Curcumin Suppresses Lung Cancer Stem Cells via Inhibiting Wnt/β‐catenin and Sonic Hedgehog Pathways

Cancer stem cells (CSCs) are highly implicated in the progression of human cancers. Thus, targeting CSCs may be a promising strategy for cancer therapy. Wnt/β‐catenin and Sonic Hedgehog pathways play an important regulatory role in maintaining CSC characteristics. Natural compounds, such as curcumin, possess chemopreventive properties. However, the interventional effect of curcumin on lung CSCs has not been clarified. In the present study, tumorsphere formation assay was used to enrich lung CSCs from A549 and H1299 cells. We showed that the levels of lung CSC markers (CD133, CD44, ALDHA1, Nanog and Oct4) and the number of CD133‐positive cells were significantly elevated in the sphere‐forming cells. We further illustrated that curcumin efficiently abolished lung CSC traits, as evidenced by reduced tumorsphere formation, reduced number of CD133‐positive cells, decreased expression levels of lung CSC markers, as well as proliferation inhibition and apoptosis induction. Moreover, we demonstrated that curcumin suppressed the activation of both Wnt/β‐catenin and Sonic Hedgehog pathways. Taken together, our data suggested that curcumin exhibited its interventional effect on lung CSCs via inhibition of Wnt/β‐catenin and Sonic Hedgehog pathways. These novel findings could provide new insights into the potential therapeutic application of curcumin in lung CSC elimination and cancer intervention. Copyright © 2017 John Wiley & Sons, Ltd.     

Capsaicin suppressed activity of prostate cancer stem cells by inhibition of Wnt/β‐catenin pathway

Cancer stem cells (CSCs) are considered as the origin and driving cells of cancer, and play a key role in the progress of cancer. Studies have shown that capsaicin exerted inhibitory effect on prostate cancer cells, however, the effects of capsaicin on prostate CSCs remain undefined. In the present study, we showed that capsaicin could downregulate prostate CSCs markers and inhibit the growth of PC‐3 and DU145 prostate cancer stem cells. Further, we found capsaicin suppressed the expression of Wnt‐2, p‐GSK3β and β‐catenin, along with downregulation of Wnt/β‐catenin pathway target genes c‐myc and cyclinD1. Using LiCl, a activator of Wnt/β‐catenin pathway, we found activation of Wnt/β‐catenin pathway could ameliorate the downregulation of prostate CSCs markers and the growth inhibition induced by capsaicin in prostate cancer stem cells. Those data suggested that the inhibition effect of capsaicin on prostate cancer stem cells and the anti‐cancer effect of capsaicin on prostate cancer stem cell may be mediated by Wnt/β‐catenin pathway. Findings from this study reveals for the first time the potential role and mechanisms of capsaicin on prostate cancer stem cells.     

Alkaloids from nux vomica suppresses colon cancer cell growth through Wnt/β‐catenin signaling pathway

Brucine and Strychnine are alkaloids isolated from the seeds of Strychnos nux vomica L., which have long been used as a traditional medicine for the treatment of tumor. However, the effect of Brucine and Strychnine on colorectal cancer (CRC) and the underlying molecular mechanism remain unclear. In the present study, Brucine and Strychnine displayed profound inhibitory effects on the growth of human colon cancer cells. The results of flow cytometric analysis demonstrated that the two alkaloids induced cellular apoptosis. Moreover, the growth of DLD1 xenografted tumors in nude mice was significantly suppressed in the Brucine or Strychnine treated group. Mechanistically, the Wnt/β‐catenin is involved in this phenomenon, which is characterized by significantly increased expression of DKK1 and APC, whereas decreased expression of β‐catenin, c‐Myc, and p‐LRP6 in CRC cells as well as tumor tissues. Collectively, Brucine and Strychnine have targeted inhibition for colon cancer proliferation both in vitro and in vivo, and it is valuable for future exploitation and utilization as an antitumor agent of CRC.     

