Proteomic analysis of the anti-cancer effect of 20S-ginsenoside Rg3 in human colon cancer cell lines

Saponins from Chinese Medicines as Anticancer Agents

Saponins are glycosides with triterpenoid or spirostane aglycones that demonstrate various pharmacological effects against mammalian diseases. To promote the research and development of anticancer agents from saponins, this review focuses on the anticancer properties of several typical naturally derived triterpenoid saponins (ginsenosides and saikosaponins) and steroid saponins (dioscin, polyphyllin, and timosaponin) isolated from Chinese medicines. These saponins exhibit in vitro and in vivo anticancer effects, such as anti-proliferation, anti-metastasis, anti-angiogenesis, anti-multidrug resistance, and autophagy regulation actions. In addition, related signaling pathways and target proteins involved in the anticancer effects of saponins are also summarized in this work.

Plant Resources, (13)C-NMR Spectral Characteristic and Pharmacological Activities of Dammarane-Type Triterpenoids

Dammarane-type triterpenoids (DTT) widely distribute in various medicinal plants. They have generated a great amount of interest in the field of new drug research and development. Generally, DTT are the main bioactive ingredients abundant in Araliaceae plants, such as Panax ginseng, P. japonicas, P. notoginseng, and P. quinquefolium. Aside from Araliaceae, DTT also distribute in other families, including Betulaceae, Cucurbitaceae, Meliaceae, Rhamnaceae, and Scrophulariaceae. Until now, about 136 species belonging to 46 families have been reported to contain DTT. In this article, the genus classifications of plant sources of the botanicals that contain DTT are reviewed, with particular focus on the NMR spectral features and pharmacological activities based on literature reports, which may be benefit for the development of new drugs or food additives.

Precision or Personalized Medicine for Cancer Chemotherapy: Is there a Role for Herbal Medicine

Although over 100 chemotherapeutic agents are currently available for the treatment of cancer patients, the overall long term clinical benefit is disappointing due to the lack of effectiveness or severe side effects from these agents. In order to improve the therapeutic outcome, a new approach called precision medicine or personalized medicine has been proposed and initiated by the U.S. National Institutes of Health. However, the limited availability of effective medications and the high cost are still the major barriers for many cancer patients. Thus alternative approaches such as herbal medicines could be a feasible and less costly option. Unfortunately, scientific evidence for the efficacy of a majority of herbal medicines is still lacking and their development to meet FDA approval or other regulatory agencies is a big challenge. However, herbal medicines may be able to play an important role in precision medicine or personalized medicine. This review will focus on the existing and future technologies that could speed the development of herbal products for treatment of resistant cancer in individual patients. Specifically, it will concentrate on reviewing the phenotypic (activity based) rather than genotypic (mechanism based) approach to develop herbal medicine useful for personalized cancer chemotherapy.

Proteomic analysis reveals that the protective effects of ginsenoside Rb1 are associated with the actin cytoskeleton in β-amyloid-treated neuronal cells

BACKGROUND

The ginsenoside Rb1 (Rb1) is the most abundant compound in the root of Panax ginseng. Recent studies have shown that Rb1 has a neuroprotective effect. However, the mechanisms underlying this effect are still unknown.

METHODS

We used stable isotope labeling with amino acids in cell culture, combined with quantitative mass spectrometry, to explore a potential protective mechanism of Rb1 in β-amyloid-treated neuronal cells.

RESULTS

A total of 1,231 proteins were commonly identified from three replicate experiments. Among these, 40 proteins were significantly changed in response to Rb1 pretreatment in β-amyloid-treated neuronal cells. Analysis of the functional enrichments and protein interactions of altered proteins revealed that actin cytoskeleton proteins might be linked to the regulatory mechanisms of Rb1. The CAP1, CAPZB, TOMM40, and DSTN proteins showed potential as molecular target proteins for the functional contribution of Rb1 in Alzheimer's disease (AD).

CONCLUSION

Our proteomic data may provide new insights into the protective mechanisms of Rb1 in AD.

