Anti-lung Cancer Effects of Polyphyllin VI and VII Potentially Correlate with Apoptosis In Vitro and In Vivo

Polyphyllins in cancer therapy: A systematic review and meta-analysis of animal studies

BACKGROUND

Polyphyllins are secondary metabolites that inhibit the growth of various tumours; however, clinical trials on their use are lacking.

HYPOTHESIS/PURPOSE

In this study, we aimed to evaluate the antitumour efficacy of polyphyllins in animal models.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Electronic bibliographic databases including PubMed, Web of Science, China Science and Technology Journal Database, Wanfang Data, and China National Knowledge Infrastructure were searched for relevant articles. The Systematic Review Centre for Laboratory Animal Experimentation's Risk of Bias tool was used to assess methodological quality. RevMan V.5.4 (Cochrane) and Stata MP 17 software were used to perform a meta-analysis.

RESULTS

Thirty articles were analysed including 33 independent experiments and 452 animals in this paper. Overall, tumour volume (standardised mean difference [SMD]: -3.35; 95 % confidence interval [CI]: -4.27 to -2.43; p < 0.00001) and tumour weight (SMD: -3.79; 95% CI: -4.75 to -2.82; p < 0.00001) were reduced by polyphyllins, which showed a good cancer therapeutic effect; mouse weight (SMD: -0.22; 95% CI: -0.61 to -0.18; p = 0.28) was insignificantly different, which indicated that polyphyllins did not affect the growth of the mice within the test range. Moreover, the molecular mechanisms of the antitumour activity of polyphyllins were explained, including the P53, NF-kB, AMPK, and ERK signalling pathways.

CONCLUSION

Polyphyllins inhibit the growth of cancers within the experimental dose. However, due to heterogeneity of the results of the included studies, more studies are needed to support this conclusion.

Modulating MGMT expression through interfering with cell signaling pathways

Guanine O6-alkylating agents are widely used as first-line chemotherapeutic drugs due to their ability to induce cytotoxic DNA damage. However, a major hurdle in their effectiveness is the emergence of chemoresistance, largely attributed to the DNA repair pathway mediated by O6-methylguanine-DNA methyltransferase (MGMT). MGMT plays an important role in removing the alkyl groups from lethal O6-alkylguanine (O6-AlkylG) adducts formed by chemotherapeutic alkylating agents. By doing so, MGMT enables tumor cells to evade apoptosis and develop drug resistance toward DNA alkylating agents. Although covalent inhibitors of MGMT, such as O6-benzylguanine (O6-BG) and O6-(4-bromothenyl)guanine (O6-4-BTG or lomeguatrib), have been explored in clinical settings, their utility is limited due to severe delayed hematological toxicity observed in most patients when combined with alkylating agents. Therefore, there is an urgent need to identify new targets and unravel the underlying molecular mechanisms and to develop alternative therapeutic strategies that can overcome MGMT-mediated tumor resistance. In this context, the regulation of MGMT expression via interfering the specific cell signaling pathways (e.g., Wnt/β-catenin, NF-κB, Hedgehog, PI3K/AKT/mTOR, JAK/STAT) emerges as a promising strategy for overcoming tumor resistance, and ultimately enhancing the efficacy of DNA alkylating agents in chemotherapy.

Paris saponins Ⅶ inhibits glycolysis of ovarian cancer via the RORC/ACK1 signaling pathway

Rhizoma Paridis is a traditional Chinese medicine commonly used for treatment of malignant tumors. Paris saponins Ⅶ (PSⅦ) is one of the components of Rhizoma Paridis, but the role of PSⅦ in glucose metabolism in ovarian cancer remains elucidated. A series of experiments in the current study demonstrated that PSⅦ inhibites glycolysis and promotes cell apoptosis in ovarian cancer cells. Expression levels of glycolysis-related proteins and apoptosis-related proteins were significantly altered by upon treatment with PSⅦ, as determined from western blot analyses. Mechanistically, PSⅦ exerted its anti-tumor effects by targeting the RORC/ACK1 signaling pathway. These findings indicate that PSⅦ inhibits glycolysis-induced cell proliferation and apoptosis through the RORC/ACK1 pathway, supporting its potential development as a candidate chemotherapeutic agent for ovarian cancer.

Polyphyllin VII protects from breast cancer-induced osteolysis by suppressing osteoclastogenesis via c-Fos/NFATc1 signaling

Bone is a preferred metastatic site of advanced breast cancer and the 5-year overall survival rate of breast cancer patients with bone metastasis is only 22.8%. Targeted inhibition of osteoclasts can treat skeletal-related events (SREs) in breast cancer patients. Polyphyllin VII (PP7), a pennogenyl saponin isolated from traditional Chinese herb Paris polyphylla, exhibits strong anti-inflammatory and anti-cancer activities. In this study, we evaluated the effect of PP7 on metastatic breast cancer-induced bone destruction in vivo and the underlying mechanisms. We found that intraperitoneal injection of 1 mg/kg PP7 significantly ameliorated the breast cancer MDA-MB-231 cell-induced osteolysis in mice. Mechanistically, PP7 (0.125-0.5 μM) inhibited the conditioned medium of MDA-MB-231 cells (MDA-MB-231 CM)-induced osteoclast formation in bone marrow-derived macrophages (BMMs). Furthermore, PP7 markedly reduced MDA-MB-231 CM-induced osteoclastic bone resorption and F-actin rings formation in vitro. During MDA-MB-231 CM-induced osteoclastogenesis, the activation of c-Fos and NFATc1 signaling was significantly downregulated by PP7, and finally osteoclast-related genes such as Oscar, Atp6v0d2, Mmp9 and β3 integrin were decreased. In addition, the formation of osteoblast was promoted by PP7 treatment. Our current findings revealed PP7 as a potential safe agent for preventing and treating bone destruction in breast cancer patients with bone metastases.

