Ginsenoside 20(S)-Rg3 induced autophagy to inhibit migration and invasion of ovarian cancer

A nanoscale natural drug delivery system for targeted drug delivery against ovarian cancer: action mechanism, application enlightenment and future potential

Ovarian cancer (OC) is one of the deadliest gynecological malignancies in the world and is the leading cause of cancer-related death in women. The complexity and difficult-to-treat nature of OC pose a huge challenge to the treatment of the disease, Therefore, it is critical to find green and sustainable drug treatment options. Natural drugs have wide sources, many targets, and high safety, and are currently recognized as ideal drugs for tumor treatment, has previously been found to have a good effect on controlling tumor progression and reducing the burden of metastasis. However, its clinical transformation is often hindered by structural stability, bioavailability, and bioactivity. Emerging technologies for the treatment of OC, such as photodynamic therapy, immunotherapy, targeted therapy, gene therapy, molecular therapy, and nanotherapy, are developing rapidly, particularly, nanotechnology can play a bridging role between different therapies, synergistically drive the complementary role of differentiated treatment schemes, and has a wide range of clinical application prospects. In this review, nanoscale natural drug delivery systems (NNDDS) for targeted drug delivery against OC were extensively explored. We reviewed the mechanism of action of natural drugs against OC, reviewed the morphological composition and delivery potential of drug nanocarriers based on the application of nanotechnology in the treatment of OC, and discussed the limitations of current NNDDS research. After elucidating these problems, it will provide a theoretical basis for future exploration of novel NNDDS for anti-OC therapy.

Regulation of Autophagy Signaling Pathways by Ginseng Saponins: A Review

Ginseng saponins (ginsenosides), bioactive compounds derived from ginseng, are widely used natural products with potent therapeutic properties in the management of various ailments, particularly tumors, cardiovascular and cerebrovascular diseases, and immune system disorders. Autophagy, a highly regulated and multistep process involving the breakdown of impaired organelles and macromolecules by autophagolysosomes and autophagy-related genes (ATGs), has gained increasing attention as a potential target for ginsenoside-mediated disease treatment. This review aims to provide a comprehensive overview of recent research advances in the understanding of autophagy-related signaling pathways and the role of ginsenoside-mediated autophagy regulation. By delving into the intricate autophagy signaling pathways underpinning the pharmacological properties of ginsenosides, we highlight their therapeutic potential in addressing various conditions. Our findings serve as a comprehensive reference for further investigation into the medicinal properties of ginseng or ginseng-related products.

Ginsenosides in cancer: Proliferation, metastasis, and drug resistance

Ginseng, the dried root of Panax ginseng C.A. Mey., is widely used in Chinese herbal medicine. Ginsenosides, the primary active components of ginseng, exhibit diverse anticancer functions through various mechanisms, such as inhibiting tumor cell proliferation, promoting apoptosis, and suppressing cell invasion and migration. In this article, the mechanism of action of 20 ginsenoside subtypes in tumor therapy and the research progress of multifunctional nanosystems are reviewed, in order to provide reference for clinical prevention and treatment of cancer.

Ginsenoside 20(S)-Rg3 reduces KIF20A expression and promotes CDC25A proteasomal degradation in epithelial ovarian cancer

Background

Ginsenoside 20(S)-Rg3 shows promising tumor-suppressive effects in ovarian cancer via inhibiting NF-κB signaling. This study aimed to explore the downstream tumor suppressive mechanisms of ginsenoside Rg3 via this signaling pathway.

Materials and methods

A systematical screening was applied to examine the expression profile of 41 kinesin family member genes in ovarian cancer. The regulatory effect of ginsenoside Rg3 on KIF20A expression was studied. In addition, we explored interacting proteins of KIF20A and their molecular regulations in ovarian cancer. RNA-seq data from The Cancer Genome Atlas (TCGA) was used for bioinformatic analysis. Epithelial ovarian cancer cell lines SKOV3 and A2780 were used as in vitro and in vivo cell models. Commercial human ovarian cancer tissue arrays were used for immunohistochemistry staining.

Results

KIF20A is a biomarker of poor prognosis among the kinesin genes. It promotes ovarian cancer cell growth in vitro and in vivo. Ginsenoside Rg3 can suppress the transcription of KIF20A. GST pull-down and co-immunoprecipitation (IP) assays confirmed that KIF20A physically interacts with BTRC (β-TrCP1), a substrate recognition subunit for SCFβ-TrCP E3 ubiquitin ligase. In vitro ubiquitination and cycloheximide (CHX) chase assays showed that via interacting with BTRC, KIF20A reduces BTRC-mediated CDC25A poly-ubiquitination and enhances its stability. Ginsenoside Rg3 treatment partly abrogates KIF20A overexpression-induced CDC25A upregulation.

Conclusion

This study revealed a novel anti-tumor mechanism of ginsenoside Rg3. It can inhibit KIF20A transcription and promote CDC25A proteasomal degradation in epithelial ovarian cancer.

How ginseng regulates autophagy: Insights from multistep process

BACKGROUND

Although autophagy is a recognized contributor to the pathogenesis of human diseases, chloroquine and hydroxychloroquine are the only two FDA-approved autophagy inhibitors to date. Emerging evidence has revealed the potential therapeutic benefits of various extracts and active compounds isolated from ginseng, especially ginsenosides and their derivatives, by mediating autophagy. Mechanistically, active components from ginseng mediate key regulators in the multistep processes of autophagy, namely, initiation, autophagosome biogenesis and cargo degradation.

AIM OF REVIEW

To date, a review that systematically described the relationship between ginseng and autophagy is still lacking. Breakthroughs in finding the key players in ginseng-autophagy regulation will be a promising research area, and will provide positive insights into the development of new drugs based on ginseng and autophagy.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Here, we comprehensively summarized the critical roles of ginseng-regulated autophagy in treating diseases, including cancers, neurological disorders, cardiovascular diseases, inflammation, and neurotoxicity. The dual effects of the autophagy response in certain diseases are worthy of note; thus, we highlight the complex impacts of both ginseng-induced and ginseng-inhibited autophagy. Moreover, autophagy and apoptosis are controlled by multiple common upstream signals, cross-regulate each other and affect certain diseases, especially cancers. Therefore, this review also discusses the cross-signal transduction pathways underlying the molecular mechanisms and interaction between ginseng-regulated autophagy and apoptosis.

