Displaying publications 61 - 80 of 86 in total

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  1. Abu Bakar MH, Sarmidi MR, Tan JS, Mohamad Rosdi MN
    Eur J Pharmacol, 2017 Mar 15;799:73-83.
    PMID: 28161417 DOI: 10.1016/j.ejphar.2017.01.043
    Accumulating evidence indicates that mitochondrial dysfunction-induced inflammation is among the convergence points for the greatest hallmarks of hepatic insulin resistance. Celastrol, an anti-inflammatory compound from the root of Tripterygium Wilfordii has been reported to mitigate insulin resistance and inflammation in animal disease models. Nevertheless, the specific mechanistic actions of celastrol in modulating such improvements at the cellular level remain obscure. The present study sought to explore the mechanistic roles of celastrol upon insulin resistance induced by palmitate in C3A human hepatocytes. The hepatocytes exposed to palmitate (0.75mM) for 48h exhibited reduced both basal and insulin-stimulated glucose uptake, mitochondrial dysfunction, leading to increased mitochondrial oxidative stress with diminished fatty acid oxidation. Elevated expressions of nuclear factor-kappa B p65 (NF-κB p65), c-Jun NH(2)-terminal kinase (JNK) signaling pathways and the amplified release of pro-inflammatory cytokines including IL-8, IL-6, TNF-α and CRP were observed following palmitate treatment. Consistently, palmitate reduced and augmented phosphorylated Tyrosine-612 and Serine-307 of insulin receptor substrate-1 (IRS-1) proteins, respectively in hepatocytes. However, celastrol at the optimum concentration of 30nM was able to reverse these deleterious occasions and protected the cells from mitochondrial dysfunction and insulin resistance. Importantly, we presented evidence for the first time that celastrol efficiently prevented palmitate-induced insulin resistance in hepatocytes at least, via improved mitochondrial functions and insulin signaling pathways. In summary, the present investigation underlines a conceivable mechanism to elucidate the cytoprotective potential of celastrol in attenuating mitochondrial dysfunction and inflammation against the development of hepatic insulin resistance.
    Matched MeSH terms: Mitochondria/drug effects*
  2. Bakar MH, Sarmidi MR, Kai CK, Huri HZ, Yaakob H
    Int J Mol Sci, 2014 Dec 02;15(12):22227-57.
    PMID: 25474091 DOI: 10.3390/ijms151222227
    A growing body of evidence suggests that activation of nuclear factor kappa B (NF-κB) signaling pathways is among the inflammatory mechanism involved in the development of insulin resistance and chronic low-grade inflammation in adipose tissues derived from obese animal and human subjects. Nevertheless, little is known about the roles of NF-κB pathways in regulating mitochondrial function of the adipose tissues. In the present study, we sought to investigate the direct effects of celastrol (potent NF-κB inhibitor) upon mitochondrial dysfunction-induced insulin resistance in 3T3-L1 adipocytes. Celastrol ameliorates mitochondrial dysfunction by altering mitochondrial fusion and fission in adipocytes. The levels of oxidative DNA damage, protein carbonylation and lipid peroxidation were down-regulated. Further, the morphology and quantification of intracellular lipid droplets revealed the decrease of intracellular lipid accumulation with reduced lipolysis. Moreover, massive production of the pro-inflammatory mediators tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were markedly depleted. Insulin-stimulated glucose uptake activity was restored with the enhancement of insulin signaling pathways. This study signified that the treatments modulated towards knockdown of NF-κB transcription factor may counteract these metabolic insults exacerbated in our model of synergy between mitochondrial dysfunction and inflammation. These results demonstrate for the first time that NF-κB inhibition modulates mitochondrial dysfunction induced insulin resistance in 3T3-L1 adipocytes.
    Matched MeSH terms: Mitochondria/drug effects
  3. Abu Bakar MH, Cheng KK, Sarmidi MR, Yaakob H, Huri HZ
    Molecules, 2015 May 07;20(5):8242-69.