Paris polyphylla Sm. Induces Reactive Oxygen Species and Caspase 3-Mediated Apoptosis in Colorectal Cancer Cells In Vitro and Potentiates the Therapeutic Significance of Fluorouracil and Cisplatin

Paris polyphylla Sm. (Melanthiaceae) is an essential, vulnerable herb with a wide range of traditional applications ranging from fever to cancer in various communities. The use of P. polyphylla in India is limited to traditional healers. Here, we demonstrated that P. polyphylla extract (PPE) has good phenol, flavonoid, saponin, and steroidal saponin content and anti-oxidant activity with IC₅₀ 35.12 ± 6.1 μg/mL in DPPH and 19.69 ± 6.7 μg/mL in ABTS. Furthermore, PPE induces cytotoxicity in HCT-116 with IC₅₀ 8.72 ± 0.71 μg/mL without significant cytotoxicity inthe normal human colon epithelial cell line, CCD 841 CoN. PPE inhibits the metastatic property and induces apoptosis in HCT-116, as measured by Annexin V/PI, by increasing the production of reactive oxygen species (ROS) and caspase 3 activation. PPE acts synergistically with 5FU and cisplatin in HCT-116 and potentiates their therapeutic significance. Steroidal saponins with anticancer activities were detected in PPE by HR-LCMS. The present study demonstrated that PPE induces apoptosis by increasing ROS and activating caspase 3, which was attributed to steroidal saponins. PPE can be used as a potential natural remedy for colon cancer.

A simple and sensitive LC-MS/MS method for the determination of polyphyllin VII in rat plasma and its application to pharmacokinetic study

Polyphyllin VII is an isoprene saponin extracted from Rhizoma paridis, and it can effectively suppress tumor initiation, growth, and metastasis. In this study, we aim to develop and validate an LC-MS/MS method for the quantification of polyphyllin VII in rat plasma using digoxin as the internal standard (IS). The plasma samples were precipitated with methanol, and the samples were separated on an ACQUITY BEH C₁₈ column (2.1 × 50 mm, 1.7 μm). The mobile phase consisted of 0.1% formic acid solution and acetonitrile. The detection was performed in the multiple reactions monitoring mode, with the precursor-to-product transitions of m/z 1075.4 > 883.3 for polyphyllin VII and m/z 779.4 > 649.6 for the IS. The method showed excellent linearity over the concentration range of 0.5-1000 ng/ml, with a correlation coefficient of 0.9996 (r = 0.9996). The lower limit of quantification was 0.5 ng/ml. The inter- and intra-day accuracy (relative error) ranged from -4.8 to 5.9%, and precision (relative standard deviation) was < 9.0%. The assay showed high extraction recovery, ranging from 90.6 to 95.6%. Polyphyllin VII was demonstrated to be stable under the storage conditions. The validated LC-MS/MS method was successfully applied to the pharmacokinetic study of polyphyllin VII in rats after oral, intraperitoneal, and intravenous administrations. The pharmacokinetic results indicated that polyphyllin VII showed low oral (5.86%) bioavailability and moderate (38.81%) intraperitoneal bioavailability.

Polyphyllin VII as a Potential Drug for Targeting Stemness in Hepatocellular Cancer via STAT3 Signaling

BACKGROUND

At present, the treatment of hepatocellular carcinoma (HCC) is disturbed by the treatment failure and recurrence caused by the residual liver cancer stem cells (CSCs). Therefore, drugs targeting HCC CSCs should be able to effectively eliminate HCC and prevent its recurrence. In this study, we demonstrated the effect of Polyphyllin VII (PP7) on HCC CSCs and explored their potential mechanism.

METHODS

HepG2 and Huh7 cells were used to analyze the antitumor activity of PP7 by quantifying cell growth and metastasis as well as to study the effect on stemness.

RESULTS

Our results demonstrated that PP7 promoted apoptosis and significantly inhibited proliferation and migration of both HepG2 and Huh7 cells. PP7 also inhibited tumor spheroid formation and induced significant changes in the expression of stemness markers (CD133 and OCT-4). These effects of PP7 were mediated by STAT3 signaling.

CONCLUSION

PP7 can effectively suppress tumor initiation, growth, and metastasis and inhibit stemness through regulation of STAT3 signaling pathway in liver cancer cells. Our data would add more evidence to further clarify the therapeutic effect of PP7 against HCC.

Therapeutic effects on cancer of the active ingredients in rhizoma paridis

Cancer is a major threat to human health, with high mortality and a low cure rate, continuously challenging public health worldwide. Extensive clinical application of traditional Chinese medicine (TCM) for patients with poor outcomes of radiotherapy and chemotherapy provides a new direction in anticancer therapy. Anticancer mechanisms of the active ingredients in TCM have also been extensively studied in the medical field. As a type of TCM against cancer, Rhizoma Paridis (Chinese name: Chonglou) has important antitumor effects in clinical application. The main active ingredients of Rhizoma Paridis (e.g., total saponins, polyphyllin I, polyphyllin II, polyphyllin VI, and polyphyllin VII) have shown strong antitumor activities in various cancers, such as breast cancer, lung cancer, colorectal cancer, hepatocellular carcinoma (HCC), and gastric cancer. Rhizoma Paridis also has low concentrations of certain other active ingredients with antitumor effects, such as saponins polyphyllin E, polyphyllin H, Paris polyphylla-22, gracillin, and formosanin-C. Many researchers have studied the anticancer mechanism of Rhizoma Paridis and its active ingredients. This review article describes research progress regarding the molecular mechanism and antitumor effects of the active ingredients in Rhizoma Paridis, suggesting that various active ingredients in Rhizoma Paridis may be potentially therapeutic against cancer.

Targeted Pyroptosis Is a Potential Therapeutic Strategy for Cancer

As a type of regulated cell death (RCD) mode, pyroptosis plays an important role in several kinds of cancers. Pyroptosis is induced by different stimuli, whose pathways are divided into the canonical pathway and the noncanonical pathway depending on the formation of the inflammasomes. The canonical pathway is triggered by the assembly of inflammasomes, and the activation of caspase-1 and then the cleavage of effector protein gasdermin D (GSDMD) are promoted. While in the noncanonical pathway, the caspase-4/5/11 (caspase 4/5 in humans and caspase 11 in mice) directly cleave GSDMD without the assembly of inflammasomes. Pyroptosis is involved in various cancers, such as lung cancer, gastric cancer, hepatic carcinoma, breast cancer, and colorectal carcinoma. Pyroptosis in gastric cancer, hepatic carcinoma, breast cancer, and colorectal carcinoma is related to the canonical pathway, while both the canonical and noncanonical pathway participate in lung cancer. Moreover, simvastatin, metformin, and curcumin have effect on these cancers and simultaneously promote the pyroptosis of cancer cells. Accordingly, pyroptosis may be an important therapeutic target for cancer.

