherapy. In the past decades, nearly 200 studies on Rh2 in the treatment of cancer have been published, however no specific reviews have been conducted by now. So the purpose of this review is to provide a systematic summary and analysis of the anticancer effects and the potential mechanisms of Rh2 extracted from Ginseng then give a future prospects about it. In the end of this paper the metabolism and derivatives of Rh2 also have been documented.

Dual boronate affinity nanoparticles-based plasmonic immunosandwich assay for specific and sensitive detection of ginsenosides

Ginsenoside is a large family of triterpenoid saponins from Panax ginseng with various important biological functions. It is crucial to develop effective analytical approach for qualitative and quantitative analysis of ginsenosides. Herein, a dual boronate affinity nanoparticles-based plasmonic immunosandwich assay has been developed for analysis of ginsenosides. An imprinted Au NPs-coated glass slide was prepared via controllable oriented surface imprinting and used as specific extraction substrate for target molecules. In the meantime, Ag-cored Raman nanotags were used for specific labeling of target molecules. The MIP-based recognitions ensured the specificity of the assay, while enhanced Raman signal derived from the imprinted substrate-target-nanotags sandwich-like complexes provided high sensitivity. The proposed immunosandwich assay exhibited wide linear range (10 ng/mL to 10 μg/mL), high sensitive (LOD: 1.7 ng/mL, LOQ: 5 ng/mL) and good reproducibility (RSD: 8.6%). For real-world applications, successful quantitative analysis of ginsenoside Re in ginseng was performed. Therefore, this dual boronate affinity nanoparticles-based plasmonic immunosandwich assay holds great promise in many important applications such as pharmaceutical analysis.

Identification of cancer prognosis-associated lncRNAs based on the miRNA-TF co-regulatory motifs and dosage sensitivity

By integrating dosage sensitivity and motif regulation data, we established a framework and identified a total of 33 cancer prognosis-associated lncRNAs.

Galla Rhois water extract inhibits lung metastasis by inducing AMPK‑mediated apoptosis and suppressing metastatic properties of colorectal cancer cells

Galla Rhois is a commonly used medicine in East Asia for the treatment of several diseases. However, the effects of Galla Rhois on the metastasis of colorectal cancer (CRC) and the underlying molecular mechanisms have not been studied. We investigated the anti-metastatic properties of Galla Rhois water extract (GRWE) on metastatic CRC cells. The effect of GRWE on the viability of colon 26 (CT26) cells was evaluated using WST-8 assay. Annexin V assay and western blot analysis were performed to elucidate the underlying molecular mechanisms involved in apoptosis. GRWE suppressed viability of CT26 cells by inducing apoptosis through the cleavage of caspase-3 and PARP, downregulation of caspase-8, caspase-9, Bcl-2 and Bcl-xL, and upregulation of Bax. Metastatic phenotypes such as epithelial-mesenchymal transition (EMT), migration, and invasion of CRC cells were investigated by real-time reverse transcription polymerase chain reaction, wound healing assay, and matrigel invasion assay, respectively. Non-cytotoxic concentrations of GRWE inhibited EMT in CRC cells by regulating the expression of EMT markers. GRWE attenuated cell migration and invasion through the inhibition of matrix metalloproteinase (MMP)-2 and MMP-9 activity. Moreover, GRWE suppressed colorectal lung metastasis in vivo, suggestive of its potential application for the treatment of colorectal metastasis.

Ginsenosides: the need to move forward from bench to clinical trials

Panax ginseng, known as Koran ginseng, one of the most commonly used traditional plants, has been demonstrated to show a wide range of pharmacological applications. Ginsenosides are the major active ingredients found in ginseng and are responsible for the biological and pharmacological activities, such as antioxidation, antiinflammation, vasorelaxation, and anticancer actions. Existing studies have mostly focused on identifying and purifying single ginsenosides and investigating pharmacological activities and molecular mechanisms in cells and animal models. However, ginsenoside studies based on clinical trials have been very limited. Therefore, this review aimed to discuss the currently available clinical trials on ginsenosides and provide insights and future directions for developing ginsenosides as efficacious and safe drugs for human disease.

