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  1. Lactoferrin and ovotransferrin contribute toward antioxidative effects of Edible Bird's Nest against hydrogen peroxide-induced oxidative stress in human SH-SY5Y cells
    Hou Z, Imam MU, Ismail M, Azmi NH, Ismail N, Ideris A, et al.
    Biosci Biotechnol Biochem, 2015;79(10):1570-8.
    PMID: 26057702 DOI: 10.1080/09168451.2015.1050989
    There are reports of improved redox outcomes due to consumption of Edible Bird's Nest (EBN). Many of the functional effects of EBN can be linked to its high amounts of antioxidants. Interestingly, dietary components with high antioxidants have shown promise in the prevention of aging and its related diseases like Alzheimer's disease. In this study, the antioxidative potentials of EBN and its constituents, lactoferrin (LF) and ovotransferrin (OVF), were determined and protective effects against hydrogen peroxide (H2O2)- induced toxicity on SH-SY5Y cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and acridine orange and propidium iodide (AO/PI) staining with microscopy were examined. Results showed that EBN and its constituents attenuated H2O2-induced cytotoxicity, and decreased radical oxygen species (ROS) through increased scavenging activity. Furthermore, LF, OVF, and EBN produced transcriptional changes in antioxidant related genes that tended towards neuroprotection as compared to H2O2-treated group. Overall, the results suggest that LF and OVF may produce synergistic or all-or-none antioxidative effects in EBN.
    Matched MeSH terms: Reactive Oxygen Species/antagonists & inhibitors*; Reactive Oxygen Species/metabolism
  2. Fulltext Mitochondrial Respiration Is Reduced in Atherosclerosis, Promoting Necrotic Core Formation and Reducing Relative Fibrous Cap Thickness
    Yu EPK, Reinhold J, Yu H, Starks L, Uryga AK, Foote K, et al.
    Arterioscler Thromb Vasc Biol, 2017 12;37(12):2322-2332.
    PMID: 28970293 DOI: 10.1161/ATVBAHA.117.310042
    OBJECTIVE: Mitochondrial DNA (mtDNA) damage is present in murine and human atherosclerotic plaques. However, whether endogenous levels of mtDNA damage are sufficient to cause mitochondrial dysfunction and whether decreasing mtDNA damage and improving mitochondrial respiration affects plaque burden or composition are unclear. We examined mitochondrial respiration in human atherosclerotic plaques and whether augmenting mitochondrial respiration affects atherogenesis.

    APPROACH AND RESULTS: Human atherosclerotic plaques showed marked mitochondrial dysfunction, manifested as reduced mtDNA copy number and oxygen consumption rate in fibrous cap and core regions. Vascular smooth muscle cells derived from plaques showed impaired mitochondrial respiration, reduced complex I expression, and increased mitophagy, which was induced by oxidized low-density lipoprotein. Apolipoprotein E-deficient (ApoE-/-) mice showed decreased mtDNA integrity and mitochondrial respiration, associated with increased mitochondrial reactive oxygen species. To determine whether alleviating mtDNA damage and increasing mitochondrial respiration affects atherogenesis, we studied ApoE-/- mice overexpressing the mitochondrial helicase Twinkle (Tw+/ApoE-/-). Tw+/ApoE-/- mice showed increased mtDNA integrity, copy number, respiratory complex abundance, and respiration. Tw+/ApoE-/- mice had decreased necrotic core and increased fibrous cap areas, and Tw+/ApoE-/- bone marrow transplantation also reduced core areas. Twinkle increased vascular smooth muscle cell mtDNA integrity and respiration. Twinkle also promoted vascular smooth muscle cell proliferation and protected both vascular smooth muscle cells and macrophages from oxidative stress-induced apoptosis.

    CONCLUSIONS: Endogenous mtDNA damage in mouse and human atherosclerosis is associated with significantly reduced mitochondrial respiration. Reducing mtDNA damage and increasing mitochondrial respiration decrease necrotic core and increase fibrous cap areas independently of changes in reactive oxygen species and may be a promising therapeutic strategy in atherosclerosis.

