Pseudo-Ginsenoside Rh2 induces A549 cells apoptosis via the Ras/Raf/ERK/p53 pathway

A Focused Review on Molecular Signalling Mechanisms of Ginsenosides Anti-Lung Cancer and Anti-inflammatory Activities

BACKGROUND

Ginseng (Panax ginseng Meyer) is a cultivated medicinal herb that has been widely available in the Asian region since the last century. Ginseng root is used worldwide in Oriental medicine. Currently, the global mortality and infection rates for lung cancer and inflammation are significantly increasing. Therefore, various preventative methods related to the activity of ginsenosides have been used for lung cancer as well as inflammation.

METHODS

Web-based searches were performed on Web of Science, Springer, PubMed, and Scopus. A cancer statistical analysis was also conducted to show the current ratio of affected cases and death from lung cancer around the world.

RESULTS

Ginsenosides regulate the enzymes that participate in tumor growth and migration, such as nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (p38 MAPK), c-Jun N-terminal kinase (JNK), extracellular signalregulated kinases 1/2 (ERK1/2), the gelatinase network metalloproteinase-2 (MMP-2/9) and activator protein 1 (AP-1). In addition, ginsenosides also possess anti-inflammatory effects by inhibiting the formation of proinflammatory cytokines (tumor necrosis factor-α) (TNF-α) and interleukin-1β (IL-1β) and controlling the activities of inflammatory signalling pathways, such as NF-κB, Janus kinase2/signal transducer, and activator of transcription 3 (Jak2/Stat3).

CONCLUSION

In several in vitro and in vivo models, P. ginseng showed potential beneficial effects in lung cancer and inflammation treatment. In this review, we provide a detailed and up-to-date summary of research evidence for antilung cancer and anti-inflammatory protective effects of ginsenosides and their potential molecular mechanisms.

Network Pharmacology-Based Prediction and Verification of Ginsenoside Rh2-Induced Apoptosis of A549 Cells via the PI3K/Akt Pathway

Ginsenoside Rh2 (G-Rh2), a rare protopanaxadiol (PPD)-type triterpene saponin, from Panax ginseng has anti-proliferation, anti-invasion, and anti-metastatic activity. However, the mechanisms by which G-Rh2 induces apoptosis of lung cancer cells are unclear. In the present work, a G-Rh2 target-lung cancer network was constructed and analyzed by the network pharmacology approach. A total of 91 compound-targets of G-Rh2 was obtained based on the compound-target network analysis, and 217 targets were identified for G-Rh2 against lung cancer by PPI network analysis. The 217 targets were significantly enriched in 103 GO terms with FDR <0.05 as threshold in the GO enrichment analysis. In KEGG pathway enrichment analysis, all the candidate targets were significantly enriched in 143 pathways, among of which PI3K-Akt signaling pathway was identified as one of the top enriched pathway. Besides, G-Rh2 induced apoptosis in human lung epithelial (A549) cells was verified in this work. G-Rh2 significantly inhibited the proliferation of A549 cells in a dose-dependent manner, and the apoptosis rate significantly increased from 4.4% to 78.7% using flow cytometry. Western blot analysis revealed that the phosphorylation levels of p85, PDK1, Akt and IκBα were significantly suppressed by G-Rh2. All the experimental findings were consistent with the network pharmacology results. Research findings in this work will provide potential therapeutic value for further mechanism investigations.

Ginsenoside Rh2 upregulates long noncoding RNA STXBP5-AS1 to sponge microRNA-4425 in suppressing breast cancer cell proliferation

Background

Ginsenoside Rh2, a major saponin derivative in ginseng extract, is recognized for its anticancer activities. Compared to coding genes, studies on long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) that are regulated by Rh2 in cancer cells, especially on competitive endogenous RNA (ceRNA) are sparse.

Methods

LncRNAs whose promoter DNA methylation level was significantly altered by Rh2 were screened from methylation array data. The effect of STXBP5-AS1, miR-4425, and RNF217 on the proliferation and apoptosis of MCF-7 breast cancer cells was monitored in the presence of Rh2 after deregulating the corresponding gene. The ceRNA relationship between STXBP5-AS1 and miR-4425 was examined by measuring the luciferase activity of a recombinant luciferase/STXBP5-AS1 plasmid construct in the presence of mimic miR-4425.

