Displaying publications 1 - 20 of 32 in total

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  1. Zinc L-carnosine suppresses inflammatory responses in lipopolysaccharide-induced RAW 264.7 murine macrophages cell line via activation of Nrf2/HO-1 signaling pathway
    Ooi TC, Chan KM, Sharif R
    Immunopharmacol Immunotoxicol, 2017 Oct;39(5):259-267.
    PMID: 28697633 DOI: 10.1080/08923973.2017.1344987
    CONTEXT: Zinc L-carnosine (ZnC) is a chelate of Zn and L-carnosine and is used clinically in the treatment of peptic ulcer.

    OBJECTIVE: In this study, we aim to investigate the involvement of heme oxygenase-1 (HO-1) in the anti-inflammatory effects of ZnC in lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophages.

    MATERIALS AND METHODS: We used immunoblotting analysis to evaluate the involvement of HO-1 in the anti-inflammatory effects of ZnC and the signaling pathway involved was measured using Dual luciferase reporter assay.

    RESULTS: Results from immunoblotting analysis demonstrated that pretreatment of cells with ZnC enhanced the expression of HO-1 in RAW 264.7 cells. Pretreatment of cells with HO-1 inhibitor (tin protoporphyrin IX dichloride) significantly attenuated the inhibitory effects of ZnC on nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression and NF-κB activation in LPS-induced RAW 264.7 cells, suggesting that HO-1 play an important role in the suppression of inflammatory responses induced by ZnC. Furthermore, results from co-immunoprecipitation of Nrf2 and Keap1 and dual luciferase reporter assay showed that pretreatment of ZnC was able to activate the Nrf2 signaling pathway. Treatment of cells with p38 inhibitor (SB203580), c-Jun N-terminal kinase inhibitor (SP600125), and MEK 1/2 inhibitor (U0126) did not significantly suppress the induction of HO-1 by ZnC. Moreover, our present findings suggest that the effects of ZnC on NO production, HO-1 expression, and Nrf2 activation were attributed to its Zn subcomponent, but not l-carnosine.

    CONCLUSION: Pretreatment with ZnC was able to activate Nrf2/HO-1 signaling pathway, thus suppressing the expression of inflammatory mediators, such as NO and iNOS in LPS-induced RAW 264.7 cells.

    Matched MeSH terms: Heme Oxygenase-1/biosynthesis*
  2. Thioredoxin-albumin fusion protein prevents copper enhanced zinc-induced neurotoxicity via its antioxidative activity
    Tanaka KI, Shimoda M, Chuang VTG, Nishida K, Kawahara M, Ishida T, et al.
    Int J Pharm, 2018 Jan 15;535(1-2):140-147.
    PMID: 29122608 DOI: 10.1016/j.ijpharm.2017.11.012
    Zinc (Zn) is a co-factor for a vast number of enzymes, and functions as a regulator for immune mechanism and protein synthesis. However, excessive Zn release induced in pathological situations such as stroke or transient global ischemia is toxic. Previously, we demonstrated that the interaction of Zn and copper (Cu) is involved in the pathogenesis of Alzheimer's disease and vascular dementia. Furthermore, oxidative stress has been shown to play a significant role in the pathogenesis of various metal ions induced neuronal death. Thioredoxin-Albumin fusion (HSA-Trx) is a derivative of thioredoxin (Trx), an antioxidative protein, with improved plasma retention and stability of Trx. In this study, we examined the effect of HSA-Trx on Cu2+/Zn2+-induced neurotoxicity. Firstly, HSA-Trx was found to clearly suppress Cu2+/Zn2+-induced neuronal cell death in mouse hypothalamic neuronal cells (GT1-7 cells). Moreover, HSA-Trx markedly suppressed Cu2+/Zn2+-induced ROS production and the expression of oxidative stress related genes, such as heme oxygenase-1. In contrast, HSA-Trx did not affect the intracellular levels of both Cu2+ and Zn2+ after Cu2+/Zn2+ treatment. Finally, HSA-Trx was found to significantly suppress endoplasmic reticulum (ER) stress response induced by Cu2+/Zn2+ treatment in a dose dependent manner. These results suggest that HSA-Trx counteracted Cu2+/Zn2+-induced neurotoxicity by suppressing the production of ROS via interfering the related gene expressions, in addition to the highly possible radical scavenging activity of the fusion protein. Based on these findings, HSA-Trx has great potential as a promising therapeutic agent for the treatment of refractory neurological diseases.