    PMID: 25961164 DOI: 10.3390/molecules20058242
    Mitochondrial dysfunction and inflammation are widely accepted as key hallmarks of obesity-induced skeletal muscle insulin resistance. The aim of the present study was to evaluate the functional roles of an anti-inflammatory compound, celastrol, in mitochondrial dysfunction and insulin resistance induced by antimycin A (AMA) in human skeletal muscle cells. We found that celastrol treatment improved insulin-stimulated glucose uptake activity of AMA-treated cells, apparently via PI3K/Akt pathways, with significant enhancement of mitochondrial activities. Furthermore, celastrol prevented increased levels of cellular oxidative damage where the production of several pro-inflammatory cytokines in cultures cells was greatly reduced. Celastrol significantly increased protein phosphorylation of insulin signaling cascades with amplified expression of AMPK protein and attenuated NF-κB and PKC θ activation in human skeletal muscle treated with AMA. The improvement of insulin signaling pathways by celastrol was also accompanied by augmented GLUT4 protein expression. Taken together, these results suggest that celastrol may be advocated for use as a potential therapeutic molecule to protect against mitochondrial dysfunction-induced insulin resistance in human skeletal muscle cells.
    Matched MeSH terms: Mitochondria/drug effects
  4. Chan ZCK, Leong KH, Kareem HS, Norazit A, Noor SM, Ariffin A
    Naunyn Schmiedebergs Arch Pharmacol, 2020 03;393(3):405-417.
    PMID: 31641820 DOI: 10.1007/s00210-019-01730-2
    The rationale of designing compounds containing a (3,4,5-trimethoxybenzyloxy) phenyl moiety is largely due to its potential antioxidant and cytotoxic activities. A previous study focused on its antioxidant mechanism, whereas in this study, we investigated the cytotoxicity of a series of 28 analogues and the mechanism of apoptosis of the most cytotoxic compound against wild-type (HCT-116) and p53 mutant (HT-29) colorectal cancer cell lines. The series of analogues comprise of different families, namely hydrazone, oxadiazole, thiosemicarbazides and triazoles. In the initial cytotoxicity screening, N-(3,4,5-trimethoxybenzylidene)-4-(3,4,5-trimethoxybenzyloxy) benzohydrazide, henceforth known as, P5H, was found to be most cytotoxic against human colorectal cancer cell lines (IC50 for HCT-116 = 11.79 μM and HT-29 = 18.52 μM). Additionally, P5H was found to have some degree of selectivity towards cancer cells compared to normal human colon cells (CCD-112 CoN). Subsequent investigation had brought insight on P5H ability to induce apoptosis in both HCT-116 and HT-29 cell lines. Cell cycle analysis showed both cell lines were arrested at the G2/M phase upon treatment. Our study concluded that P5H induced the death receptor, DR5 in HCT-116 and mitochondria-mediated apoptosis pathway in HT-29. Therefore, P5H may be a promising candidate as a chemotherapy agent against colon cancer. Graphical abstract The apoptotic pathways induced in HT-29 and HCT-116 cells upon P5H treatment.
    Matched MeSH terms: Mitochondria/drug effects
  5. 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: Mitochondria/drug effects*
  6. Khazaei S, Ramachandran V, Abdul Hamid R, Mohd Esa N, Etemad A, Moradipoor S, et al.
    Biomed Pharmacother, 2017 May;89:1216-1226.
    PMID: 28320088 DOI: 10.1016/j.biopha.2017.02.082
    Cervical cancer accounts for the second most frequent cancer and also third leading cause of cancer mortality (15%) among women worldwide. The major problems of chemotherapeutic treatment in cervical cancer are non-specific cytotoxicity and drug resistance. Plant-derived products, known as natural therapies, have been used for thousands of years in cancer treatment with a very low number of side effects. Allium atroviolaceum is a species in the genus Allium and Liliaceae family, which could prove to have beneficial effects on cancer treatment, although there is a lack of corresponding attention. The methanolic extract from the A.atroviolaceum flower displayed marked anticancer activity on HeLa human cervix carcinoma cells with much lower cytotoxic effects on normal cells (3T3). The A.atroviolaceum extract induced apoptosis, confirmed by cell cycle arrest at the sub-G0 (apoptosis) phase, characteristic morphological changes, evident DNA fragmentation, observed by fluorescent microscope, and early and late apoptosis detection by Annexin V. Furthermore, down-regulation of Bcl-2 and activation of caspase-9 and -3 strongly indicated that the mitochondrial pathway was involved in the apoptosis signal pathway. Moreover, combination of A.atroviolaceum extract with doxorubicin revealed a significant reduction of IC50and led to a synergistic effect. In summary, A.atroviolaceum displayed a significant anti-tumour effect through apoptosis induction in HeLa cells, suggesting that the A.atroviolaceum flower might have therapeutic potential against cervix carcinoma.