Machine learning and bioinformatics-based insights into the potential targets of saponins in Paris polyphylla smith against non-small cell lung cancer

Background: Lung cancer has the highest mortality rate among cancers worldwide, and non-small cell lung cancer (NSCLC) is the major lethal factor. Saponins in Paris polyphylla smith exhibit antitumor activity against non-small cell lung cancer, but their targets are not fully understood.

Methods: In this study, we used differential gene analysis, lasso regression analysis and support vector machine recursive feature elimination (SVM-RFE) to screen potential key genes for NSCLC by using relevant datasets from the GEO database. The accuracy of the signature genes was verified by using ROC curves and gene expression values. Screening of potential active ingredients for the treatment of NSCLC by molecular docking of the reported active ingredients of saponins in Paris polyphylla Smith with the screened signature genes. The activity of the screened components and their effects on key genes expression were further validated by CCK-8, flow cytometry (apoptosis and cycling) and qPCR.

Results: 204 differential genes and two key genes (RHEBL1, RNPC3) stood out in the bioinformatics analysis. Overall survival (OS), First-progression survival (FP) and post-progression survival (PPS) analysis revealed that low expression of RHEBL1 and high expression of RNPC3 indicated good prognosis. In addition, Polyphyllin VI(PPVI) and Protodioscin (Prot) effectively inhibited the proliferation of non-small cell lung cancer cell line with IC50 of 4.46 μM ± 0.69 μM and 8.09 μM ± 0.67μM, respectively. The number of apoptotic cells increased significantly with increasing concentrations of PPVI and Prot. Prot induces G1/G0 phase cell cycle arrest and PPVI induces G2/M phase cell cycle arrest. After PPVI and Prot acted on this cell line for 48 h, the expression of RHEBL1 and RNPC3 was found to be consistent with the results of bioinformatics analysis.

Conclusion: This study identified two potential key genes (RHEBL1 and RNPC3) in NSCLC. Additionally, PPVI and Prot may act on RHEBL1 and RNPC3 to affect NSCLC. Our findings provide a reference for clinical treatment of NSCLC.

Polyphyllin VII is a Potential Drug Targeting CD44 Positive Colon Cancer Cells

Background:

Current therapies for colon cancer are hindered by treatment failure and recurrence mainly due to colon cancer stem cells (CSCs). Thus, treatment using drugs targeting CSCs should be effective in eliminating colon cancer cells and impeding cancer recurrence.

Objective:

To test if PPVII can a potent drug candidate for the treatment of colon cancer by targeting CD44 positive colon cancer cells.

Methods:

In this study, we first demonstrated that CD44 is highly expressed in colon cancer tissues by TCGA/GTEX database analysis and immunohistochemical staining.

Results:

In this study, we first demonstrated that CD44 is highly expressed in colon cancer tissues by TCGA/GTEX database analysis. CD44 had high accuracy as a diagnostic and predictive index for colorectal cancer through Receiver operating characteristic curve (ROC) analysis. At the same time, survival curve analysis also showed that the high expression of CD44 was associated with poor prognosis in patients with colon cancer. CD44 higher expression in colon cancer tissues was further confirmed by immunohistochemical staining, the positive rate of CD44 expression was 87.95%. Then, one of the constituents that derives from the root of Paris polyphylla, Polyphyllin VII (PPVII) has been confirmed to inhibit the migration of colon cancer cells. Our results also demonstrated that PPVII could inhibit the sphere-forming ability of colon cancer cells. Further experiment results showed that PPVII could downregulate the expression of CD44 in colon cancer cells. In addition, PPVII was proved to have inhibitory effects against CD44 positive colon cancer cells.

Conclusion:

Therefore, PPVII might be a potent candidate reagent for the treatment of colon cancer by targeting CD44 positive colon cancer cells.

Bioactive secondary metabolites in Paris polyphylla Sm. and their biological activities: A review

Paris polyphylla Sm. is an important medicinal plant used to treat a variety of diseases through traditional medicine systems such as Ayurveda, Tibetan traditional medicines, Chinese traditional medicines, and others around the world. The IUCN red list has designated it as "vulnerable" due to a decline in wild population by over-exploitation, habitat degradation, illegal collection for trade and traditional use. This review paper aims to summarize the bioactive secondary metabolites in Paris polyphylla. Paris saponins or steroidal saponins are the main bioactive chemical constituents from this plant that account for more than 80% of the total compounds. For instance, polyphyllin D, diosgenin, paris saponins I, II, VI, VII, and H are steroidal saponins having anticancer activity comparable to synthetic anticancer medicines. Antioxidant, anticancer, anti-leishmaniasis, antibacterial, antifungal, anthelmintic, antityrosinase, and antiviral effects of extracts and pure compounds were also demonstrated in vivo and in vitro. In conclusion, this review summarizes the bioactive components from the P. polyphylla which will be useful to researchers and scientists, and for the development of potential drugs.

Natural Polyphyllins (I, II, D, VI, VII) Reverses Cancer Through Apoptosis, Autophagy, Mitophagy, Inflammation, and Necroptosis

Cancer is the second leading cause of mortality worldwide. Conventional therapies, including surgery, radiation, and chemotherapy, have limited success because of secondary resistance. Therefore, safe, non-resistant, less toxic, and convenient drugs are urgently required. Natural products (NPs), primarily sourced from medicinal plants, are ideal for cancer treatment because of their low toxicity and high success. NPs cure cancer by regulating different pathways, such as PI3K/AKT/mTOR, ER stress, JNK, Wnt, STAT3, MAPKs, NF-kB, MEK-ERK, inflammation, oxidative stress, apoptosis, autophagy, mitophagy, and necroptosis. Among the NPs, steroid saponins, including polyphyllins (I, II, D, VI, and VII), have potent pharmacological, analgesic, and anticancer activities for the induction of cytotoxicity. Recent research has demonstrated that polyphyllins (PPs) possess potent effects against different cancers through apoptosis, autophagy, inflammation, and necroptosis. This review summarizes the available studies on PPs against cancer to provide a basis for future research.

Molecular mechanisms of anticancer activities of polyphyllin VII

Cancer is the leading cause of mortality in the world. The major therapies for cancer treatment are chemotherapy, surgery, and radiation therapy. All these therapies expensive, toxic and show resistance. The plant-derived compounds are considered safe, cost-effective and target cancer through different pathways. In these pathways include oxidative stress, mitochondrial dependent and independent, STAT3, NF-kB, MAPKs, cell cycle, and autophagy pathways. One of the new plants derived compounds is Polyphyllin VII (PPVII), which target cancer through different molecular mechanisms. In literature, there is a review gap of studies on PPVII; therefore in the current review, we summarized the available studies on PPVII to provide a base for future research.