Results

Inhibition of STXBP5-AS1 decreased apoptosis but stimulated growth of the MCF-7 cells, suggesting tumor-suppressive activity of the lncRNA. MiR-4425 was identified to have a binding site on STXBP5-AS1 and proven to be downregulated by STXBP5-AS1 as well as by Rh2. In contrast to STXBP5-AS1, miR-4425 showed pro-proliferation activity by inducing a decrease in apoptosis but increased growth of the MCF-7 cells. MiR-4425 decreased luciferase activity from the luciferase/STXBP5-AS1 construct by 26%. Screening the target genes of miR-4425 and Rh2 revealed that Rh2, STXBP5-AS1, and miR-4425 consistently regulated tumor suppressor RNF217 at both the RNA and protein level.

Conclusion

LncRNA STXBP5-AS1 is upregulated by Rh2 via promoter hypomethylation and acts as a ceRNA, sponging the oncogenic miR-4425. Therefore, Rh2 controls the STXBP5-AS1/miR-4425/RNF217 axis to suppress breast cancer cell growth.

Current Advances and Outlook in Gastric Cancer Chemoresistance: A Review

BACKGROUND

Surgical resection of the lesion is the standard primary treatment of gastric cancer. Unfortunately, most patients are already in the advanced stage of the disease when they are diagnosed with gastric cancer. Alternative therapies, such as radiation therapy and chemotherapy, can achieve only very limited benefits. The emergence of cancer drug resistance has always been the major obstacle to the cure of tumors. The main goal of modern cancer pharmacology is to determine the underlying mechanism of anticancer drugs.

OBJECTIVE

Here, we mainly review the latest research results related to the mechanism of chemotherapy resistance in gastric cancer, the application of natural products in overcoming the chemotherapy resistance of gastric cancer, and the new strategies currently being developed to treat tumors based on immunotherapy and gene therapy.

CONCLUSION

The emergence of cancer drug resistance is the main obstacle in achieving alleviation and final cure for gastric cancer. Mixed therapies are considered to be a possible way to overcome chemoresistance. Natural products are the main resource for discovering new drugs specific for treating chemoresistance, and further research is needed to clarify the mechanism of natural product activity in patients. .

Advances in Biocatalytic Synthesis, Pharmacological Activities, Pharmaceutical Preparation and Metabolism of Ginsenoside Rh2

Ginsenoside Rh2 (3β-O-Glc-protopanaxadiol), a trace but characteristic pharmacological component of red ginseng, exhibited versatile pharmacological activities, such as antitumor effects, improved cardiac function and fibrosis, anti-inflammatory effects, antibiosis and excellent medicinal potential. In recent years, increased research has been performed on the biocatalytic synthesis of ginsenoside Rh2. In this paper, advances in the biocatalytic synthesis, pharmacological activities, pharmaceutical preparation and metabolism of ginsenoside Rh2 are reviewed.

Anti-Cancer Effect of Panax Ginseng and Its Metabolites: From Traditional Medicine to Modern Drug Discovery

Cancer incidence and mortality rate are growing worldwide. The effectiveness of cancer therapy depends on the degree of cancer development. Anticancer prevention, screening tests, detection of precancerous conditions or cancers at an early stage of development help to prevent the development of cancer, and in the event of cancer development, they provide the best chance for a full recovery. However, in most cases of advanced cancer, there is no method that can fully cure this disease. Recently, natural products have gained more attention in cancer therapy. Panax ginseng (PG), one of the most popular natural products, is reported to have a wide range of pharmacological activities in cancer. Therefore, the anti-cancer effects and mechanisms of PG and its metabolites (compound K, Ginsenoside Rh1, Rh2, Rh3 and F1) in five major cancers (lung cancer, breast cancer, colon cancer, prostate cancer and stomach cancer) are reviewed in this study. It is confirmed that PG and its metabolites regulated apoptosis, epithelial mesenchymal transition (EMT), angiogenesis, cell cycle arrest and multidrug resistance (MDR) in vitro and in vivo cancer models. In particular, ginsenoside Rh2 showed anticancer effects in all five major cancers. This review could improve the understanding of anticancer mechanisms of PG and its metabolites against major five cancers. Further clinical studies are needed for development anti-cancer drugs using PG and its metabolites.