Protective effects of ginseng on neurological disorders

Ginseng (Order: Apiales, Family: Araliaceae, Genus: Panax) has been used as a traditional herbal medicine for over 2000 years, and is recorded to have antianxiety, antidepressant and cognition enhancing properties. The protective effects of ginseng on neurological disorders are discussed in this review. Ginseng species and ginsenosides, and their intestinal metabolism and bioavailability are briefly introduced. This is followed by molecular mechanisms of effects of ginseng on the brain, including glutamatergic transmission, monoamine transmission, estrogen signaling, nitric oxide (NO) production, the Keap1/Nrf2 adaptive cellular stress pathway, neuronal survival, apoptosis, neural stem cells and neuroregeneration, microglia, astrocytes, oligodendrocytes and cerebral microvessels. The molecular mechanisms of the neuroprotective effects of ginseng in Alzheimer’s disease (AD) including β-amyloid (Aβ) formation, tau hyperphosphorylation and oxidative stress, major depression, stroke, Parkinson’s disease and multiple sclerosis are presented. It is hoped that this discussion will stimulate more studies on the use of ginseng in neurological disorders.

20(S)-Ginsenoside Rg3 is a novel inhibitor of autophagy and sensitizes hepatocellular carcinoma to doxorubicin

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. High mortality from HCC is mainly due to widespread prevalence and the lack of effective treatment, since systemic chemotherapy is ineffective, while the targeted agent Sorafenib extends median survival only briefly. The steroidal saponin 20(S)-ginsenoside Rg₃ from Panax ginseng C.A. Meyer is proposed to chemosensitize to various therapeutic drugs through an unknown mechanism. Since autophagy often serves as cell survival mechanism in cancer cells exposed to chemotherapeutic agents, we examined the ability of Rg₃ to inhibit autophagy and chemosensitize HCC cell lines to doxorubicin in vitro. We show that Rg₃ inhibits late stage autophagy, possibly through changes in gene expression. Doxorubicin-induced autophagy plays a protective role in HCC cells, and therefore Rg₃ treatment synergizes with doxorubicin to kill HCC cell lines, but the combination is relatively nontoxic in normal liver cells. In addition, Rg₃ was well-tolerated in mice and synergized with doxorubicin to inhibit tumor growth in HCC xenografts in vivo. Since novel in vivo inhibitors of autophagy are desirable for clinical use, we propose that Rg3 is such a compound, and that combination therapy with classical chemotherapeutic drugs may represent an effective therapeutic strategy for HCC treatment.

Novel roles of ginsenoside Rg3 in apoptosis through downregulation of epidermal growth factor receptor

Ginsenoside Rg3 (Rg3), a pharmacologically active compound from red ginseng, has been reported to induce cell death in various cancer cell lines, although the specific mechanisms have not been well established. In the present study, Rg3 treatment to A549 human lung adenocarcinoma led to cell death via not only apoptotic pathways but also the downregulation of epidermal growth factor receptor (EGFR). We used cross-linker and cell enzyme-linked immunosorbent assays to show that Rg3 inhibited EGFR dimerization by EGF stimulation and caused EGFR internalization from the cell membrane. Among several important phosphorylation sites in cytoplasmic EGFR, Rg3 increased the phosphorylation of tyrosine 1045 (pY1045) and serine 1046/1047 (pS1046/1047) for EGFR degradation and coincidently, attenuated pY1173 and pY1068 for mitogen-activated protein kinase activity. These effects were amplified under EGF-pretreated Rg3 stimulation. In vivo experiments showed that the average volume of the tumors treated with 30 mg/kg of Rg3 was significantly decreased by 40% compared with the control. Through immunohistochemistry, we detected the fragmentation of DNA, the accumulation of Rg3, and the reduction of EGFR expression in the Rg3-treated groups. Here, we provide the first description of the roles of Rg3 in the reduction of cell surface EGFR, the attenuation of EGFR signal transduction, and the eventual activation of apoptosis in A549 human lung adenocarcinoma.