    Matched MeSH terms: Heme Oxygenase-1
  3. The oxidative stress of hyperglycemia and the inflammatory process in endothelial cells
    Muniandy S, Qvist R, Yan GO, Bee CJ, Chu YK, Rayappan AV
    J. Med. Invest., 2009 Feb;56(1-2):6-10.
    PMID: 19262007
    Hyperglycemia and insulin resistance are common in many critically ill patients. Hyperglycemia increases the production of reactive oxygen species in cells, stimulates the production of the potent proinflammatory cytokines IL-8 and TNF-alpha, and enhances the expression of haem oxygenase-1, an inducible stress protein. It has been shown that administration of insulin and the semi-essential amino acid glutamine have been beneficial to the septic patient. The aim of our study is to test whether these two molecules, glutamine and insulin used in combination attenuate the proinflammatory responses in endothelial cells which have been triggered by hyperglycaemia. Our results demonstrate that a combination of insulin and glutamine are significantly more effective in reducing the expression of IL-8, TNF-alpha and HO-1 than insulin or glutamine alone.
    Matched MeSH terms: Heme Oxygenase-1/metabolism
  4. Fulltext Stability of the antimalarial drug dihydroartemisinin under physiologically relevant conditions: implications for clinical treatment and pharmacokinetic and in vitro assays
    Parapini S, Olliaro P, Navaratnam V, Taramelli D, Basilico N
    Antimicrob Agents Chemother, 2015 Jul;59(7):4046-52.
    PMID: 25918150 DOI: 10.1128/AAC.00183-15
    Artemisinins are peroxidic antimalarial drugs known to be very potent but highly chemically unstable; they degrade in the presence of ferrous iron, Fe(II)-heme, or biological reductants. Less documented is how this translates into chemical stability and antimalarial activity across a range of conditions applying to in vitro testing and clinical situations. Dihydroartemisinin (DHA) is studied here because it is an antimalarial drug on its own and the main metabolite of other artemisinins. The behaviors of DHA in phosphate-buffered saline, plasma, or erythrocyte lysate at different temperatures and pH ranges were examined. The antimalarial activity of the residual drug was evaluated using the chemosensitivity assay on Plasmodium falciparum, and the extent of decomposition of DHA was established through use of high-performance liquid chromatography with electrochemical detection analysis. The role of the Fe(II)-heme was investigated by blocking its reactivity using carbon monoxide (CO). A significant reduction in the antimalarial activity of DHA was seen after incubation in plasma and to a lesser extent in erythrocyte lysate. Activity was reduced by half after 3 h and almost completely abolished after 24 h. Serum-enriched media also affected DHA activity. Effects were temperature and pH dependent and paralleled the increased rate of decomposition of DHA from pH 7 upwards and in plasma. These results suggest that particular care should be taken in conducting and interpreting in vitro studies, prone as their results are to experimental and drug storage conditions. Disorders such as fever, hemolysis, or acidosis associated with malaria severity may contribute to artemisinin instability and reduce their clinical efficacy.
    Matched MeSH terms: Heme/chemistry
  5. Renoprotective effect of virgin coconut oil in heated palm oil diet-induced hypertensive rats
    Kamisah Y, Ang SM, Othman F, Nurul-Iman BS, Qodriyah HM
    Appl Physiol Nutr Metab, 2016 Oct;41(10):1033-1038.
