Displaying publications 21 - 40 of 106 in total

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  1. Fulltext Bile acids at neutral and acidic pH induce apoptosis and gene cleavages in nasopharyngeal epithelial cells: implications in chromosome rearrangement
    Tan SN, Sim SP
    BMC Cancer, 2018 04 12;18(1):409.
    PMID: 29649994 DOI: 10.1186/s12885-018-4327-4
    BACKGROUND: Chronic rhinosinusitis (CRS) increases the risk of developing nasopharyngeal carcinoma (NPC) while nasopharyngeal reflux is known to be one of the major aetiological factors of CRS. Bile acid (BA), the component of gastric duodenal contents, has been recognised as a carcinogen. BA-induced apoptosis was suggested to be involved in human malignancies. Cells have the potential and tendency to survive apoptosis. However, cells that evade apoptosis upon erroneous DNA repair may carry chromosome rearrangements. Apoptotic nuclease, caspase-activated deoxyribonuclease (CAD) has been implicated in mediating translocation in leukaemia. We hypothesised that BA-induced apoptosis may cause chromosome breaks mediated by CAD leading to chromosome rearrangement in NPC. This study targeted the AF9 gene located at 9p22 because 9p22 is one of the most common deletion sites in NPC.

    METHODS: We tested the ability of BA at neutral and acidic pH in inducing phosphatidylserine (PS) externalisation, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP) disruption, and caspase 3/7 activity in normal nasopharyngeal epithelial (NP69) and NPC (TWO4) cells. Inverse-PCR (IPCR) was employed to detect AF9 gene cleavages. To investigate the role of CAD in mediating these cleavages, caspase inhibition was performed. IPCR bands representing AF9 cleaved fragments were sequenced.

    RESULTS: BA-treated cells showed higher levels of PS externalisation, ROS production, MMP loss and caspase 3/7 activity than untreated control cells. The effect of BA in the induction of these intracellular events was enhanced by acid. BA at neutral and acidic pH also induced significant cleavage of the AF9 gene. These BA-induced gene cleavages were inhibited by Z-DEVD-FMK, a caspase-3 inhibitor. Intriguingly, a few chromosome breaks were identified within the AF9 region that was previously reported to participate in reciprocal translocation between the mixed lineage leukaemia (MLL) and AF9 genes in an acute lymphoblastic leukaemia (ALL) patient.

    CONCLUSIONS: These findings suggest a role for BA-induced apoptosis in mediating chromosome rearrangements in NPC. In addition, CAD may be a key player in chromosome cleavages mediated by BA-induced apoptosis. Persistent exposure of sinonasal tract to gastric duodenal refluxate may increase genomic instability in surviving cells.

    Matched MeSH terms: Membrane Potential, Mitochondrial
  2. Fulltext Neuroprotective Effects of Biochanin A against β-Amyloid-Induced Neurotoxicity in PC12 Cells via a Mitochondrial-Dependent Apoptosis Pathway
    Tan JW, Kim MK
    Molecules, 2016 Apr 25;21(5).
    PMID: 27120593 DOI: 10.3390/molecules21050548
    Alzheimer's disease is considered one of the major neurodegenerative diseases and is characterized by the production of β-amyloid (Aβ) proteins and progressive loss of neurons. Biochanin A, a phytoestrogen compound found mainly in Trifolium pratense, was used in the present study as a potential alternative to estrogen replacement therapy via the investigation of its neuroprotective effects against Aβ25-35-induced toxicity, as well as of its potential mechanisms of action in PC12 cells. Exposure of these cells to the Aβ25-35 protein significantly increased cell viability loss and apoptosis. However, the effects induced by Aβ25-35 were markedly reversed in the present of biochanin A. Pretreatment with biochanin A attenuated the cytotoxic effect of the Aβ25-35 protein by decreasing viability loss, LDH release, and caspase activity in cells. Moreover, we found that expression of cytochrome c and Puma were reduced, alongside with the restoration of Bcl-2/Bax and Bcl-xL/Bax ratio in the presence of biochanin A, which led to a decrease in the apoptotic rate. These data demonstrate that mitochondria are involved in the protective effect of biochanin A against Aβ25-35 and that this drug attenuated Aβ25-35-induced PC12 cell injury and apoptosis by preventing mitochondrial dysfunction. Thus, biochanin A might raise a possibility as a potential therapeutic agent for Alzheimer's disease and other related neurodegenerative diseases.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  3. ROS-Mediated Mitochondrial Pathway is Required for Manilkara Zapota (L.) P. Royen Leaf Methanol Extract Inducing Apoptosis in the Modulation of Caspase Activation and EGFR/NF-κB Activities of HeLa Human Cervical Cancer Cells
    Tan BL, Norhaizan ME, Chan LC
    Evid Based Complement Alternat Med, 2018;2018:6578648.