Ginsenoside Rg3-induced EGFR/MAPK pathway deactivation inhibits melanoma cell proliferation by decreasing FUT4/LeY expression

Malignant melanoma is a destructive and lethal form of skin cancer with poor prognosis. An effective treatment for melanoma is greatly needed. Ginsenoside Rg3 is a herbal medicine with high antitumor activity. It is reported that abnormal glycosylation is correlated with the tumor cell growth. However, the antitumor effect of Rg3 on melanoma and its mechanism on regulating glycosylation are unknown. We found that Rg3 did not only inhibit A375 melanoma cell proliferation in a dose-dependent manner, but also decreased the expression of fucosyltransferase IV (FUT4) and its synthetic product Lewis Y (LeY), a tumor-associated carbohydrate antigen (TACA). Knocking down FUT4 expression by siRNA dramatically reduced FUT4/LeY level and inhibited cell proliferation through preventing the activation of EGFR/MAPK pathway. Consistently, the inhibitory effect of the Rg3 and FUT4 knockdown on melanoma growth was also seen in a xenograft melanoma mouse model. In conclusion, Rg3 effectively inhibited melanoma cell growth by downregulating FUT4 both in vitro and in vivo. Targeting FUT4/LeY mediated fucosylation by Rg3 inhibited the activation of EGFR/MAPK pathway and prevented melanoma growth. Results from this study suggest Rg3 is a potential novel therapy agent for melanoma treatment.

Semi-synthesis and anti-tumor evaluation of novel 25-hydroxyprotopanaxadiol derivatives as apoptosis inducing agents

Among novel 25-OH-PPD derivatives, compounds 3xt and 9xt exhibited the most potent anti-tumor activities and significantly induced DU145 cell apoptosis.

Ginsenoside 20(S)‑Rg3 inhibits the Warburg effect through STAT3 pathways in ovarian cancer cells

Cancer cells prefer to metabolize glucose through aerobic glycolysis, known as the Warburg effect. It plays a crucial role in proliferation and progression of cancer cells. However, the complete mechanism remains elusive. In recent studies, the signal transducer and activator of transcription 3 (STAT3) signaling has been discovered to have roles in cancer‑associated changes in metabolism. In this study, we find that the ginsenoside 20(S)‑Rg3, a pharmacologically active component of the traditional Chinese herb Panax ginseng, inhibits glycolysis in ovarian cancer cells by regulating hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). We also show that 20(S)‑Rg3 regulates HK2 through downregulation of p‑STAT3 (Tyr705). Furthermore, overexpression of STAT3 in ovarian cancer cells weakened the suppression of Warburg effect induced by 20(S)‑Rg3. Importantly, 20(S)‑Rg3 treatment represses HK2 expression in nude mouse xenograft models of ovarian cancer. Taken together, our results show that 20(S)‑Rg3 inhibits the Warburg effect by targeting STAT3/HK2 pathway in ovarian cancer cells, highlighting the potentiality of 20(S)‑Rg3 to be used as a therapeutic agent for ovarian cancer.

Preventive and therapeutic roles of ginseng - focus on colon cancer

Colorectal cancer is one of the most prevalent diseases all over the world. Early screening and start of chemotherapy is effective in decreasing mortality. This type of cancer can be controlled to some extent via a healthy diet rich in fruit and vegetables. Ginseng is a plant which has been consumed as a herbal medicine for thousands of years in Asian countries. Several in vitro and in vivo studies have shown that this plant not only reduces the incidence of colorectal cancer, but also improves patient's status by enhancing the effects of chemotherapy drugs. However, further studies are needed to prove this relationship. We briefly review ginseng and its components such as ginsenosides reported anticancer effects and their mechanisms of action. Understanding these relationships may produce insights into chemical and pharmacological approaches for enhancing the chemo preventive effects of ginsenosides and for developing novel anticancer agents.