    Matched MeSH terms: Oxygen Consumption; Reactive Oxygen Species/metabolism
  3. Exposure to Electrophiles Impairs Reactive Persulfide-Dependent Redox Signaling in Neuronal Cells
    Ihara H, Kasamatsu S, Kitamura A, Nishimura A, Tsutsuki H, Ida T, et al.
    Chem Res Toxicol, 2017 09 18;30(9):1673-1684.
    PMID: 28837763 DOI: 10.1021/acs.chemrestox.7b00120
    Electrophiles such as methylmercury (MeHg) affect cellular functions by covalent modification with endogenous thiols. Reactive persulfide species were recently reported to mediate antioxidant responses and redox signaling because of their strong nucleophilicity. In this study, we used MeHg as an environmental electrophile and found that exposure of cells to the exogenous electrophile elevated intracellular concentrations of the endogenous electrophilic molecule 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), accompanied by depletion of reactive persulfide species and 8-SH-cGMP which is a metabolite of 8-nitro-cGMP. Exposure to MeHg also induced S-guanylation and activation of H-Ras followed by injury to cerebellar granule neurons. The electrophile-induced activation of redox signaling and the consequent cell damage were attenuated by pretreatment with a reactive persulfide species donor. In conclusion, exogenous electrophiles such as MeHg with strong electrophilicity impair the redox signaling regulatory mechanism, particularly of intracellular reactive persulfide species and therefore lead to cellular pathogenesis. Our results suggest that reactive persulfide species may be potential therapeutic targets for attenuating cell injury by electrophiles.
    Matched MeSH terms: Reactive Oxygen Species/analysis; Reactive Oxygen Species/metabolism
  4. Fulltext Attrition of Hepatic Damage Inflicted by Angiotensin II with α-Tocopherol and β-Carotene in Experimental Apolipoprotein E Knock-out Mice
    Gopal K, Gowtham M, Sachin S, Ravishankar Ram M, Shankar EM, Kamarul T
    Sci Rep, 2015 Dec 16;5:18300.
    PMID: 26670291 DOI: 10.1038/srep18300
    Angiotensin II is one of the key regulatory peptides implicated in the pathogenesis of liver disease. The mechanisms underlying the salubrious role of α-tocopherol and β-carotene on liver pathology have not been comprehensively assessed. Here, we investigated the mechanisms underlying the role of Angiotensin II on hepatic damage and if α-tocopherol and β-carotene supplementation attenuates hepatic damage. Hepatic damage was induced in Apoe(-/-)mice by infusion of Angiotensin II followed by oral administration with α-tocopherol and β-carotene-enriched diet for 60 days. Investigations showed fibrosis, kupffer cell hyperplasia, hepatocyte degeneration and hepatic cell apoptosis; sinusoidal dilatation along with haemorrhages; evidence of fluid accumulation; increased ROS level and increased AST and ALT activities. In addition, tPA and uPA were down-regulated due to 42-fold up-regulation of PAI-1. MMP-2, MMP-9, MMP-12, and M-CSF were down-regulated in Angiotensin II-treated animals. Notably, α-tocopherol and β-carotene treatment controlled ROS, fibrosis, hepatocyte degeneration, kupffer cell hyperplasia, hepatocyte apoptosis, sinusoidal dilatation and fluid accumulation in the liver sinusoids, and liver enzyme levels. In addition, PAI-1, tPA and uPA expressions were markedly controlled by β-carotene treatment. Thus, Angiotensin II markedly influenced hepatic damage possibly by restraining fibrinolytic system. We concluded that α-tocopherol and β-carotene treatment has salubrious role in repairing hepatic pathology.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  5. The immunomodulation potential of the synthetic derivatives of benzothiazoles: Implications in immune system disorders through in vitro and in silico studies
    Khan KM, Mesaik MA, Abdalla OM, Rahim F, Soomro S, Halim SA, et al.