Gomisin A Suppresses Colorectal Lung Metastasis by Inducing AMPK/p38-Mediated Apoptosis and Decreasing Metastatic Abilities of Colorectal Cancer Cells

Gomisin A (G.A) is a dietary lignan compound from Schisandra chinensis. In this study, the effect of G.A on the proliferation and metastasis of colorectal cancer (CRC) cells was investigated using several CRC cell lines and a lung metastasis mouse model. Both oral and intraperitoneal administration of G.A (50 mg/kg) inhibited lung metastasis of CT26 cells. Various concentrations of G.A were incubated with CRC cell lines and their viability was determined using a cell counting kit-8 assay. G.A significantly decreased the viability of various CRC cell lines, whereas it did not change the proliferation of normal colon cells. G.A induced G0/G1 phase arrest and apoptosis of CT26 and HT29 cells by regulating cyclin D1/cyclin-dependent kinase 4 (CDK4) expression and apoptotic proteins such as caspases and B-cell lymphoma-2 (Bcl-2) family proteins, respectively. G.A-induced apoptosis was mediated by AMPK/p38 activation in CRC cells. A non-cytotoxic concentration of G.A inhibited epithelial–mesenchymal transition of CRC cells by modulating E-cadherin and N-cadherin expression levels. Moreover, the migration and invasion of CRC cells were reduced by G.A treatment. Especially, G.A decreased matrix metalloproteinase (MMP)-2 and MMP-9 expressions and activities. G.A ameliorated lung metastasis of CRC cells by decreasing cell survival and metastatic abilities of CRC cells. Thus, G.A might be a potential novel therapeutic agent for metastatic CRC.

Ginsenosides synergize with mitomycin C in combating human non-small cell lung cancer by repressing Rad51-mediated DNA repair

The use of ginseng extract as an adjuvant for cancer treatment has been reported in both animal models and clinical applications, but its molecular mechanisms have not been fully elucidated. Mitomycin C (MMC), an anticancer antibiotic used as a first- or second-line regimen in the treatment for non-small cell lung carcinoma (NSCLC), causes serious adverse reactions when used alone. Here, by using both in vitro and in vivo experiments, we provide evidence for an optimal therapy for NSCLC with total ginsenosides extract (TGS), which significantly enhanced the MMC-induced cytotoxicity against NSCLC A549 and PC-9 cells in vitro when used in combination with relatively low concentrations of MMC. A NSCLC xenograft mouse model was used to confirm the in vivo synergistic effects of the combination of TGS with MMC. Further investigation revealed that TGS could significantly reverse MMC-induced S-phase cell cycle arrest and inhibit Rad51-mediated DNA damage repair, which was evidenced by the inhibitory effects of TGS on the levels of phospho-MEK1/2, phospho-ERK1/2 and Rad51 protein and the translocation of Rad51 from the cytoplasm to the nucleus in response to MMC. In summary, our results demonstrate that TGS could effectively enhance the cytotoxicity of MMC against NSCLC cells in vitro and in vivo, thereby revealing a novel adjuvant anticancer mechanism of TGS. Combined treatment with TGS and MMC can significantly lower the required concentration of MMC and can further reduce the risk of side effects, suggesting a better treatment option for NSCLC patients.

Ginsenoside Rh2 inhibits prostate cancer cell growth through suppression of microRNA-4295 that activates CDKN1A

OBJECTIVES

Ginsenoside Rh2 (GRh2) has demonstrative therapeutic effects on a variety of diseases, including some tumours. However, the effects of GRh2 on prostate cancer (PC) cell growth remain unknown, and were, thus, addressed in the present study.

MATERIALS AND METHODS

PC3 and DU145 PC cell lines were exposed to GRh2. Cell proliferation was assessed in an MTT assay and by BrdU incorporation. Apoptosis of the cells were assessed by TUNEL staining. Total RNA was assessed by RT-qPCR. Protein levels were assessed by Western blotting. Bioinformatics and dual luciferase reporter assay were applied to determine the functional binding of miRNA to mRNA of target gene.