Astragaloside I Stimulates Osteoblast Differentiation Through the Wnt/β‐catenin Signaling Pathway

Astragaloside I (As‐I), one of the main active ingredients in Astragalus membranaceus, is believed to have osteogenic properties, but this hypothesis has not been investigated in detail. In the present work, the As‐I‐induced osteogenic effects and its underlying mechanism were studied in MC3T3‐E1 cells. The results indicated that the cellular levels of ALP and extracellular matrix calcium increased in a dose‐dependent manner by As‐I. To clarify the mechanisms involved in this process, the effect of As‐I on the key osteogenic‐related genes was investigated. We found that As‐I stimulated the expression of β‐catenin and Runx2 in MC3T3‐E1 cells, which play central roles in the Wnt/β‐catenin signaling pathway, suggesting that As‐I could promote osteoblastic differentiation by regulating the Wnt/β‐catenin signaling pathway. Moreover, the osteogenic effect of As‐I could be inhibited by DKK‐1, which is the classical inhibitor of Wnt/β‐catenin‐signaling pathway. Furthermore, As‐I also increased BMP‐2, BGP and OPG/RANKL expression, which are also activated by Wnt/β‐catenin signaling pathway. Taken together, our findings show that As‐I stimulates osteoblast differentiation through the Wnt/β‐catenin signaling pathway, which also activates the BMP pathway and RANK pathway, thus highlighting the As‐I for pharmaceutical and medicinal applications such as treating bone disease. Copyright © 2016 John Wiley & Sons, Ltd.     

Polygonum aviculare L. and its active compounds,quercitrin hydrate,caffeic acid,and rutin,activate the Wnt/β‐catenin pathway and induce cutaneous wound healing

Polygonum aviculare L. is a member of the Polygonaceae family of plants, which has been known for its antioxidant and anti‐obesity effects. However, the wound healing function of P. aviculare extract has not been assessed. In this study, we identified a novel property of P. aviculare extract as a Wnt/β‐catenin pathway activator based on a screen of 350 plant extracts using HEK293‐TOP cells retaining the Wnt/β‐catenin signaling reporter gene. P. aviculare extract accelerated the migration of HaCaT keratinocytes without showing significant cytotoxicity. Moreover, P. aviculare extract efficiently re‐epithelized wounds generated on mice. Additionally, ingredients of P. aviculare extract, such as quercitrin hydrate, caffeic acid, and rutin, also accelerated the motility of HaCaT keratinocytes with the activation of Wnt/β‐catenin signaling. Therefore, based on our findings, P. aviculare extract and its active ingredients could be potential therapeutic agents for wound healing. Copyright © 2016 John Wiley & Sons, Ltd.     

Fructus Ligustri Lucidi preserves bone quality through induction of canonical Wnt/β‐catenin signaling pathway in ovariectomized rats

Fructus Ligustri Lucidi (FLL) has been preclinically and clinically used to treat musculoskeletal diseases. However, whether and how FLL affect the canonical Wnt/β‐catenin signaling in the management of osteoporosis remains largely unknown. To this end, ovariectomized (OVX) rats and primary osteoblasts were administrated with FLL aqueous extract and medicated serum, respectively. Supplement of FLL to OVX rats maintains bone quality by attenuating the reduction in bone mineral density, strength and microstructure. The maintenance may be associated with upregulating the expression of insulin‐like growth factor‐1, osteoprotegerin, phospho (p)‐low‐density lipoprotein receptor‐related protein 6, p‐glycogen synthase kinase 3 beta (GSK3β), β‐catenin, Runx2 and c‐Myc, and downregulating the expressions of sclerostin (SOST), dickkopf‐related protein 1 (DKK1), GSK3β and p‐β‐catenin in rat femurs and tibias. In addition, the medicated serum promotes osteoblastic bone formation through activation of Wnt/β‐catenin signaling via inhibition of DKK1 and SOST overexpression. Salidroside may be one of the active ingredients in FLL that are beneficial for bone homeostasis. In summary, our results suggest that FLL may preserve bone quality through induction of canonical Wnt/β‐catenin signaling via inhibition of DKK1 and SOST overexpression. And FLL may offer a new source of the DKK1 or SOST inhibitors in protection against osteoporosis.     

Inhibition of Wnt/β‐Catenin Pathway by Dehydrocostus Lactone and Costunolide in Colon Cancer Cells

Abnormal activation of β‐catenin has been reported in 90% in the sporadic and hereditary colorectal cancer. The suppression of abnormally activated β‐catenin is one of the good strategies for chemoprevention and treatment of colorectal cancer. In this study, we have isolated two main compounds from root of Saussurea lappa, dehydrocostus lactone (DCL) and costunolide (CL), and investigated their anti‐colorectal cancer activities. DCL and CL suppressed cyclin D1 and survivin through inhibiting nuclear translocation of β‐catenin. They also suppressed the nuclear translocation of galectin‐3 that is one of the coactivators of β‐catenin in SW‐480 colon cancer cells. Furthermore, DCL and CL suppressed proliferation and survival of SW‐480 colon cancer cells through the induction of cell cycle arrest and cell death. Taken together, DCL and CL from root of S. lappa have anti‐colorectal cancer activities through inhibiting Wnt/β‐catenin pathway. Copyright © 2015 John Wiley & Sons, Ltd.     