The treatment efficacy of three-layered functional polymer materials as drug carrier for orthotopic colon cancer

Colorectal cancer (CRC) is a worldwide disease posing serious threats to people’s life. Surgery and postsurgical chemotherapy are still the first choices to control the rapid progression of cancer. However, tumor recurrence and even distant metastasis are prone to occur. As a result, it is in urgent demand to find a new method to control CRC progression while inhibiting distant metastasis. On this basis, this study developed the three-layered functionalized hydrogel-fibrous membrane-hydrogel composite materials. The Chinese traditional drugs 20 (S)-ginsenoside Rg3 (Rg3) and chemotherapeutic agent 5-fluorouracil (5-Fu) were loaded in the inner hydrogel and middle fibrous membrane and could be constantly released at the same time and space. The outer hydrogel was decorated with phenylboronic acid (PA) to interact with sialic acid expressed on the CRC cell surface. The composite materials possessed biocompatibility and showed no toxicity to normal human intestinal mucosa endothelial cells HIEC. According to the results, the cell viability of CT26 could be significantly decreased in vitro. The three-layered functionalized materials inhibited the original tumor progression and distant tumor metastasis to the liver in an orthotopic colon cancer mouse model by increasing the caspase3 expression and inhibiting the expressions of Bcl-2, Ki-67, and VEGF. In addition, the functions of major organs were not significantly damaged. Our study provides a safe and efficacious method of this three-layered functionalized hydrogel-fibrous membrane-hydrogel composite materials for CRC treatment.

Salvia chinensia Benth induces autophagy in esophageal cancer cells via AMPK/ULK1 signaling pathway

Salvia chinensia Benth (Shijianchuan in Chinese, SJC) has been used as a traditional anti-cancer herb. SJC showed good anti-esophageal cancer efficacy based on our clinical application. However, the current research on SJC is minimal, and its anti-cancer effect lacks scientific certification. This study aims to clarify the inhibitory effect of SJC on esophageal cancer and explore its underlying mechanism. Q-Orbitrap high-resolution LC/MS was used to identify the primary chemical constituents in SJC. Cell proliferation and colony formation assays showed that SJC could effectively inhibit the growth of esophageal tumor cells in vitro. To clarify its mechanism of action, proteomic and bioinformatic analyses were carried out by combining tandem mass labeling and two-dimensional liquid chromatography-mass spectrometry (LC-MS). Data are available via ProteomeXchange with identifier PXD035823. The results indicated that SJC could activate AMPK signaling pathway and effectively promote autophagy in esophageal cancer cells. Therefore, we further used western blotting to confirm that SJC activated autophagy in esophageal cancer cells through the AMPK/ULK1 signaling pathway. The results showed that P-AMPK and P-ULK1 were significantly up-regulated after the treatment with SJC. The ratio of autophagosomes marker proteins LC3II/I was significantly increased. In addition, the expression of the autophagy substrate protein P62 decreased with the degradation of autophagosomes. Using lentiviral transfection of fluorescent label SensGFP-StubRFP-LC3 protein and revalidation of LC3 expression before and after administration by laser confocal microscopy. Compared with the control group, the fluorescence expression of the SJC group was significantly enhanced, indicating that it promoted autophagy in esophageal cancer cells. Cell morphology and the formation of autophagosomes were observed by transmission electron microscopy. Our study shows that the tumor suppressor effect of SJC is related to promoting autophagy in esophageal tumor cells via the AMPK/ULK1 signaling pathway.

Ginseng of different ages is affected by the accumulation of heavy metals in ginseng soil

Heavy-metal pollution has been established to affect ginseng quality. However, this effect is still unknown in ginseng of different ages, emphasizing the need to investigate the effects of heavy metals in soils on ginseng growth. Herein, we determined the content of heavy metals (Cu, Cd, Pb, Hg, and As) in ginseng of different ages (2 to 6-year-old) and the corresponding soil samples. Then, the total ginsenosides content of ginseng and rate-limiting enzyme (HMGR, SQE, CYP450) activity in the synthesis of ginsenosides were assessed. Results from 200 differently-aged Chinese ginseng showed that increased ginsenoside content in 3 to 5-year-old ginseng was paralleled by increased heavy metal element content in ginseng and its soil. The activity of rate-limiting enzymes increased in the first four years of ginseng growth and then exhibited a steady or downward trend. Further analysis suggested that heavy metal elements in soils could directly affect ginsenoside content. Moreover, we found that Cu significantly affected the rate-limiting enzyme CYP450 activity. Further principal component analysis and correlation analysis found that heavy metals could obviously inhibit ginseng growth during the 5th and 6th years. Heavy metal content in soils has huge prospects for predicting ginsenoside, Cu and As content in ginseng. This study provided support for ginseng cultivation, quality research and quality assessment.

Bioactive components of Banxia Xiexin Decoction for the treatment of gastrointestinal diseases based on flavor-oriented analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Banxia Xiexin Decoction (BXD) was first recorded in a Chinese medical classic, Treatise on Febrile Diseases and Miscellaneous Diseases, which was written in the Eastern Han dynasty of China. This ancient prescription consists of seven kinds of Chinese herbal medicine, namely, Pinellia ternata, Rhizoma Coptidis, Radix scutellariae, Rhizoma Zingiberis, Ginseng, Jujube, and Radix Glycyrrhizaepreparata. In clinic practice, its original application in China mainly has focused on the treatment of chronic gastritis for several hundred years. BXD is also effective in treating other gastrointestinal diseases (GIDs) in modern medical application. Despite available literature support and clinical experience, the treatment mechanisms or their relationships with the bioactive compounds in BXD responsible for its pharmacological actions, still need further explorations in more diversified channels. According to the analysis based on the five-flavor theory of TCM, BXD is traditionally viewed as the most representative prescription for pungent-dispersion, bitter-purgation and sweet-tonification. Consequently, based on the flavor-oriented analysis, the compositive herbs in BXD can be divided into three flavor groups, namely, the pungent, bitter, and sweet groups, each of which has specific active ingredients that are possibly relevant to GID treatment.

AIM OF THE REVIEW

This paper summarized recent literatures on BXD and its bioactive components used in GID treatment, and provided the pharmacological or chemical basis for the further exploration of the ancient prescription and the relative components.

METHOD

ology: Relevant literature was collected from various electronic databases such as Pubmed, Web of Science, and China National Knowledge Infrastructure (CNKI). Citations were based on peer-reviewed articles published in English or Chinese during the last decade.

RESULTS

Multiple components were found in the pungent, bitter, and sweet groups in BXD. The corresponding bioactive components include gingerol, shogaol, stigmasterol, and β-sitosterol in the pungent group; berberine, palmatine, coptisine, baicalein, and baicalin in the bitter group; and ginsenosides, polysaccharides, liquiritin, and glycyrrhetinic acid in the sweet group. These components have been found directly or indirectly responsible for the remarkable effects of BXD on GID.

