Induction of apoptotic cell death by Pharbitis nil extract in HER2-overexpressing MCF-7 cells

Pharbitidis Semen: A review of botany, traditional uses, phytochemistry, pharmacology, and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Pharbitidis Semen (the seeds of Ipomoea nil (L.) Roth or Ipomoea purpurea (L.) Roth), a popular traditional Chinese medicine, is also known as "Heichou" or "Baichou" (Chinese: , ). It can purge the bowels, promote diuresis, remove stagnated accumulation, and kill worms. It can be used for treating anasarca with constipation and oliguria; dyspnea and cough caused by retained fluid; abdominal pain because of intestinal parasitosis; ascariasis; and taeniasis.

AIMS

This review discusses the botany, ethnopharmacology, phytochemistry, pharmacological activities, toxicology, and quality control of Pharbitidis Semen, to obtain a complete understanding of its effects and provide a basis for further research and the development of new drugs.

MATERIALS AND METHODS

The literature on Pharbitidis Semen is mainly obtained from pharmacopoeias of different countries, masterpieces of traditional Chinese medicine, Master's and Ph.D. theses, and published articles obtained from literature retrieval websites, such as CNKI, PubMed, SciFinder, WanFang data, Web of Science, Springer, ScienceDirect, Wiley, ACS Publications, Taylor & Francis, J-STAGE, and Google Scholar. Its botany, ethnopharmacology, phytochemistry, pharmacological activities, toxicology, and quality control are discussed to understand its effects and provide a basis for further research.

RESULTS

Pharbitidis semen has been used ethnomedically in many tropical and subtropical countries as deobstruents, diuretics, and anthelmintics. About 170 chemical compounds, including terpenoids, phenylpropanoids, resin glycosides, fatty acids and other compounds, have been isolated. It has been reported to have different effects, including laxative, renal-protective, neuroprotective, insecticidal, antitumor, anti-inflammatory, and antioxidant. Moreover, a brief introduction to processing, toxicity, and quality control is provided.

CONCLUSIONS

The traditional efficacy of Pharbitidis Semen in diarrhea has been confirmed, but its bioactive and toxic ingredients are not entirely clear. It is necessary to strengthen the research and identification of effective parts or natural active components of Pharbitidis Semen, clarify the molecular mechanism of its toxicity and change rule of endogenous substances to make Pharbitidis Semen better used in clinical practice. Additionally, the imperfect quality standard is also a challenge that must be solved urgently. The study of modern pharmacology has broadened the application of Pharbitidis Semen and provided ideas for better utilization of this resource.

Plant Extracts and their Secondary Metabolites as Modulators of Kinases

Natural Products (NP), specifically from medicinal plants or herbs, have been extensively utilized to analyze the fundamental mechanisms of ultimate natural sciences as well as therapeutics. Isolation of secondary metabolites from these sources and their respective biological properties, along with their lower toxicities and cost-effectiveness, make them a significant research focus for drug discovery. In recent times, there has been a considerable focus on isolating new chemical entities from natural flora to meet the immense demand for kinase modulators, and also to overcome major unmet medical challenges in relation to signal transduction pathways. The signal transduction systems are amongst the foremost pathways involved in the maintenance of life and protein kinases play an imperative part in these signaling pathways. It is important to find a kinase inhibitor, as it can be used not only to study cell biology but can also be used as a drug candidate for cancer and metabolic disorders. A number of plant extracts and their isolated secondary metabolites such as flavonoids, phenolics, terpenoids, and alkaloids have exhibited activities against various kinases. In the current review, we have presented a brief overview of some important classes of plant secondary metabolites as kinase modulators. Moreover, a number of phytocompounds with kinase inhibition potential, isolated from different plant species, are also discussed.

Pharbitis Nil (PN) induces apoptosis and autophagy in lung cancer cells and autophagy inhibition enhances PN-induced apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Pharbitis Nil (PN) is used as a main component of the existing drug, DA-9701, which was developed to treat functional dyspepsia (FD) in Korea. PN extracts isolated from its seeds have been reported to have anticancer effects.