β‐Elemene inhibits peritoneal metastasis of gastric cancer cells by modulating FAK/Claudin‐1 signaling

Peritoneal metastasis is common in advanced gastric cancer patients and is typically associated with a worse prognosis. β‐Elemene is a natural compound that can be isolated from the Curcuma wenyujin plant and has been widely used in China to treat a variety of cancers. However, the anti‐metastatic impacts of β‐elemene on gastric cancer remain unknown. In our study, we found that β‐elemene significantly inhibited the migration and invasive capacity of gastric cells in vitro and inhibited the capacity of gastric cancer cells to peritoneally diffuse and metastasize in vivo. Mechanistically, we demonstrated that the anti‐metastatic effects of β‐elemene were exerted by downregulating the expression of Claudin‐1. Furthermore, β‐elemene was found to inhibit the metastatic capacity of cells by downregulating FAK phosphorylation, which regulated Claudin‐1. Overall, our result revealed that β‐elemene inhibited peritoneal metastases from gastric cancer by modulating the FAK/Claudin‐1 pathway.     

A Comparative Study on the Inhibitory Effects of Different Parts and Chemical Constituents of Pomegranate on α‐Amylase and α‐Glucosidase

Pomegranate has been documented for the management of diabetes in Unani and Chinese medicine. This study compared the effects of the extracts of different pomegranate parts, including juice, peels, seeds and flowers, on carbohydrate digestive enzymes (α‐amylase and α‐glucosidase) in vitro. The methanolic flower extract inhibited α‐amylase and α‐glucosidase, while the methanolic peel extract inhibited α‐glucosidase selectively. The most active flower extract was subjected to water‐ethyl acetate partition. The ethyl acetate fraction was more potent than the water fraction in inhibiting both enzymes. Gallic acid and ellagic acid also showed selective inhibition against α‐glucosidase, and their presence in the ethyl acetate fraction was confirmed by HPLC‐DAD and HPLC‐HESI‐MS. Our findings suggest that the inhibition of carbohydrate digestive enzymes and their phenolic content may contribute to the anti‐hyperglycaemic effects of pomegranate flower and peel, and support their claims in diabetes. Copyright © 2012 John Wiley & Sons, Ltd.     

Synergistic effect of berberine and HMQ1611 impairs cell proliferation and migration by regulating Wnt signaling pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a biologically complex disease. Combination chemotherapy is a good strategy after surgery treatment. In this study, we report that berberine combined with HMQ1611 (BCH) had a good synergistic effect on the HCC. Our findings concluded that BCH showed good inhibition on the HCC proliferation and colony formation, which attributed to cell cycle arrest by BCH at G1 phase through impairing the expression of cyclinD1, cyclinE, and cdc2 and downregulated the phosphorylation of Akt, mTOR, and ERK. Moreover, BCH negatively regulated Wnt signaling pathway by upregulating the Axin and inhibiting the nuclear translocation of β‐catenin. BCH suppressed the phosphorylation of LRP5/6, GSK3β, the expression of Wnt5a, Frizzled8, CK1, and APC, as well as the nucleus protein included MMP2, MMP3, MMP9, and c‐myc. The above data of Wnt signaling regulators contributed to inhibition by BCH on cell migration. In vivo studies, BCH significantly suppressed the growth of SMMC‐7721 xenograft tumors through downregulating Ki67 and β‐catenin, as well as upregulating Axin and p‐β‐catenin. In conclusion, the results revealed that BCH exhibited potential antitumor activities against human liver cancer in vitro and in vivo, and the potential mechanism underlying these activities depended on the inhibition of the Wnt/β‐catenin signaling pathway.     

Phloroglucinol Protects INS‐1 Pancreatic β‐cells Against Glucotoxicity‐Induced Apoptosis

Decreasing numbers, and impaired function, of pancreatic β‐cells are key factors in the development of type 2 diabetes. This study was designed to investigate whether phloroglucinol protected pancreatic β‐cells against glucotoxicity‐induced apoptosis using a rat insulinoma cell line (INS‐1). High glucose treatment (30 mM) induced INS‐1 cell death; however, the level of glucose‐induced apoptosis was significantly reduced in cells treated with 100‐μM phloroglucinol. Treatment with 10–100‐μM phloroglucinol increased cell viability and decreased intracellular levels of reactive oxygen species, nitric oxide, and lipid peroxidation dose‐dependently in INS‐1 cells pretreated with high glucose. Furthermore, phloroglucinol treatment markedly reduced the protein expression of Bax, cytochrome c, and caspase 9, while increasing anti‐apoptotic Bcl‐2 protein expression. Cell death type was examined using annexin V/propidium iodide staining, revealing that phloroglucinol markedly reduced high glucose‐induced apoptosis. These results demonstrated that phloroglucinol could be useful as a potential therapeutic agent for the protection of pancreatic β‐cells against glucose‐induced apoptosis. Copyright © 2015 John Wiley & Sons, Ltd.     

