Selective toxicity of ginsenoside Rg3 on multidrug resistant cells by membrane fluidity modulation

Paclitaxel-loaded ginsenoside Rg3 liposomes for drug-resistant cancer therapy by dual targeting of the tumor microenvironment and cancer cells

INTRODUCTION

Inherent or acquired resistance to paclitaxel (PTX) is a pivotal challenge for chemotherapy treatment of multidrug-resistant (MDR) breast cancer. Although various targeted drug-delivery systems, including nanoparticles and liposomes, are effective for MDR cancer treatment, their efficacy is restricted by immunosuppressive tumor microenvironment (TME).

METHODS

Ginsenosides Rg3 was used to formulate unique Rg3-based liposomes loaded with PTX to establish Rg3-PTX-LPs, which were prepared by the thin-film hydration method. The stability of the Rg3-PTX-LPs was evaluated by particle size analysis through dynamic light scattering. The active targeting effect of Rg3-based liposomes was examined in an MCF-7/T xenograft model by an in a vivo imaging system. To evaluate the antitumor activity and mechanism of Rg3-PTX-LP, MTT, apoptosis assays, TAM regulation, and TME remodeling were performed in MCF-7/T cells in vitro and in vivo.

RESULTS

Rg3-PTX-LPs could specifically distribute to MCF7/T cancer cells and TME simultaneously, mainly through the recognition of GLUT-1. The drug resistance reversing capability and in vivo antitumor effect of Rg3-PTX-LPs were significantly improved compared with conventional cholesterol liposomes. The TME remodeling mechanisms of Rg3-PTX-LPs included inhibiting IL-6/STAT3/p-STAT3 pathway activation to repolarize protumor M2 macrophages to antitumor M1 phenotype, suppressing myeloid-derived suppressor cells (MDSCs), decreasing tumor-associated fibroblasts (TAFs) and collagen fibers in TME, and promoting apoptosis of tumor cells. Hence, through the dual effects of targeting tumor cells and TME remodeling, Rg3-PTX-LPs achieved a high tumor inhibition rate of 90.3%.

CONCLUSION

Our multifunctional Rg3-based liposome developed in the present study offered a promising strategy for rescuing the drug resistance tumor treatment.

Nanotechnology-integrated ferroptosis inducers: a sharp sword against tumor drug resistance

Presently, the biggest hurdle to cancer therapy is the inevitable emergence of drug resistance. Since conventional therapeutic schedules fall short of the expectations in curbing drug resistance, the development of novel drug resistance management strategies is critical. Extensive research over the last decade has revealed that the process of ferroptosis is correlated with cancer resistance; moreover, it has been demonstrated that ferroptosis inducers reverse drug resistance. To elucidate the development and promote the clinical transformation of ferroptosis strategies in cancer therapy, we first analyzed the roles of key ferroptosis-regulating molecules in the progression of drug resistance in-depth and then reviewed the design of ferroptosis-inducing strategies based on nanotechnology for overcoming drug resistance, including glutathione depletion, reactive oxygen species generation, iron donation, lipid peroxidation aggregation, and multiple-drug resistance-associated tumor cell destruction. Finally, the prospects and challenges of regulating ferroptosis as a therapeutic strategy for reversing cancer therapy resistance were evaluated. This review aimed to provide a comprehensive understanding for researchers to develop ferroptosis-inducing nanoplatforms that can overcome drug resistance.

Phytotherapy in Integrative Oncology-An Update of Promising Treatment Options

Modern phytotherapy is part of today's conventional evidence-based medicine and the use of phytopharmaceuticals in integrative oncology is becoming increasingly popular. Approximately 40% of users of such phytopharmaceuticals are tumour patients. The present review provides an overview of the most important plants and nature-based compounds used in integrative oncology and illustrates their pharmacological potential in preclinical and clinical settings. A selection of promising anti-tumour plants and ingredients was made on the basis of scientific evidence and therapeutic practical relevance and included Boswellia, gingko, ginseng, ginger, and curcumin. In addition to these nominees, there is a large number of other interesting plants and plant ingredients that can be considered for the treatment of cancer diseases or for the treatment of tumour or tumour therapy-associated symptoms. Side effects and interactions are included in the discussion. However, with the regular and intended use of phytopharmaceuticals, the occurrence of adverse side effects is rather rare. Overall, the use of defined phytopharmaceuticals is recommended in the context of a rational integrative oncology approach.