RESULTS

GRh2 dose-dependently decreased PC cell proliferation, but did not alter cell apoptosis. Mechanistically, GRh2 dose-dependently increased the protein, but not mRNA of a cell-cycle suppressor CDKN1A in PC cells, suggesting the presence of microRNA (miRNA)-mediated protein translation control of CDKN1A by GRh2. In all candidate miRNAs that bind to 3'-UTR of CDKN1A, miR-4295 was specifically found to be suppressed dose-dependently by GRh2 in PC cells. Moreover, miR-4295 bound CDKN1A to suppress its protein translation. Furthermore, cell proliferation in PC cells that overexpressed miR-4295 did not alter in response to GRh2.

CONCLUSIONS

GRh2 may inhibit PC cell growth through suppression of microRNA-4295 that activates CDKN1A.

Role of ginsenosides in reactive oxygen species-mediated anticancer therapy

Cancer is still a global public health problem, which is the leading cause of death in most countries. Ginseng has been used for centuries all over the world as a panacea that promotes longevity. As the king of herb plants, ginseng holds great promise as a new treatment option which is used either by itself or in combination with other medicinal ingredients that is widely accepted as complementary and alternative medicine in cancer therapy. Ginsenosides, the major pharmacologically active ingredients of ginseng, have been shown to have multiple medicinal effects including prominent anticancer activity. The purpose of this review is to give our perspective about the roles of ginsenosides in reactive oxygen species (ROS)-mediated anticancer therapy. Additionally, to provide new sheds light for further improvement and carry out pre-clinical and clinical trials to develop it successfully into a potential anticancer agent. Panax herbs and their derivate/metabolites ginsenosides exert beneficial effects for treating various types of cancers. The mechanism of ROS-mediated anticancer activities of ginsenosides varies depending on the specific type of cancer cells involved. Ginsenosides may suppress cancer cell proliferation through anti-oxidation on tumor initiation and induce apoptosis, paraptosis or autophagy via generation of ROS on tumor progression, promotion, angiogenesis, invasion and metastasis by various signaling pathways e.g., activation of AMPK, MEK, ASK-1/JNK, ESR2-NCF1-ROS, ER-dependent PI3K/Akt/Nrf2, P53-CHOP, ROS-JNK-autophagy, and/or inhibition of PI3K/Akt signaling pathways. These multiple effects rather than a single may play a crucial role in emerging ginsenosides as a successful anticancer drug.

Inhibition of autophagy potentiates anticancer property of 20(S)-ginsenoside Rh2 by promoting mitochondria-dependent apoptosis in human acute lymphoblastic leukaemia cells

Acute lymphoblastic leukaemia (ALL) is the most prevalent childhood malignancy. Although most children with ALL are cured, there is still a group of patients for which therapy fails owing to severe toxicities and drug resistance. Ginsenoside Rh2 (GRh2), a major bioactive component isolated from Panax ginseng, has been shown to have a therapeutic effect on some tumors. However, the molecular mechanisms of cell death induced by 20(S)-GRh2 in ALL cells remains unclear. In this study, we showed that 20(S)-GRh2 inhibited the cell growth and induced mitochondria-dependent apoptosis and autophagy. But it has no cytotoxic effect on human normal blood cells. Furthermore, autophagy plays a protective role in 20(S)-GRh2-induced apoptosis in ALL cell lines and human primary ALL cells. We demonstrated that either genetic or pharmacologic inhibition of autophagy could be more effective in reducing viability and enhancing 20(S)-GRh2-induced toxicity than 20(S)-GRh2 treatment alone. In addition, inhibition of autophagy could aggravate mitochondrial ROS generation and mitochondrial damage, and then accelerate mitochondria-dependent apoptosis. Taken together, these results suggest that inhibition of autophagy can sensitize ALL cells towards 20(S)-GRh2. The appropriate inhibition of autophagy could provide a powerful strategy to increase the potency of 20(S)-GRh2 as a novel anticancer agent for ALL therapy.