    PMID: 27618413
    Virgin coconut oil, rich in antioxidants, was shown to attenuate hypertension. This study aimed to investigate the effects of virgin coconut oil on blood pressure and related parameters in kidneys in rats fed with 5-times-heated palm oil (5HPO). Thirty-two male Sprague-Dawley rats were divided into 4 groups. Two groups were fed 5HPO (15%) diet and the second group was also given virgin coconut oil (1.42 mL/kg, oral) daily for 16 weeks. The other 2 groups were given basal diet without (control) and with virgin coconut oil. Systolic blood pressure was measured pre- and post-treatment. After 16 weeks, the rats were sacrificed and kidneys were harvested. Dietary 5HPO increased blood pressure, renal thiobarbituric acid reactive substance (TBARS), and nitric oxide contents, but decreased heme oxygenase activity. Virgin coconut oil prevented increase in 5HPO-induced blood pressure and renal nitric oxide content as well as the decrease in renal heme oxygenase activity. The virgin coconut oil also reduced the elevation of renal TBARS induced by the heated oil. However, neither dietary 5HPO nor virgin coconut oil affected renal histomorphometry. In conclusion, virgin coconut oil has a potential to reduce the development of hypertension and renal injury induced by dietary heated oil, possibly via its antioxidant protective effects on the kidneys.
  6. Regulatory mechanisms of heme regulatory protein BACH1: a potential therapeutic target for cancer
    Arunachalam A, Lakshmanan DK, Ravichandran G, Paul S, Manickam S, Kumar PV, et al.
    Med Oncol, 2021 Sep 04;38(10):122.
    PMID: 34482423 DOI: 10.1007/s12032-021-01573-z
    A limited number of overexpressed transcription factors are associated with cancer progression in many types of cancer. BTB and CNC homology 1 (BACH1) is the first mammalian heme-binding transcription factor that belongs to the basic region leucine zipper (bZIP) family and a member of CNC (cap 'n' collar). It forms heterodimers with the small musculoaponeurotic fibrosarcoma (MAF) proteins and stimulates or suppresses the expression of target genes under a very low intracellular heme concentration. It possesses a significant regulatory role in heme homeostasis, oxidative stress, cell cycle, apoptosis, angiogenesis, and cancer metastasis progression. This review discusses the current knowledge about how BACH1 regulates cancer metastasis in various types of cancer and other carcinogenic associated factors such as oxidative stress, cell cycle regulation, apoptosis, and angiogenesis. Overall, from the reported studies and outcomes, it could be realized that BACH1 is a potential pharmacological target for discovering new therapeutic anticancer drugs.
    Matched MeSH terms: Heme; Heme Oxygenase-1
  7. Fulltext Physico-chemical changes and microbiological quality of refrigerated broiler chicken meat slaughtered by two different methods
    Ahmed, H.O., Hassan, Z., Abdul Manap, M.N.
    International Food Research Journal, 2018;25(3):913-920.
    MyJurnal
    Slaughtering is the first step in meat processing. It involves killing an animal for the production of meat. Effectiveness of slaughter is determined by the amount of blood removed from the animal. This study aimed to compare the chemical changes and microbiological quality of broiler chicken meat slaughtered by Halal and Non-Halal slaughter methods during refrigerated storage. A total of sixty (60) broiler chickens were slaughtered by: i) Neck cutting (NC) - by severing the jugular veins, carotid arteries, trachea and the oesophagus according to the Islamic ritual method of slaughter and (ii) Neck poking (NP) - by poking the neck of the bird with a sharp object. Residual blood was quantified by measuring the haem iron content in the breast meat samples. Storage stability of chicken meat was evaluated by measuring the extent of lipid oxidation determined by thiobarbituric acid reactive substances (TBARS) and by assessing the microbiological quality of the meat. Haem iron content decreased significantly (P0.05) on chicken meat lipid oxidation at 1, 3, and 9 day of storage at 4oC. However, at 5 and 7 day of storage, significant differences (P
    Matched MeSH terms: Heme
  8. PHOTOSYNTHETIC AND RESPIRATORY CHARACTERISTICS OF MALAYAN SUN AND SHADE FERNS
    Nasrulhaq-Boyce A, Mohamed MAH
    New Phytol, 1987 Jan;105(1):81-88.