    Matched MeSH terms: Mitochondria/drug effects
  7. Ahmad Hidayat AF, Chan CK, Mohamad J, Abdul Kadir H
    Biomed Pharmacother, 2018 Aug;104:806-816.
    PMID: 29860114 DOI: 10.1016/j.biopha.2018.05.073
    Dioscorea bulbifera, also known as air potato, has been cultivated as food crop mainly in tropical countries in Asia and Australia. The tubers are edible and have often been used in Traditional Chinese Medicine (TCM) and Ayurvedic medicine to treat cancer, diabetes, thyroid disease, and inflammation. This study aimed to investigate the effects of D. bulbifera on HCT116 human colorectal carcinoma cells and to unravel the plausible mechanisms underlying its apoptotic effects. The ethanol crude and fractions (hexane, ethyl acetate and water) of D. bulbifera were subjected to cell viability MTT assay against various cancer cell lines. The lowest IC50 of the extract and fractions on selected cancer cells were selected for further apoptosis assay and western blot analysis. HCT116 cancer cells were treated with D. bulbifera and stained with Annexin/PI or Hoechst 33342/PI for preliminary confirmation of apoptosis. The dissipation of mitochondria membrane potential (MMP) was determined by flow cytometry. The protein expressions of apoptosis-related proteins such as Bcl-2 family, caspases, Fas, PARP, ERK1/2 and JNK were detected by western blot analysis. Moreover, the HCT116 cells were treated with UO126 and SP600125 inhibitors to verify the involvement of ERK1/2 and JNK protein expressions in inducing apoptotic cell death. Based on the result, D. bulbifera ethyl acetate fraction (DBEAF) exhibited the most compelling cytotoxicity on HCT116 cells with an IC50 of 37.91 ± 1.30 µg/mL. The induction of apoptosis was confirmed by phosphatidylserine externalization and chromatin condensation. Depolarization of MMP further conferred the induction of apoptosis was through the regulation of Bcl-2 family proteins. Activation of caspase cascades (caspase-3, -9, -8 and -10) was elicited followed by the observation of cleaved PARP accumulation in DBEAF-treated cells. Furthermore, death receptor, Fas was activated upon exposure to DBEAF. Collective apoptotic evidences suggested the involvement of intrinsic and extrinsic pathways by DBEAF in HCT116 cells. Interestingly, the attenuation of ERK1/2 phosphorylation accompanied by the activation of JNK was detected in DBEAF-treated cells. In conclusion, the findings revealed that DBEAF induced apoptosis through intrinsic and extrinsic pathways involving ERK1/2 and JNK.
    Matched MeSH terms: Mitochondria/drug effects
  8. Chin KY, Tay SS
    Nutrients, 2018 Jul 09;10(7).
    PMID: 29987193 DOI: 10.3390/nu10070881
    Alzheimer’s disease (AD) is plaguing the aging population worldwide due to its tremendous health care and socioeconomic burden. Current treatment of AD only offers symptomatic relief to patients. Development of agents targeting specific pathologies of AD is very slow. Tocotrienol, a member of the vitamin E family, can tackle many aspects of AD, such as oxidative stress, mitochondrial dysfunction and abnormal cholesterol synthesis. This review summarizes the current evidence on the role of tocotrienol as a neuroprotective agent. Preclinical studies showed that tocotrienol could reduce oxidative stress by acting as a free-radical scavenger and promoter of mitochondrial function and cellular repair. It also prevented glutamate-induced neurotoxicity in the cells. Human epidemiological studies showed a significant inverse relationship between tocotrienol levels and the occurrence of AD. However, there is no clinical trial to support the claim that tocotrienol can delay or prevent the onset of AD. As a conclusion, tocotrienol has the potential to be developed as an AD-preventing agent but further studies are required to validate its efficacy in humans.