Pseudo-ginsenoside Rh2 Induces Protective Autophagy in Hepatocellular Carcinoma HepG2 Cells

BACKGROUND

Pseudo-ginsenoside-Rh2 (pseudo-G-Rh2), a novel derivative of ginsenoside Rh2, is reported to exert a pro-apoptotic effect on various malignancies. However, whether this anti-cancer action of pseudo-G-Rh2 involves autophagy remains to be determined and explored.

OBJECTIVES

Investigation of pseudo-G-Rh2-induced apoptosis and autophagy and the underlying mechanism.

METHODS

In the present study, the MTT assay was used for evaluating cell viability and the lactate dehydrogenase (LDH) assay was performed to assess cell toxicity. Autophagy evaluation was performed using monodansylcadaverine (MDC) staining and transmission electron microscopy (TEM). The levels of autophagy-associated and apoptosis-associated proteins were determined using Western blotting. The Annexin V FITC/propidium iodide (PI) assay was used to assess apoptosis.

RESULTS

The Annexin V FITC/PI assay revealed that the percentage of apoptotic cells in HepG2 cells at concentrations 0, 20, 40, and 60 μM was 3.75%±1.37%, 5.70%±1.04%, 12.30%±2.10%, and 34.26%±4.73%, respectively. Pseudo-G-Rh2 was observed to significantly increase the expressions of BAX, cleaved-caspase-3, and cleaved-caspase-9, while it decreased the Bcl-2 expression. MDC and TEM analyses revealed that pseudo-G-Rh2 at concentrations 20, 40, and 60 μM significantly facilitated the accumulation of autophagosomes and autolysosomes within the HepG2 cells. Moreover, pseudo-G-Rh2 significantly increased the expressions of LC3 Ⅱ/LC3 Ⅰ, and Beclin-1 and decreased the expression of p62. The Annexin V FITC/PI assay also revealed that in comparison to the pseudo-G-Rh2 group, the concurrent treatment with pseudo-G-Rh2 and an autophagy inhibitor (CQ or 3-MA) significantly induced distinct apoptosis. In addition, pseudo-G-Rh2 activated AMPK and inhibited the PI3K/Akt/mTOR pathway in a concentration-dependent manner. Pseudo-G-Rh2 is similar to the current patents, which enhanced its anti-cancer activity by combining with autophagy inhibitors.

CONCLUSION

Pseudo-G-Rh2 could induce protective autophagy in HepG2 cells, at least in part, via AMPK and the PI3K/Akt/mTOR pathway.

Zearalenone Induces Endothelial Cell Apoptosis through Activation of a Cytosolic Ca2+/ERK1/2/p53/Caspase 3 Signaling Pathway

Zearalenone (ZEN) is a mycotoxin that has been reported to damage various types of cells/tissues, yet its effects on endothelial cells (ECs) have never been investigated. Therefore, this study investigates the potential effects of ZEN using bovine aortic ECs (BAECs). In this study, we found that ZEN induced apoptosis of BAECs through increased cleavage of caspase 3 and poly ADP-ribose polymerase (PARP). ZEN also increased phosphorylation of ERK1/2 and p53, and treatment with the ERK1/2 or p53 inhibitor reversed ZEN-induced EC apoptosis. Transfection of BAECs with small interfering RNA against ERK1/2 or p53 revealed ERK1/2 as an upstream target of p53 in ZEN-stimulated apoptosis. ZEN increased the production of reactive oxygen species (ROS), yet treatment with the antioxidant did not prevent EC apoptosis. Similarly, blocking of estrogen receptors by specific inhibitors also did not prevent ZEN-induced apoptosis. Finally, chelation of cytosolic calcium (Ca²⁺) using BAPTA-AM or inhibition of endoplasmic reticulum (ER) Ca²⁺ channel using 2-APB reversed ZEN-induced EC apoptosis, but not by inhibiting ER stress using 4-PBA. Together, our findings demonstrate that ZEN induces EC apoptosis through an ERK1/2/p53/caspase 3 signaling pathway activated by Ca²⁺ release from the ER, and this pathway is independent of ROS production and estrogen receptor activation.