Polyphyllin VII suppresses cell proliferation, the cell cycle and cell migration in colorectal cancer

Colorectal cancer (CRC) is one of the most common types of human cancer. However, there is still an urgent need to identify novel treatment strategies for CRC. The present study aimed to validate the potential antitumor effects of polyphyllin VII in CRC. The present study revealed that polyphyllin VII could significantly inhibit CRC proliferation and induce cell cycle arrest and apoptosis. Moreover, the anti-metastatic effect of polyphyllin VII in CRC cells was implicated. Microarray analysis identified that polyphyllin VII could affect multiple protein coding genes and non-coding RNAs. Bioinformatics analysis revealed that polyphyllin VII regulated multiple pathways in CRC, including ‘ER to Golgi vesicle-mediated transport’, ‘response to cAMP’, ‘Ras protein signal transduction’, ‘metabolic pathways’, ‘MAPK signaling pathway’ and ‘cell cycle’. Protein-Protein Interaction network analysis identified a series of key polyphyllin VII-regulating genes in CRC, including ribonucleoside-diphosphate reductase subunit M2, structural maintenance of chromosomes protein 4 and DNA replication licensing factor MCM4. Finally, the present results demonstrated that these key polyphyllin VII-regulating genes were dysregulated in CRC. Taken together, these results indicated that polyphyllin VII could be a novel antitumor drug for the treatment of CRC.

Polyphyllin VII induces fibroblasts apoptosis via the ERK/JNK pathway

Hypertrophic scar (HS) is a pathological scar that often occurs in burn patients. Its histology is characterized by the excessive proliferation of fibroblasts (FB) and excessive accumulation of extracellular matrix (ECM). Inhibition of proliferation and activation of FB is essential for the treatment of HS. The crude extracts of traditional Chinese medicines have beneficial therapeutic effects on HS besides possessing fewer side effects and being easily available. Polyphyllin VII (PP7) is an isoprene saponin isolated from Rhizoma paridis. It has a pro-apoptotic effect on cancer cells. In the present study, we demonstrate that PP7 exerts a significant inhibitory effect on hypertrophic scar fibroblasts (HSFs) in vitro. We also demonstrate that PP7 considerably induces the apoptosis of HSFs and inhibits their activity. Our data show that the PP7-induced HSFs cell apoptosis was mainly due to the enhanced expression of apoptotic genes (Bax, Caspase-3, Caspase-9) and decreased expression of Bcl-2. Moreover, PP7 treatment also enhances the expression of JNK, but that of extracellular protein kinases (ERK) was reduced, and induces apoptosis through ERK/JNK pathways. Thus, PP7 can be used as a drug to prevent the formation of HS.

Inhibitory effects of polyphyllins I and VII on human cisplatin-resistant NSCLC via p53 upregulation and CIP2A/AKT/mTOR signaling axis inhibition

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a human oncoprotein that is overexpressed in multiple kinds of cancers including non-small cell lung cancer (NSCLC). CIP2A plays an 'oncogenic nexus' to participate in the tumorigenesis and chemoresistance in several cancer types. AKT and mTORC1 overactivation are detected in NSCLC and many other cancers. Previous studies found that the CIP2A/AKT/mTOR pathway controls cell growth, apoptosis, autophagy process. Polyphyllin I (PPI) and polyphyllin VII (PPVII) are natural components extracted from Paris polyphylla that display anti-cancer properties. In the present study, we investigated whether PPI and PPVII can be used in the cisplatin (DDP)-resistant human NSCLC cell line A549/DDP. Results demonstrated that PPI and PPVII treatment significantly suppressed A549/DDP cell proliferation, migration, invasion and EMT, induced apoptosis and autophagy. Further examination of the mechanism revealed that the PPI and PPVII significantly upregulated the p53, induced caspase-dependent apoptosis and suppressed the CIP2A/AKT/mTOR pathway. The activation of autophagy was mediated through PPI and PPVII induced inhibition of mTOR. We propose that PPI and PPVII might be developed as candidate drugs for DDP-resistant NSCLC.

Polyphyllin VI Induces Apoptosis and Autophagy via Reactive Oxygen Species Mediated JNK and P38 Activation in Glioma

Background

Polyphyllin VI (PPVI), a bioactive component derived from a traditional Chinese herb Paris polyphylla, exhibits potential antitumor activity against hepatocellular carcinoma, as well as breast and lung cancers. However, its effect on glioma remains unknown.

Methods

Five glioma cell lines (U251, U343, LN229, U87 and HEB) and an animal model were employed in the study. Anti-proliferation effects of PPVI were first determined using CCK-8 cell proliferation and clone formation assays, then reactive oxygen species (ROS), cell cycle progression and apoptosis effects measured by flow cytometry. The effect of PPVI on protein expression was quantified by Western blot analysis.

Results

Data showed that PPVI inhibited the proliferation of glioma cell lines by modulating the G2/M phase. Additionally, incubation of cells with PPVI promoted apoptosis, autophagy, increased accumulation of ROS and activated ROS-modulated JNK and p38 pathways. On the other hand, N-acetyl cysteine, a ROS inhibitor, attenuated PPVI-triggered effects. Furthermore, JNK and p38 inhibitors ameliorated PPVI-triggered autophagy and apoptosis in glioma cells. In vivo assays showed that PPVI inhibited tumor growth of U87 cell line in nude mice.

Conclusion

Overall, these data suggested that PPVI might be an effective therapeutic agent for glioma.

Polyphyllin II inhibits liver cancer cell proliferation, migration and invasion through downregulated cofilin activity and the AKT/NF-κB pathway

The morbidity and mortality of primary liver cancer is one of the highest amongst all cancers. Deficiency of effective treatment and characteristics of cancer metastasis are believed to be responsible for this situation, thus a great demand is required for new agent development. Polyphyllin II (PP2), an important steroidal saponin extracted from Rhizoma Paris, has emerged as a potential anti-cancer agent, but the effects of PP2 in liver cancers and its underlying mechanisms remain unexplored. In our study, we found that PP2 could remarkably suppress the proliferation of two liver cancer cell lines, HepG2 and BEL7402, resulting in significant cell death. Besides, low doses of PP2 have displayed properties that inhibit cellular motility and invasion of liver cancer cells. In addition, we have found that PP2-mediated cofilin activity suppression was implicated in the inhibition of liver cancer cell motility. Decreased expression of two major hydrolytic enzymes (MMP2/MMP9), through the AKT/NF-κB signaling pathway may also be also responsible for this process. Rescue experiments done with either non-phosphorylatable mutant cofilin-1 (S3A) transfection or an activator of the AKT pathway significantly reversed the inhibition effects of PP2 on liver cancer cells. Taken together, we report a potential agent for liver cancer treatment and reveal its underlying mechanisms.

