Curcumin combined with photodynamic therapy, promising therapies for the treatment of cancer.

Curcumin, a phytochemical derived from the rhizome of turmeric (Curcuma longa L.), has a broad group of substances with antibacterial, anti-inflammatory, anti-oxidant, anticancer activities. The anticancer activity of curcumin and its derivatives are mainly related to its regulation of signal transduction pathways. However, due to the low oral availability of curcumin, fast metabolism and other pharmacokinetic properties limit the application of curcumin in the treatment of cancer. Evidence suggests that curcumin combined with photodynamic therapy can overcome the limitation of curcumin's low bioavailability by acting on apoptosis pathways, such as B-cell lymphoma 2 (Bcl-2) and caspase family, and affecting cell cycle. This paper reviews the structure and pharmacokinetics of curcumin, focusing on the anticancer activity of curcumin combined with photodynamic therapy and the effects on cancer-related signal pathways.

Preclinical Evaluation of Antitumoral and Cytotoxic Properties of Viscum album Fraxini Extract on Pediatric Tumor Cells.

In Europe, especially in German-speaking countries, administration of mistletoe extracts is the most common and popular complementary and alternative therapy approach reported in oncology. Mistletoe therapy is applied to children with cancer for curative and palliative therapeutic regimes with increasing frequency, but at the same time, there are only a few studies on the effectiveness of this therapy. Therefore, we have investigated the response of various pediatric cell lines (acute myeloid leukemia, Ewing's sarcoma, hepatocellular carcinoma, medulloblastoma, neuroblastoma, and osteosarcoma) to mistletoe extract, abnobaVISCUM Fraxini. Effects on cell proliferation, cell cycle distribution as well as on mitochondrial integrity and caspase-mediated apoptosis were investigated in neuroblastoma cell lines, SH-SY5Y and Kelly. Additionally, in vitro tumor cell migration and invasion were studied. In vivo effects of the mistletoe extract were investigated in a syngeneic neuroblastoma mouse model. We could show that tumor cell lines were from 5- to 640-fold more sensitive to abnobaVISCUM Fraxini treatment than non-tumorigenic fibroblasts, whereby neuroblastoma cell lines were the most sensitive. For two neuroblastoma cell lines, SH-SY5Y and Kelly, induction of caspase-9-mediated apoptosis, a decrease of mitochondrial integrity as well as attenuation of migration and invasion were observed. In vivo experiments revealed a reduction of tumor growth and a prolonged survival of tumor-bearing animals. In summary, we can state that these results provide the first preclinical data for cytotoxic activities of abnobaVISCUM Fraxini for a broad panel of pediatric tumor cell lines, in particular, neuroblastoma cells. Thus, it might be a potential remedy for the supportive treatment of neuroblastoma.

Rhein Augments Antiproliferative Effects of Atezolizumab Based on Breast Cancer (4T1) Regression.

Rhein, an anthraquinone extracted from rhubarb, is used in traditional Chinese medicine for diuresis, diarrhoea, inflammation, and immune regulation. Atezolizumab, a programmed cell death ligand 1 monoclonal antibody, is mainly used to treat bladder cancer and non-small cell lung cancer unresponsive to chemotherapy. We explored the effects of rhein and atezolizumab in combination on breast cancer. Mice with established 4T1 breast cancer xenografts were administered rhein (10 mg/kg) and atezolizumab (10 mg/kg), alone and in combination, and the effects on tumour growth were evaluated. The proportion of CD8+ T cells in the spleen and tumour tissue, the levels of TNF-α, and interleukin-6 in serum as well as the mRNA levels of apoptotic factors (caspase-3, caspase-8, caspase-9, and Bax/Bcl-2) were also evaluated. All of the treatment groups had inhibitory effects on the xenograft tumour growth, with results that were significantly different from those in the control group. In addition, the proportion of CD8+ T cells in the spleen and tumour was significantly increased in the combination therapy group and was significantly different from the other treatment groups. The serum levels of TNF-α and IL-6 were significantly increased in the rhein and combination therapy groups. Finally, the levels of various apoptotic factors in tumour tissues were significantly higher in the combination treatment group than those in the other groups. Administration of rhein, atezolizumab, or their combination all had therapeutic effects on 4T1 breast cancer xenografts in mice, with the combination treatment having stronger effects.