Emerging Significance of Ginsenosides as Potentially Reversal Agents of Chemoresistance in Cancer Therapy

Chemoresistance has become a prevalent phenomenon in cancer therapy, which alleviates the effect of chemotherapy and makes it difficult to break the bottleneck of the survival rate of tumor patients. Current approaches for reversing chemoresistance are poorly effective and may cause numerous new problems. Therefore, it is urgent to develop novel and efficient drugs derived from natural non-toxic compounds for the reversal of chemoresistance. Researches in vivo and in vitro suggest that ginsenosides are undoubtedly low-toxic and effective options for the reversal of chemoresistance. The underlying mechanism of reversal of chemoresistance is correlated with inhibition of drug transporters, induction of apoptosis, and modulation of the tumor microenvironment(TME), as well as the modulation of signaling pathways, such as nuclear factor erythroid-2 related factor 2 (NRF2)/AKT, lncRNA cancer susceptibility candidate 2(CASC2)/ protein tyrosine phosphatase gene (PTEN), AKT/ sirtuin1(SIRT1), epidermal growth factor receptor (EGFR)/ phosphatidylinositol 3-kinase (PI3K)/AKT, PI3K/AKT/ mammalian target of rapamycin(mTOR) and nuclear factor-κB (NF-κB). Since the effects and the mechanisms of ginsenosides on chemoresistance reversal have not yet been reviewed, this review summarized comprehensively experimental data in vivo and in vitro to elucidate the functional roles of ginsenosides in chemoresistance reversal and shed light on the future research of ginsenosides.

Lipid Membranes as Key Targets for the Pharmacological Actions of Ginsenosides

In this review, we will focus on the activity of ginsenosides on membranes and their related effects, from physicochemical, biophysical, and pharmacological viewpoints. Ginsenosides are a class of saponins with a large structural diversity and a wide range of pharmacological effects. These effects can at least partly be related to their activity on membranes which results from their amphiphilic character. Some ginsenosides are able to interact with membrane lipids and associate into nanostructures, making them possible adjuvants for vaccines. They are able to modulate membrane biophysical properties such as membrane fluidity, permeability or the formation of lateral domains with some degree of specificity towards certain cell types such as bacteria, fungi, or cancer cells. In addition, they have shown antioxidant properties which protect membranes from lipid oxidation. They further displayed some activity on membrane proteins either through direct or indirect interaction. We investigate the structure activity relationship of ginsenosides on membranes and discuss the implications and potential use as anticancer, antibacterial, and antifungal agents.

Ginsenoside Rg3 attenuates the osimertinib resistance by reducing the stemness of non-small cell lung cancer cells

In the present study, we found that Ginsenoside Rg3 attenuated the stemness of non-small cell lung cancer (NSCLC) cells, evident by decreasing spheroid formation ability, ALDH1 activity and stemness marker expression. Furthermore, osimertinib-resistant NSCLC cells displayed a stronger stemness than the parental cells. Ginsenoside Rg3 reduced the stemness and osimertinib resistance of osimertinib-resistant cells. RNA-sequencing revealed that Hippo signaling was shown on the top of the most upregulated pathways regulated by Ginsenoside Rg3 in NSCLC cells, and YAP/TAZ expression was suppressed by Ginsenoside Rg3. Notably, the inhibitor of Hippo signaling attenuated the effects of Ginsenoside Rg3 on the stemness of NSCLC cells. Therefore, Ginsenoside Rg3 attenuates the osimertinib resistance of NSCLC cells via suppressing the stemness, which is dependent on Hippo pathway.

Ginsenoside Rp1, A Ginsenoside Derivative, Augments Anti-Cancer Effects of Actinomycin D via Downregulation of an AKT-SIRT1 Pathway

Novel strategies for overcoming multidrug resistance are urgently needed to improve chemotherapy success and reduce side effects. Ginsenosides, the main active components of Panax ginseng, display anti-cancer properties and reverse drug resistance; however, the biological pathways mediating this phenomenon remain incompletely understood. This study aimed to evaluate the anti-cancer effects of ginsenoside Rp1, actinomycin D (ActD), and their co-administration in drug-resistant cells and murine xenograft model of colon cancer, and explore the underlying mechanisms. ActD increased expression and activity of SIRT1 in drug-resistant LS513 colon cancer, OVCAR8-DXR ovarian cancer, and A549-DXR lung cancer cells, but not in ActD-sensitive SW620 colon cancer cells. Inhibition of SIRT1, either pharmacologically, with EX527 or through siRNA, stimulated p53 acetylation and apoptosis in LS513 cells when treated with ActD. ActD also increased AKT activation in drug-resistant cells. Inhibition of AKT abrogated ActD-induced upregulation of SIRT1, suggesting that the AKT-SIRT1 pathway is important in ActD resistance. Rp1 inhibited both ActD-induced AKT activation and SIRT1 upregulation and re-sensitized the cells to ActD. Synergistic antitumor effects of Rp1 with ActD were also observed in vivo. Our results suggest that combining Rp1 with chemotherapeutic agents could circumvent drug resistance and improve treatment efficacy.