CONCLUSION

This review provided some valuable reference to further clarify BXD treatment for GID and their possible material basis, based on the perspective of the flavor-oriented analysis.

Non-apoptotic cell death in ovarian cancer: Treatment, resistance and prognosis

Ovarian cancer is mostly diagnosed at an advanced stage due to the absence of effective screening methods and specific symptoms. Repeated chemotherapy resistance and recurrence before PARPi are used as maintenance therapies, lead to low survival rates and poor prognosis. Apoptotic cell death plays a crucial role in ovarian cancer, which is proved by current researches. With the ongoing development of targeted therapy, non-apoptotic cell death has shown substantial potential in tumor prevention and treatment, including autophagy, ferroptosis, necroptosis, immunogenic cell death, pyroptosis, alkaliptosis, and other modes of cell death. We systematically reviewed the research progress on the role of non-apoptotic cell death in the onset, development, and outcome of ovarian cancer. This review provides a more theoretical basis for exploring therapeutic targets, reversing drug resistance in refractory ovarian cancer, and establishing risk prediction models that help realize the clinical transformation of vital drugs.

Efficacy of ginsenoside Rg3 nanoparticles against Ehrlich solid tumor growth in mice

Solid tumors are fairly common and face many clinical difficulties since they are hardly surgically resectable and broadly do not respond to radiation and chemotherapy. The current study aimed to fabricate ginsenoside Rg3 nanoparticles (Rg3-NPs) and evaluate their antitumor effect against Ehrlich solid tumors (EST) in mice. Rg3-NPs were fabricated using whey protein isolates (WPI), maltodextrin (MD), and gum Arabic (GA). EST was developed by the injection of mice with Ehrlich ascites cells (2.5 × 10⁶). The mice were divided into a control group, EST group, and the EST groups that were treated orally 2 weeks for with normal Rg3 (3 mg/kg b.w.), Rg3-NPs at a low dose (3 mg/kg b.w.), and Rg3-NPs at a high dose (6 mg/kg b.w.). Serum and solid tumors were collected for different assays. The results revealed that synthesized Rg3-NPs showed a spherical shape with an average particle size of 20 nm and zeta potential of -5.58 mV. The in vivo study revealed that EST mice showed a significant increase in AFP, Casp3, TNF-α, MMP-9, VEGF, MDA, and DNA damage accompanied by a significant decrease in SOD and GPx. Treatment with Rg3 or Rg3-NPs decreased the tumor weight and size and induced a significant improvement in all the biochemical parameters. Rg3-NPs were more effective than Rg3, and the improvement was dose-dependent. It could be concluded that fabrication of Rg3-NPs enhanced the protective effect against EST development which may be due to the synergistic effect of Rg3 and MD, GA, and WPI.

Low Expression of SLC7A11 Confers Drug Resistance and Worse Survival in Ovarian Cancer via Inhibition of Cell Autophagy as a Competing Endogenous RNA

Drug resistance is the main cause of chemotherapy failure in ovarian cancer (OC), and identifying potential druggable targets of autophagy is a novel and promising approach to overcoming drug resistance. In this study, 131 genes associated with autophagy were identified from three autophagy-related databases, and of these, 14 were differentially expressed in 90 drug-resistant OC tissues versus 197 sensitive tissues according to the Cancer Genome Atlas ovarian cancer cohort. Among these 14 genes, SLC7A11 was significantly decreased in two paclitaxel-resistant OC cells (HeyA8-R and SKOV3-R) and in 90 drug-resistant tissues compared with their controls. In vitro overexpression of SLC7A11 significantly increased the sensitivity of HeyA8-R cells to paclitaxel, inhibited colony formation, induced apoptosis, and arrested cell cycle. Further, low SLC7A11 expression was correlated with poor overall survival (OS), progression-free survival (PFS), and post-progression survival (PPS) in 1815 OC patients. Mechanistically, SLC7A11 strongly regulated cell autophagy as a competing endogenous RNA (ceRNA) based on pan-cancer analyses of 32 tumor types. Specifically, as a ceRNA for autophagy genes STX17, RAB33B, and UVRAG, SLC7A11 was strongly and positively co-expressed with these three genes in 20, 12, and 12 different tumors, respectively, in 379 OC tissues and in 90 drug-resistant OC tissues, and the former two were significantly upregulated in SLC7A11-overexpressed HeyA8-R cells. Further, SLC7A11 induced the protein expression of other autophagy genes, such as LC3, Atg16L1, and Atg7, and the expression of the respective proteins was further increased when the cells were treated with paclitaxel. The results strongly suggest that SLC7A11 regulates autophagy via ceRNA interactions with the three abovementioned genes in pan-cancer and in drug-resistant OC. Moreover, low expression of STX17 and UVRAG also significantly predicted low OS, PFS, and PPS. The combination of SLC7A11 with STX17 was more predictive of OS and PFS than either individually, and the combination of SLC7A11 with UVRAG was highly predictive of OS and PPS. The above results indicated that decreased SLC7A11 resulted in drug resistance and effected low rates of survival in OC patients, probably via ceRNA interactions with autophagy genes, and thus the gene could serve as a therapeutic target and potential biomarker in OC.

Ginsenoside 20(S)-Rg3 suppresses cell viability in esophageal squamous cell carcinoma via modulating miR-324-5p-targeted PSME3

Ginsenoside 20(S)-Rg3 is identified as an active saponin monomer which derived from red ginseng and is demonstrated to play an anti-tumor role in diverse cancers. MicroRNAs (miRNAs) are important regulators in the progression of cancers, containing esophageal squamous cell carcinoma (ESCC). It was reported that microRNA 324-5p (miR-324-5p) exerted critical functions in some cancers; however, the detailed molecular mechanism of miR-324-5p mediated by 20(S)-Rg3 to suppress cell viability in ESCC has not been explored. Herein, we explored the function of 20(S)-Rg3 or miR-324-5p on ESCC cell viability by MTT assay, colony formation assay, flow cytometry analysis and western blot analysis. The binding of miR-324-5p to its target gene, proteasome activator subunit 3 (PSME3), was confirmed through RNA pull down and luciferase reporter assays. The results indicated that 20(S)-Rg3 significantly inhibited cell viability and the cell cycle and facilitated cell apoptosis. Furthermore, this effect was strengthened with the increased concentration of 20(S)-Rg3. Moreover, we found that miR-324-5p level was increased under 20(S)-Rg3 treatment. Additionally, overexpressed miR-324-5p inhibited ESCC cell viability, and downregulated miR-324-5p recovered inhibited cell viability caused by 20(S)-Rg3. Further exploration verified that miR-324-5p targeted PSME3, and PSME3 deficiency countervailed the effect of miR-324-5p inhibition on ESCC cell viability under 20(S)-Rg3 treatment. Conclusively, 20(S)-Rg3 suppresses cell viability in ESCC via mediating miR-324-5p-targeted PSME3.