Perspectives and controversies regarding the use of natural products for the treatment of lung cancer

Lung cancer is the leading cause of cancer‐related mortality both in men and women and accounts for 18.4% of all cancer‐related deaths. Although advanced therapy methods have been developed, the prognosis of lung cancer patients remains extremely poor. Over the past few decades, clinicians and researchers have found that chemical compounds extracted from natural products may be useful for treating lung cancer. Drug formulations derived from natural compounds, such as paclitaxel, doxorubicin, and camptothecin, have been successfully used as chemotherapeutics for lung cancer. In recent years, hundreds of new natural compounds that can be used to treat lung cancer have been found through basic and sub‐clinical research. However, there has not been a corresponding increase in the number of drugs that have been used in a clinical setting. The probable reasons may include low solubility, limited absorption, unfavorable metabolism, and severe side effects. In this review, we present a summary of the natural compounds that have been proven to be effective for the treatment of lung cancer, as well as an understanding of the mechanisms underlying their pharmacological effects. We have also highlighted current controversies and have attempted to provide solutions for the clinical translation of these compounds.

Dual effects of active ERK in cancer: A potential target for enhancing radiosensitivity

Ionizing radiation (IR) is an important cancer treatment approach. However, radioresistance eventually occurs, resulting in poor outcomes in patients with cancer. Radioresistance is associated with multiple signaling pathways, particularly pro-survival signaling pathways. The extracellular signal-regulated kinase 1/2 (ERK1/2) cascade is an important signaling pathway that initiates several cellular processes and is regulated by various stimuli, including IR. Although numerous studies have demonstrated the pro-survival effects of active ERK, activation of ERK has also been associated with cell death, indicating that radiosensitization may occur by ERK stimulation. In this context, the present review describes the associations between ERK signaling, cancer and IR, and discusses the association between ERK and its pro-survival function in cancer cells, including stimuli, molecular mechanisms, clinical use of inhibitors and underlying limitations. Additionally, the present review introduces the view that active ERK may induce cell death, and describes the potential factors associated with this process. This review describes the various outcomes induced by active ERK to prompt future studies to aim to enhance radiosensitivity in the treatment of cancer.

Ginsenoside Rh2 activates α-catenin phosphorylation to inhibit lung cancer cell proliferation and invasion

The efficacy of ginsenoside Rh2 (Rh2) in cancer therapy has been reported; however, its function in lung cancer remains unknown. To analyze the role of Rh2 in the inhibition of lung cancer cell proliferation in the present study, protein expression levels of E-cadherin, vimentin, β-catenin, Smo, Gli1, and α-catenin were assessed by western blotting, whilst mRNA expression levels of TCF7 FZD8, Smo, Gli1, Gli2, and Gli3 were determined by reverse transcription-quantitative PCR in the A549 cell line. Phosphorylation sites were detected by proteomic methods and cell proliferation was analyzed by MTT assay. The present study revealed that Rh2 treatment significantly inhibited cell proliferation. Western blotting indicated that the expression levels of E-cadherin were increased and vimentin was downregulated in Rh2-treated cells compared with control cells. Treatment of A549 cells with Rh2 suppressed phosphorylation of five distinct proteins and increased phosphorylation of nine proteins. Among them, the phosphorylation of α-catenin at S641 was significantly induced. Rh2 treatment suppressed the expression levels of key genes involved in Wnt (Wnt3, transcription factor 7 and frizzled class receptor 8) and hedgehog [smoothened, frizzled class receptor (Smo), GLI family zinc finger (Gli)1, Gli2, and Gli3] signaling. Immunoblotting results indicated that β-catenin, Smo and Gli1 protein expression levels were also suppressed by treatment with Rh2 compared with control treatment. Expression of α-catenin S641D, a phosphomimetic form of α-catenin, inhibited the accumulation of β-catenin and Gli1 and inhibited cell proliferation and invasion. Furthermore, knockdown of β-catenin (CTNNB1) or Gli1 with specific small interfering RNAs inhibited cell proliferation, whereas overexpression of these genes had an opposite effect. Additionally, overexpression of β-catenin or Gli1 activated cell proliferation, even in the presence of Rh2, suggesting that Rh2 affects A549 cell proliferation through inhibition of Wnt and hedgehog signaling by phosphorylation of α-catenin at S641. Together, these data suggested that Rh2 treatment may inhibit the proliferation of A549 lung cancer cells. Further exploration of the underlying mechanism by which Rh2 inhibits cell proliferation is warranted.

