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

Upregulation of NK cell activity, cytokine expression, and NF-κB pathway by ginsenoside concentrates from Panax ginseng berries in healthy mice and macrophage cell lines

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng (P. ginseng) C.A. Meyer. Has been studied for decades for its various biological activities, especially in terms of immune-regulatory properties. Traditionally, it has been known that root, leaves, and fruits of P. ginseng were eaten for improving body's Qi and homeostasis. Also, these were used to protect body from various types of infectious diseases. However, molecular mechanisms of immunomodulatory activities of ginseng berries have not been systemically studied as often as other parts of the plant.

AIM OF THE STUDY

The aim of this research is to discover the regulatory effects of P. ginseng berries, more importantly, their ginsenosides, on innate immune responses and to elucidate the molecular mechanism.

MATERIALS AND METHODS

Ginseng berry concentrate (GBC) was orally injected into BALB/c mice for 30 days, and spleens were extracted for evaluation of immune-regulatory effects. Murine macrophage RAW264.7 cells were used for detailed molecular mechanism studies. Splenic natural killer (NK) cells were isolated using the magnetic-activated cell sorting (MACS) system, and the cytotoxic activity of isolated NK cells was measured using a lactate dehydrogenase (LDH) release assay. The splenic immune cell population was determined by flow-cytometry. NF-κB promoter activity was assessed by in vitro luciferase assay. Expression of inflammatory proteins and cytokines of the spleen and RAW264.7 cells were evaluated using western blotting and real-time PCR, respectively.

RESULTS

The GBC enhanced cytotoxic activity of NK cells and the immune-regulation-related splenic cell population. Moreover, GBC promoted NF-κB promoter activity and stimulated the NF-κB signaling cascade. In spleen and RAW264.7 cells, expression of pro-inflammatory cytokines was increased upon GBC application, while expression of anti-inflammatory cytokines decreased.

CONCLUSIONS

These results suggest that P. ginseng berry can stimulate innate immune responses and help maintain a balanced immune condition, mostly due to the action of its key ginsenoside Re, along with other protopanaxadiol- and protopanaxatriol-type ginsenosides. Such finding will provide a new insight into the field of well-being diet research as well as non-chemical immune modulator, by providing nature-derived and plant-based bioactive materials.

Ginsenosides: an immunomodulator for the treatment of colorectal cancer

Ginsenosides, the primary bioactive ingredients derived from the root of Panax ginseng, are eagerly in demand for tumor patients as a complementary and alternative drug. Ginsenosides have increasingly become a "hot topic" in recent years due to their multifunctional role in treating colorectal cancer (CRC) and regulating tumor microenvironment (TME). Emerging experimental research on ginsenosides in the treatment and immune regulation of CRC has been published, while no review sums up its specific role in the CRC microenvironment. Therefore, this paper systematically introduces how ginsenosides affect the TME, specifically by enhancing immune response, inhibiting the activation of stromal cells, and altering the hallmarks of CRC cells. In addition, we discuss their impact on the physicochemical properties of the tumor microenvironment. Furthermore, we discuss the application of ginsenosides in clinical treatment as their efficacy in enhancing tumor patient immunity and prolonging survival. The future perspectives of ginsenoside as a complementary and alternative drug of CRC are also provided. This review hopes to open up a new horizon for the cancer treatment of Traditional Chinese Medicine monomers.

Silencing SIRT1 promotes the anti-HBV action of IFN-α by regulating Pol expression and activating the JAK-STAT signaling pathway

PURPOSE

The purpose this study is to investigate the impact of SIRT1 on the anti-HBV activity of IFN-α and further elucidate its underlying mechanism.

METHODS

HepG2.2.15 cells stably transfected with HBV virus were chosen as the primary study subject. IFN-α was used to stimulate the cells and regulate the expression of SIRT1, and the JAK-STAT pathway and HBV-related indices were measured by qRT-PCR, Western blotting and ELISA. Immunofluorescence (IF) was used to detect the nuclear translocation of STAT1 and STAT2. Coimmunoprecipitation (Co-IP) was used to detect the binding of SIRT1 to HBV Polymerase (Pol).

RESULTS

In HepG2.2.15 cells, we found changes in SIRT1 expression. We show that silencing SIRT1 promotes the IFN-α-triggered Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway and consequently enhances the antiviral effects of IFN-α against HBV replication. Importantly, SIRT1 can interact with Pol and increase JAK-STAT activity by regulating Pol expression. Additionally, the inhibition of SIRT1 activity by treatment with the SIRT1 inhibitor selisistat enhanced the anti-HBV effect of IFN-α and JAK-STAT pathway activity.