Inhibition of Herpes Simplex Viruses, Types 1 and 2, by Ginsenoside 20(S)-Rg3

Infections by herpes simplex viruses have an immense impact on humans, ranging from selflimiting, benign illness to serious, life-threatening diseases. While nucleoside analog drugs are available, resistance has been increasing and currently no vaccine exists. Ginsenosides derived from Panax ginseng have been documented to inhibit several viruses and bolster immune defenses. This study evaluated 12 of the most relevant ginsenosides from P. ginseng for toxicities and inhibition of herpes simplex viruses types 1 and 2 in Vero cells. The effects of test compounds and virus infection were determined using a PrestoBlue cell viability assay. Time course studies were also conducted to better understand at what points the virus life cycle was affected. Non-toxic concentrations of the ginsenosides were determined and ranged from 12.5 µM to greater than 100 µM. Ginsenoside 20(S)-Rg3 demonstrated the greatest inhibitory effect and was active against both HSV-1 and HSV-2 with an IC₅₀ of approximately 35 µM. The most dramatic inhibition-over 100% compared to controls-occurred when the virus was exposed to 20(S)-Rg3 for 4 h prior to being added to cells. 20(S)-Rg3 holds promise as a potential chemotherapeutic agent against herpes simplex viruses and, when used together with valacyclovir, may prevent increased resistance to drugs.

Pharmacokinetics comparison of 15 ginsenosides and 3 aglycones in Ginseng Radix et Rhizoma and Baoyuan decoction using ultra-fast liquid chromatography coupled with triple quadrupole tandem mass spectrometry

BACKGROUND

Ginsenosides were considered as the main bioactive constituents in Ginseng Radix et Rhizoma (GRR). However, because of high polarity, ginsenosides were hard to be absorbed in human or animal gastrointestinal tract after oral administration. Up to now, very few studies have been performed in the area of simultaneous pharmacokinetic analysis of multiple ginsenosides with similar structures.

PURPOSE

This research aimed to compare the different absorption characteristics of ginsenosides and aglycones between GRR and Baoyuan decoction (BYD), one of formulas containing GRR, with the same dosage.

METHODS

GRR and BYD extracts were prepared with same method. A single dose of GRR and BYD extracts were administrated to rats through gavage, respectively. A solid phase extraction method was used to purify the plasma samples. An ultra-fast liquid chromatography coupled with tandem mass spectrometry (UFLC-MS/MS) method was established and fully validated for quantitative analysis. In addition, an in vitro incubation of GRR extract with intestinal flora was conducted to confirm the influence of gut microbiota to the absorption of ginsenosides and aglycones.

RESULTS

The results of incubation experiments showed that most high polar ginsenosides could transform to less polar ginsenosides via intestinal flora. The validated UFLC-MS/MS method was sensitive and precise to simultaneously analyze the pharmacokinetics of multiple ginsenosides. After oral administration of GRR and BYD extracts, the pharmacokinetic results showed that a total of 11 ginsenosides and 2 aglycones could be quantitatively determined in both groups of plasma. Besides, five compounds were only quantified in BYD extract group. In addition, another 21 ginsenosides could be qualitatively measured.

CONCLUSION

The results indicated significant pharmacokinetic differences of ginsenosides and aglycones between two groups. For most less polar ginsenosides who had better bioactivity, the preparation was possessed of higher plasma concentrations. The comparative results indicated that some co-existing compounds in BYD might inhibit the exocytosis of ginsenosides. Moreover, what is worth mentioning, some ginsenosides and aglycones could only be detected and quantified a few hours later after administration to rats. Combining with the in vitro incubation experiments, the results demonstrated that transformation of ginsenosides in gastrointestinal tract via intestinal flora existed during absorption.

Reversal effect of ginsenoside Rh2 on oxaliplatin-resistant colon cancer cells and its mechanism

Chemotherapy is an important treatment modality for colon cancer, however, drug resistance is the main factor leading to treatment failure. Ginsenoside Rh2 (G-Rh2), the main bioactive metabolite of ginseng, is known to possess the ability to potently induce cell apoptosis, inhibit cell proliferation and reverse multidrug resistance in a variety of cancer cells. The present study examined the effect of G-Rh2 on oxaliplatin (L-OHP)-resistant colon cancer cells and its potential mechanism. L-OHP-resistant colon cancer cells (LoVo/L-OHP) and LoVo cells were used in the present study. The effect of G-Rh2 on LoVo/L-OHP and LoVo cell proliferation was measured using a 3-(4,5 dimethylthiazol-z-yl)-3,5-diphenyltetrazolium bromide assay. The effects of G-Rh2 on LoVo/L-OHP and LoVo cell apoptosis were detected by flow cytometry. The mRNA and protein expression of apoptosis-related genes Bax, Bcl-2 and caspase-3, drug resistance-related genes P-glycoprotein (P-gp) and Smad4, were determined in LoVo/L-OHP and LoVo cells treated with G-Rh2 by reverse transcription-quantitative polymerase chain reaction and western blot analyses. G-Rh2 treatment significantly inhibited the proliferation and induced the apoptosis of LoVo/L-OHP and LoVo cells. In addition, G-Rh2 treatment resulted in a significant increase in pro-apoptotic factors, Bax and caspase-3, and decrease in anti-apoptotic factor Bcl-2 in the LoVo/L-OHP and LoVo cells. Furthermore, G-Rh2 treatment significantly decreased the levels of P-gp and increased the levels of Smad4 in the LoVo/L-OHP and LoVo cells. It was found that L-OHP had no significant effects on LoVo/L-OHP cell proliferation or apoptosis, whereas G-Rh2 + L-OHP treatment significantly inhibited LoVo/L-OHP cell proliferation and induced apoptosis. L-OHP had no significant effects on the expression of P-gp, Smad4, Bcl-2, Bax or caspase-3 in LoVo/L-OHP cells. Treatment with G-Rh2 + L-OHP significantly reduced the expression of P-gp and Bcl-2, and enhanced the expression levels of Smad4, Bax and caspase-3. These findings demonstrated that G-Rh2 reversed the drug resistance of LoVo/L-OHP cells to L-OHP, and this may be mediated by inhibiting cell proliferation and promoting apoptosis and regulating the expression of drug resistance genes. These results suggest that G-Rh2 may function as a potent anticancer drug for drug resistance in colon cancer treatment.