AIM OF THE STUDY

The purpose of this study was to investigate the underlying mechanism of the chemotherapeutic effects of PN in lung cancer cells.

MATERIALS AND METHODS

We performed MTT assays, colony formation assays, flow cytometry assays, Western blot analysis, reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence analysis, and cell counting assays to study the molecular mechanism of chemotherapeutic effects of PN in lung cancer cells.

RESULTS

Our results indicate that PN induced autophagy as well as apoptosis. PN inhibited cell proliferation and survival by inducing apoptosis in several lung cancer cell lines. PN-treated cells also exhibited induction of autophagy, as evidenced by increased protein expression levels and punctuate patterns of LC3 II. Moreover, activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), which plays an important role in autophagy activation, was shown to be related with PN-induced autophagy. Interestingly, pharmacological blockade of autophagy activation with wortmannin and inhibition of ERK1/2 phosphorylation by U0126 markedly enhanced PN-induced apoptosis and reduced cell viability, suggesting that autophagy induced by PN may have a cytoprotective effect by suppressing apoptosis. PN- induced apoptosis was regulated by signal transducer and activator of transcription 3 (STAT3) deactivation. Moreover, decrease of STAT3 activation in PN-treated cells was associated with reduced survivin expression, further demonstrating that PN-induced apoptosis was regulated by STAT3 deactivation.

CONCLUSION

We believe that PN, which is already proven to treat human patients with FD, might be a potential anticancer drug for human lung cancer. In addition, our data suggest that the combination of PN treatment with an autophagy inhibitor or traditional anticancer agents may be an effective anticancer therapy.

Suppression of ERK1/2 and hypoxia pathways by four Phyllanthus species inhibits metastasis of human breast cancer cells

Chemotherapies remain far from ideal due to drug resistance; therefore, novel chemotherapeutic agents with higher effectiveness are crucial. The extracts of four Phyllanthus species, namely Phyllanthus niruri, Phyllanthus urinaria, Phyllanthus watsonii, and Phyllanthus amarus, were shown to induce apoptosis and inhibit metastasis of breast carcinoma cells (MCF-7). The main objective of this study was to determine the pathways utilized by these four Phyllanthus species to exert anti-metastatic activities. A cancer 10-pathway reporter was used to investigate the pathways affected by the four Phyllanthus species. Results indicated that these Phyllanthus species suppressed breast carcinoma metastasis and proliferation by suppressing matrix metalloprotein 2 and 9 expression via inhibition of the extracellular signal-related kinase (ERK) pathway. Additionally, inhibition of hypoxia-inducible factor 1-α in the hypoxia pathway caused reduced vascular endothelial growth factor and inducible nitric oxide synthase expression, resulting in anti-angiogenic effects and eventually anti-metastasis. Two-dimensional gel electrophoresis identified numerous proteins suppressed by these Phyllanthus species, including invasion proteins, anti-apoptotic protein, protein-synthesis proteins, angiogenic and mobility proteins, and various glycolytic enzymes. Our results indicated that ERK and hypoxia pathways are the most likely targets of the four Phyllanthus species for the inhibition of MCF-7 metastasis.

Morinda citrifolia edible leaf extract enhanced immune response against lung cancer

In the search for functional foods as complementary therapies against lung cancer, the immuno-stimulatory properties of the vegetable Morinda citrifolia leaves were investigated and compared with the anti-cancer drug erlotinib.

Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT), one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE) inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin) in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2.