    PMID: 29977314 DOI: 10.1155/2018/6578648
    Manilkara zapota (L.) P. Royen (family: Sapotaceae) is commonly called sapodilla, or locally known as ciku. The detailed mechanisms underlying Manilkara zapota leaf methanol extract against HeLa human cervical cancer cells have yet to be investigated. Therefore, our present study is designed to investigate the ability to induce apoptosis and the underlying mechanisms of Manilkara zapota leaf methanol extract inducing cytotoxicity in HeLa cells. The apoptotic cell death was assessed using Annexin V-propidium iodide staining. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential activities were measured using dichlorodihydrofluorescein diacetate and MitoLite Orange, respectively, by NovoCyte Flow Cytometer. Bax and Bcl-2 expression were evaluated using Enzyme-Linked Immunosorbent Assay. Caspase-3 activity was determined using a colorimetric assay. The associated biological interaction pathways were evaluated using quantitative real-time PCR. Our data showed that HeLa cells were relatively more sensitive to Manilkara zapota leaf methanol extract than other cancer cell lines studied. Overall analyses revealed that Manilkara zapota leaf methanol extract can inhibit the viability of HeLa cells, induce mitochondrial ROS generation, and inhibit nuclear factor-kappa B (NF-κB) and epidermal growth factor receptor (EGFR) transcriptional activities. Our results suggested that Manilkara zapota leaf methanol extract might represent a potential anticervical cancer agent.
    Matched MeSH terms: Membrane Potential, Mitochondrial
  4. Thymoquinone induces apoptosis and increase ROS in ovarian cancer cell line
    Taha MM, Sheikh BY, Salim LZ, Mohan S, Khan A, Kamalidehghan B, et al.
    Cell Mol Biol (Noisy-le-grand), 2016 May 30;62(6):97-101.
    PMID: 27262811
    Nigella sativa is also known for its properties as a traditional herbal healing for many ailments. In this study, the anticancer properties of thyomquinone (TQ), the active ingredient of N. sativa, were studied using ovarian cancer cell line (Caov-3 cells). The anti-proliferative activity of TQ was determined using MTT and the apoptosis was investigated using Flowcytometry and Annexin-V Assays. Multiparameteric cytotoxicity bioassays were used to quantify the changes in cell permeability and mitochondrial membrane potential. Reactive oxygen species (ROS) and apoptosis-involved cell markers were examined to verify cell death mechanism. The MTT-assay showed that TQ induces anti-proliferative activity on Caov-3 with an IC50 of 6.0±0.03 μg/mL, without any cytotoxic activity towards WRL-68 normal hepatocytes. A significant induction of early phase of apoptosis was shown by annexin-V analysis. Treatment of Caov-3 cells with TQ induces decreases in plasma membrane permeability and mitochondrial membrane potential. Visible decrease in the nuclear area was also observed. A significant decrease is observed in Bcl-2 while Bax is down-regulated. TQ-triggered ROS-mediated has found to be associated with Hsp70 dysregulation, an indicator of oxidative injury. We found that TQ induced anti-cancer effect involves intrinsic pathway of apoptosis and cellular oxidative stress. Our results considered collectively indicated that thyomquinone may be a potential agent for ovarian cancer drug development.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  5. Fulltext (6E,10E) Isopolycerasoidol and (6E,10E) Isopolycerasoidol Methyl Ester, Prenylated Benzopyran Derivatives from Pseuduvaria monticola Induce Mitochondrial-Mediated Apoptosis in Human Breast Adenocarcinoma Cells
    Taha H, Looi CY, Arya A, Wong WF, Yap LF, Hasanpourghadi M, et al.
    PLoS One, 2015;10(5):e0126126.