Cytotoxic Sesquiterpenes from Sonchus oleraceus

BACKGROUND

Sonchus oleraceus is a large and widespread plant in the world. It is edible to humans as a leaf vegetable and is also used as a folklore medicinal herb in the treatment of infections and inflammatory disease, but limited research on its chemical constituents has been done.

OBJECTIVE

To isolate and identify the bioactive ingredients from S. oleraceus.

METHODS

20kg of S. oleraceus was extracted twice with 75% alcohol. The concentrated extract was suspended in H2O and partitioned with petroleum ether, dichloromethane, ethyl acetate and n-butanol, respectively. The ethyl acetate phase was subjected to repeated normal chromatography on a silica gel column chromatography and eluted with a gradient of CH2Cl2-MeOH to give 12 crude fractions. Fraction 6 was subjected to ODS silica gel column chromatography, Sephadex LH-20 and HPLC to yield 1 and 2. Cell viability of 1 and 2 on A549, H292 and Caco2 cell lines were assayed by MTT method. Apoptosis analysis and apoptosis related proteins were detected subsequently.

RESULTS

Two new sesquiterpenes were isolated from S. oleraceus and identified by NMR spectra and HR-ESIMS. 1 selectively suppressed the viability of A549 and H292 cells with IC50 values of 14.2, and 19.5μM respectively, while possessing no cytotoxicity against Caco2 cells (IC50 > 100μM). 2 did not exhibit cytotoxicity against A549, H292 and Caco2 cells (IC50 > 100μM). 1 significantly decreased the density of live cells and could cause cell apoptosis at 10 and 20μM in a dose-dependent manner. After treatment of 1 for 24h, the level of cleaved caspase-3 was increased accompanied by the reduction in procaspase-3 expression, and the downregulation of Bcl-2 was associated with the enhancement of Bax expression. 1 could lead to the up-regulation of cytochrome c and activation of caspase-9.

CONCLUSION

1 and 2 are new sesquiterpenes from S. oleraceus. 1 could induce apoptosis in A549 and H292 cells through Bax/caspase-9 pathway.

Transcriptome Analyses of the Anti-Proliferative Effects of 20(S)-Ginsenoside Rh2 on HepG2 Cells

20(S)-ginsenoside Rh2 (Rh2), a well-known protopanaxadiol-type ginsenoside from Panax ginseng has especially gained attention for its anticancer activities on various types of human cancer cells. However, the molecular mechanism through which Rh2 promotes apoptosis in hepatocellular carcinoma (HePG2) cells is not known at the transcriptome level. Rh2 can specifically inhibit the proliferation of HePG2 in a dose- and time-dependent manner. Moreover, Rh2 can significantly increase the apoptosis which was related with an increase in protein expression levels of caspase-3, caspase-6, and poly (ADP-ribose) polymerase. Comparison of RNA-seq transcriptome profiles from control group and Rh2-treated group yielded a list of 2116 genes whose expression was significantly affected, which includes 971 up-regulated genes and 1145 down-regulated genes. The differentially expressed genes in p53 signaling pathway and DNA replication may have closely relationships to the cells apoptosis caused by Rh2 treatment. The results of qPCR validation showed that dynamic changes in mRNA, such as CDKN1A, CCND2, PMAIP1, GTSE1, and TP73.

Photoluminescent And Self-Assembled Hyaluronic Acid-Zinc Oxide-Ginsenoside Rh2 Nanoparticles And Their Potential Caspase-9 Apoptotic Mechanism Towards Cancer Cell Lines

Background

Zinc oxide nanoparticles (ZnO NPs) are used in modern cancer therapy based on their specific target, efficacy, low toxicity and biocompatibility. The photocatalytic performance of Zinc oxide (ZnO) nanocomposites with hyaluronic acid (HA) was used to study anticancer properties against various human cancer cell lines.