Celastrol, a plant-derived triterpene, induces cisplatin-resistance nasopharyngeal carcinoma cancer cell apoptosis though ERK1/2 and p38 MAPK signaling pathway.

BACKGROUND: Developing resistance to chemotherapeutic drugs has become a major problem in the management of nasopharyngeal carcinoma (NPC). To overcome this issue, use of natural plant products as chemosensitizers is gaining importance at a fast pace. HYPOTHESIS/PURPOSE: The present study was designed to evaluate the cytotoxic effect and mode of action of a natural pentacyclic triterpenoid, celastrol, on cisplatin-resistant NPC cells. RESULTS: Study results revealed that celastrol treatment significantly reduced the viability of NPC cells in dose and time dependent manners, as compared to untreated control cells. The cytotoxic effect of celastrol was mediated by cell cycle arrest at G2/M phase and induction of intrinsic and extrinsic apoptotic pathways. With further analysis, we observed that celastrol-induced activation of caspases was accompanied by increased phosphorylation of MAPK pathway proteins, p38, ERK1/2. CONCLUSION: Taken together, our observation provides a novel insight on use of a natural plant product, celastrol, in the management of chemoresistant NPC.

Cytotoxicity of isoflavones and biflavonoids from Ormocarpum kirkii towards multi-factorial drug resistant cancer.

BACKGROUND: While incidences of cancer are continuously increasing, drug resistance of malignant cells is observed towards almost all pharmaceuticals. Several isoflavonoids and flavonoids are known for their cytotoxicity towards various cancer cells. PURPOSE: The aim of this study was to determine the cytotoxicity of isoflavones: osajin (1), 5,7-dihydroxy-4'-methoxy-6,8-diprenylisoflavone (2) and biflavonoids: chamaejasmin (3), 7,7″-di-O-methylchamaejasmin (4) and campylospermone A (5), a dimeric chromene [diphysin(6)] and an ester of ferullic acid with long alkyl chain [erythrinasinate (7)] isolated from the stem bark and roots of the Kenyan medicinal plant, Ormocarpum kirkii. The mode of action of compounds 2 and 4 was further investigated. METHODS: The cytotoxicity of compounds was determined based on the resazurin reduction assay. Caspases activation was evaluated using the caspase-Glo assay. Flow cytometry was used to analyze the cell cycle (propodium iodide (PI) staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP) (JC-1) and reactive oxygen species (ROS) (H2DCFH-DA). CCRF-CEM leukemia cells were used as model cells for mechanistic studies. RESULTS: Compounds 1, 2 and 4 displayed IC50 values below 20 µM towards CCRF-CEM and CEM/ADR5000 leukemia cells, and were further tested towards a panel of 7 carcinoma cells. The IC50 values of the compounds against carcinoma cells varied from 16.90 µM (in resistant U87MG.ΔEGFR glioblastoma cells) to 48.67 µM (against HepG2 hepatocarcinoma cells) for 1, from 7.85 µM (in U87MG.ΔEGFR cells) to 14.44 µM (in resistant MDA-MB231/BCRP breast adenocarcinoma cells) for 2, from 4.96 µM (towards U87MG.ΔEGFRcells) to 7.76 µM (against MDA-MB231/BCRP cells) for 4, and from 0.07 µM (against MDA-MB231 cells) to 2.15 µM (against HepG2 cells) for doxorubicin. Compounds 2 and 4 induced apoptosis in CCRF-CEM cells mediated by MMP alteration and increased ROS production. CONCLUSION: The present report indicates that isoflavones and biflavonoids from Ormocarpum kirkii are cytotoxic compounds with the potential of being exploited in cancer chemotherapy. Compounds 2 and 4 deserve further studies to develop new anticancer drugs to fight sensitive and resistant cancer cell lines.