    PMID: 25946039 DOI: 10.1371/journal.pone.0126126
    Phytochemicals from Pseuduvaria species have been reported to display a wide range of biological activities. In the present study, a known benzopyran derivative, (6E,10E) isopolycerasoidol (1), and a new benzopyran derivative, (6E,10E) isopolycerasoidol methyl ester (2), were isolated from a methanol extract of Pseuduvaria monticola leaves. The structures of the isolated compounds were elucidated by spectroscopic methods including 1D and 2D NMR, IR, UV, and LCMS-QTOF, and by comparison with previously published data. The anti-proliferative and cytotoxic effects of these compounds on human breast cancer cell-lines (MCF-7 and MDA-MB-231) and a human normal breast epithelial cell line (MCF-10A) were investigated. MTT results revealed both (1) and (2) were efficient in reducing cell viability of breast cancer cells. Flow cytometry analysis demonstrated that (1) and (2) induced cell death via apoptosis, as demonstrated by an increase in phosphotidylserine exposure. Both compounds elevated ROS production, leading to reduced mitochondrial membrane potential and increased plasma membrane permeability in breast cancer cells. These effects occurred concomitantly with a dose-dependent activation of caspase 3/7 and 9, a down-regulation of the anti-apoptotic gene BCL2 and the accumulation of p38 MAPK in the nucleus. Taken together, our data demonstrate that (1) and (2) induce intrinsic mitochondrial-mediated apoptosis in human breast cancer cells, which provides the first pharmacological evidence for their future development as anticancer agents.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  6. Fulltext Gallic acid induced apoptotic events in HCT-15 colon cancer cells
    Subramanian AP, Jaganathan SK, Mandal M, Supriyanto E, Muhamad II
    World J Gastroenterol, 2016 Apr 21;22(15):3952-61.
    PMID: 27099438 DOI: 10.3748/wjg.v22.i15.3952
    AIM: To investigate the inhibitory action of diet-derived phenolic compound gallic acid (GA) against HCT-15 colon cancer cells.
    METHODS: The antiproliferative effect of GA against colon cancer cells was determined by performing thiazolyl blue tetrazolium bromide (MTT) assay. The colony forming ability of GA treated colon cancer cells was evaluated using the colony forming assay. The cell cycle changes induced by GA in HCT-15 cells were analyzed by propidium iodide staining. Levels of reactive oxygen species (ROS) and mitochondrial membrane potential of HCT-15 exposed to GA was assessed using 2',7'-dichlorfluorescein-diacetate and rhodamine-123 respectively, with the help of flow cytometry. Morphological changes caused by GA treatment in the colon cancer cells were identified by scanning electron microscope and photomicrograph examination. Apoptosis was confirmed using flow cytometric analysis of GA treated HCT-15 cells after staining with Yo-Pro-1.
    RESULTS: MTT assay results illustrated that GA has an inhibitory effect on HCT-15 cells with IC50 value of 740 μmol/L. A time-dependent inhibition of colony formation was evident with GA treatment. Cell cycle arrest was evident from the accumulation of GA treated HCT-15 cells at sub-G1 phase (0.98 ± 1.03 vs 58.01 ± 2.05) with increasing exposure time. Flow cytometric analysis of GA treated HCT-15 cells depicted early events associated with apoptosis like lipid layer breakage and fall in mitochondrial membrane potential apart from an increase in the generation of ROS which were in a time dependent manner. SEM and photomicrograph images of the GA-treated cells displayed membrane blebbing and cell shrinking characteristics of apoptosis. Further apoptosis confirmation by Yo-Pro-1 staining also showed the time-dependent increase of apoptotic cells after treatment.
    CONCLUSION: These results show that GA induced ROS dependent apoptosis and inhibited the growth of colon cancer cells.
    KEYWORDS: Apoptosis; Cell cycle; Colon cancer; Gallic acid; Lipid layer break; Reactive oxygen species
    Matched MeSH terms: Membrane Potential, Mitochondrial
  7. Fulltext Vitamin C suppresses cell death in MCF-7 human breast cancer cells induced by tamoxifen
    Subramani T, Yeap SK, Ho WY, Ho CL, Omar AR, Aziz SA, et al.
    J Cell Mol Med, 2014 Feb;18(2):305-13.