Burmannic Acid Inhibits Proliferation and Induces Oxidative Stress Response of Oral Cancer Cells

Burmannic acid (BURA) is a new apocarotenoid bioactive compound derived from Indonesian cinnamon; however, its anticancer effect has rarely been investigated in oral cancer cells. In this investigation, the consequences of the antiproliferation of oral cancer cells effected by BURA were evaluated. BURA selectively suppressed cell proliferation of oral cancer cells (Ca9-22 and CAL 27) but showed little cytotoxicity to normal oral cells (HGF-1). In terms of mechanism, BURA perturbed cell cycle distribution, upregulated mitochondrial superoxide, induced mitochondrial depolarization, triggered γH2AX and 8-hydroxy-2-deoxyguanosine DNA damage, and induced apoptosis and caspase 3/8/9 activation in oral cancer cells. Application of N-acetylcysteine confirmed oxidative stress as the critical factor in promoting antiproliferation, apoptosis, and DNA damage in oral cancer cells.

The Sonic Hedgehog signaling pathway regulates autophagy and migration in ovarian cancer

Background

The Sonic Hedgehog (SHH) signaling pathway plays an important role in various types of human cancers including ovarian cancer; however, its function and underlying mechanism in ovarian cancer are still not entirely understood.

Methods

We detected the expressions of SHH and SQSTM1 in borderline ovarian tumor tissues, epithelial ovarian cancer (EOC) tissues and benign ovarian tumor tissues. Cyclopamine (Cyp, a well‐known inhibitor of SHH signaling pathway) and chloroquine (CQ, the pharmaceutical inhibitor of autophagy) were used in vivo and in vitro (autophagic flux, CCK‐8 assay, wound healing assay, transwell assay, tumor xenograft model). The mechanism of action was explored through Quantitative RT‐PCR and Western Blot.

Results

We found up‐regulation of SHH and accumulation of SQSTM1/P62 in epithelial ovarian cancer. Cyp induced autophagy through the PI3K/AKT signaling pathway. Moreover, low‐dose Cyp and chloroquine (CQ) significantly promoted the migratory ability of SKOV3 cells.

Conclusions

Our findings suggest that inhibition of the SHH pathway and autophagy may be a potential and effective therapy for the treatment of ovarian cancer.

Paving the Road Toward Exploiting the Therapeutic Effects of Ginsenosides: An Emphasis on Autophagy and Endoplasmic Reticulum Stress

Programmed cell death processes such as apoptosis and autophagy strongly contribute to the onset and progression of cancer. Along with these lines, modulation of cell death mechanisms to combat cancer cells and elimination of resistance to apoptosis is of great interest. It appears that modulation of autophagy and endoplasmic reticulum (ER) stress with specific agents would be beneficial in the treatment of several disorders. Interestingly, it has been suggested that herbal natural products may be suitable candidates for the modulation of these processes due to few side effects and significant therapeutic potential. Ginsenosides are derivatives of ginseng and exert modulatory effects on the molecular mechanisms associated with autophagy and ER stress. Ginsenosides act as smart phytochemicals that confer their effects by up-regulating ATG proteins and converting LC3-I to -II, which results in maturation of autophagosomes. Not only do ginsenosides promote autophagy but they also possess protective and therapeutic properties due to their capacity to modulate ER stress and up- and down-regulate and/or dephosphorylate UPR transducers such as IRE1, PERK, and ATF6. Thus, it would appear that ginsenosides are promising agents to potentially restore tissue malfunction and possibly eliminate cancer.

Triptolide inhibits JAK2/STAT3 signaling and induces lethal autophagy through ROS generation in cisplatin‑resistant SKOV3/DDP ovarian cancer cells

Advanced and recurrent ovarian cancer has a poor prognosis and is frequently resistant to numerous therapeutics; thus, safe and effective drugs are needed to combat this disease. Previous studies have demonstrated that triptolide (TPL) exhibits anticancer and sensitization effects against cisplatin (DDP)-resistant ovarian cancer both in vitro and in vivo by inducing apoptosis; however, the involvement of autophagy induced by TPL in resistant ovarian carcinoma remains unclear. In the present study, the results revealed that TPL induced autophagy to facilitate SKOV3/DDP ovarian cancer cell death. The xenograft experiment revealed that the autophagy inhibitor CQ significantly reduced TPL-mediated chemosensitization and tumor growth inhibition. Mechanically, TPL-induced autophagy in SKOV3/DDP cells was associated with the induction of ROS generation and inhibition of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription-3 (STAT3) pathway. The inhibitory effect of TPL on the JAK2/STAT3 pathway could be restored in the presence of the antioxidant NAC. Furthermore, it was further determined that TPL disrupted the interaction between Mcl-1 and Beclin1, which was prevented by the JAK2/STAT3 signaling activator IL-6. Overall, the present results revealed a novel molecular mechanism whereby TPL induced lethal autophagy through the ROS-JAK2/STAT3 signaling cascade in SKOV3/DDP cells. The present study has provided the groundwork for future application of TPL in the treatment of ovarian cancer.

Insights into the antitumor mechanism of ginsenosides Rg3

Panax ginseng, an ancient herb, belonging to Chinese traditional medicine, is an important herb that has a remarkable impact on various diseases. Ginsenoside Rg3, one of the most abundant ginsenosides, exerts significant functions in the prevention of various types of cancers with few side effects. In the present review, its functional molecular mechanisms are explored, including the improvement of antioxidant and anti-inflammation properties, immune regulation, induction of tumor apoptosis, prevention of tumor invasion and metastasis, tumor proliferation and angiogenesis, and reduction of chemoresistance and radioresistance. On the other hand, metabolism, pharmacokinetics and clinical indications of Rg3 are also discussed. The biological functional role of ginsenoside Rg3 may be associated with that it is a steroid glycoside with diverse biological activities and many signaling pathway can be regulated. Many clinical trials are highly needed to confirm the functions of ginsenoside Rg3.

The inhibitory effect of TU-100 on hepatic stellate cell activation in the tumor microenvironment

INTRODUCTION

The tumor microenvironment is involved in acquiring tumor malignancies of colorectal liver metastasis (CRLM). We have reported that TU-100 (Daikenchuto) suppresses hepatic stellate cell (HSC) activation in obstructive jaundice. In this study, we report new findings as the direct and indirect inhibitory effects of TU-100 on cancer cell growth through the suppression of HSC activation.