Vitamin D enhances omega-3 polyunsaturated fatty acids-induced apoptosis in breast cancer cells.

Breast cancer is a leading type of cancer in women and generally classified into three subtypes of ER+ /PR+ , HER2+ and triple negative. Both omega-3 polyunsaturated fatty acids and vitamin D3 play positive role in the reduction of breast cancer incidence. However, whether combination of omega-3 polyunsaturated fatty acids and vitamin D3 has stronger protective effect on breast carcinogenesis still remains unknown. In this study, we show that the combination of ω-3 free fatty acids (ω-3 FFAs) and 1α, 25-dihydroxy-vitamin D3 (VD3 ) dramatically enhances cell apoptosis among three subtypes of breast cancer cell lines. Bcl-2 and total PARP protein levels are decreased in combined treatment MCF-7 and SK-BR-3 cells. Caspase signals play a vital role in cell apoptosis induced by combination. Moreover, Raf-MAPK signaling pathway is involved in the apoptosis induction by combination of ω-3 FFAs+VD3 . These results demonstrate that the induction of cell apoptosis by combined treatment is dependent on different signaling pathways in three subtypes of breast cancer cell lines.

Peanut sprout extract attenuates cisplatin-induced ototoxicity by induction of the Akt/Nrf2-mediated redox pathway.

OBJECTIVE: Cisplatin is commonly used to treat solid tumors. However, permanent hearing loss is a major side effect of cisplatin chemotherapy and often results in dose reduction of the cisplatin chemotherapy. Peanut sprouts show cytoprotective properties owing to their antioxidant activities. This study was designed to investigate the effect of peanut sprout extract (PSE) on cisplatin-induced ototoxicity in an auditory cell line, HEI-OC1 cells. METHODS: Cells were exposed to cisplatin for 24 h, with or without pre-treatment with PSE, cell viability was examined using the MTT assay. Apoptotic cells were identified by double staining with Hoechst 33258 and propidium iodide. Western blot analysis was performed to examine apoptotic proteins including C-PARP and C-caspase, anti-apoptotic protein Bcl-2, and Nrf2 redox system activation. Mitochondrial reactive oxygen species (ROS) were investigated to examine whether PSE could scavenge cisplatin-induced ROS. Real-time PCR analyses were performed to investigate the mRNA levels of antioxidant enzymes including NQO1, HO-1, GPx2, Gclc, and catalase. RESULTS: The cisplatin-treated group showed reduced cell viability, increased apoptotic properties and markers, and increased ROS levels. PSE pre-treatment before cisplatin exposure significantly increased cell viability and reduced apoptotic properties and ROS production. These effects resulted from the up-regulation of antioxidant genes, including NQO1, HO-1, GPx2, Gclc, and catalase through Akt phosphorylation and Nrf2 activation. CONCLUSION: Our results demonstrate that PSE protects from cisplatin-induced cytotoxicity by activating the antioxidant effects via the Akt/Nrf-2 pathway in this auditory cell line, and indicate that PSE may provide novel treatment to prevent cisplatin-induced ototoxicity.

Pinus radiata bark extract induces caspase-independent apoptosis-like cell death in MCF-7 human breast cancer cells.