    Bioorg Chem, 2016 Feb;64:21-8.
    PMID: 26637945 DOI: 10.1016/j.bioorg.2015.11.004
    Benzothiazole and its natural or synthetic derivatives have been used as precursors for several pharmacological agents for neuroprotective, anti-bacterial, and anti-allergic activities. The objective of the present study was to evaluate effects of benzothiazole analogs (compounds 1-26) for their immunomodulatory activities. Eight compounds (2, 4, 5, 8-10, 12, and 18) showed potent inhibitory activity on PHA-activated peripheral blood mononuclear cells (PBMCs) with IC50 ranging from 3.7 to 11.9 μM compared to that of the standard drug, prednisolone <1.5 μM. Some compounds (2, 4, 8, and 18) were also found to have potent inhibitory activities on the production of IL-2 on PHA/PMA-stimulated PBMCs with IC50 values ranging between <4.0 and 12.8 μM. The binding interaction of these compounds was performed through silico molecular docking. Compounds 2, 8, 9, and 10 significantly suppressed oxidative burst ROS production in phagocytes with IC50 values between <4.0 and 15.2 μM. The lipopolysaccharide (LPS)-induced nitrites in murine macrophages cell line J774 were found to be inhibited by compounds 4, 8, 9, and 18 at a concentration of 25 μg/mL by 56%, 91%, 58%, and 78%, respectively. Furthermore, compounds 5, 8, 12, and 18 showed significant (P<0.05) suppressive activity on Th-2 cytokine, interleukin 4 (IL-4) with an IC50 range of <4.0 to 40.3 μM. Interestingly compound 4 has shown a selective inhibitory activity on IL-2 and T cell proliferation (naïve T cell proliferation stage) rather than on IL-4 cytokine, while compound 12 displayed an interference with T-cell proliferation and IL-4 generation. Moreover compound 8 and 18 exert non-selective inhibition on both IL-2 and IL-4 cytokines, indicating a better interference with stage leading to humoral immune response and hence possible application in autoimmune diseases.
    Matched MeSH terms: Reactive Oxygen Species/antagonists & inhibitors
  6. Skin intervention of fullerene-integrated nanoemulsion in structural and collagen regeneration against skin aging
    Ngan CL, Basri M, Tripathy M, Abedi Karjiban R, Abdul-Malek E
    Eur J Pharm Sci, 2015 Apr 5;70:22-8.
    PMID: 25619806 DOI: 10.1016/j.ejps.2015.01.006
    Despite the fact that intrinsic oxidative stress is inevitable, the extrinsic factor such as ultraviolet radiation enhances reactive oxygen species (ROS) generation resulting in premature skin aging. Nanoemulsion was loaded with fullerene, a strong free radical scavenger, and its efficacy to provide protection and regenerative effect against ROS-induced collagen breakdown in human skin was studied. Stable fullerene nanoemulsions were formulated using high shear homogenization and ultrasonic dispersion technique. An open trial was conducted using fullerene nanoemulsion on skin twice a day for 28 days. The mean collagen score significantly increased (P<0.05) from 36.53±4.39 to 48.69±5.46 with 33.29% increment at the end of the treatment. Biophysical characteristics of skin revealed that skin hydration was increased significantly (P<0.05) from 40.91±7.01 to 58.55±6.08 corneometric units (43.12% increment) and the water was able to contain within the stratum corneum without any increased in transepidermal water loss. In the in vitro safety evaluation, fullerene nanoemulsion showed no acute toxicity on 3T3 fibroblast cell line for 48h and no indication of potential dermal irritation. Hence, the fullerene nanoemulsion may assist in protecting collagen from breakdown with cosmeceutical benefit.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  7. Allogeneic and autologous mode of stem cell transplantation in regenerative medicine: which way to go?
    Mamidi MK, Dutta S, Bhonde R, Das AK, Pal R
    Med Hypotheses, 2014 Dec;83(6):787-91.