Towards natural mimetics of metformin and rapamycin

Aging is now at the forefront of major challenges faced globally, creating an immediate need for safe, widescale interventions to reduce the burden of chronic disease and extend human healthspan. Metformin and rapamycin are two FDA-approved mTOR inhibitors proposed for this purpose, exhibiting significant anti-cancer and anti-aging properties beyond their current clinical applications. However, each faces issues with approval for off-label, prophylactic use due to adverse effects. Here, we initiate an effort to identify nutraceuticals-safer, naturally-occurring compounds-that mimic the anti-aging effects of metformin and rapamycin without adverse effects. We applied several bioinformatic approaches and deep learning methods to the Library of Integrated Network-based Cellular Signatures (LINCS) dataset to map the gene- and pathway-level signatures of metformin and rapamycin and screen for matches among over 800 natural compounds. We then predicted the safety of each compound with an ensemble of deep neural network classifiers. The analysis revealed many novel candidate metformin and rapamycin mimetics, including allantoin and ginsenoside (metformin), epigallocatechin gallate and isoliquiritigenin (rapamycin), and withaferin A (both). Four relatively unexplored compounds also scored well with rapamycin. This work revealed promising candidates for future experimental validation while demonstrating the applications of powerful screening methods for this and similar endeavors.

20(S)-Ginsenoside Rh2 suppresses proliferation and migration of hepatocellular carcinoma cells by targeting EZH2 to regulate CDKN2A-2B gene cluster transcription

20(S)-Ginsenoside Rh2 (20(S)-GRh2) exerts important pharmacological effects with regard to the control of human hepatocellular carcinoma (HCC). EZH2 is a potent histone methyltransferase of H3K27me³, which has been determined as an oncogene in many malignancies. The CDKN2A-2B gene cluster encodes three important tumor suppressors, P14, P15 and P16. In this study, the anticancer effect and molecular mechanism of 20(S)-GRh2 on HCC was investigated. Treatment of HCC cells with 20(S)-GRh2 inhibited cell proliferation, migration and induced cell cycle arrest at the G0/G1 phase, and inhibited tumor growth in vivo. We demonstrate for the first time that this effect was specifically mediated by down-regulating expression of EZH2. Further molecular mechanism study indicated that the decreased EZH2 promoted P14, P15 and P16 gene transcription through reducing H3K27me³ modification in the promoter of CDKN2A-2B gene cluster loci. Similarly, silencing of EZH2 by siRNA down-regulated P14, P15, P16 mRNA levels and inhibited HCC cell proliferation. Our results suggested that EZH2 could be a potentially therapeutic target by 20(S)-GRh2 in HCC, which provided a rationale for the development of drugs that inhibited histone methylase as a strategy against various cancers.

Effect of Korean Red Ginseng extract on colorectal lung metastasis through inhibiting the epithelial-mesenchymal transition via transforming growth factor-β1/Smad-signaling-mediated Snail/E-cadherin expression

Background

In colorectal cancer (CRC), 40-60% of patients develop metastasis. The epithelial-mesenchymal transition (EMT) is a pivotal and intricate process that increases the metastatic potential of CRC. The aim of this study was to investigate the effect of Korean Red Ginseng extract (RGE) on colorectal metastasis through inhibition of EMT and the metastatic abilities of CRC cells.

Methods

To investigate the effect of RGE on the metastatic phenotypes of CRC cells, CT26 and HT29 cells were evaluated by using an adhesion assay, a wound-healing assay, an invasion assay, zymography, and real-time reverse transcription-polymerase chain reaction. Western-blot analysis was conducted to elucidate the molecular mechanisms of RGE, which showed an inhibitory effect on the transforming growth factor-β1 (TGF-β1)-induced EMT in HT29 cells. Additionally, the antimetastatic effect of RGE was evaluated in a mouse model of lung metastasis injected with CT26 cells.

Results

RGE decreased the adhesion and migration ability of the CT26 cells and TGF-β1-treated HT29 cells. The invasion ability was also reduced by RGE treatment through the inhibition of matrix metalloproteinase-9 expression and activity. Moreover, RGE suppressed the TGF-β1-induced EMT via TGF-β1/Smad-signaling-mediated Snail/E-cadherin expression in HT29 cells and lung tissue in CT26 tumor-bearing mice.