    PMID: 24266867 DOI: 10.1111/jcmm.12188
    Vitamin C is generally thought to enhance immunity and is widely taken as a supplement especially during cancer treatment. Tamoxifen (TAM) has both cytostatic and cytotoxic properties for breast cancer. TAM engaged mitochondrial oestrogen receptor beta in MCF-7 cells and induces apoptosis by activation of pro-caspase-8 followed by downstream events, including an increase in reactive oxygen species and the release of pro-apoptotic factors from the mitochondria. In addition to that, TAM binds with high affinity to the microsomal anti-oestrogen-binding site and inhibits cholesterol esterification at therapeutic doses. This study aimed to investigate the role of vitamin C in TAM-mediated apoptosis. Cells were loaded with vitamin C by exposure to dehydroascorbic acid, thereby circumventing in vitro artefacts associated with the poor transport and pro-oxidant effects of ascorbic acid. Pre-treatment with vitamin C caused a dose-dependent attenuation of cytotoxicity, as measured by acridine-orange/propidium iodide (AO/PI) and Annexin V assay after treatment with TAM. Vitamin C dose-dependently protected cancer cells against lipid peroxidation caused by TAM treatment. By real-time PCR analysis, an impressive increase in FasL and tumour necrosis factor-α (TNF-α) mRNA was detected after TAM treatment. In addition, a decrease in mitochondrial transmembrane potential was observed. These results support the hypothesis that vitamin C supplementation during cancer treatment may detrimentally affect therapeutic response.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  8. Nordamnacanthal potentiates the cytotoxic effects of tamoxifen in human breast cancer cells
    Subramani T, Yeap SK, Ho WY, Ho CL, Osman CP, Ismail NH, et al.
    Oncol Lett, 2015 Jan;9(1):335-340.
    PMID: 25435988
    Tamoxifen (TAM) is the mainline drug treatment for breast cancer, despite its side effects and the development of resistance. As an alternative approach, in the present study a novel combination therapy was established through combining TAM with nordamnacanthal (NDAM) in order to investigate the additive effect of these drugs in MCF-7 human breast cancer cells. A significant dose-dependent reduction in cell viability and an increase in apoptosis were observed in the MCF-7 cells cotreated with TAM and NDAM compared with the untreated control cells or the cells treated with TAM and NDAM alone (P<0.05). The cytotoxic influence of the combination of TAM and NDAM was found to be two-fold that of the individual agents. Annexin V/propidium iodide double-staining revealed the typical nuclear features of apoptosis. Furthermore, an increase in the proportion of apoptotic, Annexin V-positive cells was observed with the combination therapy. Moreover, this apoptotic induction was associated with a collapse of the mitochondrial membrane potential and the generation of reactive oxygen species. To the best of our knowledge, the findings of the present study are the first to suggest that combining TAM with NDAM may be a potential combination therapy for the treatment of breast cancer and may have the potential to minimize or eliminate the side effects associated with high doses of TAM.
    Matched MeSH terms: Membrane Potential, Mitochondrial
  9. Fulltext Malaysian macroalga Padina australis Hauck attenuates high dose corticosterone-mediated oxidative damage in PC12 cells mimicking the effects of depression
    Subermaniam K, Yow YY, Lim SH, Koh OH, Wong KH
    Saudi J Biol Sci, 2020 Jun;27(6):1435-1445.
    PMID: 32489279 DOI: 10.1016/j.sjbs.2020.04.042
    Oxidative damage has been associated with the pathophysiology of depression. Macroalgae are equipped with antioxidant defense system to counteract the effects of free radicals. We explored the use of Malaysian Padina australis to attenuate high dose corticosterone-mediated oxidative damage in a cellular model mimicking depression. Fresh specimen of P. australis was freeze-dried and extracted sequentially with hexanes, ethyl acetate and ethanol. The extracts were screened for their phytochemical contents and antioxidant activities. Ethanol extract demonstrated the most potent antioxidant capacity and was selected for subsequent assays against high dose corticosterone of 600 µM-mediated oxidative damage in the rat pheochromocytoma (PC12) cells. The corticosterone reduced the cell viability, glutathione (GSH) level, aconitase activity, and mitochondrial membrane potential (MMP); and increased the lactate dehydrogenase (LDH) release, intracellular reactive oxygen species (ROS) level and apoptosis. However, the extent of oxidative damage was reversed by 0.25-0.5 mg/mL ethanol extract suggesting a possible role of P. australis-based antioxidants in the mitochondrial defense against constant ROS generation and regulation of antioxidant pathway. The effects were similar to that of desipramine, a tricyclic antidepressant. Our findings indicate that P. australis can be developed as a mitochondria-targeted antioxidant to mitigate antidepressant-like effects.