MATERIALS AND METHODS

The HSCs (LX2) were cultured in colon cancer cells (HCT116 and HT29)-conditioned medium (CM) with or without TU-100 treatment (90, 270, 900 μg/ml). Activated HSCs (aHSCs) were detected by α-SMA and IL-6 mRNA expressions and cytokine arrays of HSC's culture supernatants. Cancer cell growth was analyzed for proliferation and migration ability, compared with TU-100 treatment. To investigate the direct anti-tumor effect of TU-100, cancer cells were cultured in the presence of aHSC-CM and TU-100 (90, 270, 900) or aHSC-CM alone, and assessed autophagosomes, conversion to LC3-II protein, and Beclin-1 mRNA expression.

RESULTS

Colon cancer-CM significantly increased α-SMA and IL-6 mRNA expressions of aHSC. α-SMA and IL-6 mRNA expressions of aHSC, and IL-6 secretions from aHSCs were significantly decreased with TU-100 (270, 900) treatment, compared to colon cancer-CM alone. Compared with normal culture medium, aHSC-CM led to a significantly increased cell number and modified HSC-CM (TU-100; 270, 900) significantly suppressed cancer cell growth and migration. TU-100 (900) treatment induced autophagy and significantly promoted the autophagic cell death.

CONCLUSIONS

TU-100 inhibited colon cancer cell malignant potential by both suppressing HSC activation and inducing directly autophagy of cancer cells.

Recent Advances in Characterizing Natural Products that Regulate Autophagy

Autophagy, an intricate response to nutrient deprivation, pathogen infection, Endoplasmic Reticulum (ER)-stress and drugs, is crucial for the homeostatic maintenance in living cells. This highly regulated, multistep process has been involved in several diseases including cardiovascular and neurodegenerative diseases, especially in cancer. It can function as either a promoter or a suppressor in cancer, which underlines the potential utility as a therapeutic target. In recent years, increasing evidence has suggested that many natural products could modulate autophagy through diverse signaling pathways, either inducing or inhibiting. In this review, we briefly introduce autophagy and systematically describe several classes of natural products that implicated autophagy modulation. These compounds are of great interest for their potential activity against many types of cancer, such as ovarian, breast, cervical, pancreatic, and so on, hoping to provide valuable information for the development of cancer treatments based on autophagy.

Antitumor effects and molecular mechanisms of action of natural products in ovarian cancer

Ovarian cancer is a common malignancy and the second leading cause of mortality among females with genital tract cancer. At present, postoperative platinum drugs and paclitaxel-based chemotherapy is the gold standard treatment for ovarian cancer. However, patients who receive this chemotherapy often develop cumulative toxic effects and are prone to chemotherapy resistance. Therefore, it is necessary to determine more effective treatment options that would be better tolerated by patients. Recent studies have reported the therapeutic effects of numerous natural products in patients with ovarian cancer. Notably, these natural ingredients do not induce adverse effects in healthy cells and tissues, suggesting that natural products may serve as a safe alternative treatment for ovarian cancer. The antitumor effects of natural products are attributed to suppression of cell proliferation and metastasis, stimulation of autophagy, improved chemotherapy sensitivity, and induction of apoptosis. The present review focused on the antitumor effects of several natural products, including curcumin, resveratrol, ginsenosides, (-)-epigallocatechin-3-gallate and quercetin, which are increasingly being investigated as therapeutic options in ovarian cancer, and discussed the molecular mechanisms involved in cell proliferation, apoptosis, autophagy, metastasis and sensitization.

Anticancer activities of phytoconstituents and their liposomal targeting strategies against tumor cells and the microenvironment

Various bioactive ingredients have been extracted from Chinese herbal medicines (CHMs) that affect tumor progression and metastasis. To further understand the mechanisms of CHMs in cancer therapy, this article summarizes the effects of five categories of CHMs and their active ingredients on tumor cells and the tumor microenvironment. Despite their treatment potential, the undesirable physicochemical properties (poor permeability, instability, high hydrophilicity or hydrophobicity, toxicity) and unwanted pharmacokinetic profiles (short half-life in blood and low bioavailability) restrict clinical studies of CHMs. Therefore, development of liposomes through relevant surface modifying techniques to achieve targeted CHM delivery for cancer cells, i.e., extracellular and intracellular targets and targets in tumor microenvironment or vasculature, have been reviewed. Current challenges of liposomal targeting of these phytoconstituents and future perspective of CHM applications are discussed to provide an informative reference for interested readers.

Ginsenoside Rg3 protects heart against isoproterenol-induced myocardial infarction by activating AMPK mediated autophagy

Background

Panax ginseng is a well-known medicinal herb that is widely used in traditional Chinese medicine for treating various diseases. Ginsenoside Rg3 (Rg3) is thought to be one of the most important active ingredients of Panax ginseng. However, the molecular mechanism underlying the beneficial effects of Rg3 has been elusive.

Methods

In the mouse heart injury model induced by isoproterenol (ISO), we used brain natriuretic peptide (BNP), lactate dehydrogenase (LDH) and caspase-3 ELISA kits to test myocardium injury. To test whether Rg3 protects myocardial injury through AMPK mediated autophagy, we used specific AMPK inhibitor in combination with Rg3. NLRP3 inflammasome related molecules such as NLRP3, ASC and caspase-1 were measured by western-blot following Rg3 treatment.

Results

We found that Rg3 significantly reduced ISO induced myocardial injury indicated by the downregulation of serum BNP and LDH. In addition, we showed that the improvement of myocardial injury by Rg3 was associated with enhanced expression of autophagy related protein and activation of AMPK downstream signaling pathway.

Conclusions

We observed that inhibition of AMPK significantly reversed the myocardial protective effect of Rg3, which is associated with a decrease of Rg3 induced autophagy. These together suggested that Rg3 may improve myocardial injury during MI through AMPK mediated autophagy. Our study also provides important translational evidence for using Rg3 in treating myocardial infarction (MI).

Diverse autophagy and apoptosis in myeloid leukemia cells induced by 20(s)-GRh2 and blue LED irradiation

Autophagy is an important mechanism for cell death regulation. To improve the anticancer effect during the treatment of leukemia and promote the apoptosis of leukemic cells, it is important to define the relationship between autophagy and apoptosis. A key bioactive compound in traditional Chinese medicine, 20(s)-Ginsenoside (GRh2), demonstrated an advancement in leukemia treatment. Blue LED therapy (BL) is a physical treatment method that can induce leukemic cell death. In this study, we tested the effect of 20(s)-GRh2, BL, and their combination (BL-GRh2) on the activation of leukemic cell apoptosis and autophagy. Both treatments, whether used individually or simultaneously, induce apoptosis through the induction of reactive oxygen species (ROS), disrupted mitochondrial membrane potential (MMP) and regulated the expression of apoptosis-related genes and proteins. Furthermore, using western blotting to analyze the autophagy markers LC3B and P62, we detected the activation of autophagy. In cells treated with autophagy inhibitor 3-MA, both autophagy and apoptosis were inhibited, either by BL alone or by BL-GRh2. However, apoptosis in 20(s)-GRh2-treated cells was enhanced. In cells treated with apoptosis suppressor Z-VAD-FMK, autophagy was inhibited in the BL and BL-GRh2-treated cells, although it was enhanced in cells treated with 20(s)-GRh2 alone. Moreover, we observed a stronger induction of apoptosis by BL-GRh2 in myeloid leukemia cells. Our data indicate that autophagy induced by different factors can play diverse roles on the same cells. Our results also indicate that the combination of traditional Chinese medicine with physical therapy may be a new strategy for anti-cancer therapy.