In the present study, we investigated the anticancer activity of Pinus radiata bark extract (PRE) against MCF-7 human breast cancer cells. First, we observed that PRE induces potent cytotoxic effects in MCF-7 cells. The cell death had features of cytoplasmic vacuolation, plasma membrane permeabilization, chromatin condensation, phosphatidylserine externalization, absence of executioner caspase activation, insensitivity to z-VAD-fmk (caspase inhibitor), increased accumulation of autophagic markers, and lysosomal membrane permeabilization (LMP). Both the inhibition of early stage autophagy flux and lysosomal cathepsins did not improve cell viability. The antioxidant, n-acetylcysteine, and the iron chelator, deferoxamine, failed to restore the lysosomal integrity indicating that PRE-induced LMP is independent of oxidative stress. This was corroborated with the absence of enhanced ROS production in PRE-treated cells. Chelation of both intracellular calcium and zinc promotes PRE-induced LMP. Geranylgeranylacetone, an inducer of Hsp70 expression, also had no significant protective effect on PRE-induced LMP. Moreover, we found that PRE induces endoplasmic reticulum (ER) stress and mitochondrial membrane depolarization in MCF-7 cells. The ER stress inhibitor, 4-PBA, did not restore the mitochondrial membrane integrity, whereas cathepsin inhibitors demonstrated significant protective effects. Collectively, our results suggest that PRE induces an autophagic block, LMP, ER stress, and mitochondrial dysfunction in MCF-7 cells. However, further studies are clearly warranted to explore the exact mechanism behind the anticancer activity of PRE in MCF-7 human breast cancer cells.

Platelet protective efficacy of 3,4,5 trisubstituted isoxazole analogue by inhibiting ROS-mediated apoptosis and platelet aggregation.

Thrombocytopenia is a major hematological concern in oxidative stress-associated pathologies and chronic clinical disorders, where premature platelet destruction severely affects the normal functioning of thrombosis and hemostasis. In addition, frequent exposure of platelets to chemical entities and therapeutic drugs immensely contributes in the development of thrombocytopenia leading to huge platelet loss, which might be fatal sometimes. Till date, there are only few platelet protective molecules known to combat thrombocytopenia. Hence, small molecule therapeutics are extremely in need to relieve the burden on limited treatment strategies of thrombocytopenia. In this study, we have synthesized a series of novel 3,4,5 trisubstituted isoxazole derivatives, among which compound 4a [4-methoxy-N'-(5-methyl-3-phenylisoxazole-4-carbonyl) benzenesulfonohydrazide] was found to significantly ameliorate the oxidative stress-induced platelet apoptosis by restoring various apoptotic markers such as ROS content, cytosolic Ca(2+) levels, eIF2-α phosphorylation, mitochondrial membrane depolarization, cytochrome c release, caspase activation, PS externalization, and cytotoxicity markers. Additionally, compound 4a dose dependently inhibits collagen-induced platelet aggregation. Hence, compound 4a can be considered as a prospective molecule in the treatment regime of platelet activation and apoptosis and other clinical conditions of thrombocytopenia. Further studies might ensure the use of compound 4a as a supplementary therapeutic agent to treat, thrombosis and CVD-associated complications. Over all, the study reveals a platelet protective efficacy of novel isoxazole derivative 4a with a potential to combat oxidative stress-induced platelet apoptosis.

Diosmectite-zinc oxide composite improves intestinal barrier restoration and modulates TGF-ß1, ERK1/2, and Akt in piglets after acetic acid challenge.