    PMID: 25456787 DOI: 10.1016/j.mehy.2014.10.010
    Stem cell transplantation is a generic term covering different techniques. However there is argument over the pros and cons of autologous and allogeneic transplants of mesenchymal stem cells (MSCs) for regenerative therapy. Given that the MSCs have already been proven to be safe in patients, we hypothesize that allogeneic transplantation could be more effective and cost-effective as compared to autologous transplantation specifically in older subjects who are the likely victims of degenerative diseases. This analysis is based on the scientific logic that allogeneic stem cells extracted in large numbers from young and healthy donors could be physiologically, metabolically and genetically more stable. Therefore stem cells from young donors may be expected to exhibit higher vigor in secreting trophic factors leading to activation of host tissue-specific stem cells and also be more efficient in remodeling the micro-environmental niche of damaged tissue.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  8. Fulltext In situ normoxia enhances survival and proliferation rate of human adipose tissue-derived stromal cells without increasing the risk of tumourigenesis
    Choi JR, Pingguan-Murphy B, Wan Abas WA, Yong KW, Poon CT, Noor Azmi MA, et al.
    PLoS One, 2015;10(1):e0115034.
    PMID: 25615717 DOI: 10.1371/journal.pone.0115034
    Adipose tissue-derived stromal cells (ASCs) natively reside in a relatively low-oxygen tension (i.e., hypoxic) microenvironment in human body. Low oxygen tension (i.e., in situ normoxia), has been known to enhance the growth and survival rate of ASCs, which, however, may lead to the risk of tumourigenesis. Here, we investigated the tumourigenic potential of ASCs under their physiological condition to ensure their safe use in regenerative therapy. Human ASCs isolated from subcutaneous fat were cultured in atmospheric O2 concentration (21% O2) or in situ normoxia (2% O2). We found that ASCs retained their surface markers, tri-lineage differentiation potential, and self-renewal properties under in situ normoxia without altering their morphology. In situ normoxia displayed a higher proliferation and viability of ASCs with less DNA damage as compared to atmospheric O2 concentration. Moreover, low oxygen tension significantly up-regulated VEGF and bFGF mRNA expression and protein secretion while reducing the expression level of tumour suppressor genes p16, p21, p53, and pRb. However, there were no significant differences in ASCs telomere length and their relative telomerase activity when cultured at different oxygen concentrations. Collectively, even with high proliferation and survival rate, ASCs have a low tendency of developing tumour under in situ normoxia. These results suggest 2% O2 as an ideal culture condition for expanding ASCs efficiently while maintaining their characteristics.
    Matched MeSH terms: Oxygen/metabolism*
  9. Chronic hepatitis C virus infection triggers spontaneous differential expression of biosignatures associated with T cell exhaustion and apoptosis signaling in peripheral blood mononucleocytes
    Barathan M, Gopal K, Mohamed R, Ellegård R, Saeidi A, Vadivelu J, et al.
    Apoptosis, 2015 Apr;20(4):466-80.