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

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

Permeability of Ciprofloxacin-Loaded Polymeric Micelles Including Ginsenoside as P-glycoprotein Inhibitor through a Caco-2 Cells Monolayer as an Intestinal Absorption Model

The low oral bioavailability of ciprofloxacin is associated with two distinct challenges: its low aqueous solubility and efflux by p-glycoproteins (P-gp) in the intestinal membrane. Several studies were conducted in order to improve its solubility and permeability through the gastrointestinal membrane. In this study, in a full factorial design study, eight polymeric micelles were prepared and their characteristics, including particle size, loading and release rate were evaluated. Polymeric micelles demonstrated particle sizes below 190 nm and 27⁻88% loading efficiency. Drug release was affected by drug solubility, polymeric micelle erosion and swelling in simulated gastrointestinal fluids. An optimized polymeric micelle was prepared based on appropriate characteristics such as high drug loading and low particle size; and was used for a permeation study on Caco-2 cells. Optimized polymeric micelles with and without ginsenoside and ginsenoside alone enhanced drug permeability through Caco-2 cells significantly in the absorptive direction. The effect of ginsenoside was dose dependent and the maximum effect was seen in 0.23 mg/mL concentration. Results showed that P-gp may not be responsible for ciprofloxacin secretion into the gut. The main mechanism of ciprofloxacin transport through Caco-2 cells in both directions is active diffusion and P-gp has inhibitory effects on ciprofloxacin permeability in the absorptive direction that was blocked by ginsenoside and micelles without ginsenoside.

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

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

Effect of Korean Red Ginseng extracts on drug-drug interactions

Background

Ginseng has been the subject of many experimental and clinical studies to uncover the diverse biological activities of its constituent compounds. It is a traditional medicine that has been used for its immunostimulatory, antithrombotic, antioxidative, anti-inflammatory, and anticancer effects. Ginseng may interact with concomitant medications and alter metabolism and/or drug transport, which may alter the known efficacy and safety of a drug; thus, the role of ginseng may be controversial when taken with other medications.

Methods

We extensively assessed the effects of Korean Red Ginseng (KRG) in rats on the expression of enzymes responsible for drug metabolism [cytochrome p450 (CYP)] and transporters [multiple drug resistance (MDR) and organic anion transporter (OAT)] in vitro and on the pharmacokinetics of two probe drugs, midazolam and fexofenadine, after a 2-wk repeated administration of KRG at different doses.

Results

The results showed that 30 mg/kg KRG significantly increased the expression level of CYP3A11 protein in the liver and 100 mg/kg KRG increased both the mRNA and protein expression of OAT1 in the kidney. Additionally, KRG significantly increased the mRNA and protein expression of OAT1, OAT3, and MDR1 in the liver. Although there were no significant changes in the metabolism of midazolam to its major metabolite, 1′-hydroxymidazolam, KRG significantly decreased the systemic exposure of fexofenadine in a dose-dependent manner.

Conclusion

Because KRG is used as a health supplement, there is a risk of KRG overdose; thus, a clinical trial of high doses would be useful. The use of KRG in combination with P-glycoprotein substrate drugs should also be carefully monitored.

Anticancer effects of ginsenoside Rg3 (Review)

Cancer is a life-threatening disease with an alarmingly increased annual mortality rate globally. Although various therapies are employed for cancer, the final effect is not satisfactory. Chemotherapy is currently the most commonly used treatment option. However, the unsatisfactory efficacy, severe side-effects and drug resistance hinder the therapeutic efficacy of chemotherapeutic drugs. There is increasing evidence indicating that ginsenoside Rg3, a naturally occurring phytochemical, plays an important role in the prevention and treatment of cancer. The suggested mechanisms mainly include the induction of apoptosis, and the inhibition of proliferation, metastasis and angiogenesis, as well as the promotion of immunity. In addition, ginsenoside Rg3 can be used as an adjuvant to conventional cancer therapies, improving the efficacy and/or reducing adverse effects via synergistic activities. Ginsenoside Rg3 may be a widely applied natural medicine against cancer. To date however, there is no systematic summary available of the anticancer effects of ginsenoside Rg3. Therefore, in this review, all available literature over the past 10 years was reviewed and discussed in order to facilitate further research of ginsenoside Rg3.