The present study evaluated the beneficial effect of diosmectite-zinc oxide composite (DS-ZnO) on improving intestinal barrier restoration in piglets after acetic acid challenge and explored the underlying mechanisms. Twenty-four 35-d-old piglets (Duroc × Landrace × Yorkshire), with an average weight of 8.1 kg, were allocated to 4 treatment groups. On d 1 of the trial, colitis was induced via intrarectal injection of acetic acid (10 mL of 10% acetic acid [ACA] solution for ACA, DS-ZnO, and mixture of diosmectite [DS] and ZnO [DS+ZnO] groups) and the control group was infused with saline. Twenty-four hours after challenged, piglets were fed with the following diets: 1) control group (basal diet), 2) ACA group (basal diet), 3) DS-ZnO group (basal diet supplemented with DS-ZnO), and 4) DS+ZnO group (mixture of 1.5 g diosmectite [DS]/kg and 500 mg Zn/kg from ZnO [equal amount of DS and ZnO in the DS-ZnO treatment group]). On d 8 of the trial, piglets were sacrificed. The results showed that DS-ZnO supplementation improved (P < 0.05) ADG, ADFI, and transepithelial electrical resistance and decreased (P < 0.05) fecal scores, crypt depth, and fluorescein isothiocyanate-dextran 4 kDa (FD4) influx as compared with ACA group. Moreover, DS-ZnO increased (P < 0.05) occludin, claudin-1, and zonula occluden-1 expressions; reduced (P < 0.05) caspase-9 and caspase-3 activity and Bax expression; and improved (P < 0.05) Bcl2, XIAP, and PCNA expression. Diosmectite-zinc oxide composite supplementation also increased (P < 0.05) TGF-ß1 expression and ERK1/2 and Akt activation. These results suggest that DS-ZnO attenuates the acetic acid-induced colitis by improving mucosa barrier restoration, inhibiting apoptosis, and improving intestinal epithelial cells proliferation and modulation of TGF-ß1 and ERK1/2 and Akt signaling pathway.

In vitro and in vivo antitumor activity of tiliacorinine in human cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a fatal cancer with poor prognosis and less than 10% of CCA patients can be offered surgical cure. Conventional chemotherapy results in unfavorable outcomes. At present, plant-derived compounds are gaining interest as potential cancer therapeutics, particularly for treatment-refractory cancers. In this study, antitumor activity of tiliacorinine, the major alkaloid isolated from a tropical plant, on CCA was first demonstrated. Antiproliferative effects of tiliacorinine on human CCA cell lines were investigated using SRB assays. Acridine orange/ethidium bromide staining, flow cytometric analysis and DNA laddering assays were used for apoptotic determination. Apoptosis-related proteins were verified by Western blotting and antitumor activity of tiliacorinine in vivo was demonstrated in CCA xenografted mice. Tiliacorinine significantly inhibited proliferation of human CCA cell lines with IC50 4.5-7 µM by inducing apoptosis through caspase activation, up- regulation of BAX, and down-regulation of BclxL and XIAP. Tiliacorinine considerably reduced tumor growth in CCA xenografted mice. These results demonstrated antitumor effects of tiliacorinine on human CCA in vitro and in vivo. Tiliacorinine may be an effective agent for CCA treatment.

Isoangustone A induces apoptosis in SW480 human colorectal adenocarcinoma cells by disrupting mitochondrial functions.

Licorice and its components have been reported to posses various anti-tumor activities, but its active ingredients and underlying mechanisms are not well understood yet. In the present study, a group of representative licorice-derived compounds that could be detected in rat plasma or urine were screened for anti-tumor activity. Among these compounds, isoangustone A (IAA) was found to promptly inhibit the viability of SW480 human colorectal adenocarcinoma cells in a time- and concentration-dependent manner. Further analyses indicate that IAA activated caspase-dependent pro-apoptotic signaling and induced significant apoptosis, while had little effect on cell cycle. IAA strongly inhibited Akt phosphorylation within 5 min; however, overexpression of constitutively activated Akt could not rescue IAA-mediated inhibition, indicating that inhibition of Akt was not involved in IAA-induced apoptosis. Further examinations show that IAA induced dissipation of mitochondria membrane potential and release of cytochrome C within 1h, accompanied by swelling of mitochondrial matrix and disrupting of mitochondrial outer membrane, and followed by decreasing of cellular ATP. The above results suggest that IAA induced apoptosis in colorectal cancer cells principally by inducing mitochondrial outer membrane permeabilization, and deserves further investigations as a novel anti-colorectal cancer agent.