CONCLUSION

In conclusion, our results demonstrate that silencing SIRT1 activates the JAK-STAT pathway and enhances the anti-HBV activity of IFN-α by inhibiting Pol expression. This would be a promising therapeutic target to improve the efficacy of IFN-α in the treatment of CHB.

Hypophyllanthin and Phyllanthin from Phyllanthus niruri Synergize Doxorubicin Anticancer Properties against Resistant Breast Cancer Cells

Doxorubicin (DOX) is a cornerstone chemotherapeutic agent for the treatment of several malignancies such as breast cancer; however, its activity is ameliorated by the development of a resistant phenotype. Phyllanthus species have been studied previously for their potential anticancer properties. The current work is aimed to study the potential cytotoxicity and chemomodulatory effects of hypophyllanthin (PN4) and phyllanthin (PN5) isolated from Phyllanthus niruri to DOX against the adriamycin multidrug-resistant breast cancer cells (MCF-7ADR) and elucidate their mechanism of action. The major compounds of the active methylene chloride fraction were isolated and assessed for their potential cytotoxicity and chemomodulatory effects on DOX against naïve (MCF-7) and resistant breast (MCF-7ADR) cancer cells. The mechanism of action of both compounds in terms of their impacts on programmed/non-programmed cell death (apoptosis and autophagy/necrosis), cell cycle progression/arrest, and tumor cell migration/invasion was investigated. Both compounds PN4 and PN5 showed a moderate but similar potency against MCF-7 as well as MCF-7ADR and significantly synergized DOX-induced anticancer properties against MCF-7ADR. The chemomodulatory effect of both compounds to DOX was found to be via potentiating DOX-induced cell cycle interference and apoptosis induction. It was found that PN4 and PN5 blocked the apoptosis-escape autophagy pathway in MCF-7ADR. On the molecular level, both compounds interfered with SIRT1 expression and consequently suppressed Akt phosphorylation, and PN5 blocked apoptosis escape. Furthermore, PN4 and PN5 showed promising antimigratory and anti-invasive effects against MCF-7ADR, as confirmed by suppression of N-cadherin/β-catenin expression. In conclusion, for the first time, hypophyllanthin and phyllanthin isolated from P. niruri showed promising chemomodulatory effects to the DOX-induced chemotherapeutic activity against MCF-7ADR. Both compounds significantly synergized DOX-induced anticancer properties against MCF-7ADR. This enhanced activity was explained by further promoting DOX-induced apoptosis and suppressing the apoptosis-escape autophagy feature of the resistant breast cancer cells. Both compounds (hypophyllanthin and phyllanthin) interfered with the SIRT1/Akt pathway and suppressed the N-cadherin/β-catenin axis, confirming the observed antiproliferative, cytotoxic, and anti-invasive effects of hypophyllanthin and phyllanthin.

Research progress of ginseng in the treatment of gastrointestinal cancers

Cancer has become one of the major causes of human death. Several anticancer drugs are available; howeve their use and efficacy are limited by the toxic side effects and drug resistance caused by their continuous application. Many natural products have antitumor effects with low toxicity and fewer adverse effects. Moreover, they play an important role in enhancing the cytotoxicity of chemotherapeutic agents, reducing toxic side effects, and reversing chemoresistance. Consequently, natural drugs are being applied as potential therapeutic options in the field of antitumor treatment. As natural medicinal plants, some components of ginseng have been shown to have excellent efficacy and a good safety profile for cancer treatment. The pharmacological activities and possible mechanisms of action of ginseng have been identified. Its broad range of pharmacological activities includes antitumor, antibacterial, anti-inflammatory, antioxidant, anti-stress, anti-fibrotic, central nervous system modulating, cardioprotective, and immune-enhancing effects. Numerous studies have also shown that throuth multiple pathways, ginseng and its active ingredients exert antitumor effects on gastrointestinal (GI) tract tumors, such as esophageal, gastric, colorectal, liver, and pancreatic cancers. Herein, we introduced the main components of ginseng, including ginsenosides, polysaccharides, and sterols, etc., and reviewed the mechanism of action and research progress of ginseng in the treatment of various GI tumors. Futhermore, the pathways of action of the main components of ginseng are discussed in depth to promote the clinical development and application of ginseng in the field of anti-GI tumors.