    PMID: 33874033 DOI: 10.1111/j.1469-8137.1987.tb00112.x
    A comparative study of four Malayan ferns, Christensenia aesculifolia (Bl.) Maxon, Tectaria singaporeana (Wall.) Ching, Abacopteris multilineata (Wall.) Ching and Hymenophyllum polyanthos Sw. from shady habitats and another four, Dicranopteris linearis (Burm.) Und., Lygodium scandens (L.) Sw., Blechnum orientate Linn, and Stenochlaena palustris (Burm.) Bedd. from sunlit habitats showed that the total chlorophyll content expressed on a gram fresh weight basis was greater in the shade ferns. There was little difference in the chlorophyll content between the sun and shade ferns when it was expressed on a per unit leaf area basis. The protein and protohaem content was greater in the sun ferns. Measurements of the in vitro photochemical activities of the photosystems I and II in isolated chloroplasts by means of an oxygen electrode showed higher rates in the sun ferns. As determined by spectrophotometric analysis, the photosynthetic cytochrome content from isolated chloroplasts was greater in the sun ferns. The results indicate that the sun ferns have physiological characteristics favouring greater capacity for photosynthesis. Mitochondria isolated from the sun ferns showed faster rates of electron transport using exogenous NADH as substrate.
    Matched MeSH terms: Heme
  9. Nucleotide sequencing, cloning, and expression of Capra hircus Heme Oxygenase-1 in caprine islets to promote insulin secretion in vitro
    Vakhshiteh F, Allaudin ZN, Lila MA, Abbasiliasi S, Ajdari Z
    Mol Biotechnol, 2015 Jan;57(1):75-83.
    PMID: 25218408 DOI: 10.1007/s12033-014-9803-8
    Transplantation of islets of Langerhans that have been isolated from whole pancreas is an attractive alternative for the reversal of Type 1 diabetes. However, in vitro culture of isolated pancreatic islets has been reported to cause a decrease in glucose response over time. Hence, the improvement in islet culture conditions is an important goal in islet transplantation. Heme Oxygenase-1 (HO-1) is a stress protein that has been described as an inducible protein with the capacity of preventing apoptosis and cytoprotection via radical scavenging. Therefore, this study was aimed to assess the influence of endogenous HO-1 gene transfer on insulin secretion of caprine islets. The full-length cDNA sequence of Capra hircus HO-1 was determined using specific designed primers and rapid amplification of cDNA ends of pancreatic tissue. The HO-1 cDNA was then cloned into the prokaryotic expression vectors and transfected into caprine islets using lipid carriers. Efficiency of lipid carriers to transfect caprine islets was determined by flow cytometry. Insulin secretion assay was carried out by ovine insulin ELISA. The finding demonstrated that endogenous HO-1 gene transfer could improve caprine islet function in in vitro culture. Consequently, strategies using HO-1 gene transfer to islets might lead to better outcome in islet transplantation.
    Matched MeSH terms: Heme Oxygenase-1/genetics*
  10. Nrf2/HO-1 Mediated Protective Activity of Genistein Against Doxorubicin-Induced Cardiac Toxicity
    Chen M, Samuel VP, Wu Y, Dang M, Lin Y, Sriramaneni R, et al.
    J Environ Pathol Toxicol Oncol, 2019;38(2):143-152.