Chelidonine inhibits TNF‐α‐induced inflammation by suppressing the NF‐κB pathways in HCT116 cells

Nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) is a complex that regulates several hundreds of genes, including those involved in immunity and inflammation, survival, proliferation, and the negative feedback of NF‐κB signaling. Chelidonine, a major bioactive, isoquinoline alkaloid ingredient in Chelidonium majus, exhibits antiinflammatory pharmacological properties. However, its antiinflammatory molecular mechanisms remain unclear. In this work, we explored the effect of chelidonine on TNF‐induced NF‐κB activation in HCT116 cells. We found chelidonine inhibited the phosphorylation and degradation of the inhibitor of NF‐κB alpha and nuclear translocation of RELA. Furthermore, by inhibiting the activation of NF‐κB, chelidonine downregulated target genes involved in inflammation, proliferation, and apoptosis. Chelidonine also inhibited mitogen‐activated protein kinase pathway activation by blocking c‐Jun N‐terminal kinase and p38 phosphorylation. These results suggest that chelidonine may be a potential therapeutic agent against inflammatory diseases in which inhibition of NF‐κB activity plays an important role.     

Astragaloside IV inhibits TGF‐β1‐induced epithelial‐mesenchymal transition through inhibition of the PI3K/Akt/NF‐κB pathway in gastric cancer cells

Astragaloside IV (AS‐IV) has been reported to possess anti‐metastasis activity in cancer cells. However, it is unknown whether AS‐IV could inhibit epithelial‐mesenchymal transition (EMT), a cellular de‐differentiation program that promotes metastasis, in cancer cells. The aim of this study was to study the effect and mechanism of AS‐IV on EMT in gastric cancer (GC) cells. The results showed that AS‐IV significantly inhibited cell viability, invasion, and migration of GC cells. The E‐cadherin to N‐cadherin switch and expression of Vimentin and metastasis‐related genes were induced by transforming growth factor β1 (TGF‐β1), whereas AS‐IV reversed the induction. In addition, AS‐IV inhibited TGF‐β1‐induced activation of PI3K/Akt/NF‐κB. Inhibition of the PI3K/Akt/NF‐κB pathway reversed TGF‐β1‐induced EMT. In conclusion, AS‐IV inhibited TGF‐β1‐induced EMT through inhibition of the PI3K/Akt/NF‐κB pathway in GC cells. AS‐IV might be an effective candidate for the treatment for GC.     

Hydroxy‐Safflower Yellow A inhibits the TNFR1‐Mediated Classical NF‐κB Pathway by Inducing Shedding of TNFR1

Hydroxy‐safflower yellow A (HSYA) is the major active component of safflower, a traditional Asia herbal medicine well known for its cardiovascular protective activities. The purpose of this study was to investigate the effect of HSYA on TNF‐α‐induced inflammatory responses in arterial endothelial cells (AECs) and to explore the mechanisms involved. The results showed that HSYA suppressed the up‐regulation of ICAM‐1 expression in TNF‐α‐stimulated AECs in a dose‐dependent manner. High concentration (120 μM) HSYA significantly inhibited the TNF‐α‐induced adhesion of RAW264.7 cells to AECs. HSYA blocked the TNFR1‐mediated phosphorylation and degradation of IκBα and also prevented the nuclear translocation of NF‐κB p65. Moreover, HSYA reduced the cell surface level of TNFR1 and increased the content of sTNFR1 in the culture media. TNF‐α processing inhibitor‐0 (TAPI‐0) prevented the HSYA inhibition of TNFR1‐induced IκBα degradation, implying the occurrence of TNFR1 shedding. Furthermore, HSYA induced phosphorylation of TNF‐α converting enzyme (TACE) at threonine 735, which is thought to be required for its activation. Conclusively, HSYA suppressed TNF‐α‐induced inflammatory responses in AECs, at least in part by inhibiting the TNFR1‐mediated classical NF‐κB pathway. TACE‐mediated TNFR1 shedding can be involved in this effect. Our study provides new evidence for the antiinflammatory and anti‐atherosclerotic effects of HSYA. Copyright © 2016 John Wiley & Sons, Ltd.     