Polyphyllin VI Induces Caspase-1-Mediated Pyroptosis via the Induction of ROS/NF-κB/NLRP3/GSDMD Signal Axis in Non-Small Cell Lung Cancer

Trillium tschonoskii Maxim (TTM), a traditional Chinese medicine, has been demonstrated to have a potent anti-tumor effect. Recently, polyphyllin VI (PPVI), a main saponin isolated from TTM, was reported by us to significantly suppress the proliferation of non-small cell lung cancer (NSCLC) via the induction of apoptosis and autophagy in vitro and in vivo. In this study, we further found that the NLRP3 inflammasome was activated in PPVI administrated A549-bearing athymic nude mice. As is known to us, pyroptosis is an inflammatory form of caspase-1-dependent programmed cell death that plays an important role in cancer. By using A549 and H1299 cells, the in vitro effect and action mechanism by which PPVI induces activation of the NLRP3 inflammasome in NSCLC were investigated. The anti-proliferative effect of PPVI in A549 and H1299 cells was firstly measured and validated by MTT assay. The activation of the NLRP3 inflammasome was detected by using Hoechst33324/PI staining, flow cytometry analysis and real-time live cell imaging methods. We found that PPVI significantly increased the percentage of cells with PI signal in A549 and H1299, and the dynamic change in cell morphology and the process of cell death of A549 cells indicated that PPVI induced an apoptosis-to-pyroptosis switch, and, ultimately, lytic cell death. In addition, belnacasan (VX-765), an inhibitor of caspase-1, could remarkably decrease the pyroptotic cell death of PPVI-treated A549 and H1299 cells. Moreover, by detecting the expression of NLRP3, ASC, caspase-1, IL-1β, IL-18 and GSDMD in A549 and h1299 cells using Western blotting, immunofluorescence imaging and flow cytometric analysis, measuring the caspase-1 activity using colorimetric assay, and quantifying the cytokines level of IL-1β and IL-18 using ELISA, the NLRP3 inflammasome was found to be activated in a dose manner, while VX-765 and necrosulfonamide (NSA), an inhibitor of GSDMD, could inhibit PPVI-induced activation of the NLRP3 inflammasome. Furthermore, the mechanism study found that PPVI could activate the NF-κB signaling pathway via increasing reactive oxygen species (ROS) levels in A549 and H1299 cells, and N-acetyl-L-cysteine (NAC), a scavenger of ROS, remarkably inhibited the cell death, and the activation of NF-κB and the NLRP3 inflammasome in PPVI-treated A549 and H1299 cells. Taken together, these data suggested that PPVI-induced, caspase-1-mediated pyroptosis via the induction of the ROS/NF-κB/NLRP3/GSDMD signal axis in NSCLC, which further clarified the mechanism of PPVI in the inhibition of NSCLC, and thereby provided a possibility for PPVI to serve as a novel therapeutic agent for NSCLC in the future.

Polyphyllin VII induces apoptotic cell death via inhibition of the PI3K/Akt and NF‑κB pathways in A549 human lung cancer cells

Polyphyllin VII is an active compound isolated from Paris polyphylla, which is termed Chonglou in China. The present study was designed to investigate the underlying mechanisms of the antitumor effect of Polyphyllin VII in lung cancer cells. The cytotoxic effect of Polyphyllin VII in human lung cancer A549 cells was analyzed; the results revealed an IC₅₀ value of 0.41±0.10 µM at 24 h. The associated mechanisms were investigated by phase-contrast microscopy, fluorescence microscopy, flow cytometry and western blot analysis. Exposure of A549 cells to Polyphyllin VII resulted in apoptosis. Pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB, and wortmannin, an inhibitor of PI3K, both decreased the proportion of viable A549 cells in the presence of Polyphyllin VII. The ratio of apoptotic cells increased in the presence of wortmannin and PDTC. Western blot analysis revealed that PI3K, phosphorylated (p)-PI3K, Akt, p-Akt, NF-κB and p-NF-κB were downregulated following treatment with Polyphyllin VII. Increased caspase-3 activity, increased poly-(ADP-ribose) polymerase cleavage and a downregulation of inhibitor of caspase-activated DNase were observed following treatment with Polyphyllin VII, and these effects were enhanced by either wortmannin or PDTC. The present results revealed that Polyphyllin VII was able to induce apoptotic cell death in A549 human lung cancer cells via inhibition of the PI3K/Akt and NF-κB pathways.

Polyphyllin VII Promotes Apoptosis and Autophagic Cell Death via ROS-Inhibited AKT Activity, and Sensitizes Glioma Cells to Temozolomide

The high recurrence frequency of gliomas but deficiency of effective treatment and prevalent chemoresistance have elicited interests in exploring and developing new agents. Paris polyphyllins are monomers extracted from rhizome of Paris polyphylla var. yunnanensis. Here, we first reported that polyphyllin VII (PP7) exhibited cytotoxic effect on glioma cells. PP7 significantly suppressed the viability and induced cell death of U87-MG and U251 cells after 24 h, with the IC50 values 4.24 ± 0.87 μM and 2.17 ± 0.14 μM, respectively. Both apoptotic and autophagic processes were involved in the cytotoxic effect of PP7, as PP7 activated the Bcl2/Bax pathway and the inhibition of autophagy partly rescued the toxicity of PP7 in glioma cells. In addition, an inhibition of AKT/mTORC1 activity was found after PP7 administration, and it seemed that the overproduction of reactive oxygen species (ROS) was responsible for this effect. Namely, the removal of ROS by NAC treatment mitigated PP7-induced cell death, autophagy, and its effect on the AKT/mTORC1 signaling. Additionally, a combination assay of PP7 with temozolomide (TMZ), the most used chemotherapy for glioma patients, was performed resulting in synergism, while PP7 reduced TMZ resistance through inhibition of MGMT expression. Thus, our study reports PP7 as a potential agent for glioma treatment and reveals its underlying mechanisms of action.