    PMID: 31679277 DOI: 10.1615/JEnvironPatholToxicolOncol.2019029341
    The current study evaluated the cardioprotective activity of genistein in cases of doxorubicin-(Dox) induced cardiac toxicity and a probable mechanism underlying this protection, such as an antioxidant pathway in cardiac tissues. Animals used in this study were categorized into four groups. The first group was treated with sodium carboxymethylcellulose (0.3%; CMC-Na) solution. The second group received Dox (3.0 mg/kg, i.p.) on days 6, 12, 18, and 24. The third and fourth groups received Dox (3 mg/kg, i.p.) on days 6, 12, 18, and 24 and received protective doses of genistein (100 [group 3] and 200 [group 4] mg/kg/day, p.o.) for 30 days. Treatment with genistein significantly improved the altered cardiac function markers and oxidative stress markers. This was coupled with significant improvement in cardiac histopathological features. Genistein enhanced the Nrf2 and HO-1 expression, which showed protection against oxidative insult induced by Dox. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed substantial inhibition of apoptosis by genistein in myocardia. The study showed that genistein has a strong reactive oxygen species scavenging property and potentially (P ≤ .001) decreases the lipid peroxidation as well as inhibits DNA damage in cardiac toxicity induced by Dox. In conclusion, the potential antioxidant effect of genistein may be because of its modulatory effect on Nrf2/HO-1 signalling pathway and by this means exhibits cardioprotective effects from Dox-induced oxidative injury.
    Matched MeSH terms: Heme Oxygenase-1/genetics*; Heme Oxygenase-1/metabolism
  11. Mitochondrial targeting of bilirubin regulatory enzymes: An adaptive response to oxidative stress
    Muhsain SN, Lang MA, Abu-Bakar A
    Toxicol Appl Pharmacol, 2015 Jan 1;282(1):77-89.
    PMID: 25478736 DOI: 10.1016/j.taap.2014.11.010
    The intracellular level of bilirubin (BR), an endogenous antioxidant that is cytotoxic at high concentrations, is tightly controlled within the optimal therapeutic range. We have recently described a concerted intracellular BR regulation by two microsomal enzymes: heme oxygenase 1 (HMOX1), essential for BR production and cytochrome P450 2A5 (CYP2A5), a BR oxidase. Herein, we describe targeting of these enzymes to hepatic mitochondria during oxidative stress. The kinetics of microsomal and mitochondrial BR oxidation were compared. Treatment of DBA/2J mice with 200mgpyrazole/kg/day for 3days increased hepatic intracellular protein carbonyl content and induced nucleo-translocation of Nrf2. HMOX1 and CYP2A5 proteins and activities were elevated in microsomes and mitoplasts but not the UGT1A1, a catalyst of BR glucuronidation. A CYP2A5 antibody inhibited 75% of microsomal BR oxidation. The inhibition was absent in control mitoplasts but elevated to 50% after treatment. An adrenodoxin reductase antibody did not inhibit microsomal BR oxidation but inhibited 50% of mitochondrial BR oxidation. Ascorbic acid inhibited 5% and 22% of the reaction in control and treated microsomes, respectively. In control mitoplasts the inhibition was 100%, which was reduced to 50% after treatment. Bilirubin affinity to mitochondrial and microsomal CYP2A5 enzyme is equally high. Lastly, the treatment neither released cytochrome c into cytoplasm nor dissipated membrane potential, indicating the absence of mitochondrial membrane damage. Collectively, the observations suggest that BR regulatory enzymes are recruited to mitochondria during oxidative stress and BR oxidation by mitochondrial CYP2A5 is supported by mitochondrial mono-oxygenase system. The induced recruitment potentially confers membrane protection.
    Matched MeSH terms: Heme Oxygenase-1/metabolism*
  12. Fulltext Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats
    Jaarin K, Foong WD, Yeoh MH, Kamarul ZY, Qodriyah HM, Azman A, et al.
    Clinics (Sao Paulo), 2015 Nov;70(11):751-7.
    PMID: 26602523 DOI: 10.6061/clinics/2015(11)07
    This study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers.
  13. Fulltext Meat and haem iron intake in relation to glioma in the European Prospective Investigation into Cancer and Nutrition study
    Ward HA, Gayle A, Jakszyn P, Merritt M, Melin B, Freisling H, et al.
    Eur J Cancer Prev, 2018 Jul;27(4):379-383.