    PMID: 25577277 DOI: 10.1007/s10495-014-1084-y
    Persistent hepatitis C virus (HCV) infection appears to trigger the onset of immune exhaustion to potentially assist viral persistence in the host, eventually leading to hepatocellular carcinoma. The role of HCV on the spontaneous expression of markers suggestive of immune exhaustion and spontaneous apoptosis in immune cells of chronic HCV (CHC) disease largely remain elusive. We investigated the peripheral blood mononuclear cells of CHC patients to determine the spontaneous recruitment of cellular reactive oxygen species (cROS), immunoregulatory and exhaustion markers relative to healthy controls. Using a commercial QuantiGenePlex(®) 2.0 assay, we determined the spontaneous expression profile of 80 different pro- and anti-apoptotic genes in persistent HCV disease. Onset of spontaneous apoptosis significantly correlated with the up-regulation of cROS, indoleamine 2,3-dioxygenase (IDO), cyclooxygenase-2/prostaglandin H synthase (COX-2/PGHS), Foxp3, Dtx1, Blimp1, Lag3 and Cd160. Besides, spontaneous differential surface protein expression suggestive of T cell inhibition viz., TRAIL, TIM-3, PD-1 and BTLA on CD4+ and CD8+ T cells, and CTLA-4 on CD4+ T cells was also evident. Increased up-regulation of Tnf, Tp73, Casp14, Tnfrsf11b, Bik and Birc8 was observed, whereas FasLG, Fas, Ripk2, Casp3, Dapk1, Tnfrsf21, and Cflar were moderately up-regulated in HCV-infected subjects. Our observation suggests the spontaneous onset of apoptosis signaling and T cell exhaustion in chronic HCV disease.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  10. Fulltext Protective effect of Momordica charantia fruit extract on hyperglycaemia-induced cardiac fibrosis
    Abas R, Othman F, Thent ZC
    Oxid Med Cell Longev, 2014;2014:429060.
    PMID: 25371774 DOI: 10.1155/2014/429060
    In diabetes mellitus, cardiac fibrosis is characterized by increase in the deposition of collagen fibers. The present study aimed to observe the effect of Momordica charantia (MC) fruit extract on hyperglycaemia-induced cardiac fibrosis. Diabetes was induced in the male Sprague-Dawley rats with a single intravenous injection of streptozotocin (STZ). Following 4 weeks of STZ induction, the rats were subdivided (n = 6) into control group (Ctrl), control group treated with MC (Ctrl-MC), diabetic untreated group (DM-Ctrl), diabetic group treated with MC (DM-MC), and diabetic group treated with 150 mg/kg of metformin (DM-Met). Administration of MC fruit extract (1.5 g/kg body weight) in diabetic rats for 28 days showed significant increase in the body weight and decrease in the fasting blood glucose level. Significant increase in cardiac tissues superoxide dismutase (SOD), glutathione contents (GSH), and catalase (CAT) was observed following MC treatment. Hydroxyproline content was significantly reduced and associated morphological damages reverted to normal. The decreased expression of type III and type IV collagens was observed under immunohistochemical staining. It is concluded that MC fruit extract possesses antihyperglycemic, antioxidative, and cardioprotective properties which may be beneficial in the treatment of diabetic cardiac fibrosis.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  11. Fulltext The role of Hibiscus sabdariffa L. (Roselle) in maintenance of ex vivo murine bone marrow-derived hematopoietic stem cells
    Abdul Hamid Z, Lin Lin WH, Abdalla BJ, Bee Yuen O, Latif ES, Mohamed J, et al.
    ScientificWorldJournal, 2014;2014:258192.
    PMID: 25405216 DOI: 10.1155/2014/258192
    Hematopoietic stem cells- (HSCs-) based therapy requires ex vivo expansion of HSCs prior to therapeutic use. However, ex vivo culture was reported to promote excessive production of reactive oxygen species (ROS), exposing HSCs to oxidative damage. Efforts to overcome this limitation include the use of antioxidants. In this study, the role of Hibiscus sabdariffa L. (Roselle) in maintenance of cultured murine bone marrow-derived HSCs was investigated. Aqueous extract of Roselle was added at varying concentrations (0-1000 ng/mL) for 24 hours to the freshly isolated murine bone marrow cells (BMCs) cultures. Effects of Roselle on cell viability, reactive oxygen species (ROS) production, glutathione (GSH) level, superoxide dismutase (SOD) activity, and DNA damage were investigated. Roselle enhanced the survival (P < 0.05) of BMCs at 500 and 1000 ng/mL, increased survival of Sca-1(+) cells (HSCs) at 500 ng/mL, and maintained HSCs phenotype as shown from nonremarkable changes of surface marker antigen (Sca-1) expression in all experimental groups. Roselle increased (P < 0.05) the GSH level and SOD activity but the level of reactive oxygen species (ROS) was unaffected. Moreover, Roselle showed significant cellular genoprotective potency against H2O2-induced DNA damage. Conclusively, Roselle shows novel property as potential supplement and genoprotectant against oxidative damage to cultured HSCs.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  12. Fulltext Induction of cell cycle arrest and apoptosis in caspase-3 deficient MCF-7 cells by Dillenia suffruticosa root extract via multiple signalling pathways
    Foo JB, Yazan LS, Tor YS, Armania N, Ismail N, Imam MU, et al.