Paris saponin VII enhanced the sensitivity of HepG2/ADR cells to ADR via modulation of PI3K/AKT/MAPK signaling pathway

To find the effect of Paris saponin VII (PS VII)-mediated PI3K/AKT/MAPK signaling pathway on the sensitivity of ADR-resistant HepG2 cell (HepG2/ADR) cells to ADR. The proliferation inhibitory rates were detected by using MTT assay. Flow cytometry was employed to examine the intracellular accumulation of ADR. The expressions of drug-resistant genes (P-gp, MRP and BCRP) were detected by qRT-PCR, cell apoptosis by Annexin-V-FITC/PI staining, and the expressions of drug-resistance-related proteins, apoptosis-related proteins, and PI3K/AKT/MAPK pathway-related proteins were determined by Western blotting. HepG2/ADR and HepG2 cells treated with PS VII (0.88, 1.32, 1.98, and 2.97 μM) for 48 hours showed increased proliferation inhibitory rate in a dose-dependent manner. HepG2/ADR cells treated PS VII (0.88, 1.32, 1.98 μM) for 48 hours showed decreased IC50 of ADR. Compared with HepG2/ADR cells treated with ADR (5 nM), those treated with PS VII (≤1.98 μM) and ADR (5 nM) showed enhanced ADR accumulation, decreased drug-resistant gene expressions, increased cell apoptosis with unregulated Bax and cleaved caspase-3 and downregulated Bcl-2, as well as the inhibition of PI3K/AKT/MAPK pathway. Moreover, the combination of ADR (5 nM), PS VII (1.98 μM), and LY294002 (PI3K/AKT inhibitor, 20 μM)/SB203580 (P38 inhibitor, 20 μM) for 48 hours could further decreased the HepG2/ADR cell viability, but induced cell apoptosis, accompanying with the decreased expressions of drug-resistant genes. PS VII could downregulate the expressions of drug-resistance genes, increase intracellular accumulation of ADR, promote cell apoptosis, and enhance the sensitivity of HepG2/ADR cells to ADR via PI3K/AKT/MAPK.

Polyphyllin I and VII potentiate the chemosensitivity of A549/DDP cells to cisplatin by enhancing apoptosis, reversing EMT and suppressing the CIP2A/AKT/mTOR signaling axis

Poor response and resistance to cisplatin (DDP)-based chemotherapy frequently leads to treatment failure in advanced non-small cell lung cancer (NSCLC). The underlying molecular mechanism is extremely complex and currently remains unclear. The overexpression of cancerous inhibitor of protein phosphatase 2A (CIP2A) indicates poor prognosis and promotes the epithelial-to-mesenchymal transition (EMT) and metastasis. The EMT has been reported to promote drug resistance in numerous previous studies. CIP2A and its downstream protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway also plays a role in mediating DDP resistance. Polyphyllin I (PPI) and polyphyllin VII (PPVII) are natural components extracted from Paris polyphylla that display anti-cancer properties. In the present study, the chemosensitizing effects of PPI and PPVII were investigated in the DDP-resistant NSCLC cell line A549/DDP, as well as the underlying molecular mechanisms. The results demonstrated that PPI and PPVII could significantly inhibit cell proliferation and enhance the sensitivities of A549/DDP cells to DDP. When assessing the underlying molecular mechanism, it was revealed that PPI and PPVII enhanced DDP-induced apoptosis in A549/DDP cells via p53 upregulation and the caspase-dependent pathway. Furthermore, PPI and PPVII reversed the EMT and suppressed CIP2A and its downstream AKT/mTOR signaling cascade in A549/DDP cells. Overall, the results from the present study demonstrated that PPI and PPVII may function as chemosensitizers by enhancing apoptosis via the p53 pathway, reversing EMT and suppressing the CIP2A/AKT/mTOR signaling axis, and the combination with DDP may be a promising strategy for the development of new therapeutic agents.

Polyphyllin VI induces apoptosis and autophagy in human osteosarcoma cells by modulation of ROS/JNK activation

Purpose

Polyphyllin VI, a main active saponin isolated from traditional medicinal plant Paris polyphylla, has exhibited antitumor activities in several cancer cell lines. In the present study, we investigated the antitumor effect of Polyphyllin VI against human osteosarcoma cells (U2OS) and the underlying molecular mechanisms.

Methods

The U2OS cell lines were used to determine the antiproliferative effect of Polyphyllin VI by CCK8 assay. Cell cycle was analyzed by flow cytometry. The Polyphyllin VI-induced apoptosis was determined by Annexin V-APC/7-AAD apoptosis detection kit and JC-1 staining. Meanwhile, the autophagy was determined by acridine orange staining. The apoptosis and autophagy-related proteins were monitored by Western blot assay. Subsequently, intracellular hydrogen peroxide (H₂O₂) and the activation of ROS/JNK pathway were detected.

Results

Polyphyllin VI could potently inhibit cell proliferation by causing G2/M phase arrest. Polyphyllin VI induced mitochondria-mediated apoptosis with the upregulation of proapoptotic proteins Bax and poly ADP-ribose polymerase, and downregulation of antiapoptotic protein Bcl-2 in U2OS cells. Concomitantly, Polyphyllin VI provoked autophagy with the upregulation of critical Atg proteins and accumulation of LC3B-II. Intracellular H₂O₂ production was triggered upon exposure to Polyphyllin VI, which could be blocked by ROS scavenger. Polyphyllin VI dramatically promoted JNK phosphorylation, whereas it decreased the levels of phospho-p38 and ERK.

Conclusion

Our results reveal that Polyphyllin VI may effectively induce apoptosis and autophagy to suppress cell growth via ROS/JNK activation in U2OS cells, suggesting that Polyphyllin VI is a potential drug candidate for the treatment of osteosarcomas.