Induction of apoptosis in human breast cancer cells via caspase pathway by vernodalin isolated from Centratherum anthelminticum (L.) seeds.

BACKGROUND: Centratherum anthelminticum (L.) seeds (CA) is a well known medicinal herb in Indian sub-continent. We recently reported anti-oxidant property of chloroform fraction of Centratherum anthelminticum (L.) seeds (CACF) by inhibiting tumor necrosis factor-α (TNF-α)-induced growth of human breast cancer cells. However, the active compounds in CACF have not been investigated previously. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we showed that CACF inhibited growth of MCF-7 human breast cancer cells. CACF induced apoptosis in MCF-7 cells as marked by cell size shrinkage, deformed cytoskeletal structure and DNA fragmentation. To identify the cytotoxic compound, CACF was subjected to bioassay-guided fractionation which yielded 6 fractions. CACF fraction A and B (CACF-A, -B) demonstrated highest activity among all the fractions. Further HPLC isolation, NMR and LC-MS analysis of CACF-A led to identification of vernodalin as the cytotoxic agent in CACF-A, and -B. 12,13-dihydroxyoleic acid, another major compound in CACF-C fraction was isolated for the first time from Centratherum anthelminticum (L.) seeds but showed no cytotoxic effect against MCF-7 cells. Vernodalin inhibited cell growth of human breast cancer cells MCF-7 and MDA-MB-231 by induction of cell cycle arrest and apoptosis. Increased of reactive oxygen species (ROS) production, coupled with downregulation of anti-apoptotic molecules (Bcl-2, Bcl-xL) led to reduction of mitochondrial membrane potential (MMP) and release of cytochrome c in both human breast cancer cells treated with vernodalin. Release of cytochrome c from mitochondria to cytosol triggered activation of caspase cascade, PARP cleavage, DNA damage and eventually cell death. CONCLUSIONS/SIGNIFICANCE: To the best of our knowledge, this is the first comprehensive study on cytotoxic and apoptotic mechanism of vernodalin isolated from the Centratherum anthelminticum (L.) seeds in human breast cancer cells. Overall, our data suggest a potential therapeutic value of vernodalin to be further developed as new anti-cancer drug.

The protective effect of 3-deoxysappanchalcone on in vitro influenza virus-induced apoptosis and inflammation.

Influenza virus is one of the most important causes of acute respiratory disease. Viral infection and viral replication activate multiple cell signalling pathways. Apoptosis of infected cells and immune response against viral replication, which are generally considered to be protective mechanisms, are also probably mediated by viruses, which lead to severe health problems. We previously reported that 3-deoxysappanchalcone (3-DSC), a compound that is isolated from Caesalpinia sappan, exhibited in vitro anti-influenza activity. In the present study, we further identified that 3-DSC inhibited viral genomic replication and transcription only at a relatively high concentration. We then evaluated the effect of 3-DSC on the regulation of virus-induced cellular apoptosis. 3-DSC ameliorated virus-induced DNA fragmentation in a concentration-dependent manner, which tends to be a consequence of its inhibition of upstream caspase activation. 3-DSC also protected host cells against influenza-induced inflammation by suppressing CCL5 and CXCL10 secretions in endothelial cells and reducing the production of IL-6 and IL-1ß in monocytes/macrophages. In conclusion, our results demonstrate that anti-influenza virus mechanisms of 3-DSC involved anti-apoptosis and anti-inflammation activities in vitro. Moreover, 3-DSC could be a promising drug candidate for influenza treatment.

Isoegomaketone induces apoptosis through caspase-dependent and caspase-independent pathways in human DLD1 cells.