    Matched MeSH terms: Mitochondria/drug effects
  9. Malami I, Abdul AB, Abdullah R, Kassim NK, Rosli R, Yeap SK, et al.
    PLoS One, 2017;12(1):e0170233.
    PMID: 28103302 DOI: 10.1371/journal.pone.0170233
    Uridine-cytidine kinase 2 is an enzyme that is overexpressed in abnormal cell growth and its implication is considered a hallmark of cancer. Due to the selective expression of UCK2 in cancer cells, a selective inhibition of this key enzyme necessitates the discovery of its potential inhibitors for cancer chemotherapy. The present study was carried out to demonstrate the potentials of natural phytochemicals from the rhizome of Alpinia mutica to inhibit UCK2 useful for colorectal cancer. Here, we employed the used of in vitro to investigate the effectiveness of natural UCK2 inhibitors to cause HT-29 cell death. Extracts, flavokawain B, and alpinetin compound from the rhizome of Alpinia mutica was used in the study. The study demonstrated that the expression of UCK2 mRNA were substantially reduced in treated HT-29 cells. In addition, downregulation in expression of 18S ribosomal RNA was also observed in all treated HT-29 cells. This was confirmed by fluorescence imaging to measure the level of expression of 18S ribosomal RNA in live cell images. The study suggests the possibility of MDM2 protein was downregulated and its suppression subsequently activates the expression of p53 during inhibition of UCK2 enzyme. The expression of p53 is directly linked to a blockage of cell cycle progression at G0/G1 phase and upregulates Bax, cytochrome c, and caspase 3 while Bcl2 was deregulated. In this respect, apoptosis induction and DNA fragmentation were observed in treated HT-29 cells. Initial results from in vitro studies have shown the ability of the bioactive compounds of flavokawain B and alpinetin to target UCK2 enzyme specifically, inducing cell cycle arrest and subsequently leading to cancer cell death, possibly through interfering the MDM2-p53 signalling pathway. These phenomena have proven that the bioactive compounds could be useful for future therapeutic use in colon cancer.
    Matched MeSH terms: Mitochondria/drug effects
  10. Sok SPM, Ori D, Wada A, Okude H, Kawasaki T, Momota M, et al.
    Int Immunol, 2021 06 18;33(7):373-386.
    PMID: 33830232 DOI: 10.1093/intimm/dxab016
    The nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing (NLRP) 3 inflammasome is a multiprotein complex that triggers Caspase-1-mediated IL-1β production and pyroptosis, and its dysregulation is associated with the pathogenesis of inflammatory diseases. 1'-Acetoxychavicol acetate (ACA) is a natural compound in the rhizome of tropical ginger Alpinia species with anti-microbial, anti-allergic and anti-cancer properties. In this study, we found that ACA suppressed NLRP3 inflammasome activation in mouse bone marrow-derived macrophages and human THP-1 monocytes. ACA inhibited Caspase-1 activation and IL-1β production by NLRP3 agonists such as nigericin, monosodium urate (MSU) crystals, and ATP. Moreover, it suppressed oligomerization of the adapter molecule, apoptosis-associated speck-like protein containing a CARD (ASC), and Caspase-1-mediated cleavage of pyroptosis executor Gasdermin D. Mechanistically, ACA inhibited generation of mitochondrial reactive oxygen species (ROS) and prevented release of oxidized mitochondrial DNA, which trigger NLRP3 inflammasome activation. ACA also prevented NLRP3 inflammasome activation in vivo, as evidenced in the MSU crystal-induced peritonitis and dextran sodium sulfate-induced colitis mouse models accompanied by decreased Caspase-1 activation. Thus, ACA is a potent inhibitor of the NLRP3 inflammasome for prevention of NLRP3-associated inflammatory diseases.
    Matched MeSH terms: Mitochondria/drug effects*
  11. 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: Mitochondria/drug effects
  12. Abubakar IB, Lim KH, Kam TS, Loh HS
    Phytomedicine, 2017 Jul 01;30:74-84.