    Matched MeSH terms: Membrane Potential, Mitochondrial
  10. Antiproliferative and apoptosis inducing effects of citral via p53 and ROS-induced mitochondrial-mediated apoptosis in human colorectal HCT116 and HT29 cell lines
    Sheikh BY, Sarker MMR, Kamarudin MNA, Mohan G
    Biomed Pharmacother, 2017 Dec;96:834-846.
    PMID: 29078261 DOI: 10.1016/j.biopha.2017.10.038
    Despite various anticancer reports, antiproliferative and apoptosis inducing activity of citral in HCT116 and HT29 cells have never been reported. This study aimed to evaluate the cytotoxic and apoptosis inducing effects of citral in colorectal cancer cell lines. The citral-treated cells were subjected to MTT assay followed by flow cytometric Annexin V-FITC/PI, mitochondrial membrane potential and intracellular reactive oxygen species (ROS) determination. The apoptotic proteins expression was investigated by Western blot analysis. Citral inhibited the growth of HCT116 and HT29 cells by dose- and time-dependent manner without inducing cytotoxicity in CCD841-CoN normal colon cells. Flow cytometric analysis showed that citral (50-200μM; 24-48h) induced the externalization of phoshpotidylserine and reduced the mitochondrial membrane potential in HCT116 and HT29 cells. Citral elevated intracellular ROS level while attenuating GSH levels in HCT116 and HT29 cells which were reversed with N-acetycysteine (2mM) pre-treatment indicating that citral induced mitochondrial-mediated apoptosis via augmentation of intracellular ROS. Citral induced the phosphorylation of p53 protein and the expression of Bax while decreasing Bc-2 and Bcl-xL expression which promoted the cleavage of caspase-3. Collectively, our data suggest that citral induced p53 and ROS-mediated mitochondrial-mediated apoptosis in human colorectal cancer HCT116 and HT29 cells.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects*
  11. Anticancer Activity and Molecular Mechanism of Polyphenol Rich Calophyllum inophyllum Fruit Extract in MCF-7 Breast Cancer Cells
    Shanmugapriya, Chen Y, Kanwar JR, Sasidharan S
    Nutr Cancer, 2017 10 25;69(8):1308-1324.
    PMID: 29068745 DOI: 10.1080/01635581.2017.1367944
    This study was conducted to investigate the anticancer effects and mechanism of Calophyllum inophyllum fruit extract against MCF-7 cells. C. inophyllum fruit extract was found to have markedly cytotoxic effect against MCF-7 cells in a dose-dependent manner with the IC50 for 24 h of 23.59 µg/mL. Flow cytometry analysis revealed that C. inophyllum fruit extract mediated cell cycle at G0/G1 and G2/M phases, and MCF-7 cells entered the early phase of apoptosis. The expression of anti-apoptotic proteins Bcl-2 was decreased whereas the expression of the pro-apoptotic protein Bax, cytochrome C and p53 were increased after treatment. C. inophyllum fruit extract led to apoptosis in MCF-7 cells via the mitochondrial pathway in a dose dependent manner. This is evidenced by the elevation of intracellular ROS, the loss of mitochondria membrane potential (Δψm), and activation of caspase-3. Meanwhile, dose-dependent genomic DNA fragmentation was observed after C. inophyllum fruits extract treatment by comet assay. This study shows that C. inophyllum fruits extract-induced apoptosis is primarily p53 dependent and mediated through the activation of caspase-3. C. inophyllum fruit extract could be an excellent source of chemopreventive agent in the treatment of breast cancer and has potential to be explored as green anticancer agent.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  12. Fulltext The neuroprotective effects of tocotrienol rich fraction and alpha tocopherol against glutamate injury in astrocytes
    Selvaraju TR, Khaza'ai H, Vidyadaran S, Abd Mutalib MS, Vasudevan R
    Bosn J Basic Med Sci, 2014 Nov 16;14(4):195-204.
    PMID: 25428670 DOI: 10.17305/bjbms.2014.4.91
    Tocotrienol rich fraction (TRF) is an extract of palm oil, which consists of 25% alpha tocopherol (α-TCP) and 75% tocotrienols. TRF has been shown to possess potent antioxidant, anti-inflammatory, anticancer, neuroprotection, and cholesterol lowering activities. Glutamate is the main excitatory amino acid neurotransmitter in the central nervous system of mammalian, which can be excitotoxic, and it has been suggested to play a key role in neurodegenerative disorders like Parkinson's and Alzheimer's diseases. In this present study, the effects of vitamin E (TRF and α-TCP) in protecting astrocytes against glutamate injury were elucidated. Astrocytes induced with 180 mM of glutamate lead to significant cell death. However, glutamate mediated cytotoxicity was diminished via pre and post supplementation of TRF and α-TCP. Hence, vitamin E acted as a potent antioxidant agent in recovering mitochondrial injury due to elevated oxidative stress, and enhanced better survivability upon glutamate toxicity.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  13. Fulltext Geranylated 4-phenylcoumarins extracted from Mesua elegans induced caspase-independent cell death in prostate cancer cell lines through calpain-2 and cathepsin B
    Sapili H, Ho CS, Malagobadan S, Arshad NM, Nagoor NH
    Sci Rep, 2020 01 22;10(1):986.