Isoegomaketone (IK) is an essential oil component of Perilla frutescens (L.), but the mechanism by which IK induces apoptosis has never been studied. The purpose of this study was to elucidate the IK-induced apoptotic pathway in DLD1 human colon cancer cells. We observed that IK treatment over 24 h significantly inhibited cell viability in a dose-dependent manner. We also found that IK triggered cleavage of PARP. Moreover, IK treatment resulted in cleavage of caspase-8, -9, and -3 in a dose- and time-dependent manner. IK treatment also resulted in cleavage of Bid and translocation of Bax, and triggered the release of cytochrome c from the mitochondria to the cytoplasm. Furthermore, it resulted in the translocation of apoptosis inducing factor (AIF), a caspase-independent mitochondrial apoptosis factor, from the mitochondria into the nucleus. Overall, these results suggest that IK induces apoptosis through caspase-dependent and capase-independent pathways in DLD1 cells.

Induction of apoptosis by cordycepin via reactive oxygen species generation in human leukemia cells.

Cordycepin (3'-deoxyadenosin), a specific polyadenylation inhibitor, is the main functional component in Cordyceps militaris, one of the top three renowned traditional Chinese medicines. Cordycepin has been shown to possess many pharmacological activities including immunological stimulation, and anti-bacterial, anti-viral, and anti-tumor effects. However, the mechanisms underlying its anti-cancer mechanisms are not yet understood. In this study, the apoptotic effects of cordycepin were investigated in human leukemia cells. Treatment with cordycepin significantly inhibited cell growth in a concentration-dependent manner by inducing apoptosis but not necrosis. This induction was associated with generation of reactive oxygen species (ROS), mitochondrial dysfunction, activation of caspases, and cleavage of poly(ADP-ribose) polymerase protein. However, apoptosis induced by cordycepin was attenuated by caspase inhibitors, indicating an important role for caspases in cordycepin responses. Administration of N-acetyl-l-cysteine, a scavenger of ROS, also significantly inhibited cordycepin-induced apoptosis and activation of caspases. These results support a mechanism whereby cordycepin induces apoptosis of human leukemia cells through a signaling cascade involving a ROS-mediated caspase pathway.

Apoptotic effect of Polygonum Cuspidatum in oral cancer cells through the regulation of specificity protein 1.

OBJECTIVES: The aim of this study was to evaluate the growth inhibitory and apoptosis-inducing effects and mechanisms of Polygonum cuspidatum root in oral cancer cells. MATERIALS AND METHODS: The testing materials were separated by normal-phase silica gel liquid chromatography. The effect of P. cuspidatum root on apoptotsis and its mechanism were performed using 3-(4,5-dimethylthiazol-20yl)-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium) (MTS) assay, western blot analysis, RT-PCR, promoter assay, and (4'-6-Diamidino-2-phenylindole) (DAPI) staining. RESULTS: The methanol extract of P. cuspidatum (MEPC) inhibited the proliferation of oral cancer cells by inducing caspase-dependent apoptosis. Protein and mRNA expression levels and the transactivation of Specificity protein 1 (Sp1) were markedly decreased in KB cells treated with MEPC. Ethyl acetate fraction (EA) from MEPC was more potent than aqueous fraction (AQ) from MEPC to induce apoptosis. F2, F3, and F4 from EA differentially inhibited the growth of KB cells, and it depends on the amount of Emodin in F2, F3, and F4. Moreover, Emodin inhibited oral cancer cell growth and induced caspase-dependent apoptosis by decreasing Sp1. MEPC also decreased an apoptosis-related downstream target of Sp1 protein, survivin. CONCLUSION: The results from this study strongly suggest that MEPC, its fraction, and Emodin may be potential bioactive materials to cause apoptosis mechanism via the down-regulation of Sp1 in oral cancer cells.

Houttuynia cordata Thunb extract inhibits cell growth and induces apoptosis in human primary colorectal cancer cells.