Identification of anti-metastatic drug and natural compound targets in isogenic colorectal cancer cells

Therapeutic strategies for cancer treatment often remain challenging due to the cumulative risk derived from metastasis, which has been described as an aggressive state of cancer cell proliferation often resulting in failure of clinical therapy. In the current study, anti-metastatic properties of three chemotherapeutic drugs and three compounds from natural sources were investigated by comparative proteomic analysis. Proteomic profile comparison of the isogenic primary and metastatic colon cancer cell lines SW480 and SW620 identified two potential metastasis related molecular targets: fatty acid synthase and histone H4. To demonstrate their biological roles in cancer metastasis, the expression of these target genes was suppressed by siRNA transfection. Subsequent cell migration assays demonstrated reduced migratory effects. SW620 cells were treated with six anti-cancerous components. Through comprehensive proteomic analysis, three of the tested compounds, oxaliplatin, ginsenoside 20(S)-Rg3 and curcumin, were revealed to have a suppressive effect on FASN and histone H4 expression. SW620 cells treated with these drugs showed significantly reduced migratory activity, which suggests that drug-induced targeted suppression of these genes may affect cell migration. The validity of the proteomic datasets was verified by knowledgebase pathway analysis and immunoblotting assays. The anti-metastatic components revealed by the current proteomic analysis represent promising chemotherapeutic candidates for the treatment of colorectal adenocarcinoma.

BIOLOGICAL SIGNIFICANCE

The current study demonstrates anti-metastatic activity of chemotherapeutics and natural components by the suppression of target molecules, fatty acid synthase and histone H4 identified by a comparative proteomic analysis employing the isogenic primary and metastatic colon cancer cell lines, SW480 and SW620. Three tested drugs, namely, oxaliplatin, ginsenoside 20(S)-Rg3 and curcumin were revealed to possess suppressive effects on fatty acid synthase and histone H4 and reduce metastasis as determined by cell migration assay. Data were confirmed by the correlation between spectral counts from proteomic data and Western blot analysis, which were in good agreement with immunohistochemistry.

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

The prognosis of patients with ovarian cancer has remained poor mainly because of aggressive cancer progression. Since epithelial-mesenchymal transition (EMT) is an important mechanism mediating invasion and metastasis of cancer cells, targeting the EMT process with more efficacious and less toxic compounds to inhibit metastasis is of great therapeutic value for the treatment of ovarian cancer. We have found for the first time that the ginsenoside 20(S)-Rg3, a pharmacologically active component of the traditional Chinese herb Panax ginseng, potently blocks hypoxia-induced EMT of ovarian cancer cells in vitro and in vivo. Mechanistic studies confirm the mode of action of 20(S)-Rg3, which reduces the expression of hypoxia-inducible factor 1α (HIF-1α) by activating the ubiquitin-proteasome pathway to promote HIF-1α degradation. A decrease in HIF-1α in turn leads to up-regulation, via transcriptional suppression of Snail, of the epithelial cell-specific marker E-cadherin and down-regulation of the mesenchymal cell-specific marker vimentin under hypoxic conditions. Importantly, 20(S)-Rg3 effectively inhibits EMT in nude mouse xenograft models of ovarian cancer, promising a novel therapeutic agent for anticancer therapy.

Ginsenoside Rg3 enhances the inhibitory effects of chemotherapy on esophageal squamous cell carcinoma in mice

The present study was conducted in order to investigate the inhibitory effects of ginsenoside Rg3 combined with chemotherapy on Eca-109 esophageal squamous cell carcinoma (ESCC) in mice. Tumor xenograft models were established in the right forelimb of 20 BALB/c nude mice by subcutaneous injection. The tumor-bearing mice were randomly assigned to 4 treatment groups (n=5 per group) as follows: the control group (saline), the ginsenoside Rg3 alone group (6 mg/kg/day, once a day for 3 weeks), the chemotherapy alone group (paclitaxel 10 mg/kg/day + cisplatin 5 mg/kg/day on days 1, 7, 14 and 21) and the chemotherapy + Rg3 group (combined treatment). The length and width of the tumor were directly measured with calipers at different time points and the tumor volume (cm³) was calculated using the formula 0.52 × length × width² every other day. The mice were sacrificed by cervical dislocation following completion of therapy, the tumors were removed and weighed and the expression levels of Ki-67 were determined by immunohistochemistry. The results indicated that the coadministration of ginsenoside Rg3 significantly enhanced the inhibitory effects of chemotherapy on tumor growth. In addition, the expression levels of Ki-67 in the chemotherapy + Rg3 group were significantly lower compared to those in the other 3 groups. The chemotherapy + Rg3 group also exhibited the lowest microvascular density among all four groups. These findings suggested that ginsenoside Rg3 may improve the antitumor efficacy of chemotherapy in Eca-109 ESCC in mice.