Conclusion

Our results demonstrated that RGE inhibited colorectal lung metastasis through a reduction in metastatic phenotypes, such as migration, invasion, and the EMT of CRC cells.

Functional role of ginseng-derived compounds in cancer

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

Octyl Ester of Ginsenoside Rh2 Induces Apoptosis and G1 Cell Cycle Arrest in Human HepG2 Cells by Activating the Extrinsic Apoptotic Pathway and Modulating the Akt/p38 MAPK Signaling Pathway

Ginsenoside Rh2 is a potential active metabolite of ginseng that has antitumor activity against a variety of tumor cells. Previously, we reported that Rh2-O, an octyl ester derivative of ginsenoside Rh2, had a higher anticancer activity than Rh2 through activating the intrinsic apoptotic pathway. In this study, we found that the extrinsic apoptotic pathway was also involved in Rh2-O-induced HepG2 cells apoptosis as evidenced by the up-regulation of Fas, FasL, TNFR1, and TNF-α as well as the cleavage of caspase 8. Moreover, flow cytometric analysis demonstrated that Rh2-O induced G1 cell cycle arrest in HepG2 cells. Rh2-O-induced G1 phase arrest was accompanied by the down-regulation of cyclin D3 and cyclin E and cyclin-dependent kinases (CDK) 4 and 6 and the up-regulation of p21^WAF1/CIP1 and p27^KIP1. In addition, Rh2-O down-regulated the phosphorylation of Akt, and its inhibitor LY294002 promoted Rh2-O-induced G1 phase arrest. Rh2-O treatment also activated p38 MAPK, JNK, and ERK expression. Inhibitors of p38 MAPK (SB203580), but not those of JNK (SP600125) or ERK (PB98095), promoted Rh2-O-induced G1 phase arrest in HepG2 cells. These results indicated that the disruption of Akt and p38 MAPK cascades played a pivotal role in Rh2-O-induced G1 phase arrest.

A ROS-mediated lysosomal-mitochondrial pathway is induced by ginsenoside Rh2 in hepatoma HepG2 cells

Ginsenoside Rh2 (GRh2), isolated from Panax ginseng C. A. Meyer, has been proven as an anticancer compound both in vitro and in vivo. In the present study, we investigated the role of the lysosomes during the apoptosis of HepG2 cells induced by GRh2. The results showed that GRh2 significantly induced intracellular reactive oxygen species (ROS) generation in the HepG2 cells, which consequently resulted in early lysosomal membrane permeabilization with the release of cathepsin B (Cat B) to the cytosol. Western blot analysis showed that the released Cat B in the cytosol contributed to Bid cleavage. Subsequently mitochondrial damage was observed in the HepG2 cells. Interestingly, when the HepG2 cells were pre-treated with N-Acetyl-L-Cysteine (NAC) for 1 h, which inhibited ROS generation before being exposed to GRh2, the permeabilization of lysosomal membranes and the levels of Cat B in the cytosol were down-regulated. Moreover, mitochondrial damage was alleviated when the HepG2 cells were pre-treated with leupeptin (Leu). From the above results, it could be concluded that GRh2 induced apoptosis of the HepG2 cells through accumulation of ROS and activation of the lysosomal-mitochondrial apoptotic pathway involving the release of Cat B.

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.

20(S)-ginsenoside Rh2 inhibits the proliferation and induces the apoptosis of KG-1a cells through the Wnt/β-catenin signaling pathway

Previous research has shown that total saponins of Panax ginseng (TSPG) and other ginsenoside monomers inhibit the proliferation of leukemia cells. However, the effect has not been compared among them. Cell viability was determined by Cell Counting Kit-8 assay, and ultra-structural characteristics were observed under transmission electron microscopy. Cell cycle distribution and apoptosis were determined by flow cytometry (FCM). Real-time fluorescence quantitative‑PCR, western blotting and immunofluorescence were used to measure the expression of β-catenin, TCF4, cyclin D1 and NF-κBp65. β-catenin/TCF4 target gene transcription were observed by ChIP-PCR assay. We found that 20(S)-ginsenoside Rh2 [(S)Rh2] inhibited the proliferation of KG-1a cells more efficiently than the other monomers. Moreover, (S)Rh2 arrested KG-1a cells in the G0/G1 phase and induced apoptosis. In addition, the levels of β-catenin, TCF4, cyclin D1 mRNA and protein were decreased. The ChIP-PCR showed that (S)Rh2 downregulated the transcription of β-catenin/TCF4 target genes, such as cyclin D1 and c-myc. These results indicated that (S)Rh2 induced cell cycle arrest and apoptosis through the Wnt/β-catenin signaling pathway, demonstrating its potential as a chemotherapeutic agent for leukemia therapy.