    PMID: 28545672 DOI: 10.1016/j.phymed.2017.03.004
    BACKGROUND: γ-Tocotrienol, a vitamin E isomer possesses pronounced in vitro anticancer activities. However, the in vivo potency has been limited by hardly achievable therapeutic levels owing to inefficient high-dose oral delivery which leads to subsequent metabolic degradation. Jerantinine A, an Aspidosperma alkaloid, originally isolated from Tabernaemontana corymbosa, has proved to possess interesting anticancer activities. However, jerantinine A also induces toxicity to non-cancerous cells.

    PURPOSE: We adopted a combinatorial approach with the joint application of γ-tocotrienol and jerantinine A at lower concentrations in order to minimize toxicity towards non-cancerous cells while improving the potency on brain cancer cells.

    METHODS: The antiproliferative potency of individual γ-tocotrienol and jerantinine A as well as combined in low-concentration was firstly evaluated on U87MG cancer and MRC5 normal cells. Morphological changes, DNA damage patterns, cell cycle arrests and the effects of individual and combined low-concentration compounds on microtubules were then investigated. Finally, the potential roles of caspase enzymes and apoptosis-related proteins in mediating the apoptotic mechanisms were investigated using apoptosis antibody array, ELISA and Western blotting analysis.

    RESULTS: Combinatorial study between γ-tocotrienol at a concentration range (0-24µg/ml) and fixed IC20 concentration of jerantinine A (0.16µg/ml) induced a potent antiproliferative effect on U87MG cells and led to a reduction on the new half maximal inhibitory concentration of γ-tocotrienol (i.e.tIC50=1.29µg/ml) as compared to that of individual γ-tocotrienol (i.e. IC50=3.17µg/ml). A reduction on undesirable toxicity to MRC5 normal cells was also observed. G0/G1 cell cycle arrest was evident on U87MG cells receiving IC50 of individual γ-tocotrienol and combined low-concentration compounds (1.29µg/ml γ-tocotrienol + 0.16µg/ml jerantinine A), whereas, a profound G2/M arrest was evident on cells treated with IC50 of individual jerantinine A. Additionally, individual jerantinine A and combined compounds (except individual γ-tocotrienol) caused a disruption of microtubule networks triggering Fas- and p53-induced apoptosis mediated via the death receptor and mitochondrial pathways.

    CONCLUSIONS: These findings demonstrated that the combined use of lower concentrations of γ-tocotrienol and jerantinine A induced potent cytotoxic effects on U87MG cancer cells resulting in a reduction on the required individual concentrations and thereby minimizing toxicity of jerantinine A towards non-cancerous MRC5 cells as well as probably overcoming the high-dose limiting application of γ-tocotrienol. The multi-targeted mechanisms of action of the combination approach have shown a therapeutic potential against brain cancer in vitro and therefore, further in vivo investigations using a suitable animal model should be the way forward.

    Matched MeSH terms: Mitochondria/drug effects
  13. Khanam R, Kumar R, Hejazi II, Shahabuddin S, Meena R, Jayant V, et al.
    Apoptosis, 2018 02;23(2):113-131.
    PMID: 29349707 DOI: 10.1007/s10495-018-1439-x
    Piperazine scaffolds or 2-azetidinone pharmacophores have been reported to show anti-cancer activities and apoptosis induction in different types of cancer cells. However, the mechanistic studies involve in induction of apoptosis addressing these two moieties for human cervical cancer cells remain uncertain. The present study emphasizes on the anti-proliferating properties and mechanism involved in induction of apoptosis for these structurally related azoles derivatives in HeLa cancer cells. 1-Phenylpiperazine clubbed with 2-azetidione derivatives (5a-5h) were synthesized, characterized using various spectroscopic techniques and evaluated for their in-vitro anti-proliferative activities and induction of apoptosis. Further, we also evaluated oxidative stress generated by these synthetic derivatives (5a-5h). Cell viability studies revealed that among all, the compound N-(3-chloro-2-(3-nitrophenyl)-4-oxoazetidin-1-yl)-2-(4-phenylpiperazin-1-yl) acetamide 5e remarkably inhibited the growth of HeLa cells in a concentration dependent manner having IC50 value of 29.44 ± 1.46 µg/ml. Morphological changes, colonies suppression and inhibition of migration clearly showed the antineoplasicity in HeLa cells treated with 5e. Simultaneously, phosphatidylserine externalization, DNA fragmentation and cell-cycle arrest showed ongoing apoptosis in the HeLa cancer cells induced by compound 5e in concentration dependent manner. Additionally, generation of intracellular ROS along with the decrease in mitochondrial membrane potential supported that compound 5e caused oxidative stress resulting in apoptosis through mitochondria mediated pathway. Elevation in the level of cytochrome c and upregulation in expression of caspase-3 clearly indicated the involvement of the intrinsic pathway of programmed cell death. In brief; compound 5e could serve as a promising lead for the development of an effective antitumor agent.