    PMID: 31969640 DOI: 10.1038/s41598-020-57781-6
    Geranylated 4-phenylcoumarins DMDP-1 and DMDP-2 isolated from Mesua elegans were elucidated for their role in inducing caspase-independent programmed cell death (CI-PCD) in prostate cancer cell lines, PC-3 and DU 145, respectively. Cell homeostasis disruption was demonstrated upon treatment, as shown by the increase in calcium ion through colourimetric assay and endoplasmic reticulum (ER) stress markers GRP 78 and p-eIF2α through western blot. Subsequently, cytoplasmic death protease calpain-2 also showed increased activity during DMDP-1 & -2 treatments, while lysosomic death protease cathepsin B activity was significantly increased in PC-3 treated with DMDP-1. Flow cytometry showed a reduction in mitochondrial membrane potential in both cell lines, while western blotting showed translocation of mitochondrial death protease AIF into the cytoplasm in its truncated form. Furthermore, DMDP-1 & -2 treatments caused significant increase in superoxide level and oxidative DNA damage. Concurrent inhibition of calpain-2 and cathepsin B during the treatment showed an attenuation of cell death in both cell lines. Hence, DMDP-1 & -2 induce CI-PCD in prostate cancer cell lines through calpain-2 and cathepsin B.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  14. Fulltext Novel piperazine core compound induces death in human liver cancer cells: possible pharmacological properties
    Samie N, Muniandy S, Kanthimathi MS, Haerian BS, Azudin RE
    Sci Rep, 2016 Apr 13;6:24172.
    PMID: 27072064 DOI: 10.1038/srep24172
    The current study evaluates the cytotoxic mechanism of a novel piperazine derivate designated as PCC against human liver cancer cells. In this context, human liver cancer cell lines, SNU-475 and 243, human monocyte/macrophage cell line, CRL-9855, and human B lymphocyte cell line, CCL-156, were used to determine the IC50 of PCC using the standard MTT assay. PCC displayed a strong suppressive effect on SNU-475 and SNU-423 cells with an IC50 value of 6.98 ± 0.11 μg/ml and 7.76 ± 0.45 μg/ml respectively, after 24 h of treatment. Significant dipping in the mitochondrial membrane potential and elevation in the released of cytochrome c from the mitochondria indicated the induction of the intrinsic apoptosis pathway by PCC. Activation of this pathway was further evidenced by significant activation of caspase 3/7 and 9. PCC was also shown to activate the extrinsic pathways of apoptosis via activation of caspase-8 which is linked to the suppression of NF-ƙB translocation to the nucleus. Cell cycle arrest in the G1 phase was confirmed by flow cytometry and up-regulation of glutathione reductase expression was quantified by qPCR. This study suggests that PCC is a simultaneous inducer of intrinsic and extrinsic pathways of apoptosis in liver cancer cell lines.
    Matched MeSH terms: Membrane Potential, Mitochondrial
  15. Fulltext Mechanism of Action of the Novel Nickel(II) Complex in Simultaneous Reactivation of the Apoptotic Signaling Networks Against Human Colon Cancer Cells
    Samie N, Haerian BS, Muniandy S, Marlina A, Kanthimathi MS, Abdullah NB, et al.
    Front Pharmacol, 2015;6:313.