The Octyl Ester of Ginsenoside Rh2 Induces Lysosomal Membrane Permeabilization via Bax Translocation

Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O), has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu) and Cat D inhibitor (pepA) inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p < 0.05) in lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome.

Anti-Proliferative and Pro-Apoptotic Activities of 4-Methyl-2,6-bis(1-phenylethyl)phenol in Cancer Cells

It has been found that 4-isopropyl-2,6-bis(1-phenylethyl)phenol (KTH-13), a novel compound isolated from Cordyceps bassiana, is able to suppress tumor cell proliferation by inducing apoptosis. To mass-produce this compound, we established a total synthesis method. Using those conditions, we further synthesized various analogs with structural similarity to KTH-13. In this study, we aimed to test their anti-cancer activity by measuring anti-proliferative and pro-apoptotic activities. Of 8 compounds tested, 4-methyl-2,6-bis(1-phenylethyl)phenol (KTH-13-Me) exhibited the strongest anti-proliferative activity toward MDA-MB 231 cells. KTH-13-Me also similarly suppressed the survival of various cancer cell lines, including C6 glioma, HCT-15, and LoVo cells. Treatment of KTH-13-Me induced several apoptotic signs in C6 glioma cells, such as morphological changes, induction of apoptotic bodies, and nuclear fragmentation and chromatin condensation. Concordantly, early-apoptotic cells were also identified by staining with FITC-Annexin V/PI. Moreover, KTH-13-Me highly enhanced the activation of caspase-3 and caspase-9, and decreased the protein level of Bcl-2. In addition, the phosphorylation levels of Src and STAT3 were diminished in KTH-13-Me-treated C6 cells. Therefore, these results suggest that KTH-13-Me can be developed as a novel anti-cancer drug capable of blocking proliferation, inducing apoptosis, and blocking cell survival signaling in cancer cells.

Esterification of Ginsenoside Rh2 Enhanced Its Cellular Uptake and Antitumor Activity in Human HepG2 Cells

Our previous research had indicated that the octyl ester derivative of ginsenoside Rh2 (Rh2-O) might have a higher bioavailability than Rh2 in the Caco-2 cell line. The aim of this study was to investigate the cellular uptake and antitumor effects of Rh2-O in human HepG2 cells as well as its underlying mechanism compared with Rh2. Results showed that Rh2-O exhibited a higher cellular uptake (63.24%) than Rh2 (36.76%) when incubated with HepG2 cells for 24 h. Rh2-O possessed a dose- and time-dependent inhibitory effect against the proliferation of HepG2 cells. The IC50 value of Rh2-O for inhibition of HepG2 cell proliferation was 20.15 μM, which was roughly half the value of Rh2. Rh2-O induced apoptosis of HepG2 cells through a mitochondrial-mediated intrinsic pathway. In addition, the accumulation of ROS was detected in Rh2-O-treated HepG2 cells, which participated in the apoptosis of HepG2 cells. Conclusively, the findings above all suggested that Rh2-O as well as Rh2 inducing HepG2 cells apoptosis might involve similar mechanisms; however, Rh2-O had better antitumor activities than Rh2, probably due to its higher cellular uptake.