Ginsenoside F(2) induces apoptosis in humor gastric carcinoma cells through reactive oxygen species-mitochondria pathway and modulation of ASK-1/JNK signaling cascade in vitro and in vivo

Ginsenoside F(2) (F(2)) is a potential bioactive metabolite of major ginsenosides. The potential anti-cancer effect of F(2) in gastric cancer cells has not been appraised. This study investigated the effects of F(2) on the production of reactive oxygen species (ROS). We also investigated the in vitro and in vivo effects of F(2) on the downstream signaling pathways leading to apoptosis in human gastric cancer cells. The in vitro data revealed that F(2) induces ROS accumulation followed by a decrease in mitochondrial transmembrane potential (MTP), and the release of cytochrome c (cyto c), which induced the caspase-dependent apoptosis. Further assay indicated that modulation of ASK-1/JNK pathway contributes to apoptosis. In vivo, F(2) exhibits the obvious anti-cancer effect compared with cisplatin with no obvious toxicity. Jointly, these results suggest that F(2) induces apoptosis by causing an accumulation of ROS and activating the ASK-1/JNK signaling pathway. This provides further support for the use of F(2) as a novel anticancer therapeutic candidate.

25-Methoxylprotopanaxadiol derivatives and their anti-proliferative activities

(20R)-25-Methoxyl-dammarane-3β,12β,20-triol (25-OCH₃-PPD) is a dammarane-type sapogenin showing anti-proliferative potential. In our study, two series of analogs substituted at the C-3 or C-3 and C-12 positions with fatty acids were prepared conveniently. The cytotoxic activity of these compounds was evaluated using four different human tumor cell lines (A549, Hela, HT-29 and MCF-7) and a normal cell line (IOSE144). As compared with 25-OCH₃-PPD, compounds 1a, 1b, 2a and 2b showed better anti-proliferative activities against all tumor cell lines and all the derivatives, with low toxicities in the normal cell line. Compound 1a (C-3 monoformiate) exhibited the strongest activity with the IC₅₀ value of 5.2 μM towards HT29 cells. The results indicated that the difference in the substituents may affect the anti-proliferative activity of the compounds. The longer the side chain of 25-OCH₃-PPD is, the lower the anti-proliferative activity would be. This information may be useful for evaluating the structure-activity relationship of other dammarane-type sapogenins and for development of novel antineoplastic agents.

Mass production of the ginsenoside Rg3(S) through the combinative use of two glycoside hydrolases

The ginsenoside Rg3(S), which is one of the exceptional components of Korean red ginseng extract, has been known to have anti-cancer, anti-metastatic, and anti-obesity effects. An enzymatic bioconversion method was developed to obtain the ginsenoside Rg3(S) with a high specificity, yield, and purity. Two glycoside hydrolases (BglBX10 and Abf22-3) were employed to produce Rg3(S) as a 100g unit. The conversion reaction transformed ginsenoside Rc to Rd using Abf22-3, followed by Rb1 and Rd to Rg3(S), using BglBX10. It was performed in a 10L jar fermenter at pH 6.0 and 37°C for 24h, with a high concentration of 50mg/ml of purified ginsenoside mixture obtained from ginseng roots. Finally, 144g of Rg3(S) was produced from 250g of root extract with 78±1.2% chromatographic purity. These results suggest that this enzymatic method would be useful in the preparation of ginsenoside Rg3(S) for the functional food and pharmaceutical industries.