    PMID: 27845960 DOI: 10.1097/CEJ.0000000000000331
    Diets high in red or processed meat have been associated positively with some cancers, and several possible underlying mechanisms have been proposed, including iron-related pathways. However, the role of meat intake in adult glioma risk has yielded conflicting findings because of small sample sizes and heterogeneous tumour classifications. The aim of this study was to examine red meat, processed meat and iron intake in relation to glioma risk in the European Prospective Investigation into Cancer and Nutrition study. In this prospective cohort study, 408 751 individuals from nine European countries completed demographic and dietary questionnaires at recruitment. Multivariable Cox proportional hazards models were used to examine intake of red meat, processed meat, total dietary iron and haem iron in relation to incident glioma. During an average follow-up of 14.1 years, 688 incident glioma cases were diagnosed. There was no evidence that any of the meat variables (red, processed meat or subtypes of meat) or iron (total or haem) were associated with glioma; results were unchanged when the first 2 years of follow-up were excluded. This study suggests that there is no association between meat or iron intake and adult glioma. This is the largest prospective analysis of meat and iron in relation to glioma and as such provides a substantial contribution to a limited and inconsistent literature.
    Matched MeSH terms: Heme/administration & dosage*; Heme/adverse effects
  14. Fulltext Iron and Virulence in Stenotrophomonas Maltophilia: All We Know So Far
    Kalidasan V, Joseph N, Kumar S, Awang Hamat R, Neela VK
    Front Cell Infect Microbiol, 2018;8:401.
    PMID: 30483485 DOI: 10.3389/fcimb.2018.00401
    Stenotrophomonas maltophilia is a multi-drug-resistant global opportunistic nosocomial pathogen, which possesses a huge number of virulence factors and antibiotics resistance characteristics. Iron has a crucial contribution toward growth and development, cell growth and proliferation, and pathogenicity. The bacterium found to acquire iron for its cellular process through the expression of two iron acquisition systems. Two distinct pathways for iron acquisition are encoded by the S. maltophilia genome-a siderophore-and heme-mediated iron uptake system. The entAFDBEC operon directs the production of the enterobactin siderophore of catecholate in nature, while heme uptake relies on hgbBC and potentially hmuRSTUV operon. Fur and sigma factors are regulators of S. maltophilia under iron-limited condition. Iron potentially act as a signal which plays an important role in biofilm formation, extracellular polymeric substances (EPS), extracellular enzymes production, oxidative stress response, diffusible signal factor (DSF) and siderophore production in S. maltophilia. This review summarizes the current knowledge of iron acquisition in S. maltophilia and the critical role of iron in relation to its pathogenicity.
    Matched MeSH terms: Heme/metabolism
  15. Fulltext Inhibitory effects of palm tocotrienol-rich fraction supplementation on bilirubin-metabolizing enzymes in hyperbilirubinemic adult rats
    Kamisah Y, Lim JJ, Lim CL, Asmadi AY
    PLoS One, 2014;9(2):e89248.
    PMID: 24586630 DOI: 10.1371/journal.pone.0089248
    Phenylhydrazine, a hemolytic agent, is widely used as a model of experimental hyperbilirubinemia. Palm tocotrienol-rich fraction (TRF) was shown to exert beneficial effects in hyperbilirubinemic rat neonates.
  16. Fulltext In Vitro Antiplasmodium and Chloroquine Resistance Reversal Effects of Andrographolide
    Ibraheem ZO, Majid RA, Sidek HM, Noor SM, Yam MF, Abd Rachman Isnadi MF, et al.
    Evid Based Complement Alternat Med, 2019;2019:7967980.