    PMID: 26858642 DOI: 10.3389/fphar.2015.00313
    The aim of this study was to evaluate the cytotoxic potential of a novel nickel(II) complex (NTC) against WiDr and HT-29 human colon cancer cells by determining the IC50 using the standard MTT assay. The NTC displayed a strong suppressive effect on colon cancer cells with an IC50 value of 6.07 ± 0.22 μM and 6.26 ± 0.13 μM against WiDr and HT-29 respectively, after 24 h of treatment. Substantial reduction in the mitochondrial membrane potential and increase in the release of cytochrome c from the mitochondria directed the induction of the intrinsic apoptosis pathway by the NTC. Activation of this pathway was further evidenced by significant activation of caspase 3/7 and 9. The NTC was also shown to activate the extrinsic pathway of apoptosis via activation of caspase-8 which is linked to the suppression of NF-κB translocation to the nucleus. Cell cycle arrest in the G1 phase was confirmed by flow cytometry and up-regulation of glutathione reductase expression was quantified by qPCR. Results of the current work indicates that NTC possess a potent cancer cell abolishing activity by simultaneous induction of intrinsic and extrinsic pathways of apoptosis in colon cancer cell lines.
    Matched MeSH terms: Membrane Potential, Mitochondrial
  16. Fulltext Inhibitory effect of Curcuma purpurascens BI. rhizome on HT-29 colon cancer cells through mitochondrial-dependent apoptosis pathway
    Rouhollahi E, Zorofchian Moghadamtousi S, Paydar M, Fadaeinasab M, Zahedifard M, Hajrezaie M, et al.
    BMC Complement Altern Med, 2015;15:15.
    PMID: 25652758 DOI: 10.1186/s12906-015-0534-6
    BACKGROUND: Curcuma purpurascens BI. (Zingiberaceae) commonly known as 'Koneng Tinggang' and 'Temu Tis' is a Javanese medicinal plant which has been used for numerous ailments and diseases in rural Javanese communities. In the present study, the apoptogenic activity of dichloromethane extract of Curcuma purpurascens BI. rhizome (DECPR) was investigated against HT-29 human colon cancer cells.
    METHODS: Acute toxicity study of DECPR was performed in Sprague-Dawley rats. Compounds of DECPR were analyzed by the gas chromatography-mass spectrometry-time of flight (GC-MS-TOF) analysis. Cytotoxic effect of DECPR on HT-29 cells was analyzed by MTT and lactate dehydrogenase (LDH) assays. Effects of DECPR on reactive oxygen species (ROS) formation and mitochondrial-initiated events were investigated using a high content screening system. The activities of the caspases were also measured using a fluorometric assay. The quantitative PCR analysis was carried out to examine the gene expression of Bax, Bcl-2 and Bcl-xl proteins.
    RESULTS: The in vivo acute toxicity study of DECPR on rats showed the safety of this extract at the highest dose of 5 g/kg. The GC-MS-TOF analysis of DECPR detected turmerone as the major compound in dichloromethane extract. IC50 value of DECPR towards HT-29 cells after 24 h treatment was found to be 7.79 ± 0.54 μg/mL. In addition, DECPR induced LDH release and ROS generation in HT-29 cells through a mechanism involving nuclear fragmentation and cytoskeletal rearrangement. The mitochondrial-initiated events, including collapse in mitochondrial membrane potential and cytochrome c leakage was also triggered by DECPR treatment. Initiator caspase-9 and executioner caspase-3 was dose-dependently activated by DECPR. The quantitative PCR analysis on the mRNA expression of Bcl-2 family of proteins showed a significant up-regulation of Bax associated with down-regulation in Bcl-2 and Bcl-xl mRNA expression.
    CONCLUSIONS: The findings presented in the current study showed that DECP suppressed the proliferation of HT-29 colon cancer cells and triggered the induction of apoptosis through mitochondrial-dependent pathway.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects*
  17. 3,5-dibenzyloxy-4'-hydroxystilbene induces early caspase-9 activation during apoptosis in human K562 chronic myelogenous leukemia cells
    Roslie H, Chan KM, Rajab NF, Velu SS, Kadir SA, Bunyamin I, et al.
    J Toxicol Sci, 2012 Feb;37(1):13-21.