Polyphyllin VI, a saponin from Trillium tschonoskii Maxim. induces apoptotic and autophagic cell death via the ROS triggered mTOR signaling pathway in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers. Our previous studies have proven that Trillium tschonoskii Maxim. (TTM), a traditional Chinese medicine, possesses potent anti-tumor effect. However, the detailed components and molecular mechanism of TTM in anti-NSCLC are still unknown. In the present experiment, polyphyllin VI (PPVI) was successfully isolated from TTM with guidance of the anti-proliferative effect in A549 cells, and the cell death of PPVI treated A549 and H1299 cells was closely linked with the increased intracellular ROS levels. In addition, PPVI induced apoptosis by promoting the protein expression of Bax/Bcl2, caspase-3 and caspase-9, and activated autophagy by improving LC3 II conversion and GFP-LC3 puncta formation in A549 and H1299 cells. The mechanism study found that the activity of mTOR which regulates cell growth, proliferation and autophagy was significantly suppressed by PPVI. Accordingly, the PI3K/AKT and MEK/ERK pathways positively regulating mTOR were inhibited, and AMPK negatively regulating mTOR was activated. In addition, the downstream of mTOR, ULK1 at Ser 757 which downregulates autophagy was inhibited by PPVI. The apoptotic cell death induced by PPVI was confirmed, and it was significantly suppressed by the overexpression of AKT, ERK and mTOR, and the induced autophagic cell death which was depended on the Atg7 was decreased by the inhibitors, such as LY294002 (LY), Bafilomycin A1 (Baf), Compound C (CC) and SBI-0206965 (SBI). Furthermore, the mTOR signaling pathway was regulated by the increased ROS as the initial signal in A549 and H1299 cells. Finally, the anti-tumor growth activity of PPVI in vivo was validated in A549 bearing athymic nude mice. Taken together, our data have firstly demonstrated that PPVI is the main component in TTM that exerts the anti-proliferative effect by inducing apoptotic and autophagic cell death in NSCLC via the ROS-triggered mTOR signaling pathway, and PPVI may be a promising candidate for the treatment of NSCLC in future.

In Vitro Effects on Thrombin of Paris Saponins and In Vivo Hemostatic Activity Evaluation of Paris fargesii var. brevipetala

The resource shortage of Rhizoma Paridis has never been effectively addressed, and the industry continues to search for alternative resources. The in vitro effects on thrombin of Paris saponins and in vivo hemostatic activity of Paris fargesii var. brevipetala (PF) were evaluated in this study. PF is considered to be an alternative source of Rhizoma Paridis (RP). The in vitro incubation experiment was designed to investigate the effects on thrombin activity of Paris saponin H (PS H) and saponin extract in PF. The bleeding time of mouse tail snipping was used to evaluate the in vivo hemostatic effects of Paris saponins. Also, in vivo changes in four blood coagulation parameters in rats after oral administration of different groups of Paris saponins were compared. The effects of Paris saponins on liver function and blood lipid parameters were examined in order to avoid drug-induced liver injury. Activity studies of thrombin after ultra-filtration centrifugation showed that Paris saponins were able to enhance thrombin activity. Ultra performance liquid chromatography mass spectrometry (UPLC-MS) analysis results of the substrates led us to speculate that there is a specific binding between Paris saponins and thrombin. PS H and Paris saponins in PF significantly shortened the bleeding time in mice. One pathway by which Paris saponins enhance in vivo blood coagulation is by increasing fibrinogen (FIB), among the four blood coagulation parameters in rats. At the same time, the effects on liver and blood lipid parameters were insignificant. P. fargesii var. brevipetala can be developed as an alternative medicinal source of Rhizoma Paridis.

Targeted regulation of Rell2 by microRNA-18a is implicated in the anti-metastatic effect of polyphyllin VI in breast cancer cells

Polyphyllin VI (PP-VI) is one of the major saponins present in Paris polyphylla Sm., a medicinal plant primarily used for cancer treatment in China and India. However, its anti-metastatic activity remains largely unknown. The current study thus investigated the anti-metastatic activity of PP-VI in mouse mammary carcinoma 4T1 and human breast cancer MDA-MB-231 cells. The anti-metastatic effect of PP-VI was investigated at a sub-cytotoxic dose in migration and invasion assays in vitro. Experimental metastasis mouse model was used to examine the anti-metastatic effect of PP-VI in vivo. Additionally, target prediction, real-time PCR, Western blotting and luciferase assay were performed to identify the target gene of a pro-metastatic microRNA, miR-18a in 4T1 cells. The effect of PP-VI on the identified target of miR-18a was further investigated. The results showed that PP-VI impaired the viability of 4T1 and MDA-MB-231 cells. Moreover, when applied at a sub-cytotoxic dose, PP-VI suppressed the metastatic potential of 4T1 and MDA-MB-231 cells. Receptor expressed in lymphoid tissue (RELT)-like 2 (Rell2) was identified as a direct target of miR-18a with anti-metastatic functions in 4T1 and MDA-MB-231 cells. PP-VI treatment resulted in increased expression of Rell2 and decreased level of miR-18a in 4T1 and MDA-MB-231 cells. PP-VI treatment also attenuated miR-18a mimic or Rell2 siRNA-augmented migration of MDA-MB-231 cells. The current work thus demonstrates for the first time that targeted regulation of Rell2 by miR-18a is in part implicated in the anti-metastatic effect of PP-VI in breast cancer cells, providing novel pharmacological insights into the anti-cancer effect of PP-VI.

The synergistic anticancer effect of formosanin C and polyphyllin VII based on caspase-mediated cleavage of Beclin1 inhibiting autophagy and promoting apoptosis

OBJECTIVES

Drug combination has a promising and potential development prospect in the treatment of various cancers. The objective of this study is to investigate the synergistic mechanisms of polyphyllin VII (PVII) and formosanin C (FC) in lung cancer.

MATERIALS AND METHODS

The combination of FC and PVII influenced on the apoptosis, autophagy, and the relative signalling pathways were analysed in lung cancer cells.

RESULTS

The combination of FC and PVII demonstrated a concentration- dependent growth inhibition in human lung cancer cells. The combination index (CI) obtained from four lung cancer cells was smaller than 1. This synergistic antitumour effect was based on the increase of their single proapoptotic effect but inhibiting FC-induced autophagy in NCI-H460 cells. FC and PVII activated proapoptotic elements like cleaved-caspase-3, -8, and -9 to induce Beclin1 cleaved into Beclin1-C which suppressed FC-triggered autophagy and enhanced apoptosis.

CONCLUSIONS

Formosanin C and PVII showed a synergistic antitumour effect on lung cancer cells. The findings would provide the foundation for the use of combination drugs in the future.