    PMID: 31915453 DOI: 10.1155/2019/7967980
    The emergence of drug-resistant strains of Plasmodium falciparum is the worst catastrophe that has ever confronted the dedicated efforts to eradicate malaria. This urged for searching other alternatives or sensitizers that reverse chloroquine resistance. In this experiment, the potential of andrographolide to inhibit plasmodial growth and reverse CQ resistance was tested in vitro using the SYBRE green-1-based drug sensitivity assay and isobologram technique, respectively. Its safety level toward mammalian cells was screened as well against Vero cells and RBCs using MTT-based drug sensitivity and RBC hemolysis assays, respectively. Its effect against hemozoin formation was screened using β-hematin formation and heme fractionation assays. Its molecular characters were determined using the conventional tests for the antioxidant effect measurement and the in silico molecular characterization using the online free chemi-informatic Molinspiration software. Results showed that andrographolide has a moderate antiplasmodium effect that does not entitle it to be a substituent for chloroquine. Furthermore, andrographolide ameliorated the sensitivity of the parasite to chloroquine. Besides, it showed an indirect inhibitory effect against hemozoin formation within the parasite and augmented the chloroquine-induced inhibition of hemozoin formation. The study suggests that its chloroquine resistance reversal effect may be due to inhibition of chloroquine accumulation or due to its impact on the biological activity of the parasite. Overall, this in vitro study is a clue for the reliability of andrographolide to be added with chloroquine for reversal of chloroquine resistance and tolerance, but further in vivo studies are recommended to confirm this notion. In spite of its prominent and safe in vitro and in vivo growth inhibitory effect and its in vitro chloroquine resistance reversing effect, it is inapplicable to implement it in malaria chemotherapy to substitute chloroquine or to reverse its resistance.
    Matched MeSH terms: Heme; Hemeproteins
  17. Global Transcriptome Analysis of Gracilaria changii (Rhodophyta) in Response to Agarolytic Enzyme and Bacterium
    Lim EL, Siow RS, Abdul Rahim R, Ho CL
    Mar Biotechnol (NY), 2016 Apr;18(2):189-200.
    PMID: 26631182 DOI: 10.1007/s10126-015-9680-6
    Many bacterial epiphytes of agar-producing seaweeds secrete agarase that degrade algal cell wall matrix into oligoagars which elicit defense-related responses in the hosts. The molecular defense responses of red seaweeds are largely unknown. In this study, we surveyed the defense-related transcripts of an agarophyte, Gracilaria changii, treated with β-agarase through next generation sequencing (NGS). We also compared the defense responses of seaweed elicited by agarase with those elicited by an agarolytic bacterium isolated from seaweed, by profiling the expression of defense-related genes using quantitative reverse transcription real-time PCR (qRT-PCR). NGS detected a total of 391 differentially expressed genes (DEGs) with a higher abundance (>2-fold change with a p value <0.001) in the agarase-treated transcriptome compared to that of the non-treated G. changii. Among these DEGs were genes related to signaling, bromoperoxidation, heme peroxidation, production of aromatic amino acids, chorismate, and jasmonic acid. On the other hand, the genes encoding a superoxide-generating NADPH oxidase and related to photosynthesis were downregulated. The expression of these DEGs was further corroborated by qRT-PCR results which showed more than 90 % accuracy. A comprehensive analysis of their gene expression profiles between 1 and 24 h post treatments (hpt) revealed that most of the genes analyzed were consistently upregulated or downregulated by both agarase and agarolytic bacterial treatments, indicating that the defense responses induced by both treatments are highly similar except for genes encoding vanadium bromoperoxidase and animal heme peroxidase. Our study has provided the first glimpse of the molecular defense responses of G. changii to agarase and agarolytic bacterial treatments.
    Matched MeSH terms: Heme
  18. Gelam honey inhibits lipopolysaccharide-induced endotoxemia in rats through the induction of heme oxygenase-1 and the inhibition of cytokines, nitric oxide, and high-mobility group protein B1
    Kassim M, Yusoff KM, Ong G, Sekaran S, Yusof MY, Mansor M
    Fitoterapia, 2012 Sep;83(6):1054-9.