Ginsenoside Rg3 suppresses the NLRP3 inflammasome activation through inhibition of its assembly

Ginsenoside Rg3 is one of the main constituents of Panax ginseng. Compelling evidence has demonstrated that ginsenoside Rg3 is capable of inhibiting inflammation. However, the mechanism mediating its anti-inflammatory effects remain unclear. Here we show that ginsenoside Rg3 blocks IL-1β secretion and caspase-1 activation through inhibiting LPS priming and the NLRP3 inflammasome activation in human and mouse macrophages. Rg3 specifically inhibits activation of NLRP3 but not the NLRC4 or AIM2 inflammasomes. In addition, Rg3 has no effect on upstream regulation of NLRP3 inflammasome, such as K⁺ efflux, ROS production, or mitochondrial membrane potential. Mechanistically, Rg3 abrogates NEK7-NLRP3 interaction, and subsequently inhibits NLRP3-ASC interaction, ASC oligomerization, and speckle formation. More importantly, Rg3 can reduce IL-1β secretion induced by LPS in mice and protect mice from lethal endotoxic shock. Thus, our findings reveal an anti-inflammatory mechanism for Rg3 and suggest its potential use in NLRP3-driven diseases.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Ginsenoside Rg3 attenuates endometriosis by inhibiting the viability of human ectopic endometrial stromal cells through the nuclear factor-kappaB signaling pathway

OBJECTIVE

To investigate the effects of ginsenoside Rg3 on human ectopic endometriotic stromal cells in vitro.

MATERIALS AND METHODS

Ectopic endometrial tissue specimens were obtained from 6 female patients with ovarian endometriosis who underwent laparoscopic surgical procedures. Endometrial stromal cells derived from isolated ectopic endometriotic lesions were cultured, and the purity and homogeneity of cells were verified by Immunocytochemistry. The effect of Rg3 on cell proliferation was detected by Cell Counting Kit-8 (CCK8). After treatment with Rg3, the protein expression of NF-κB p65 subunit, VEGF, and caspases3 were measured by western blot analysis. Meanwhile, the mRNA expression of NF-κB p65 subunit was determined by Quantitative real-time polymerase chain reaction (RT-PCR).

RESULTS

Rg3 inhibited the proliferation of ectopic endometriotic cells in a time- and dose-dependent manner. The treatment with Rg3 significantly diminished the level of NF-κB p65 subunit as well as TNF-α induced nuclear translocation of NF-κB p65 subunit in ectopic endometriotic cells. Moreover, Rg3 upregulated the expression of caspases3 but suppressed the expression of VEGF.

CONCLUSION

Our results indicate that Ginsenoside Rg3 suppresses endometriosis by reducing the viability of human ectopic endometrial stromal cells involving the nuclear factor-kappaB signaling pathway in vitro.

Effect of Alkylresorcinols on Autophagy, Migration, and Invasion of HepG2 Cells

Alkylresorcinols are phenolic lipids that mainly exist in the cortex of grains, and they exhibit anticancer activity against various cancer cells in vitro. However, the underlying action mechanisms are still unclear. In our study, the influence of alkylresorcinols C_19:0 and C_21:0 (ARs) upon migration, invasion, and autophagy in human hepatoblastoma HepG2 cells was evaluated. Results showed that ARs at 80 and 160 µg/mL significantly suppressed cells proliferation, migration, and invasion, downregulated the expression of proteins RhoA and MMP-7 associated with migration and invasion. ARs at 160 µg/mL, the rate of LC3 puncta was appreciably increased. After autophagy was blocked by 3-MA or CQ, the expression of LC3II was significantly increased in 3-MA+ARs group and p62 was significantly decreased in CQ+ARs group. The results indicate that ARs may promote autophagic flow. ARs (80, 160 µg/mL) significantly inhibited the expression of proteins p-mTOR, p-PI3K, and p-Akt related to the PI3K/Akt pathway. The results of the present study suggest that ARs can activate autophagy and suppresses the biological behaviors of HepG2 cells by inhibiting the activation of MMP-7, Rho/Rho-associated protein kinase, and activation of the phosphatidylinositol 3-kinase/Akt signaling pathway. PRACTICAL APPLICATION: The anticancer mechanism of ARs in wheat bran was studied, which provided a basis for the development of anticancer functional auxiliary food with wheat bran as raw material. It is of great practical significance to promote the effective utilization of grain processing by-products and improve the economic benefits of the grain industry.

Effects of ginsenoside Rg3 on epigenetic modification in ovarian cancer cells

Epigenetic modifications are closely related to oncogene activation and tumor suppressor gene inactivation. The aim of this study was to determine the effects of ginsenoside Rg3 on epigenetic modification in ovarian cancer cells. Cell proliferation, metastasis, invasion and apoptosis were respectively determined using Cell Counting Kit‑8 (CCK‑8), wound healing, Transwell and flow cytometric assays. Methylation levels were determined using methylation specific PCR (MSP). Related‑factor expression was detected by conducting real‑time‑qPCR (RT‑qPCR) and western blotting. The results revealed that cell proliferation was inhibited by ginsenoside Rg3 (0, 25, 50, 100 and 200 µg/ml) in a time‑dependent manner (12, 24 and 48 h). Ginsenoside Rg3 (50, 100 and 200 µg/ml) was selected to treat cells in various experiments. When ovarian cells were treated with ginsenoside Rg3, cell apoptosis was observed to be promoted, while cell metastasis and invasion were inhibited at 48 h. The results of the present study revealed that in the promoter regions of p53, p16 and hMLH1, the methylation levels decreased, while the mRNA and protein levels significantly increased. The activities of DNMTs and mRNA as well as protein levels of DNMT1, DNMT3a and DNMT3b were decreased by Rg3. The data also demonstrated that the mRNA and protein levels of acetyl‑H3 K14/K9 and acetyl‑H4 K12/K5/K16 were increased by Rg3. Hence, ginsenoside Rg3 inhibited ovarian cancer cell viability, migration and invasion as well as promoted cell apoptosis.