Membrane Interactions of Phytochemicals as Their Molecular Mechanism Applicable to the Discovery of Drug Leads from Plants

In addition to interacting with functional proteins such as receptors, ion channels, and enzymes, a variety of drugs mechanistically act on membrane lipids to change the physicochemical properties of biomembranes as reported for anesthetic, adrenergic, cholinergic, non-steroidal anti-inflammatory, analgesic, antitumor, antiplatelet, antimicrobial, and antioxidant drugs. As well as these membrane-acting drugs, bioactive plant components, phytochemicals, with amphiphilic or hydrophobic structures, are presumed to interact with biological membranes and biomimetic membranes prepared with phospholipids and cholesterol, resulting in the modification of membrane fluidity, microviscosity, order, elasticity, and permeability with the potencies being consistent with their pharmacological effects. A novel mechanistic point of view of phytochemicals would lead to a better understanding of their bioactivities, an insight into their medicinal benefits, and a strategic implication for discovering drug leads from plants. This article reviews the membrane interactions of different classes of phytochemicals by highlighting their induced changes in membrane property. The phytochemicals to be reviewed include membrane-interactive flavonoids, terpenoids, stilbenoids, capsaicinoids, phloroglucinols, naphthodianthrones, organosulfur compounds, alkaloids, anthraquinonoids, ginsenosides, pentacyclic triterpene acids, and curcuminoids. The membrane interaction’s applicability to the discovery of phytochemical drug leads is also discussed while referring to previous screening and isolating studies.

The amphiphilic nature of saponins and their effects on artificial and biological membranes and potential consequences for red blood and cancer cells

Saponins, amphiphiles of natural origin with numerous biological activities, are widely used in the cosmetic and pharmaceutical industry. Some saponins exhibit relatively selective cytotoxic effects on cancer cells but the tendency of saponins to induce hemolysis limits their anticancer potential. This review focused on the effects of saponin activity on membranes and consequent implications for red blood and cancer cells. This activity seems to be strongly related to the amphiphilic character of saponins that gives them the ability to self-aggregate and interact with membrane components such as cholesterol and phospholipids. Membrane interactions of saponins with artificial membrane models, red blood and cancer cells are reviewed with respect to their molecular structures. The review considered the mechanisms of these membrane interactions and their consequences including the modulation of membrane dynamics, interaction with membrane rafts, and membrane lysis. We summarized current knowledge concerning the mechanisms involved in the interactions of saponins with membrane lipids and examined the structure activity relationship of saponins regarding hemolysis and cancer cell death. A critical analysis of these findings speculates on their potential to further develop new anticancer compounds.

Pharmacokinetic interactions of herbs with cytochrome p450 and p-glycoprotein

The concurrent use of drugs and herbal products is becoming increasingly prevalent over the last decade. Several herbal products have been known to modulate cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp) which are recognized as representative drug metabolizing enzymes and drug transporter, respectively. Thus, a summary of knowledge on the modulation of CYP and P-gp by commonly used herbs can provide robust fundamentals for optimizing CYP and/or P-gp substrate drug-based therapy. Herein, we review ten popular medicinal and/or dietary herbs as perpetrators of CYP- and P-gp-mediated pharmacokinetic herb-drug interactions. The main focus is placed on previous works on the ability of herbal extracts and their phytochemicals to modulate the expression and function of CYP and P-gp in several in vitro and in vivo animal and human systems.

In vivo early intervention and the therapeutic effects of 20(s)-ginsenoside rg3 on hypertrophic scar formation

BACKGROUND

Intra-lesional injections of corticosteroids, interferon, and chemotherapeutic drugs are currently the most popular treatments of hypertrophic scar formation. However, these drugs can only be used after HS is formed, and not during the inflammatory phase of wound healing, which regulates the HS forming process.

OBJECTIVE

To investigate a new, effective, combining therapeutic and safe drug for early intervention and treatment for hypertrophic scars.

METHODS

Cell viability assay and flow cytometric analysis were studied in vitro. Animal studies were done to investigate the combining therapeutic effects of 20(S)-ginsenoside Rg3 (Rg3) on the inflammatory phase of wound healing and HS formation.

RESULTS

In vitro studies showed that Rg3 can inhibit HS fibroblasts proliferation and induce HSF apoptosis in a concentration-dependent manner. In vivo studies demonstrated that Rg3 can limit the exaggerated inflammation, and do not delay the wound healing process, which indicates that Rg3 could be used as an early intervention to reduce HS formation. Topical injection of 4 mg/mL Rg3 can reduce HS formation by 34%. Histological and molecular studies revealed that Rg3 injection inhibits fibroblasts proliferation thus reduced the accumulation of collagen fibers, and down-regulates VEGF expression in the HS tissue.

CONCLUSION

Rg3 can be employed as an early intervention and a combining therapeutic drug to reduce inflammation and HS formation as well.