Chronic administration of anti-stroke herbal medicine TongLuoJiuNao reduces amyloidogenic processing of amyloid precursor protein in a mouse model of Alzheimer's disease

Composed of Ginsenoside Rg1 and Geniposide, the herbal medicine TongLuoJiuNao (TLJN) injection liquid has anti-inflammatory properties and can improve learning and memory in mice. Recently, TLJN has been used to treat the patients with cerebral ischemic stroke and vascular dementia, which significantly increase the risk of developing Alzheimer’s disease (AD) in the early human beings. Although beneficial effects of TLJN have been reported in the vascular-associated brain disorders, the roles of TLJN in AD brains are still not clear. In this study, we chronically administered TLJN in amyloid precursor protein (APP) Swedish mutant transgenic mice (APP23) from 6 months old of age, which is at the onset of Aβ plaques, to 12 months old. We found that TLJN significantly decreased Aβ production and deposition in the brain of APP23 mice. Furthermore, we observed that TLJN down-regulated the levels and activity of β-secretase 1 (BACE1) protein as well as the expression levels of γ-secretase complex components: PS1, nicastrin and anterior pharynx-defective 1 (APH1) but not presenilin enhancer 2 (PEN2). The results suggest an inhibitory effect of TLJN on amyloidogenic APP processing by down-regulating the cleavage enzymes BACE1 and γ-secretase.

Synthesis and anti-tumor evaluation of novel 25-hydroxyprotopanaxadiol analogs incorporating natural amino acids

In the current study, derivatives of 25-hydroxyprotopanaxadiol (25-OH-PPD) were prepared and their in vitro anti-tumor activities were tested on six different human tumor cell lines by standard MTT assay. The results showed that combining an ester group combined with the presence of an amino acid moiety led to a 10-fold improved anti-tumor activity. Compound 1c exhibited the best anti-tumor activity in the in vitro assays. Compounds 2c, 3c, 4c, 5c, 6c and 8b showed better anti-tumor activities compared to the parent compound 25-OH-PPD. The current results may provide useful data for researching and developing new anti-cancer agents.

Toxicity of a novel anti-tumor agent 20(S)-ginsenoside Rg3: a 26-week intramuscular repeated administration study in rats

The purpose of this study is to investigate the potential subchronic toxicity of 20(S)-Ginsenoside Rg3(Rg3), by a 26-week repeated intramuscular administration in rats. Rg3 was administrated to rats at dose levels of 0, 4.2, 10.0 or 20.0 mg/kg/day. There was no treatment-related mortality and, at the scheduled autopsy, dose-dependent increases in the absolute and relative spleen weights, of both the 10.0 mg/kg and 20.0 mg/kg dose groups were observed. Absolute and relative kidney weights were significantly elevated in the female 10.0 mg/kg dose group and in the male 20.0 mg/kg dose group. Hematological investigations revealed a dose-dependent increase in the total white blood cell (WBC) count and in the percentage of neutrophils, but a decrease in the percentage of lymphocytes, in rats treated with doses of 10.0/20.0 mg/kg. These effects were completely reversible during the recovery period, and no other adverse effects were observed. It was concluded that the 26-week repeated intramuscular dose of Rg3 caused increases in the spleen and kidney weights, WBC counts and in the percentage of neutrophils, but a decrease in the percentage of lymphocytes, with doses of 10.0 or 20.0 mg/kg/day. The no-observed-adverse-effect level for rats was considered to be 4.2 mg/kg/day.

Steroidal saponins from the roots of Smilax sp.: structure and bioactivity

Phytochemical characterization of a commercial herb sample supplied as Smilax ornata Lem. (sarsaparilla) led to the isolation of five steroidal saponins, including two new furostanol saponins sarsaparilloside B (1) and sarsaparilloside C (2), whose structures were elucidated via a combination of multistage mass spectrometry (MS(n)), 1D and 2D NMR experiments, and chemical degradation. The previously unreported spectroscopic characterization of sarsaparilloside (3), Δ(20(22))-sarsaparilloside (4), and parillin (5) is also provided. The antiproliferative activity of the isolated saponins was compared in six human cell lines derived from different tumor types and one of the structures (2) was particularly active against the HT29 colon tumor cell line.

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.

Anti-cancer natural products isolated from chinese medicinal herbs

In recent years, a number of natural products isolated from Chinese herbs have been found to inhibit proliferation, induce apoptosis, suppress angiogenesis, retard metastasis and enhance chemotherapy, exhibiting anti-cancer potential both in vitro and in vivo. This article summarizes recent advances in in vitro and in vivo research on the anti-cancer effects and related mechanisms of some promising natural products. These natural products are also reviewed for their therapeutic potentials, including flavonoids (gambogic acid, curcumin, wogonin and silibinin), alkaloids (berberine), terpenes (artemisinin, β-elemene, oridonin, triptolide, and ursolic acid), quinones (shikonin and emodin) and saponins (ginsenoside Rg3), which are isolated from Chinese medicinal herbs. In particular, the discovery of the new use of artemisinin derivatives as excellent anti-cancer drugs is also reviewed.