Sense Ginsenosides From Ginsengs: Structure-Activity Relationship in Autophagy

The term ginseng refers to the dried roots of several plants belonging to the genus Panax of the Araliaceae family. The 3 major commercial ginsengs are Panax notoginseng (Burk.) F.H. Chen (Notoginseng), P. ginseng C.A. Meyer (Ginseng), and P. quinquefolius L. (American ginseng), which have been used as herbal medicines. Over 18,000 papers on ginsengs have been published on the basis of their structural diversity and biological activities. Many reviews have summarized the phytochemistry, pharmacology, and clinical use of ginsengs, but the structure-activity relationship (SAR) of ginsenosides from ginsengs in autophagy is unavailable. Herein, we review the structural diversity of ginsenosides, especially the ones in notoginseng, and the SAR in autophagic activity is discussed in detail.

20(S)-ginsenoside Rg3 sensitizes human non-small cell lung cancer cells to icotinib through inhibition of autophagy

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have become a standard therapy for non-small cell lung cancer (NSCLC) patients with sensitive mutations. However, acquired resistance inevitably emerges after a median of 6-12 months. It has been demonstrated that autophagy plays an important role in EGFR-TKI resistance. 20(S)-ginsenoside Rg3 (Rg3) is proposed to sensitize the cancer cells to chemotherapy by inhibiting autophagy. We examined the ability of Rg3 to inhibit autophagy and increase the sensitivity of NSCLC cells to icotinib. We show that the induction of autophagy in response to icotinib contributes to the development of icotinib resistance. Rg3 is capable of inhibiting autophagic flux and enhancing the sensitivity of NSCLC cells to icotinib. The resistance to icotinib could also be reversed through Rg3-induced autophagy inhibition. Autophagy inhibition by Rg3 increases the therapeutic response in both icotinib-sensitive and icotinib-resistant NSCLC cells with an EGFR-activating mutation and may be an effective new treatment strategy for this disease.

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.

Six new dammarane-type triterpene saponins from Panax ginseng flower buds and their cytotoxicity

Background

Panax ginseng has been used for a variety of medical purposes in eastern countries for more than two thousand years. From the extensive experiences accumulated in its long medication use history and the substantial strong evidence in modern research studies, we know that ginseng has various pharmacological activities, such as antitumor, antidiabetic, antioxidant, and cardiovascular system–protective effects. The active chemical constituents of ginseng, ginsenosides, are rich in structural diversity and exhibit a wide range of biological activities.

Methods

Ginsenoside constituents from P. ginseng flower buds were isolated and purified by various chromatographic methods, and their structures were identified by spectroscopic analysis and comparison with the reported data. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H- tetrazolium bromide method was used to test their cytotoxic effects on three human cancer cell lines.

Results

Six ginsenosides, namely 6'–malonyl formyl ginsenoside F₁ (1), 3β–acetoxyl ginsenoside F₁ (2), ginsenoside Rh₂₄ (6), ginsenoside Rh₂₅ (7), 7β–hydroxyl ginsenoside Rd (8) and ginsenoside Rh₂₆ (10) were isolated and elucidated as new compounds, together with four known compounds (3–5 and 9). In addition, the cytotoxicity of these isolated compounds was shown as half inhibitory concentration values, a tentative structure–activity relationship was also discussed based on the results of our bioassay.

Conclusion

The study of chemical constituents was useful for the quality control of P. ginseng flower buds. The study on antitumor activities showed that new Compound 1 exhibited moderate cytotoxic activities against HL-60, MGC80-3 and Hep-G2 with half inhibitory concentration values of 16.74, 29.51 and 20.48 μM, respectively.

Ginsenoside Rg3 suppresses the proliferation of prostate cancer cell line PC3 through ROS-induced cell cycle arrest

To investigate the potential antitumor effects of ginsenoside Rg3 in prostate cancer cells, the androgen-insensitive prostate cancer cell line PC3 was cultured and incubated with ginsenoside Rg3 in vitro. Cell number counts, cell proliferation assays and senescence-associated β-galactosidase (SA-β-gal) staining were performed to evaluate cell proliferation. The results demonstrated that ginsenoside Rg3 led to cell proliferation arrest; ginsenoside Rg3 decreased the number of cells and increased the positive SA-β-gal staining rate in PC3 cells. Cell cycle analysis by flow cytometry revealed that ginsenoside Rg3 interfered with the G1/S transition in PC3 cells. The mechanism involved in ginsenoside Rg3-induced cell proliferation arrest was then further investigated. This indicated that the level of reactive oxygen species (ROS) in PC3 cells was upregulated by ginsenoside Rg3 treatment. Furthermore, pretreatment with N-acetyl-L-cysteine, a scavenger of ROS, was able to reverse the effects on cell number and cell cycle arrest induced by ginsenoside Rg3 in PC3 cells. These results indicate that ginsenoside Rg3 exhibits anticancer effects on prostate cancer cells through ROS-mediated arrest of the cell cycle.

Genome-Wide Methylation Analysis Identifies NOX4 and KDM5A as Key Regulators in Inhibiting Breast Cancer Cell Proliferation by Ginsenoside Rg3

Ginsenoside Rg3 is a key metabolite of ginseng and is known to inhibit cancer cell growth. However, the epigenetics of CpG methylation and its regulatory mechanism have yet to be determined. Genome-wide methylation analysis of MCF-7 breast cancer cells treated with Rg3 was performed to identify epigenetically regulated genes and pathways. The effect of Rg3 on apoptosis and cell proliferation was examined by a colony formation assay and a dye-based cell proliferation assay. The association between methylation and gene expression was monitored by RT-PCR and Western blot analysis. Genome-wide methylation analysis identified the "cell morphology"-related pathway as the top network. Rg3 induced late stage apoptosis but inhibited cell proliferation up to 60%. Hypermethylated TRMT1L, PSMC6 and NOX4 were downregulated by Rg3, while hypomethylated ST3GAL4, RNLS and KDM5A were upregulated. In accordance, downregulation of NOX4 by siRNA abrogated the cell growth effect of Rg3, while the effect was opposite for KDM5A. Notably, breast cancer patients with a higher expression of NOX4 and KDM5A showed poor and good prognosis of survival, respectively. In conclusion, Rg3 deregulated tumor-related genes through alteration of the epigenetic methylation level leading to growth inhibition of cancer cells.