Compounds from Chinese herbal medicines as reversal agents for P-glycoprotein-mediated multidrug resistance in tumours

Multidrug resistance (MDR) is a major obstacle to successful cancer chemotherapy. One of the main underlying mechanisms of this resistance is the over-expression of P-glycoprotein (P-gp), an ATP-dependent transmembrane transporter protein encoded by the MDR1 gene. P-gp might transport anti-cancer drugs out of cancer cells and decrease effective intracellular drug concentrations. An effective approach to overcome MDR is to inhibit the function of P-gp or its expression on the surface of cancer cells. Thus, application of MDR reversal agents can be seen as a potentially important means by which to overcome the clinical drug resistance of tumour cells and improve the efficacy of chemotherapy. Recently, research efforts worldwide have focused on reversal mechanisms for MDR and on the identification of reversal agents. Chinese scholars have performed a great deal of exploratory work by screening for efficacy and low toxicity in drug resistance reversal compounds. These compounds may provide more lead compounds with greater activity, leading to the development of more effective therapies for MDR cancer cells. In this review, the function and efficiency of novel compounds derived from traditional Chinese medicines are described.

Ginsenoside Rp1, a Ginsenoside Derivative, Blocks Promoter Activation of iNOS and COX-2 Genes by Suppression of an IKKβ-mediated NF-кB Pathway in HEK293 Cells

Ginsenoside (G) Rp₁ is a ginseng saponin derivative with anti-cancer and anti-inflammatory activities. In this study, we examined the mechanism by which G-Rp₁ inhibits inflammatory responses of cells. We did this using a strategy in which DNA constructs containing cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) promoters were transfected into HEK293 cells. G-Rp₁ strongly inhibited the promoter activities of COX-2 and iNOS; it also inhibited lipopolysaccharide induced upregulation of COX-2 and iNOS mRNA levels in RAW264.7 cells. In HEK293 cells G-Rp₁ did not suppress TANK binding kinase 1-, Toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-β (TRIF)-, TRIFrelated adaptor molecule (TRAM)-, or activation of interferon regulatory factor (IRF)-3 and nuclear factor (NF)-кB by the myeloid differentiation primary response gene (MyD88)-induced. However, G-Rp₁ strongly suppressed NF-кB activation induced by IкB kinase (IKK)β in HEK293 cells. Consistent with these results, G-Rp₁ substantially inhibited IKKβ-induced phosphorylation of IкBɑ and p65. These results suggest that G-Rp₁ is a novel anti-inflammatory ginsenoside analog that can be used to treat IKKβ/NF-кB-mediated inflammatory diseases.

Lipid raft modulation by Rp1 reverses multidrug resistance via inactivating MDR-1 and Src inhibition

Multidrug resistance (MDR) is a major obstacle to effective cancer therapy. The membrane transporter MDR-1 (P-gp, ABCB1), a member of the ATP-binding cassette (ABC) transporter family, effluxes anti-cancer drugs from cancer cells. Increased activity of MDR-1 is known to be the main mechanism for multidrug resistance. MDR-1 is known to be localized in the cholesterol- and sphingolipid-enriched plasma membrane microdomains, known as lipid rafts. Disruption of lipid rafts by cholesterol depletion alters lipid raft functions, indicating that cholesterol is critical for raft function. Because ginsenosides are structurally similar to cholesterol, in this study, we investigated the effect of Rp1, a novel ginsenoside derivative, on drug resistance using drug-sensitive OVCAR-8 and drug-resistant NCI/ADR-RES and DXR cells. Rp1 treatment resulted in an accumulation of doxorubicin or rhodamine 123 by decreasing MDR-1 activity in doxorubicin-resistant cells. Rp1 synergistically induced cell death with actinomycin D in DXR cells. Rp1 appeared to redistribute lipid rafts and MDR-1 protein. Moreover, Rp1 reversed resistance to actinomycin D by decreasing MDR-1 protein levels and Src phosphorylation with modulation of lipid rafts. Addition of cholesterol attenuated Rp1-induced raft aggregation and MDR-1 redistribution. Rp1 and actinomycin D reduced Src activity, and overexpression of active Src decreased the synergistic effect of Rp1 with actinomycin D. Rp1-induced drug sensitization was also observed with several anti-cancer drugs, including doxorubicin. These data suggest that lipid raft-modulating agents can be used to inhibit MDR-1 activity and thus overcome drug resistance.

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.