The effects of Ginsenosides on PI3K/AKT signaling pathway

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

Pseudo-sapogenin DQ 3-mimaleate acid derivative induces ovarian carcinoma cell apoptosis via mitochondrial pathway

In the present study, four novel ginsenosides fatty acid and aromatic acid derivatives were designed and synthesized, and their cytotoxic effects on human ovarian carcinoma cells (SKOV3) were assessed using the MTT assay. The results demonstrated that all derivatives inhibited SKOV3 cell growth, and Compound 3 showed the most outstanding anti-proliferative effect on SKOV3 cells. The IC₅₀ value of Compound 3 was 33.8 ± 2.21 μM, less than half of that of cis-platinum (70.1 ± 7.64 μM). Subsequent analysis revealed that Compound 3 could promote SKOV3 cell apoptosis, and the percentage of apoptotic cell population increased with increasing Compound 3 concentrations. In addition, the expression ratios of Bax/Bcl-2, cleaved-Caspase-3/Caspase-3 and cleaved-Caspase-9/Caspase-9 were gradually elevated in Compound 3-treated SKOV3 cells compared with control cells. Furthermore, translocation of Bax to mitochondria was associated with the release of Cytochrome C. Molecular docking analysis revealed three hydrogen-bonds existed in Compound 3 with PARP receptor (PDB code: 5DSY), which may be the target of the anti-ovarian cancer effect of Compound 3. Altogether, our study indicates that Compound 3 induces SKOV3 cell apoptosis via ROS-dependent mitochondrial pathway, and can serve as an anti-cancer agent for treating ovarian carcinoma.

Antibiotic heliomycin and its water-soluble 4-aminomethylated derivative provoke cell death in T24 bladder cancer cells by targeting sirtuin 1 (SIRT1)

Bladder cancer is one of the most frequent cancers among males, and a poor survival rate reflects problems with aggressiveness and chemo-resistance. Accumulating evidence indicates that SIRT1 is involved in bladder cancer tumorigenesis and is positively associated with chemo-resistance and poor prognosis. We recently synthesized water-soluble chemical derivatives of heliomycin, an antibiotic from Streptomyces resistomycificus, and demonstrated that they possess anticancer properties. In this present study, we used the cellular thermal shift assay (CETSA) in T24 bladder cancer cells to show that heliomycin (designated compound (H1)) and its 4-(tert-butylamino)methyl derivative (HD2) directly engaged with SIRT1 in the native cellular environment, whereas another derivative (HD3) did not. Upon binding, heliomycin downregulated SIRT1 protein expression without altering its transcript level, and subsequently induced autophagy. Interestingly, the derivative (HD2) triggered apoptosis. The interaction between SIRT1 protein and heliomycin or its derivatives was also speculated by a molecular docking simulation, suggesting heliomycin (H1) and derivative (HD2) acting with the different binding modes to SIRT1. Given the increased water-solubility, hydrogen bonds were found on Ala262 and Ile347 residues in the docked complex of derivative (HD2) to produce more steady interaction and initiate signaling pathways that were not observed in the case of heliomycin. Meanwhile, it is evident that derivative (HD3) did not engage with SIRT1 by CETSA or molecular docking studies, nor did it downregulate SIRT1 expression. Taken together, these findings clearly show that SIRT1 is targeted and downregulated by heliomycin and its water-soluble 4-aminomethylated derivative (HD2) possibly through autophagic and/or proteasomal degradation, leading to cell death and growth suppression of T24 bladder cancer cells.

A Critical YAP in Malignancy of HCC Is Regulated by Evodiamine

Liver cancer has relatively few early symptoms and is usually diagnosed in the advanced stage. Sorafenib is the only first-line anticancer drug approved by the Food and Drug Administration (FDA) for advanced HCC; however, its use is limited due to resistance. Therefore, the development of new drugs is essential to achieving customized treatment. Many studies have suggested that Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ) is associated with metastasis and cancer formation and progression in various cancers. In the present study, YAP was overexpressed in various patient-derived hepatocarcinoma (HCC) tissues. In addition, this study examined whether evodiamine (which has anticancer effects) can inhibit YAP and, if so, modulate HCC. Evodiamine significantly reduced both the YAP level and cell growth of HCC in a dose-dependent manner. Biochemical analysis indicated mitochondria dysfunction-mediated apoptosis to be the cause of the reduction in HCC cell growth by evodiamine. YAP was overexpressed in metastatic HCC tissues as well when compared to primary HCC tissues. Migration and invasion analysis showed that evodiamine has anti-metastatic ability on Hep3B and Huh-7 cells and reduces the level of vimentin, an EMT marker. In conclusion, YAP is a critical target in HCC therapy, and evodiamine can be an effective HCC anticancer drug by reducing the YAP level.