    Matched MeSH terms: Mitochondria/drug effects*
  14. Aziz MNM, Hussin Y, Che Rahim NF, Nordin N, Mohamad NE, Yeap SK, et al.
    Molecules, 2018 Jan 05;23(1).
    PMID: 29303982 DOI: 10.3390/molecules23010075
    Osteosarcoma is one of the primary malignant bone tumors that confer low survival rates for patients even with intensive regime treatments. Therefore, discovery of novel anti-osteosarcoma drugs derived from natural products that are not harmful to the normal cells remains crucial. Curcumin is one of the natural substances that have been extensively studied due to its anti-cancer properties and is pharmacologically safe considering its ubiquitous consumption for centuries. However, curcumin suffers from a poor circulating bioavailability, which has led to the development of a chemically synthesized curcuminoid analog, namely (Z)-3-hydroxy-1-(2-hydroxyphenyl)-3-phenylprop-2-en-1-one (DK1). In this study, the cytotoxic effects of the curcumin analog DK1 was investigated in both U-2OS and MG-63 osteosarcoma cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell death was microscopically examined via acridine orange/propidium iodide (AO/PI) double staining. Flow cytometer analysis including Annexin V/Fluorescein isothiocyanate (FITC), cell cycle analysis and JC-1 were adapted to determine the mode of cell death. Subsequently in order to determine the mechanism of cell death, quantitative polymerase chain reaction (qPCR) and proteome profiling was carried out to measure the expression of several apoptotic-related genes and proteins. Results indicated that DK1 induced U-2 OS and MG-63 morphological changes and substantially reduced cell numbers through induction of apoptosis. Several apoptotic genes and proteins were steadily expressed after treatment with DK1; including caspase 3, caspase 9, and BAX, which indicated that apoptosis occurred through a mitochondria-dependent signaling pathway. In conclusion, DK1 could be considered as a potential candidate for an anti-osteosarcoma drug in the near future, contingent upon its ability to induce apoptosis in osteosarcoma cell lines.
    Matched MeSH terms: Mitochondria/drug effects
  15. Chan CK, Goh BH, Kamarudin MN, Kadir HA
    Molecules, 2012 May 31;17(6):6633-57.
    PMID: 22728359 DOI: 10.3390/molecules17066633
    The aim of this study was to investigate the cytotoxic and apoptotic effects of Nephelium ramboutan-ake (pulasan) rind in selected human cancer cell lines. The crude ethanol extract and fractions (ethyl acetate and aqueous) of N. ramboutan-ake inhibited the growth of HT-29, HCT-116, MDA-MB-231, Ca Ski cells according to MTT assays. The N. ramboutan-ake aqueous fraction (NRAF) was found to exert the greatest cytotoxic effect against HT-29 in a dose-dependent manner. Evidence of apoptotic cell death was revealed by features such as chromatin condensation, nuclear fragmentation and apoptotic body formation. The result from a TUNEL assay strongly suggested that NRAF brings about DNA fragmentation in HT-29 cells. Phosphatidylserine (PS) externalization on the outer leaflet of plasma membranes was detected with annexin V-FITC/PI binding, confirming the early stage of apoptosis. The mitochondrial permeability transition is an important step in the induction of cellular apoptosis, and the results clearly suggested that NRAF led to collapse of mitochondrial transmembrane potential in HT-29 cells. This attenuation of mitochondrial membrane potential (Δψm) was accompanied by increased production of ROS and depletion of GSH, an increase of Bax protein expression, and induced-activation of caspase-3/7 and caspase-9. These combined results suggest that NRAF induces mitochondrial-mediated apoptosis.