Cell-type-specific regulation of raft-associated Akt signaling

20S-protopanaxadiol (aPPD) is a metabolite of ginseng saponins, which is reported to be pro-apoptotic in some cells but anti-apoptotic in neuronal cells by regulating Akt signaling. Owing to its cholesterol-like structure, we hypothesized that aPPD may regulate Akt signaling by interacting with lipid rafts. Here, we compared Akt signaling in glioblastoma U87MG and neuroblastoma Neuro-2a cells treated with aPPD. aPPD did not change Akt activity in the total plasma membranes of each cell type, but drastically altered the activity of raft-associated Akt. Strikingly, Akt activity was decreased in the rafts of U87MG cells but increased in N2a cells by aPPD through regulating raft-associated dephosphorylation. The bidirectional regulation of raft-associated Akt signaling by aPPD enhanced the chemotoxicity of Paclitaxel or Vinblastine in U87MG cells but attenuated the excitotoxicity of N-methyl--aspartate in N2a cells. Our results demonstrated that the activity of raft-associated but not total membrane Akt determines its cellular functions. Lipid rafts differ in different types of cells, which allows for the possibility of cell-type-specific targeting for which aPPD might prove to be a useful agent.

Plasma membrane sterol complexation, generated by filipin, triggers signaling responses in tobacco cells

The effects of changes in plasma membrane (PM) sterol lateral organization and availability on the control of signaling pathways have been reported in various animal systems, but rarely assessed in plant cells. In the present study, the pentaene macrolide antibiotic filipin III, commonly used in animal systems as a sterol sequestrating agent, was applied to tobacco cells. We show that filipin can be used at a non-lethal concentration that still allows an homogeneous labeling of the plasma membrane and the formation of filipin-sterol complexes at the ultrastructural level. This filipin concentration triggers a rapid and transient NADPH oxidase-dependent production of reactive oxygen species, together with an increase in both medium alkalinization and conductivity. Pharmacological inhibition studies suggest that these signaling events may be regulated by phosphorylations and free calcium. By conducting FRAP experiments using the di-4-ANEPPDHQ probe and spectrofluorimetry using the Laurdan probe, we provide evidence for a filipin-induced increase in PM viscosity that is also regulated by phosphorylations. We conclude that filipin triggers ligand-independent signaling responses in plant cells. The present findings strongly suggest that changes in PM sterol availability could act as a sensor of the modifications of cell environment in plants leading to adaptive cell responses through regulated signaling processes.

Non-organ-specific preventive effect of long-term administration of Korean red ginseng extract on incidence of human cancers

Previously, two case-control studies and a cohort study strongly suggested that Panax ginseng C.A. Meyer exerted non-organ-specific preventive effects against cancer. The purpose of the present study was to evaluate the effects of red ginseng extract on the incidence of human primary cancer. We conducted a randomized, double-blinded, placebo-controlled trial on 643 chronic atrophic gastritis patients in four hospitals in Zhejiang Province, China. Red ginseng extract powder (1 g) was administered orally to each patient per week for 3 years and followed up for 8 years. The development of various cancers in the red ginseng subjects was compared to that of a placebo group. The red ginseng extract powder was specified in terms of its components. Twenty-four cancers of various organs were diagnosed from these subjects during the 11 years: eight lung cancers, six stomach cancers, two liver cancers, two colorectal cancers, and one cancer each of the nasopharynx, esophagus, pancreas, urinary bladder, prostate, and gallbladder. The red ginseng group, which included both genders, demonstrated a relative cancer risk of 0.54 (95% confidence interval, 0.23-1.28; P = .13) compared to the placebo group, which was not statistically significant. Among the 24 cancer patients, 21 were male. The male red ginseng group showed a relative cancer risk of 0.35 (95% confidence interval, 0.13-0.96; P = .03) compared to the male placebo group, which was highly significant statistically. In the present clinical trial on chronic atrophic gastritis patients, administration of red ginseng extract powder for 3 years exerted significant preventive effects on the incidence of non-organ-specific human cancers in males.

Pharmacology of ginsenosides: a literature review

The therapeutic potential of ginseng has been studied extensively, and ginsenosides, the active components of ginseng, are shown to be involved in modulating multiple physiological activities. This article will review the structure, systemic transformation and bioavailability of ginsenosides before illustration on how these molecules exert their functions via interactions with steroidal receptors. The multiple biological actions make ginsenosides as important resources for developing new modalities. Yet, low bioavailability of ginsenoside is one of the major hurdles needs to be overcome to advance its use in clinical settings.

The distribution of saponins in vivo affects their synergy with chimeric toxins against tumours expressing human epidermal growth factor receptors in mice

BACKGROUND AND PURPOSE

Certain saponins synergize with antitumour drugs to enhance their efficacy, but the mechanisms underlying this synergy in vivo are not well studied. Here, we describe the distribution of Saponinum album (Spn) from Gypsophila paniculata L. in mice after subcutaneous injection.

EXPERIMENTAL APPROACH

The [(3)H]-labelled Spn used for in vivo experiments was biologically active, as it still increased the cytotoxicity of a chimeric toxin in vitro. Distribution of [(3)H]-Spn was measured in BALB/c mice, with or without subcutaneous tumours in the flank. Labelled Spn was subcutaneously injected in the neck, and samples of organs, blood, urine and tumour tissue were analysed for radioactivity, 5-240 min after the injection.