Oxidative stress-modulating drugs have preferential anticancer effects - involving the regulation of apoptosis, DNA damage, endoplasmic reticulum stress, autophagy, metabolism, and migration

To achieve preferential effects against cancer cells but less damage to normal cells is one of the main challenges of cancer research. In this review, we explore the roles and relationships of oxidative stress-mediated apoptosis, DNA damage, ER stress, autophagy, metabolism, and migration of ROS-modulating anticancer drugs. Understanding preferential anticancer effects in more detail will improve chemotherapeutic approaches that are based on ROS-modulating drugs in cancer treatments.

Ginsenoside 20(S)-Rh2 exerts anti-cancer activity through the Akt/GSK3β signaling pathway in human cervical cancer cells

Ginsenoside 20(S)-Rh2 (GRh2) is a bioactive compound derived from ginseng that is believed to maintain health in traditional Chinese medicine. Emerging evidence has suggested that GRh2 exhibits anti‑cancer activity. The present study hypothesized that GRh2 has an anti‑cancer function in human cervical cancer cells. An MTS assay demonstrated that GRh2 attenuated proliferation of HeLa cells in a dose‑ and time‑dependent manner. In addition, GRh2 inhibited migration and invasion, as determined by wound healing and transwell invasion assays, respectively. Furthermore, GRh2 treatment reduced expression of mesenchymal markers N‑cadherin and vimentin as well as epithelial mesenchymal transition transcriptional factor zinc finger E‑box‑binding homeobox 1 and snail1, and increased the protein expression levels of epithelial marker E‑cadherin. In addition, the results revealed that GRh2 prevented activation of the protein kinase B (Akt)/glycogen synthase kinase (GSK)3β signaling pathway in HeLa cells. In conclusion, the results suggested that GRh2 inhibits cervical cancer cell proliferation by targeting the Akt pathway, and prevents cervical cancer cell migration and invasion by suppressing the Akt/GSK3β regulated EMT process, and therefore, GRh2 may have the potential to be a novel anti‑cancer agent for cervical cancer.

Ginsenoside improves papillary thyroid cancer cell malignancies partially through upregulating connexin 31

Connexin 31 (Cx31) is considered a suppressor for many tumors. Ginsenoside (Rg1) is a traditional Chinese herb that is widely acknowledged due to its anti-tumor characteristics. However, limited studies have focused on the role of Rg1 in papillary thyroid cancer (PTC) cells. In the current study, we found that the expression of Cx31 in thyroid cancer tissues and thyroid cancer cell lines was significantly lower than that in normal thyroid epithelial tissues and cell lines. Overexpression of Cx31 reduced thyroid cancer cell proliferation, migration and invasion. Furthermore, we found that Rg1 significantly enhanced the expression of Cx31. Moreover, the proliferation and migration of IHH-4 and BCPAP cells were significantly reduced by Rg1 treatment. In contrast, the silencing of Cx31 enhanced the expression of Ki67 and proliferating cell nuclear antigen (PCNA). Meanwhile, treatment with Rg1 significantly decreased the protein levels of Ki67 and PCNA, but these effects could be abolished by transfection with si-Cx31. In summary, we provide novel evidence that the expression of Cx31 was decreased in thyroid cancer cells, but Rg1 treatment could significantly enhance the expression of Cx31 thereby suppressing thyroid cancer cell proliferation and migration.

Natural agents mediated autophagic signal networks in cancer

Recent studies suggested that natural compounds are important in finding targets for cancer treatments. Autophagy (“self-eating”) plays important roles in multiple diseases and acts as a tumor suppressor in cancer. Here, we examined the molecular mechanism by which natural agents regulate autophagic signals. Understanding the relationship between natural agents and cellular autophagy may provide more information for cancer diagnosis and chemoprevention.

Therapeutic potentials of natural compounds acting on cyclic nucleotide phosphodiesterase families

Intracellular cyclic AMP and/or cyclic GMP are characterized in the 1960th. These second messengers, hydrolysed specifically by cyclic nucleotide phosphodiesterase (PDE), play a major role in intracellular signalling. Natural products have been a rich source of drug discovery, Theophylline and Methylxanthine originated from tea leaves used for asthma treatment, whereas, Papaverine, a natural isoquinolein originated from Papaver somniferum traditionally used in impotency, altogether as caffeine where firstly described as PDE-inhibiting compounds. Since that time, the knowledge in PDE field has been drastically increased, allowing the design and development of new therapeutic drugs acting against different pathologies in the nanomolar range. During this period some natural compounds have been identified as PDE inhibitors and used in that context to investigate their therapeutic potential effects. The aim of this literature review is to point out the reported data and demonstrating the contribution of natural characterized molecules as PDE inhibitors in various pathologies that can open new fields of research for drug discovery, notably in epigenetic regulation.

Ginkgo biloba exocarp extracts induces autophagy in Lewis lung cancer cells involving AMPK / mTOR / p70S6k signaling pathway

OBJECTIVES

Ginkgo biloba L. is called a living fossil plant, and could be used for the treatment of cancer thousands of years ago in China. The extracts prepared from the Ginkgo biloba exocarp (Ginkgo biloba exocarp extracts, GBEE) has a significant anti-cancer effect. Autophagy plays an important role in the occurrence and development of cancer as programmed cell death (PCD) type II. Thus it would be interesting to study the effects and mechanisms of GBEE inducing autophagy in Lewis lung cancer (LLC) cells.

METHODS

MTT method was used to detect the inhibitory effect of GBEE on LLC cells. Monodansylcadaverine (MDC) staining method was applied to observe the formation of acidic vacuoles in cells. The ultrastructure of LLC cells was observed using transmission electron microscope (TEM) to confirm the formation of autophagosomes. Quantify reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the mRNA levels of Beclin1 and Atg5. Western Blot was used to detect the protein levels of Beclin1, Atg5, LC3I/II, p-AMPK, AMPK, p-mTOR, mTOR, p-p70S6k and p70S6K in LLC cells.

RESULTS

GBEE (5-160μg/mL) inhibited the proliferation of LLC cells in vitro with the half maximal inhibitory concentration (IC50) value of 161.26μg/mL. The formation and activation of acidic vacuoleswere increased by the action of GBEE (10, 20 and 40μg/mL) on LLC cells. The autophagosomes were also increased. Meanwhile, it up-regulated both the mRNA and protein levels of Beclin1 and Atg5. The ratio of LC3-I/LC3-II protein was down-regulated. In addition, the protein level of p-AMPK was increased, and the p-mTOR and p-p70S6K was decreased. But the AMPK, mTOR and p70S6K proteins were not significantly changed.

CONCLUSIONS

The inhibitory effect of GBEE on LLC is associate with inducing autophagy in LLC cells, which may be closely relevant to the regulation of AMPK/mTOR/p70S6k signaling pathways.