Regulation of AMP-activated protein kinase by natural and synthetic activators

The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that is almost universally expressed in eukaryotic cells. While it appears to have evolved in single-celled eukaryotes to regulate energy balance in a cell-autonomous manner, during the evolution of multicellular animals its role has become adapted so that it also regulates energy balance at the whole body level, by responding to hormones that act primarily on the hypothalamus. AMPK monitors energy balance at the cellular level by sensing the ratios of AMP/ATP and ADP/ATP, and recent structural analyses of the AMPK heterotrimer that have provided insight into the complex mechanisms for these effects will be discussed. Given the central importance of energy balance in diseases that are major causes of morbidity or death in humans, such as type 2 diabetes, cancer and inflammatory disorders, there has been a major drive to develop pharmacological activators of AMPK. Many such activators have been described, and the various mechanisms by which these activate AMPK will be discussed. A particularly large class of AMPK activators are natural products of plants derived from traditional herbal medicines. While the mechanism by which most of these activate AMPK has not yet been addressed, I will argue that many of them may be defensive compounds produced by plants to deter infection by pathogens or grazing by insects or herbivores, and that many of them will turn out to be inhibitors of mitochondrial function.

Synergistic Anticancer Activities of Natural Substances in Human Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is highly resistant to currently available chemotherapeutic agents. The clinical outcome of HCC treatment remains unsatisfactory. Therefore, new effective and well-tolerated therapy strategies are needed. Natural products are excellent sources for the development of new medications for disease treatment. Recently, we and other researchers have suggested that the combined effect of natural products may improve the effect of chemotherapy treatments against the proliferation of cancer cells. In addition, many combination treatments with natural products augmented intracellular reactive oxygen species (ROS). In this review we will demonstrate the synergistic anticancer effects of a combination of natural products with chemotherapeutic agents or natural products against human HCC and provide new insight into the development of novel combination therapies against HCC.

Flavisolibacter ginsenosidimutans sp. nov., with ginsenoside-converting activity isolated from soil used for cultivating ginseng

A Gram-reaction-negative, aerobic, non-motile and rod-shaped bacterial strain designated Gsoil 636T was isolated from soil of a ginseng cultivation field in Pocheon Province, South Korea and its taxonomic position was investigated using a polyphasic approach. Gsoil 636T grew at 18-30 °C and at pH 6.0-8.0 on R2A medium. Gsoil 636T possessed β-glucosidase activity, which was responsible for its ability to transform ginsenoside Rb1 (ones of the dominant active components of ginseng) to F2. On the basis of 16S rRNA gene sequence similarity, Gsoil 636T was shown to belong to the family Chitinophagaceae and to be related to Flavisolibacter ginsengiterrae Gsoil 492T (96.7 % sequence similarity), Flavisolibacter ginsengisoli Gsoil 643T (96.6 %) and Flavisolibacter rigui 02SUJ3T (96.6 %). The G+C content of the genomic DNA was 48.9 %. The predominant respiratory quinone was MK-7 and the major fatty acids were iso-C15 : 0, summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c) and iso-C17 : 0 3-OH. DNA and chemotaxonomic data supported the affiliation of Gsoil 636T to the genus Flavisolibacter. Gsoil 636T could be differentiated genotypically and phenotypically from the species of the genus Flavisolibacter with validly published names. The isolate therefore represents a novel species, for which the name Flavisolibacter ginsenosidimutans sp. nov. is proposed, with the type strain Gsoil 636T (KCTC 22818T = JCM 18197T = KACC 14277T).

Research Progress on Natural Triterpenoid Saponins in the Chemoprevention and Chemotherapy of Cancer

Triterpenoid saponins are glycosides with remarkable structural and bioactive diversity. They are becoming increasingly significant in the treatment of cancer due to their efficacy and safety. This chapter provides an update on the sources, pharmacological effects, structure-activity relationships, and clinical studies of anticancer triterpenoid saponins with a particular focus on the molecular mechanisms underlying their therapeutic properties. The correlative references and study reports described were collected through PubMed. The anticancer triterpenoid saponins enable the inhibition of cancer formation and progression by modulating multiple signaling targets related to cellular proliferation, apoptosis, autophagy, metastasis, angiogenesis, inflammation, oxidative stress, multidrug resistance, cancer stem cells, and microRNAs. This review provides new insights into the molecular basis of triterpenoid saponins in the chemoprevention and chemotherapy of cancer.