Mollugin inhibits proliferation and induces apoptosis by suppressing fatty acid synthase in HER2-overexpressing cancer cells

Mollugin is a naphthohydroquine found in the roots of Rubia cordifolia, and has been reported to have a variety of biological activities, including anti-inflammatory and apoptotic effects. In the present study, we investigated the molecular mechanisms by which mollugin exerts anti-tumor effect in HER2-overexpressing cancer cells. Our results showed that mollugin exhibited potent inhibitory effects on cancer cell proliferation, especially in HER2-overexpressing SK-BR-3 human breast cancer cells and SK-OV-3 human ovarian cancer cells in a dose- and time-dependent manner without affecting immortalized normal mammary epithelial cell line MCF-10A. Furthermore, we found that a blockade of Akt/SREBP-1c signaling through mollugin treatment significantly reduced FAS expression and subsequently suppressed cell proliferation and induced apoptosis in HER2-overexpressing cancer cells. Mollugin treatment caused a dose-dependent inhibition of HER2 gene expression at the transcriptional level, potentially in part through suppression of NF-κB activation. The combination of mollugin with a MEK1/2 inhibitor may be required in order to achieve optimal efficacy in HER2-overexpressing cancers. These data provide evidence that mollugin inhibits proliferation and induces apoptosis in HER2-overexpressing cancer cells by blocking expression of the FAS gene through modulation of a HER2/Akt/SREBP-1c signaling pathway. Our findings suggest that mollugin is a novel modulator of the HER2 pathway in HER2-overexpressing cancer cells with a potential role in the treatment and prevention of human breast and ovarian cancer with HER2 overexpression.

Ethanol extract of paeonia suffruticosa Andrews (PSE) induced AGS human gastric cancer cell apoptosis via fas-dependent apoptosis and MDM2-p53 pathways

Background

The root bark of Paeonia suffruticosa Andrews (PSE), also known as Moutan Cortex, has been widely used in Asia to treat various diseases. The molecular mechanisms by which PSE exerts its anti-oxidant and anti-inflammatory activities are well known, but its anti-cancer activity is not yet well understood. Here, we present evidence demonstrating that PSE can be used as a potent anti-cancer agent to treat gastric cancer.

Methods

The effects of the ethanol extract of PSE on cell proliferation were determined using an MTT (1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan) assay. Cell cytotoxicity induced by the PSE extact is measured using an LDH leakage assay. Flow cytometry was used to analyze the cell cycle and to measure the subG0/G1 apoptotic cell fraction. Apoptosis induced by the PSE extact is also examined using a DNA fragmentation assay. Western blot analysis is used to measure the levels of apoptotic proteins such as Fas receptor, caspase-8, caspase-3, PARP, Bax, Bcl-2, MDM2, and p53.

Results

This study demonstrated that treating AGS cells with the PSE extact significantly inhibited cell proliferation and induced cytotoxicity in a dose- and time-dependent manner. The PSE extract also induced apoptosis in AGS cells, as measured by flow cytometry and a DNA fragmentation assay. We found that the PSE extract induced apoptosis via the extrinsic Fas-mediated apoptosis pathway, which was concurrent with the activation of caspases, including caspase-8 and caspase-3, and cleavage of PARP. The MDM2-p53 pathway also played a role in the apoptosis of AGS cells that was induced by the PSE extract.

Conclusions

These results clearly demonstrate that the PSE extact displays growth-suppressive activity and induces apoptosis in AGS cells. Our data suggest that the PSE extact might be a potential anti-cancer agent for gastric cancer.

Rhein induces apoptosis in human breast cancer cells

Human breast cancers cells overexpressing HER2/neu are more aggressive tumors with poor prognosis, and resistance to chemotherapy. This study investigates antiproliferation effects of anthraquinone derivatives of rhubarb root on human breast cancer cells. Of 7 anthraquinone derivatives, only rhein showed antiproliferative and apoptotic effects on both HER2-overexpressing MCF-7 (MCF-7/HER2) and control vector MCF-7 (MCF-7/VEC) cells. Rhein induced dose- and time-dependent manners increase in caspase-9-mediated apoptosis correlating with activation of ROS-mediated activation of NF-κB- and p53-signaling pathways in both cell types. Therefore, this study highlighted rhein as processing anti-proliferative activity against HER2 overexpression or HER2-basal expression in breast cancer cells and playing important roles in apoptotic induction of human breast cancer cells.