High glucose mediates apoptosis and osteogenesis of MSCs via downregulation of AKT-Sirt1-TWIST

BACKGROUND

Mesenchymal stem cells have been widely used in the treatment of diabetes mellitus. However, hyperglycemia associated with DM promotes cell apoptosis and affects osteogenic differentiation of MSCs in varying degrees, leading to osteoporosis in DM patients. Therefore, in this paper, the effect of high glucose on apoptosis and osteogenesis of MSCs was investigated and underlying mechanism was further determined.

METHODS AND RESULTS

Intracellular ROS levels were determined using probe DCFH-DA. MMP was detected using JC-1 staining. Cell apoptosis was detected using Annexin V-FITC/PI and Flow Cytometer. The expression of genes and protein was detected by qRT-PCR and Western blot respectively. The results showed high glucose induced MSC apoptosis but promoted its osteogenesis. Western blot analysis revealed that high glucose downregulated AKT-Sirt1-TWIST pathway. Activation of Sirt1 via SRT1720 increased TWIST expression, alleviated MSC apoptosis and promoted osteogenesis of MSCs. TWIST knockdown studies demonstrated that inhibition of TWIST intensified high glucose-induced apoptosis but promoted osteogenesis differentiation of MSCs. TWIST is likely to be a new regulator for cross talk between Sirt1 and its downstream targets.

CONCLUSION

Our data demonstrates that high glucose induces MSC apoptosis and enhances osteogenesis differentiation via downregulation of AKT-Sirt1-TWIST.

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.

A novel stilbene derivative (GMQ3) suppressed proliferation and induced apoptosis in lung cancer via the p38-MAPK/SIRT1 pathway

BACKGROUND

Lung cancer is the primary cause of cancer-related mortality worldwide. The anticancer effect of stilbene has been noted in various tumor types. GMQ3, which has a stilbene-mimicking skeleton, is a novel small-molecule compound with promising antitumor activity. Our results revealed that GMQ3 not only suppressed cell proliferation and cell migration of lung cancer cells but also led to G1 phase cell cycle arrest and triggered caspase-dependent apoptosis. Furthermore, investigation of the molecular mechanism showed that GMQ3 could inhibited proliferation and induced apoptosis via the p38-MAPK/SIRT1 pathway both in vitro and in vivo. Xenograft tumor mouse models showed that GMQ3 significantly inhibited tumor growth in vivo without affecting body weight. Our findings indicated that GMQ3 exerts a strong anticancer action by suppressing cell proliferation, inhibiting cell migration and inducing cell apoptosis. Moreover, the efficacy of GMQ3 was enhanced in the presence of CDK4/6 inhibitor Abemaciclib. We conclude that GMQ3 is a promising agent with potential for lung cancer.

NMNAT1 Is a Survival Factor in Actinomycin D-Induced Osteosarcoma Cell Death

Osteosarcoma is a frequent and extremely aggressive type of pediatric cancer. New therapeutic approaches are needed to improve the overall survival of osteosarcoma patients. Our previous results suggest that NMNAT1, a key enzyme in nuclear NAD+ synthesis, facilitates the survival of cisplatin-treated osteosarcoma cells. A high-throughput cytotoxicity screening was performed to identify novel pathways or compounds linked to the cancer-promoting role of NMNAT1. Nine compounds caused higher toxicity in the NMNAT1 KO U2OS cells compared to their wild type counterparts, and actinomycin D (ActD) was the most potent. ActD-treatment of NMNAT1 KO cells increased caspase activity and secondary necrosis. The reduced NAD+ content in NMNAT1 KO cells was further decreased by ActD, which partially inhibited NAD+-dependent enzymes, including the DNA nick sensor enzyme PARP1 and the NAD+-dependent deacetylase SIRT1. Impaired PARP1 activity increased DNA damage in ActD-treated NMNAT1 knockout cells, while SIRT1 impairment increased acetylation of the p53 protein, causing the upregulation of pro-apoptotic proteins (NOXA, BAX). Proliferation was decreased through both PARP- and SIRT-dependent pathways. On the one hand, PARP inhibitors sensitized wild type but not NMNAT1 KO cells to ActD-induced anti-clonogenic effects; on the other hand, over-acetylated p53 induced the expression of the anti-proliferative p21 protein leading to cell cycle arrest. Based on our results, NMNAT1 acts as a survival factor in ActD-treated osteosarcoma cells. By inhibiting both PARP1- and SIRT1-dependent cellular pathways, NMNAT1 inhibition can be a promising new tool in osteosarcoma chemotherapy.