    PMID: 22626749 DOI: 10.1016/j.fitote.2012.05.008
    Malaysian Gelam honey has anti-inflammatory and antibacterial properties, a high antioxidant capacity, and free radical-scavenging activity. Lipopolysaccharide (LPS) stimulates immune cells to sequentially release early pro- and anti-inflammatory cytokines and induces the synthesis of several related enzymes. The aim of this study was to investigate the effect of the intravenous injection of honey in rats with LPS-induced endotoxemia. The results showed that after 4h of treatment, honey reduced cytokine (tumor necrosis factor-α, interleukins 1β, and 10) and NO levels and increased heme oxygenase-1 levels. After 24h, a decrease in cytokines and NO and an increase in HO-1 were seen in all groups, whereas a reduction in HMGB1 occurred only in the honey-treated groups. These results support the further examination of honey as a natural compound for the treatment of a wide range of inflammatory diseases.
    Matched MeSH terms: Heme Oxygenase-1/metabolism*
  19. Functional role of Ile264 in CYP2C8: mutations affect haem incorporation and catalytic activity
    Singh R, Ting JG, Pan Y, Teh LK, Ismail R, Ong CE
    Drug Metab. Pharmacokinet., 2008;23(3):165-74.
    PMID: 18574320
    The work described in this study aimed to express CYP2C8 wild-type and mutant proteins in bacterial expression system and to use the expressed proteins to investigate the structural and functional consequences of a reported allele CYP2C8(*)4 (carrying Ile264Met substitution) on protein activity. Ile264 was replaced by three different amino acids resulting in three mutant constructs, 2C8I264M, 2C8I264R and 2C8I264D. The presence of isoleucine at position 264 in CYP2C8 was found to be important for proper haem insertion and protein folding; whereas bulkier or charged residues were highly disruptive resulting in inactive proteins with minimum spectral and catalytic activities. This was evidenced from the low levels of Soret peak at 450 nm and negligible levels of tolbutamide methylhydroxylase activity. Kinetic study using paclitaxel indicated that all three mutants exhibited only 9.7 to 35.4% of the activity level observed in the wild-type. In addition, the mutants were more sensitive to proteinase K digestion, indicating a possible alteration of conformation. The combined effects of protein instability and compromised catalytic activity resulted in defective CYP2C8 protein which may have clinical implications in carriers of CYP2C8*4, particularly in terms of their capacity to clear potent drugs and their susceptibility to adverse drug reactions.
    Matched MeSH terms: Heme/metabolism*
  20. Effect of repeatedly heated palm olein on blood pressure-regulating enzymes activity and lipid peroxidation in rats
    Leong XF, Salimon J, Mustafa MR, Jaarin K
    Malays J Med Sci, 2012 Jan;19(1):20-9.
    PMID: 22977371
    BACKGROUND: Oxidative stress is associated with the pathogenesis of cardiovascular diseases. The process of deep-fat frying in dietary cooking oil plays a role in the generation of free radicals. In this study, palm olein heated to 180 °C was tested for its effect on the activity of blood pressure-regulating enzymes and lipid peroxidation.

    METHODS: Forty-two adult male Sprague-Dawley rats were equally assigned into 6 groups.The first group was fed with normal rat chow as the control group, and the subsequent groups were fed with rat chow fortified with 15% weight/weight of the following: fresh palm olein, palm olein heated once, palm olein heated twice, palm olein heated 5 times, or palm olein heated 10 times. The duration of feeding was 6 months. Fatty acid analyses of oil were performed using gas chromatography. Peroxide values were determined using standard titration. Plasma was collected for biochemical analyses.

    RESULTS: Repeatedly heated palm olein increased the levels of peroxide, angiotensin-converting enzyme, and lipid peroxidation as well as reduced the level of heme oxygenase. Fresh palm olein and palm olein heated once had lesser effects on lipid peroxidation and a better effect on the activity of blood pressure-regulating enzymes than repeatedly heated palm olein.

    CONCLUSION: Repeatedly heated palm olein may negatively affect the activity of blood pressure-regulating enzymes and increase lipid peroxidation.

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