Methods

Zinc oxide (ZnO) nanocomposites functionalized by hyaluronic acid (HA) were prepared by a co-precipitation method (HA-ZnONcs). The submicron-flower-shaped nanocomposites were further functionalized with ginsenoside Rh2 by a cleavable ester bond via carbodiimide chemistry to form Rh2HAZnO. The physicochemical behaviors of the synthesized ZnO nanocomposites were characterized by various analytical and spectroscopic techniques. We carried out 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay to evaluate the toxicity of Rh2HAZnO in various human cancer cells (A549, MCF-7, and HT29). Furthermore, to confirm the apoptotic effects of Rh2HAZnO and to determine the role of the Caspase-9/p38 MAPK pathways by various molecular techniques such as RT-PCR and Western blotting. Furthermore, Rh2HAZnO induced morphological changes of these cell lines, mainly intracellular reactive oxygen species (ROS) were observed by ROS staining and nucleus by Hoechst staining.

Results

We confirmed that Rh2HAZnO exhibits the anti-cancer effects on A549 lung cancer, HT29 colon cancer, and MCF7 breast cancer cells. Moreover, intracellular reactive oxygen species (ROS) were observed in three cancer cell lines. Rh2HAZnO induced apoptotic process through p53-mediated pathway by upregulating p53 and BAX and downregulating BCL2. Specifically, Rh2HAZnO induced activation of cleaved PARP (Asp214) in A549 lung cancer cells and upregulated Caspase-9/phosphorylation of p38 MAPK in other cell lines (HT29 and MCF-7). Furthermore, Rh2HAZnO induced morphological changes in the nucleus of these cell lines.

Conclusion

These results suggest that the potential anticancer activity of novel Rh2HAZnO nanoparticles might be linked to induction of apoptosis through the generation of ROS by activation of the Caspase-9/p38 MAPK pathway.

Novel ginsenoside-based multifunctional liposomal delivery system for combination therapy of gastric cancer

The clinical treatment of gastric cancer (GC) is hampered by the development of anticancer drug resistance and the unfavorable pharmacokinetics, off-target toxicity, and inadequate intratumoral accumulation of the current chemotherapy treatments. Ginsenosides combined with paclitaxel (PTX) have been shown to exert synergistic inhibition of human GC cell proliferation. In the present study, we developed a novel multifunctional liposome system, in which ginsenosides functioned as the chemotherapy adjuvant and membrane stabilizer. These had long blood circulation times and active targeting abilities, thus creating multifunctionality of the liposomes and facilitating drug administration to the GC cells. Methods: Three ginsenosides with different structures were used to formulate the unique nanocarrier, which was prepared using the thin-film hydration method. The stability of the ginsenoside liposomes was determined by particle size analysis using dynamic light scattering. The long circulation time of ginsenoside liposomes was compared with that of conventional liposome and polyethylene glycosylated liposomes in vivo. The active targeting effect of ginsenoside liposomes was examined with a GC xenograft model using an in vivo imaging system. To examine the antitumor activity of ginsenoside liposomes against GC, MTT, cell cycle, and apoptosis assays were performed on BGC-823 cells in vitro and PTX-loaded ginsenoside liposomes were prepared to evaluate the therapeutic efficacy on GC in vivo. Results: The ginsenosides stabilized the liposomes in a manner similar to cholesterol. We confirmed the successful delivery of the bioactive combination drugs and internalization into GC cells via analysis of the glucose-related transporter recognition and longer blood circulation time. PTX was encapsulated in different liposomal formulations for use as a combination therapy, in which ginsenosides were found to exert their inherent anticancer activity, as well as act synergistically with PTX. The combination therapy using these targeted liposomes significantly suppressed GC tumor growth and outperformed most reported PTX formulations, including Lipusu® and Abraxane®. Conclusion: We established novel ginsenoside-based liposomes as a tumor-targeting therapy, in which ginsenoside functioned not only as a chemotherapy adjuvant, but also as a functional membrane material. Ginsenoside-based liposomes offer a novel platform for anticancer drug delivery and may lead to a new era of nanocarrier treatments for cancer.