    BMC Complement Altern Med, 2014;14:197.
    PMID: 24947113 DOI: 10.1186/1472-6882-14-197
    Dillenia suffruticosa root dichloromethane extract (DCM-DS) has been reported to exhibit strong cytotoxicity towards breast cancer cells. The present study was designed to investigate the cell cycle profile, mode of cell death and signalling pathways of DCM-DS-treated human caspase-3 deficient MCF-7 breast cancer cells.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  13. Impact of low oxygen tension on stemness, proliferation and differentiation potential of human adipose-derived stem cells
    Choi JR, Pingguan-Murphy B, Wan Abas WA, Noor Azmi MA, Omar SZ, Chua KH, et al.
    Biochem Biophys Res Commun, 2014 May 30;448(2):218-24.
    PMID: 24785372 DOI: 10.1016/j.bbrc.2014.04.096
    Adipose-derived stem cells (ASCs) have been found adapted to a specific niche with low oxygen tension (hypoxia) in the body. As an important component of this niche, oxygen tension has been known to play a critical role in the maintenance of stem cell characteristics. However, the effect of O2 tension on their functional properties has not been well determined. In this study, we investigated the effects of O2 tension on ASCs stemness, differentiation and proliferation ability. Human ASCs were cultured under normoxia (21% O2) and hypoxia (2% O2). We found that hypoxia increased ASC stemness marker expression and proliferation rate without altering their morphology and surface markers. Low oxygen tension further enhances the chondrogenic differentiation ability, but reduces both adipogenic and osteogenic differentiation potential. These results might be correlated with the increased expression of HIF-1α under hypoxia. Taken together, we suggest that growing ASCs under 2% O2 tension may be important in expanding ASCs effectively while maintaining their functional properties for clinical therapy, particularly for the treatment of cartilage defects.
    Matched MeSH terms: Oxygen/metabolism*
  14. Swietenia macrophylla King induces mitochondrial-mediated apoptosis through p53 upregulation in HCT116 colorectal carcinoma cells
    Goh BH, Chan CK, Kamarudin MN, Abdul Kadir H
    J Ethnopharmacol, 2014 Apr 28;153(2):375-85.
    PMID: 24613274 DOI: 10.1016/j.jep.2014.02.036
    Swietenia macrophylla King is a traditional herb used to treat various diseases including hypertension, diabetes and cancer. Previous study demonstrated its anti-tumor effect but the potential mechanisms have not been clearly defined. The current study was to further investigate the underlying mechanism of ethyl acetate fraction of Swietenia macrophylla (SMEAF)-induced anti-proliferative effect and apoptosis in HCT116 colorectal carcinoma cell.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  15. Fulltext A Schiff base-derived copper (II) complex is a potent inducer of apoptosis in colon cancer cells by activating the intrinsic pathway
    Hajrezaie M, Paydar M, Moghadamtousi SZ, Hassandarvish P, Gwaram NS, Zahedifard M, et al.
    ScientificWorldJournal, 2014;2014:540463.