    Matched MeSH terms: Mitochondria/drug effects*
  16. Aminuddin A, Ng PY, Leong CO, Chua EW
    Sci Rep, 2020 May 12;10(1):7885.
    PMID: 32398775 DOI: 10.1038/s41598-020-64664-3
    Cisplatin is the first-line chemotherapeutic agent for the treatment of oral squamous cell carcinoma (OSCC). However, the intrinsic or acquired resistance against cisplatin remains a major obstacle to treatment efficacy in OSCC. Recently, mitochondrial DNA (mtDNA) alterations have been reported in a variety of cancers. However, the role of mtDNA alterations in OSCC has not been comprehensively studied. In this study, we evaluated the correlation between mtDNA alterations (mtDNA content, point mutations, large-scale deletions, and methylation status) and cisplatin sensitivity using two OSCC cell lines, namely SAS and H103, and stem cell-like tumour spheres derived from SAS. By microarray analysis, we found that the tumour spheres profited from aberrant lipid and glucose metabolism and became resistant to cisplatin. By qPCR analysis, we found that the cells with less mtDNA were less responsive to cisplatin (H103 and the tumour spheres). Based on the findings, we theorised that the metabolic changes in the tumour spheres probably resulted in mtDNA depletion, as the cells suppressed mitochondrial respiration and switched to an alternative mode of energy production, i.e. glycolysis. Then, to ascertain the origin of the variation in mtDNA content, we used MinION, a nanopore sequencer, to sequence the mitochondrial genomes of H103, SAS, and the tumour spheres. We found that the lower cisplatin sensitivity of H103 could have been caused by a constellation of genetic and epigenetic changes in its mitochondrial genome. Future work may look into how changes in mtDNA translate into an impact on cell function and therefore cisplatin response.
    Matched MeSH terms: Mitochondria/drug effects
  17. Moghadamtousi SZ, Kadir HA, Paydar M, Rouhollahi E, Karimian H
    PMID: 25127718 DOI: 10.1186/1472-6882-14-299
    BACKGROUND: Annona muricata leaves have been reported to have antiproliferative effects against various cancer cell lines. However, the detailed mechanism has yet to be defined. The current study was designed to evaluate the molecular mechanisms of A. muricata leaves ethyl acetate extract (AMEAE) against lung cancer A549 cells.

    METHODS: The effect of AMEAE on cell proliferation of different cell lines was analyzed by MTT assay. High content screening (HCS) was applied to investigate the suppression of NF-κB translocation, cell membrane permeability, mitochondrial membrane potential (MMP) and cytochrome c translocation from mitochondria to cytosol. Reactive oxygen species (ROS) formation, lactate dehydrogenase (LDH) release and activation of caspase-3/7, -8 and -9 were measured while treatment. The western blot analysis also carried out to determine the protein expression of cleaved caspase-3 and -9. Flow cytometry analysis was used to determine the cell cycle distribution and phosphatidylserine externalization. Quantitative PCR analysis was performed to measure the gene expression of Bax and Bcl-2 proteins.

    RESULTS: Cell viability analysis revealed the selective cytotoxic effect of AMEAE towards lung cancer cells, A549, with an IC50 value of 5.09 ± 0.41 μg/mL after 72 h of treatment. Significant LDH leakage and phosphatidylserine externalization were observed in AMEAE treated cells by fluorescence analysis. Treatment of A549 cells with AMEAE significantly elevated ROS formation, followed by attenuation of MMP via upregulation of Bax and downregulation of Bcl-2, accompanied by cytochrome c release to the cytosol. The incubation of A549 cells with superoxide dismutase and catalase significantly attenuated the cytotoxicity caused by AMEAE, indicating that intracellular ROS plays a pivotal role in cell death. The released cytochrome c triggered the activation of caspase-9 followed by caspase-3. In addition, AMEAE-induced apoptosis was accompanied by cell cycle arrest at G0/G1 phase. Moreover, AMEAE suppressed the induced translocation of NF-κB from cytoplasm to nucleus.