Anti-cancer natural products isolated from chinese medicinal herbs

In recent years, a number of natural products isolated from Chinese herbs have been found to inhibit proliferation, induce apoptosis, suppress angiogenesis, retard metastasis and enhance chemotherapy, exhibiting anti-cancer potential both in vitro and in vivo. This article summarizes recent advances in in vitro and in vivo research on the anti-cancer effects and related mechanisms of some promising natural products. These natural products are also reviewed for their therapeutic potentials, including flavonoids (gambogic acid, curcumin, wogonin and silibinin), alkaloids (berberine), terpenes (artemisinin, β-elemene, oridonin, triptolide, and ursolic acid), quinones (shikonin and emodin) and saponins (ginsenoside Rg₃), which are isolated from Chinese medicinal herbs. In particular, the discovery of the new use of artemisinin derivatives as excellent anti-cancer drugs is also reviewed.

Protective effect of dammarane sapogenins against chemotherapy-induced myelosuppression in mice

Chemotherapy is the most common way to treat malignancies, but myelosuppression, one of its common side-effects, is a formidable problem. The present study described the protective role of dammarane sapogenins (DS), an active fraction from oriental ginseng, on myelosuppression induced by cyclophosphamide (CP) in mice. DS was orally administered at different dosages (37.5, 75, and 150 mg/kg) for 10 d after CP administration (200 mg/kg intraperitoneally). The results showed that DS increased the number of white blood cells (WBC) on day 3 and day 7 (P < 0.05), such that WBC levels were increased by 105.7 ± 29.5% at 75 mg/kg of DS on day 3 (P < 0.05, compared with the CP group). Similar results were observed in red blood cells and platelets in DS-treated groups. The colony-forming assay demonstrated that the depressed numbers of CFU-GM (colony-forming unit-granulocyte and macrophage), CFU-E (colony-forming unit-erythroid), BFU-E (burst-forming unit-erythroid), CFU-Meg (colony-forming unit-megakaryocyte) and CFU-GEMM (colony-forming unit-granulocyte, -erythrocyte, -monocyte and -megakaryocyte) induced by CP were significantly reversed after DS treatment. Moreover, the ameliorative effect of DS on myelosuppression was also observed in the femur by hematoxylin/eosin staining. In DS-treated groups, ConA-induced splenocyte proliferation was enhanced significantly at all the doses (37.5, 75, 150 mg/kg) on day 3 at the rate of 50.3 ± 8.0%, 77.6 ± 8.5% and 44.5 ± 8.4%, respectively, while lipopolysaccharide-induced proliferation was increased mainly on day 7 (P < 0.01), with an increased rate of 39.8 ± 5.6%, 34.9 ± 6.6% and 38.3 ± 7.3%, respectively. The thymus index was also markedly increased by 70.4% and 36.6% at 75 mg/kg on days 3 and 7, respectively, as compared with the CP group. In summary, DS has a protective function against CP-induced myelosuppression. Its mechanism might be related to stimulating hematopoiesis recovery, as well as enhancing the immunological function.

Toxicity of a novel anti-tumor agent 20(S)-ginsenoside Rg3: a 26-week intramuscular repeated administration study in Beagle dogs

The potential subchronic toxicity of a dammarane-type triterpenoid saponin with antitumor effect, 20(S)-Ginsenoside Rg3, was studied repeated intramuscular administration in Beagle dogs over a 26-week period. 20(S)-Ginsenoside Rg3 was administrated intramuscularly at 0, 0.70, 2.86 or 7.20 mg/kg/day doses for 26 weeks in both male and female dogs (n = 4 for male and female dogs for each dose). During the test period as well as during the 8-week recovery period, clinical signs, mortality, body weights, food consumption, respiratory frequency, electrocardiogram, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, organ weights and histopathology were examined. In dogs treated with doses of 2.86 or 7.20 mg/kg, hematological investigations revealed a dose-dependent increase in the total white blood cell (WBC) count and in the percentage of neutrophils, but a decrease in the percentage of lymphocytes. These effects were completely reversed during the recovery period, and no other adverse effects were observed. The no-observed-adverse-effect levels for both male and female dogs were considered to be 7.20 mg/kg/day.