Molecular Mechanisms of Apoptosis in HepaRG Cell Line Induced by Polyphyllin VI via the Fas Death Pathway and Mitochondrial-Dependent Pathway

Polyphyllin VI, which is an active saponin, is mainly isolated from traditional medicinal plant Paris polyphylla, which causes liver damage in rats. In the present study, we aimed to explore the potential cytotoxicity of polyphyllin VI on the growth of HepaRG cells and to determine the molecular mechanism. The results revealed that polyphyllin VI changed cell morphology and induced apoptosis in HepaRG cells. Flow cytometric assay displayed that polyphyllin VI promoted the generation of reactive oxygen species (ROS), depolarized the mitochondrial membrane potential (MMP), and induced S phase cell cycle arrest by decreasing the expression of cyclin A2 and CDK2, while significantly increasing the expression of p21 protein. Polyphyllin VI induced the release of cytochrome c from the mitochondria to the cytosol and activated Fas, caspase-3, -8, -9, and PARP proteins. Pretreatment with NAC and Z-VAD-FMK (ROS scavenger and caspase inhibitor, respectively) on HepaRG cells increased the percentage of viable cells, which indicated that polyphyllin VI induced cell apoptosis through mitochondrial pathway by the generation of ROS and Fas death-dependent pathway. All of the effects are in dose- and time-dependent manners. Taken together, these findings emphasize the necessity of risk assessment to polyphyllin VI and offer an insight into polyphyllin VI-induced apoptosis of HepaRG cells.

Polyphyllin G induce apoptosis and autophagy in human nasopharyngeal cancer cells by modulation of AKT and mitogen-activated protein kinase pathways in vitro and in vivo

Polyphyllin G (also call polyphyllin VII), extract from rhizomes of Paris yunnanensis Franch, has been demonstrated to have strong anticancer activities in a wide variety of human cancer cell lines. Previous studies found that Polyphyllin G induced apoptotic cell death in human hepatoblastoma cancer and lung cancer cells. However, the underlying mechanisms of autophagy in human nasopharyngeal carcinoma (NPC) remain unclear. In this study, Polyphyllin G can potently induced apoptosis dependent on the activations of caspase-8, -3, and -9 and the changes of Bcl-2, Bcl-xL and Bax protein expression in different human NPC cell lines (HONE-1 and NPC-039). The amount of both LC3-II and Beclin-1 was intriguingly increased suggest that autophagy was induced in Polyphyllin G-treated NPC cells. To further clarify whether Polyphyllin G-induced apoptosis and autophagy depended on AKT/ERK/JNK/p38 MAPK signaling pathways, cells were combined treated with AKT inhibitor (LY294002), ERK1/2 inhibitor (U0126), p38 MAPK inhibitor (SB203580), or JNK inhibitor (SP600125). These results demonstrated that Polyphyllin G induced apoptosis in NPC cells through activation of ERK, while AKT, p38 MAPK and JNK were responsible for Polyphyllin G-induced autophagy. Finally, an administration of Polyphyllin G effectively suppressed the tumor growth in the NPC carcinoma xenograft model in vivo. In conclusion, our results reveal that Polyphyllin G inhibits cell viability and induces apoptosis and autophagy in NPC cancer cells, suggesting that Polyphyllin G is an attractive candidate for tumor therapies. Polyphyllin G may promise candidate for development of antitumor drugs targeting nasopharyngeal carcinoma.

Polyphyllin G induces apoptosis and autophagy cell death in human oral cancer cells

BACKGROUND

Polyphyllin G (also called polyphyllin VII), extract from rhizomes of Paris yunnanensis Franch, has been shown to have strong anticancer activities in a wide variety of human cancer cell lines. However, the underlying influences of autophagy in human oral squamous cell carcinoma (OSCC) remain unclear.

METHODS

In this study, the roles of apoptosis and autophagy in polyphyllin G-induced death in human oral cancer cells were investigated. Moreover, the molecular mechanism of the anticancer effects of polyphyllin G in human oral cancer cells was investigated.

RESULTS

The results revealed that polyphyllin G significantly inhibited cell proliferation in human oral cancer cells; it dose-dependently induced apoptosis in SAS and OECM-1 cells through caspase-3, -8, and -9 activation and poly (ADP-ribose) polymerase cleavage. In addition, changes were observed in Bcl-2 and proapoptosis-related protein expression in different human oral cancer cell lines. The expression of both LC3-II and beclin-1 was markedly increased, suggesting the induction of autophagy in polyphyllin G-treated oral cells. To further clarify whether polyphyllin G-induced apoptosis and autophagy depended on Akt/extracellular signal-regulated kinases (ERK)/c-Jun N-terminal kinases (JNK)/p38 mitogen-activated protein kinases (MAPK) signaling pathways, the cells were cotreated with inhibitors. The results demonstrated polyphyllin G-induced apoptosis in oral cells through the activation of ERK, Akt, p38 MAPK, and JNK, whereas ERK and JNK accounted for polyphyllin G-induced autophagy.

CONCLUSION

This study is the first to demonstrate apoptosis and autophagy during polyphyllin G-induced cell death in human oral cancer cell lines. These results suggest that polyphyllin G is a promising candidate for developing antitumor drugs targeting human oral squamous cell carcinoma.

Cytoskeletal reorganization and cell death in mitoxantrone-treated lung cancer cells

The aim of this study was to investigate the cytotoxic effect of mitoxantrone on two human non-small cell lung cancer cell lines, A549 (p53+) and H1299 (p53-). To our knowledge, this is the first study to evaluate the impact of MXT on the organization of cytoskeletal proteins. Analyses were performed using fluorescence and transmission electron microscopy, spectrophotometric techniques, flow cytometry and Western blotting. It was shown that H1299 cells are significantly more sensitive to mitoxantrone than the A549 cell line, and that the growth-inhibitory effect of the drug is dose-dependent only after longer incubation. The observed presence of ring-like microtubule structures and mitochondria surrounding the nuclei of H1299 cells could be a manifestation of increased tubulin polymerization requiring large amounts of energy, whereas the loss of actin stress fibers was presumably not the cause but rather the consequence of cell death induction. Treatment with mitoxantrone also led to the appearance of structures resembling agresomes in H1299 cells and to nucleolar segregation in both cell lines. It was demonstrated that cells arrested in the S phase were most susceptible to cell death induction, and that triggered intracellular changes led mainly to apoptosis. High concentrations induced necrosis and some H1299 cells exhibited morphological features of mitotic catastrophe.

Paris saponin I inhibits proliferation and promotes apoptosis through down-regulating AKT activity in human non-small-cell lung cancer cells and inhibiting ERK expression in human small-cell lung cancer cells

PSI regulated AKT activity in NSCLC and inhibited ERK expression in SCLC.