Baicalein enhances the antitumor efficacy of docetaxel on nonsmall cell lung cancer in a β‐catenin‐dependent manner

The side effects of docetaxel have limited its antitumor performances in the treatment of nonsmall cell lung cancer (NSCLC). To address the problem, baicalein, a bioactive flavone that exhibits antitumor activity, was combined with docetaxel so as to achieve better efficacy and lower toxicity. The combination treatment enhanced the stabilization of microtubules and halted the cell‐cycle progression, thus synergistically inhibiting the proliferation and inducing the apoptosis of A549 cells and Lewis lung carcinoma cells. The decreased expression of Cyclin‐dependent kinase 6 and Cyclin B1 confirmed its regulation in cell cycle, with β‐catenin being an important upstream effector, as evidenced by the decreased expression in the cytoplasm and nucleus as well as the attenuated aggregation in the nucleus. Furthermore, baicalein plus docetaxel evinced better antitumor efficacy by the suppressed tumor growth, increased apoptosis, and decreased tumor angiogenesis in vivo, with no increased toxicity discovered in both tumor‐bearing and non‐tumor‐bearing mice, and an improvement in therapeutic index. This study has demonstrated that baicalein plus docetaxel is an appropriate combination simultaneously with augmented antitumor efficacy and acceptable safety, which might be a promising strategy for patients with advanced NSCLC.     

Luteoloside attenuates anoxia/reoxygenation‐induced cardiomyocytes injury via mitochondrial pathway mediated by 14‐3‐3η protein

Ischemia/reperfusion (I/R) injury is the major cause of acute cardiovascular disease worldwide. 14‐3‐3η protein has been demonstrated to protect myocardium against I/R injury. Luteoloside (Lut), a flavonoid found in many Chinese herbs, exerts myocardial protection effects. However, the mechanism remains unclear. We hypothesize that the cardioprotective role of Lut is exerted by regulating the 14‐3‐3η signal pathway. To investigate our hypothesis, an in vitro I/R model was generated in H9C2 cardiomyocytes by anoxia/reoxygenation (A/R) treatment. The effects of Lut on cardiomyocytes with A/R injury were assessed by determining the cell viability, lactate dehydrogenase levels, intracellular reactive oxygen species levels, mitochondrial permeability transition pores (mPTP) openness, caspase‐3 activity, and apoptosis rate. The effects on protein expression were tested using western blot analysis. Lut attenuated A/R‐induced injury to cardiomyocytes by increasing the expression of 14‐3‐3η protein and cell viability; decreasing levels of lactate dehydrogenase, reactive oxygen species, mPTP openness, caspase‐3 activity, and low apoptosis rate were observed. However, the cardioprotective effects of Lut were blocked by AD14‐3‐3ηRNAi, an adenovirus knocking down the intracellular 14‐3‐3η expression. In conclusion, to our knowledge, this is the first study to demonstrate that Lut protected cardiomyocytes from A/R‐induced injury via the regulation of 14‐3‐3η signaling pathway.     

Zerumbone Suppresses IL‐1β‐induced Cell Migration and Invasion by Inhibiting IL‐8 and MMP‐3 Expression in Human Triple‐negative Breast Cancer Cells

Inflammation is a key regulatory process in cancer development. Prolonged exposure of breast tumor cells to inflammatory cytokines leads to epithelial‐mesenchymal transition, which is the principal mechanism involved in metastasis and tumor invasion. Interleukin (IL)‐1β is a major inflammatory cytokine in a variety of tumors. To date, the regulatory mechanism of IL‐1β‐induced cell migration and invasion has not been fully elucidated. Here, we investigated the effect of zerumbone (ZER) on IL‐1β‐induced cell migration and invasion in breast cancer cells. The levels of IL‐8 and matrix metalloproteinase (MMP)‐3 mRNA were analyzed by real‐time polymerase chain reaction. The levels of secreted IL‐8 and MMP‐3 protein were analyzed by enzyme‐linked immunosorbent assay and western blot analysis, respectively. Cell invasion and migration was detected by Boyden chamber assay. The levels of IL‐8 and MMP‐3 expression were significantly increased by IL‐1β treatment in Hs578T and MDA‐MB231 cells. On the other hand, IL‐1β‐induced IL‐8 and MMP‐3 expression was decreased by ZER. Finally, IL‐1β‐induced cell migration and invasion were decreased by ZER in Hs578T and MDA‐MB231 cells. ZER suppresses IL‐1β‐induced cell migration and invasion by inhibiting IL‐8 expression and MMP‐3 expression in TNBC cells. ZER could be a promising therapeutic drug for treatment of triple‐negative breast cancer patients. Copyright © 2014 John Wiley & Sons, Ltd.