Ginsenoside Rg3 inhibits CXCR4 expression and related migrations in a breast cancer cell line

BACKGROUND

Ginsenoside Rg3 is an extract from the natural product ginseng. Previous studies have linked Rg3 with anti-metastasis of cancer in vivo and in vitro. CXC receptor 4 (CXCR4) is a vital molecule in migration and homing of cancer to the docking regions.

METHODS

In this study, the effects of Rg3 on CXCR4 expression were investigated in a breast cancer cell line. Immunohistochemistry, chemotaxis and wound healing mobility assays were performed in cultured MDA-MB-231 cells.

RESULTS

At a dosage without obvious cytotoxicity, Rg3 treatment elicits a weak CXCR4 stain color, decreases the number of migrated cells in CXCL12-elicited chemotaxis and reduces the width of the scar in wound healing.

CONCLUSION

This work suggests that Rg3 is a new CXCR4 inhibitor from a natural product.

American ginseng: potential structure-function relationship in cancer chemoprevention

Ginseng has a prominent position on the list of best-selling herbal products in the world, and its main active constituents are thought to be ginsenosides. Compared with the long history of use and widespread research on Asian ginseng, studies of American ginseng are relatively limited, especially regarding cancer chemoprevention. In recent studies of American ginseng, steaming or heating altered the ginsenoside profile and thereby increased anticancer effects. Yet the ginsenoside structures and their activities have not been systematically elucidated. In this commentary, we introduce the different ginsenosides in American ginseng, both the naturally occurring compounds and those resulting from steaming or biotransformation. We briefly review American ginseng's reported anticancer effects and their mechanisms of action, and explore the possible structural-function relationship with a focus on sugar molecules, hydroxyl groups and stereoselectivity in ginsenosides. Understanding these relationships may produce insights into chemical and pharmacological approaches for enhancing the chemopreventive effects of ginsenoside and for developing novel anticancer agents.

Transcript profiles of Panax quinquefolius from flower, leaf and root bring new insights into genes related to ginsenosides biosynthesis and transcriptional regulation

American ginseng (Panax quinquefolius L.) has been used for a wide range of therapeutic purposes in China. The major bioactive phytochemicals responsible for this plant's pharmacological features are ginsenosides. Thus far, little is known regarding the genes involved in ginsenosides biosynthesis in this species. As a non-model plant, information about its genomes is generally not available. In this study, we generated 6678 expressed sequence tags (ESTs) from the flower, leaf and root cDNA libraries of American ginseng. Assembly of ESTs resulted in 3349 unigenes including 534 contigs (with ESTs number ranging from 2 to 52) and 2815 singletons. By analyzing the predominant transcripts within specific tissues, a gene expression pattern was obtained in a tissue-specific manner. They were assigned according to the functional classification of unigenes to broad ranges of Gene Ontology categories which include biological processes, cellular components and molecular functions. Based on blastx search results, 24 unigenes representing candidates related to ginsenosides biosynthesis were identified. Cloning and characterization of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR, EC: 1.1.1.34), the rate-limiting enzyme in mevalonic acid pathway, demonstrated that it belonged to the plant HMGR family and was highly expressed in leaves. Putative transcription factors were detected in 63 unigenes, including zinc finger, WRKY, homeobox and MADS-box family proteins. Five hundred and eighty-eight simple sequence repeat motifs were identified, of which, dimer was the most abundant motif. These data will provide useful information on transcript profiles, gene discovery, transcriptional regulation, flower biogenesis and marker-assisted selections. The analysis and information from this study will greatly contribute to the improvement of this medicinal plant as well as of other species in the Araliaceae family, for the purpose of ensuring adequate drug resources.