    PMID: 22293408
    A series of 22 stilbene derivatives based on resveratrol were synthesized incorporating acetoxy-, benzyloxy-, carboxy-, chloro-, hydroxy- and methoxy functional groups. We examined the cytotoxicity of these 22 stilbenes in human K562 chronic myelogenous leukemia cells. Only four compounds were cytotoxic namely 4'-hydroxy-3-methoxystilbene (15), 3'-acetoxy-4-chlorostilbene (19), 4'-hydroxy-3,5-dimethoxystilbene or pterostilbene (3) and 3,5-dibenzyloxy-4'-hydroxystilbene (28) with IC(50)s of 78 µM, 38 µM, 67 µM and 19.5 µM respectively. Further apoptosis assessment on the most potent compound, 28, confirmed that the cells underwent apoptosis based on phosphatidylserine externalization and loss of mitochondrial membrane potential. Importantly, we observed a concentration-dependent activation of caspase-9 as early as 2 hr with resultant caspase-3 cleavage in 28-induced apoptosis. Additionally, a structure-activity relationship (SAR) study proposed a possible mechanism of action for compound 28. Taken together, our data suggests that the pro-apoptotic effects of 28 involve the intrinsic mitochondrial pathway characterized by an early activation of caspase-9.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  18. Chalepin: isolated from Ruta angustifolia L. Pers induces mitochondrial mediated apoptosis in lung carcinoma cells
    Richardson JS, Sethi G, Lee GS, Malek SN
    BMC Complement Altern Med, 2016 Oct 12;16(1):389.
    PMID: 27729078
    Cancer has been one of the leading causes of mortality in this era. Ruta angustifolia L. Pers has been traditionally used as an abortifacient, antihelmintic, emmenagogue and ophthalmic. In Malaysia and Singapore, the local Chinese community used it for the treatment of cancer.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects*
  19. para-Phenylenediamine induces apoptosis through activation of reactive oxygen species-mediated mitochondrial pathway, and inhibition of the NF-κB, mTOR, and Wnt pathways in human urothelial cells
    Reena K, Ng KY, Koh RY, Gnanajothy P, Chye SM
    Environ Toxicol, 2017 Jan;32(1):265-277.
    PMID: 26784575 DOI: 10.1002/tox.22233
    para-Phenylenediamine (PPD) has long been used in two-thirds of permanent oxidative hair dye formulations. Epidemiological studies and in vivo studies have shown that hair dye is a suspected carcinogen of bladder cancer. However, the toxicity effects of PPD to human bladder remains elusive. In this study, the effects of PPD and its involvement in the apoptosis pathways in human urothelial cells (UROtsa) was investigated. It was demonstrated that PPD decreased cell viability and increased the number of sub-G1 hypodiploid cells in UROtsa cells. Cell death due to apoptosis was detected using Annexin V binding assay. Further analysis showed PPD generated reactive oxygen species (ROS), induced mitochondrial dysfunction through the loss of mitochondrial membrane potential and increased caspase-3 level in UROtsa cells. Western blot analysis of PPD-treated UROtsa cells showed down-regulation of phosphorylated proteins from NF-κB, mTOR, and Wnt pathways. In conclusion, PPD induced apoptosis via activation of ROS-mediated mitochondrial pathway, and possibly through inhibition of NF-κB, mTOR, and Wnt pathways. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 265-277, 2017.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
  20. Cytoprotective Effect of Tocotrienol-Rich Fraction and α-Tocopherol Vitamin E Isoforms Against Glutamate-Induced Cell Death in Neuronal Cells
    Rati Selvaraju T, Khaza'ai H, Vidyadaran S, Sokhini Abd Mutalib M, Ramachandran V, Hamdan Y
    Int J Vitam Nutr Res, 2014;84(3-4):140-51.
    PMID: 26098478 DOI: 10.1024/0300-9831/a000201
    Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. We aimed to clarify the potential of the following vitamin E isomers, tocotrienol-rich fraction (TRF) and α-tocopherol (α-TCP), as potent neuroprotective agents against glutamate-induced injury in neuronal SK-N-SH cells. Cells were treated before and after glutamate injury (pre- and post-treatment, respectively) with 100-300 ng/ml TRF/α-TCP. Exposure to 120 mM glutamate significantly reduced cell viability to 76% and 79% in the pre- and post-treatment studies, respectively; however, pre- and post-treatment with TRF/α-TCP attenuated the cytotoxic effect of glutamate. Compared to the positive control (glutamate-injured cells not treated with TRF/α-TCP), pre-treatment with 100, 200, and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 95.2%, 95.0%, and 95.6%, respectively (p<0.05).The isomers not only conferred neuroprotection by enhancing mitochondrial activity and depleting free radical production, but also increased cell viability and recovery upon glutamate insult. Our results suggest that vitamin E has potent antioxidant potential for protecting against glutamate injury and recovering glutamate-injured neuronal cells. Our findings also indicate that both TRF and α-TCP could play key roles as anti-apoptotic agents with neuroprotective properties.
    Matched MeSH terms: Membrane Potential, Mitochondrial/drug effects
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