KEY RESULTS

The majority of [(3)H]-Spn distributed within 10 min throughout the entire animal, with high levels of radioactivity in the urine by 30 min. No preferential accumulation in tumour tissue or other organs was observed. In tumour-bearing mice, using a sequential combination of Spn (given first) and a chimeric toxin against the epidermal growth factor receptor, ErbB1, we tested two different pretreatment times for Spn. There was high antitumour efficacy (66% inhibition of tumour growth) after 60 min pre treatment with Spn, but no significant inhibition after 10 min pre treatment with Spn.

CONCLUSIONS AND IMPLICATIONS

[(3)H]-Spn was rapidly cleared from the mice after s.c. injection, and antitumour synergy with chimeric toxins was correlated with the removal of excess Spn from tissues. Disposition of Spn in vivo may critically determine antitumour synergy with chimeric toxins.

Inhibition of tumor growth by targeted toxins in mice is dramatically improved by saponinum album in a synergistic way

The application of targeted toxins in cancer therapy remains a challenge due to the severe side effects as a consequence of the high systemic doses required. Here, we describe the combined application of a glycosylated triterpenoid (Spn) and epidermal growth factor receptor (EGFR)-targeted chimeric toxins (SA2E). The cytotoxicity of SA2E on murine TSA tumor cells transfected with human EGFR was enhanced 20,000-fold by low nonpermeabilizing Spn concentrations in a synergistic manner. Subcutaneous application of Spn and SA2E in BALB/c mice bearing a solid TSA cells transfected with epidermal growth factor receptor tumor resulted in 94% tumor volume reduction with a 50-fold lower chimeric toxin concentration compared with pure SA2E treatment. Side effects as monitored by observable complications, body weight, blood parameters; histologic analyses and antibody responses were only moderate and usually reversible.

Ginseng compounds: an update on their molecular mechanisms and medical applications

Ginseng is one of the most widely used herbal medicines and is reported to have a wide range of therapeutic and pharmacological applications. Ginsenosides, the major pharmacologically active ingredients of ginseng, appear to be responsible for most of the activities of ginseng including vasorelaxation, antioxidation, anti-inflammation and anti-cancer. Approximately 40 ginsenoside compounds have been identified. Researchers now focus on using purified individual ginsenoside to reveal the specific mechanism of functions of ginseng instead of using whole ginseng root extracts. Individual ginsenosides may have different effects in pharmacology and mechanisms due to their different chemical structures. Among them the most commonly studied ginsenosides are Rb1, Rg1, Rg3, Re, Rd and Rh1. The molecular mechanisms and medical applications of ginsenosides have attracted much attention and hundreds of papers have been published in the last few years. The general purpose of this update is to provide information of recently described effects of ginsenosides on antioxidation, vascular system, signal transduction pathways and interaction with receptors. Their therapeutic applications in animal models and humans as well as the pharmacokinetics and toxicity of ginsenosides are also discussed in this review. This review concludes with some thoughts for future directions in the further development of ginseng compounds as effective therapeutic agents.

Ginseng compounds: an update on their molecular mechanisms and medical applications

Ginseng is one of the most widely used herbal medicines and is reported to have a wide range of therapeutic and pharmacological applications. Ginsenosides, the major pharmacologically active ingredients of ginseng, appear to be responsible for most of the activities of ginseng including vasorelaxation, antioxidation, anti-inflammation and anti-cancer. Approximately 40 ginsenoside compounds have been identified. Researchers now focus on using purified individual ginsenoside to reveal the specific mechanism of functions of ginseng instead of using whole ginseng root extracts. Individual ginsenosides may have different effects in pharmacology and mechanisms due to their different chemical structures. Among them the most commonly studied ginsenosides are Rb1, Rg1, Rg3, Re, Rd and Rh1. The molecular mechanisms and medical applications of ginsenosides have attracted much attention and hundreds of papers have been published in the last few years. The general purpose of this update is to provide information of recently described effects of ginsenosides on antioxidation, vascular system, signal transduction pathways and interaction with receptors. Their therapeutic applications in animal models and humans as well as the pharmacokinetics and toxicity of ginsenosides are also discussed in this review. This review concludes with some thoughts for future directions in the further development of ginseng compounds as effective therapeutic agents.

Antiangiogenic effect of capecitabine combined with ginsenoside Rg3 on breast cancer in mice

Capecitabine is a novel fluoropyrimidine carbamate, which has a broader spectrum of antitumor activity than other fluoropyrimidines, such as 5-FU, DFUR, or UFT; it has proved effective over a wide dose range. Recent research has suggested that frequent administration of lower doses of certain chemotherapeutic drugs might enhance their antiangiogenic effect. The present study investigated the antiangiogenic effect of capecitabine on breast cancer. In order to augment its efficacy, we combined capecitabine chemotherapy with ginsenoside Rg3. Our results indicate that a metronomic regimen of capecitabine inhibited angiogenesis in breast cancer, and its antiangiogenic effects may be further enhanced by the concurrent administration of ginsenoside Rg3. As an antiangiogenic method, this regimen presented better antitumor effects, less toxicity, and reduced susceptibility to drug resistance.