It is reported that Houttuynia cordata Thunb. (HCT), a traditional Chinese herbal medicine, has many biological properties such as antiviral, antibacterial and antileukemic activities. However, the molecular mechanisms of cytotoxicity and apoptosis in human primary colorectal cancer cells are not clear. In this study, whether HCT induced cytotoxicity in primary colorectal cancer cells obtained from three patients was investigated. The results indicated that HCT inhibited growth of cancer cells in a dose-dependent manner. After treatment with HCT (250 µg/ml) for 24 h, cells exhibited chromatin condensation (an apoptotic characteristic). HCT increased reactive oxygen species (ROS) production and decreased the mitochondrial membrane potential (ΔΨ(m)) in examined cells. Mitochondria-dependent apoptotic signaling pathway was shown to be involved as determined by increase in the levels of cytochrome c, Apaf-1, and caspase-3 and -9. The decrease in the level of ΔΨ(m) was associated with an increase in the BAX/BCL-2 ratio which led to activation of caspase-9 and -3. Based on our results, HCT induced apoptotic cell death in human primary colorectal cancer cells through a mitochondria-dependent signaling pathway.

Triptolide inactivates Akt and induces caspase-dependent death in cervical cancer cells via the mitochondrial pathway.

Triptolide, the main active component of the traditional Chinese herbal medicine Tripterygium wilfordii Hook F, has been shown to have potent immunosuppressive and anti-inflammatory properties. Here, we investigated the pro-apoptotic effect of triptolide in human cervical cancer cells and its underlying mechanisms. Exposure of cervical cancer cells to triptolide induced apoptosis, which was accompanied by loss of mitochondrial membrane potential, caspase processing (caspase-8, -9 and -3), and cleavage of the caspase substrate, poly(ADP-ribose) polymerase. The cytotoxic effects of triptolide were significantly inhibited by the caspase inhibitor, z-VAD-fmk. Triptolide-induced apoptosis was associated with a marked reduction in Akt phosphorylation and was exacerbated by LY294002 (phosphatidylinositol-3'-kinase inhibitor). Conversely, it was attenuated by Akt overexpression. Triptolide-induced apoptosis was also associated with downregulation of Mcl-1 and was significantly inhibited by Mcl-1 overexpression. These findings show that triptolide induces caspase-dependent, mitochondria-mediated apoptosis in cervical cancer cells, in part, by negatively regulating Akt and Mcl-1.

Dichloromethane fraction from Gardenia jasminoides: DNA topoisomerase 1 inhibition and oral cancer cell death induction.

CONTEXT: A growing body of evidence shows that compounds of plant origin have the ability to prevent cancer. The fruit of gardenia, Gardenia jasminoides Ellis (Rubiaceae), has long been used as a food additive and herbal medicine, and its pharmacological actions, such as protective activity against oxidative damage, cytotoxic effect, and anti-inflammatory and anti-tumor activity, have already been reported. OBJECTIVE: The purpose of the present study was to investigate the presence of DNA topoisomerase 1 inhibitor in various solvent fractions of Gardenia extract and examine the induction of oral cancer cell death upon treatment with Gardenia extract. MATERIALS AND METHODS: The methanol extract of Gardenia was partitioned with n-hexane, dichloromethane, ethyl acetate, n-butanol, and water. RESULTS: In the DNA topoisomerase 1 assay, n-hexane and dichloromethane fractions inhibited topoisomerase 1 and led to a decrease in the cell viability of KB cells. The dichloromethane fraction (0.1 mg/mL) also showed 77% inhibition of cell viability in KB cells compared with HaCaT cells. Treatment with dichloromethane fraction led to apoptotic cell death as evidenced by flow cytometric analysis and morphological changes. In addition, treatment with Gardenia extract dichloromethane fraction led to the partial increase of caspase-3, caspase-8 and caspase-9 activities and the cleavage of poly (ADP-ribose) polymerase. CONCLUSION: Taken together, these results suggest that the dichloromethane fraction from Gardenia extract induces apoptotic cell death by DNA topoisomerase 1 inhibition in KB cells. These findings suggest the possibility that Gardenia extract could be developed as an anticancer modality.