    PMID: 24737979 DOI: 10.1155/2014/540463
    Metal-based drugs with extensive clinical applications hold great promise for the development of cancer chemotherapeutic agents. In the last few decades, Schiff bases and their complexes have become well known for their extensive biological potential. In the present study, we examined the antiproliferative effect of a copper (II) complex on HT-29 colon cancer cells. The Cu(BrHAP)2 Schiff base compound demonstrated a potent antiproliferative effect in HT-29 cells, with an IC50 value of 2.87  μg/ml after 72 h of treatment. HT-29 cells treated with Cu (II) complexes underwent apoptosis death, as exhibited by a progressive elevation in the proportion of the G1 cell population. At a concentration of 6.25  μg/ml, the Cu(BrHAP)2 compound caused significant elevation in ROS production following perturbation of mitochondrial membrane potential and cytochrome c release, as assessed by the measurement of fluorescence intensity in stained cells. Furthermore, the activation of caspases 3/7 and 9 was part of the Cu (II) complex-induced apoptosis, which confirmed the involvement of mitochondrial-mediated apoptosis. Meanwhile, there was no significant activation of caspase-8. Taken together, these results imply that the Cu(BrHAP)2 compound is a potential candidate for further in vivo and clinical colon cancer studies to develop novel chemotherapeutic agents derived from metal-based agents.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  16. Fulltext Dengue virus type 2 (DENV2)-induced oxidative responses in monocytes from glucose-6-phosphate dehydrogenase (G6PD)-deficient and G6PD normal subjects
    Al-Alimi AA, Ali SA, Al-Hassan FM, Idris FM, Teow SY, Mohd Yusoff N
    PLoS Negl Trop Dis, 2014 Mar;8(3):e2711.
    PMID: 24625456 DOI: 10.1371/journal.pntd.0002711
    Dengue virus is endemic in peninsular Malaysia. The clinical manifestations vary depending on the incubation period of the virus as well as the immunity of the patients. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is prevalent in Malaysia where the incidence is 3.2%. It has been noted that some G6PD-deficient individuals suffer from more severe clinical presentation of dengue infection. In this study, we aim to investigate the oxidative responses of DENV2-infected monocytes from G6PD-deficient individuals.
    Matched MeSH terms: Reactive Oxygen Species/analysis
  17. The inhibition of human T cell proliferation by the caspase inhibitor z-VAD-FMK is mediated through oxidative stress
    Rajah T, Chow SC
    Toxicol Appl Pharmacol, 2014 Jul 15;278(2):100-6.
    PMID: 24768707 DOI: 10.1016/j.taap.2014.04.014
    The caspase inhibitor benzyloxycarbony (Cbz)-l-Val-Ala-Asp (OMe)-fluoromethylketone (z-VAD-FMK) has recently been shown to inhibit T cell proliferation without blocking caspase-8 and caspase-3 activation in primary T cells. We showed in this study that z-VAD-FMK treatment leads to a decrease in intracellular glutathione (GSH) with a concomitant increase in reactive oxygen species (ROS) levels in activated T cells. The inhibition of anti-CD3-mediated T cell proliferation induced by z-VAD-FMK was abolished by the presence of low molecular weight thiols such as GSH, N-acetylcysteine (NAC) and l-cysteine, whereas d-cysteine which cannot be metabolised to GSH has no effect. These results suggest that the depletion of intracellular GSH is the underlying cause of z-VAD-FMK-mediated inhibition of T cell activation and proliferation. The presence of exogenous GSH also attenuated the inhibition of anti-CD3-induced CD25 and CD69 expression mediated by z-VAD-FMK. However, none of the low molecular weight thiols were able to restore the caspase-inhibitory properties of z-VAD-FMK in activated T cells where caspase-8 and caspase-3 remain activated and processed into their respective subunits in the presence of the caspase inhibitor. This suggests that the inhibition of T cell proliferation can be uncoupled from the caspase-inhibitory properties of z-VAD-FMK. Taken together, the immunosuppressive effects in primary T cells mediated by z-VAD-FMK are due to oxidative stress via the depletion of GSH.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  18. Paeonol protects against premature senescence in endothelial cells by modulating Sirtuin 1 pathway
    Jamal J, Mustafa MR, Wong PF
    J Ethnopharmacol, 2014 Jun 11;154(2):428-36.