    CONCLUSIONS: Our data showed for the first time that the ethyl acetate extract of Annona muricata inhibited the proliferation of A549 cells, leading to cell cycle arrest and programmed cell death through activation of the mitochondrial-mediated signaling pathway with the involvement of the NF-kB signalling pathway.

    Matched MeSH terms: Mitochondria/drug effects
  18. Srinivasan V, Pandi-Perumal SR, Maestroni GJ, Esquifino AI, Hardeland R, Cardinali DP
    Neurotox Res, 2005;7(4):293-318.
    PMID: 16179266
    The pineal product melatonin has remarkable antioxidant properties. It scavenges hydroxyl, carbonate and various organic radicals, peroxynitrite and other reactive nitrogen species. Melatonyl radicals formed by scavenging combine with and, thereby, detoxify superoxide anions in processes terminating the radical reaction chains. Melatonin also enhances the antioxidant potential of the cell by stimulating the synthesis of antioxidant enzymes like superoxide dismutase, glutathione peroxidase and glutathione reductase, and by augmenting glutathione levels. The decline in melatonin production in aged individuals has been suggested as one of the primary contributing factors for the development of age-associated neurodegenerative diseases, e.g., Alzheimer's disease. Melatonin has been shown to be effective in arresting neurodegenerative phenomena seen in experimental models of Alzheimer's disease, Parkinsonism and ischemic stroke. Melatonin preserves mitochondrial homeostasis, reduces free radical generation, e.g., by enhancing mitochondrial glutathione levels, and safeguards proton potential and ATP synthesis by stimulating complex I and IV activities. Therapeutic trials with melatonin have been effective in slowing the progression of Alzheimer's disease but not of Parkinson's disease. Melatonin's efficacy in combating free radical damage in the brain suggests that it may be a valuable therapeutic agent in the treatment of cerebral edema after traumatic brain injury.
    Matched MeSH terms: Mitochondria/drug effects
  19. Ashwaq AS, Al-Qubaisi MS, Rasedee A, Abdul AB, Taufiq-Yap YH, Yeap SK
    Int J Mol Sci, 2016 Oct 18;17(10).
    PMID: 27763535
    Dentatin (DEN), purified from the roots of Clausena excavata Burm f., has poor aqueous solubility that reduces its therapeutic application. The aim of this study was to assess the effects of DEN-HPβCD (hydroxypropyl-β-cyclodextrin) complex as an anticancer agent in HT29 cancer cell line and compare with a crystal DEN in dimethyl sulfoxide (DMSO). The exposure of the cancer cells to DEN or DEN-HPβCD complex leads to cell growth inhibition as determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. To analyze the mechanism, in which DEN or DEN-HPβCD complex causes the death in human colon HT29 cancer cells, was evaluated by the enzyme-linked immunosorbent assay (ELIZA)-based assays for caspase-3, 8, 9, and reactive oxygen species (ROS). The findings showed that an anti-proliferative effect of DEN or DEN-HPβCD complex were via cell cycle arrest at the G2/M phase and eventually induced apoptosis through both mitochondrial and extrinsic pathways. The down-regulation of poly(ADP-ribose) polymerase (PARP) which leaded to apoptosis upon treatment, was investigated by Western-blotting. Hence, complexation between DEN and HPβCD did not diminish or eliminate the effective properties of DEN as anticancer agent. Therefore, it would be possible to resolve the conventional and current issues associated with the development and commercialization of antineoplastic agents in the future.
    Matched MeSH terms: Mitochondria/drug effects
  20. Lim SW, Loh HS, Ting KN, Bradshaw TD, Zeenathul NA
    PMID: 25480449 DOI: 10.1186/1472-6882-14-469
    Tocotrienols, especially the gamma isomer was discovered to possess cytotoxic effects associated with the induction of apoptosis in numerous cancers. Individual tocotrienol isomers are believed to induce dissimilar apoptotic mechanisms in different cancer types. This study was aimed to compare the cytotoxic potency of alpha-, gamma- and delta-tocotrienols, and to explore their resultant apoptotic mechanisms in human lung adenocarcinoma A549 and glioblastoma U87MG cells which are scarcely researched.
    Matched MeSH terms: Mitochondria/drug effects
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