Anti-Angiogenic Properties of Ginsenoside Rg3 Epimers: In Vitro Assessment of Single and Combination Treatments

Tumour angiogenesis plays a key role in tumour growth and progression. The application of current anti-angiogenic drugs is accompanied by adverse effects and drug resistance. Therefore, finding safer effective treatments is needed. Ginsenoside Rg3 (Rg3) has two epimers, 20(S)-Rg3 (SRg3) and 20(R)-Rg3 (RRg3), with stereoselective activities. Using response surface methodology, we optimised a combination of these two epimers for the loop formation of human umbilical vein endothelial cell (HUVEC). The optimised combination (C3) was tested on HUVEC and two murine endothelial cell lines. C3 significantly inhibited the loop formation, migration, and proliferation of these cells, inducing apoptosis in HUVEC and cell cycle arrest in all of the cell lines tested. Using molecular docking and vascular endothelial growth factor (VEGF) bioassay, we showed that Rg3 has an allosteric modulatory effect on vascular endothelial growth factor receptor 2 (VEGFR2). C3 also decreased the VEGF expression in hypoxic conditions, decreased the expression of aquaporin 1 and affected AKT signaling. The proteins that were mostly affected after C3 treatment were those related to mammalian target of rapamycin (mTOR). Eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1) was one of the important targets of C3, which was affected in both hypoxic and normoxic conditions. In conclusion, these results show the potential of C3 as a novel anti-angiogenic drug.

Pharmacological properties of ginsenosides in inflammation-derived cancers

Ginseng is commonly used as an herbal medicine for improvement of life quality. It is also used as a supplemental medication with anti-cancer drugs to enhance chemotherapy efficacy and shows some beneficial effects. Ginsenosides, also known as saponins, are the major active pharmacological compounds found in ginseng and have been extensively using in treatment of not only cancers but also the other inflammatory diseases such as atherosclerosis, diabetes, acute lung injury, cardiovascular, and infectious diseases. The anti-cancer activities of ginsengs and ginsenosides in different types of cancers have been well studied experimentally and clinically. The major anti-cancer mechanisms of ginseng compounds include inhibition of angiogenesis and metastasis as well as induction of cell cycle arrest and apoptosis. Herein, we review and summarize the current knowledge on the pharmacological effects of ginsengs and ginseng-derived compounds in the treatment of cancers. Moreover, the molecular and cellular mechanism(s) by which ginsengs and ginsenosides modulate the immune response in cancer diseases as well as ginsengs-drugs interaction are also discussed.

Targeting Sirtuin 1 signaling pathway by ginsenosides

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng is a kind of traditional Chinese herbal medicine, known as "king of herbs" and widely used in China, South Korea, and other Asian countries. Ginsenosides are one of active components of Panax ginseng Meyer, which have many pharmacological effects, such as enhancing memory, improving immunity and cardiovascular system, delaying aging, and preventing cancer.

AIMS OF THE REVIEW

This review aims to summarize the recent findings for ginsenosides targeting Sirtuin 1 (SIRT1) signaling pathway for the prevention and treatment of a series of diseases.

MATERIALS AND METHODS

An up-to-August 2020 search was carried out in databases such as PubMed, ScienceDirect, Google Scholar, China National Knowledge Infrastructure, and classic books of traditional Chinese medicine using the keywords: "SIRT1", and/or paired with "ginseng", and "ginsenosides".

RESULTS

SIRT1 is a class-III histone deacetylase (HDAC), a nicotinamide adenine dinucleotide (NAD⁺)-dependent enzyme, which is deeply involved in a series of pathological processes. Based on specific intracellular localization, SIRT1 has various cytoplasmic and nuclear targets and plays a potential role in energy metabolism, oxidative stress, inflammation, tumorigenesis, and aging. Ginsenosides are generally classified into three groups and microbially transformed to final metabolites. Among of them, most ginsenosides have been reported as SIRT1 activators, especially those ginsenosides with two glucopyranosyl groups on the C-3 position. Importantly, many ginsenosides can be used to prevent and treat oxidative stress, inflammation, aging, tumorigenesis, depression, and others by targeting SIRT1 signaling pathway.

CONCLUSIONS

This paper reviews recent evidences of ginsenosides targeting SIRT1 for the first time, which could provide new insights on the preclinical and clinical researches for ginsenosides against multiple disorders.