    PMID: 24768807 DOI: 10.1016/j.jep.2014.04.025
    Paeonol is a phenolic compound isolated mainly from Moutan cortex, root bark of Chinese Peony tree. Moutan cortex holds a significant value in traditional Chinese medicine for alleviating various oxidative stress-related diseases mainly atherosclerosis and myocardial infarction. The present study seeks to identify the protective mechanisms of paeonol in oxidative stress-induced premature senescence in endothelial cells.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  19. Fulltext C-phycocyanin confers protection against oxalate-mediated oxidative stress and mitochondrial dysfunctions in MDCK cells
    Farooq SM, Boppana NB, Devarajan A, Asokan D, Sekaran SD, Shankar EM, et al.
    PLoS One, 2014;9(4):e93056.
    PMID: 24691130 DOI: 10.1371/journal.pone.0093056
    Oxalate toxicity is mediated through generation of reactive oxygen species (ROS) via a process that is partly dependent on mitochondrial dysfunction. Here, we investigated whether C-phycocyanin (CP) could protect against oxidative stress-mediated intracellular damage triggered by oxalate in MDCK cells. DCFDA, a fluorescence-based probe and hexanoyl-lysine adduct (HEL), an oxidative stress marker were used to investigate the effect of CP on oxalate-induced ROS production and membrane lipid peroxidation (LPO). The role of CP against oxalate-induced oxidative stress was studied by the evaluation of mitochondrial membrane potential by JC1 fluorescein staining, quantification of ATP synthesis and stress-induced MAP kinases (JNK/SAPK and ERK1/2). Our results revealed that oxalate-induced cells show markedly increased ROS levels and HEL protein expression that were significantly decreased following pre-treatment with CP. Further, JC1 staining showed that CP pre-treatment conferred significant protection from mitochondrial membrane permeability and increased ATP production in CP-treated cells than oxalate-alone-treated cells. In addition, CP treated cells significantly decreased the expression of phosphorylated JNK/SAPK and ERK1/2 as compared to oxalate-alone-treated cells. We concluded that CP could be used as a potential free radical-scavenging therapeutic strategy against oxidative stress-associated diseases including urolithiasis.
    Matched MeSH terms: Reactive Oxygen Species/metabolism
  20. Antibacterial and wound healing analysis of gelatin/zeolite scaffolds
    Ninan N, Muthiah M, Bt Yahaya NA, Park IK, Elain A, Wong TW, et al.
    Colloids Surf B Biointerfaces, 2014 Mar 1;115:244-52.
    PMID: 24362063 DOI: 10.1016/j.colsurfb.2013.11.048
    In this article, gelatin/copper activated faujasites (CAF) composite scaffolds were fabricated by lyophilisation technique for promoting partial thickness wound healing. The optimised scaffold with 0.5% (w/w) of CAF, G (0.5%), demonstrated pore size in the range of 10-350 μm. Agar disc diffusion tests verified the antibacterial role of G (0.5%) and further supported that bacterial lysis was due to copper released from the core of CAF embedded in the gelatin matrix. The change in morphology of bacteria as a function of CAF content in gelatin scaffold was studied using SEM analysis. The confocal images revealed the increase in mortality rate of bacteria with increase in concentration of incorporated CAF in gelatin matrix. Proficient oxygen supply to needy cells is a continuing hurdle faced by tissue engineering scaffolds. The dissolved oxygen measurements revealed that CAF embedded in the scaffold were capable of increasing oxygen supply and thereby promote cell proliferation. Also, G (0.5%) exhibited highest cell viability on NIH 3T3 fibroblast cells which was mainly attributed to the highly porous architecture and its ability to enhance oxygen supply to cells. In vivo studies conducted on Sprague Dawley rats revealed the ability of G (0.5%) to promote skin regeneration in 20 days. Thus, the obtained data suggest that G (0.5%) is an ideal candidate for wound healing applications.
    Matched MeSH terms: Oxygen/analysis
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