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21.
Lipid peroxidation and scavenging enzyme levels in the liver of streptozotocin-induced diabetic rats
Bukan N Sancak B Yavuz O Koca C Tutkun F Ozçelikay AT Altan N 《Indian journal of biochemistry & biophysics》2003,40(6):447-450
In this study, alterations in the liver antioxidant enzymes status and lipid peroxidation in short-term (8-weeks) and long-term (24-weeks) diabetic rats were examined. Glutathione peroxidase (GSH-Px) activity and malondialdehyde (MDA) levels were significantly increased, but superoxide dismutase (SOD) activity was significantly reduced in 8-weeks diabetic rats, compared to control. Catalase (CAT) activity, however, was found unchanged. In 24-weeks diabetic rats, while GSH-Px activity was unchanged, but SOD and CAT activities and MDA levels were significantly increased, compared to control. These results suggest that diabetes-induced alterations in tissue antioxidant system may reflect a generalized increase in tissue oxidative stress. It can be concluded that lipid peroxidation and antioxidant enzyme levels are elevated in diabetic condition. Hence, diabetes mellitus, if left untreated, may increase degenerative processes due to accumulation of oxidative free radicals. 相似文献
22.
Betul Can Gulnihal Kulaksiz Erkmen Ozlem Dalmizrak I. Hamdi Ogus Nazmi Ozer 《The protein journal》2010,29(4):250-256
Glutathione reductase [GR, E.C.1.8.1.7] catalyses NADPH dependent reduction of glutathione disulfide (GSSG) to reduced glutathione
(GSH). Thus, it is the crucial enzyme to maintain high [GSH]/[GSSG] ratio and physiological redox status in cells. Kidney
and liver tissues were considered as a rich source of GR. In this study, rat kidney GR was purified and some of its properties
were investigated. The enzyme was purified 2,356 fold with a yield of 16% by using heat-denaturation and Sephadex G25 gel
filtration, 2′,5′-ADP Agarose 4B, PBE94 column chromatographies. The purified enzyme had a specific activity (Vm) of 250 U/mg protein and the ratio of absorbances at wavelengths of A
273/A
463,
A
280/A
460, A
365/A
460, and A
379/A
463, were 7.1, 6.8, 1.2 and 1.0, respectively. Each mol of GR subunit bound 0.97 mol of FAD. NADH was used as a coenzyme by rat
kidney GR but with a lower efficiency (32.7%) than NADPH. Its subunit molecular weight was estimated as 53 kDa. An optimum
pH of 6.5 and optimum temperature of 65 °C were found for rat kidney GR. Its activation energy (Ea) and temperature coefficient
(Q10) were calculated as 7.02 kcal/mol and 1.42, respectively. The Km(NADPH) and kcat/Km (NADPH) values were found to be 15.3 ± 1.4 μM and 1.68 × 107 M−1 s−1 for the concentration range of 10-200 μM NADPH and when GSSG is the variable substrate, the Km(GSSG) and the kcat/Km(GSSG) values of 53.1 ± 3.4 μM and 4.85 × 106 M−1 s−1 were calculated for the concentration range of 20–1,200 μM GSSG. 相似文献
23.
Post‐translational modifications of transthyretin affect the triiodonine‐binding potential 下载免费PDF全文
Andrea Henze Thomas Homann Mustafa Serteser Ozge Can Ozlem Sezgin Abdurrahman Coskun Ibrahim Unsal Florian J. Schweigert Aysel Ozpinar 《Journal of cellular and molecular medicine》2015,19(2):359-370
Transthyretin (TTR) is a visceral protein, which facilitates the transport of thyroid hormones in blood and cerebrospinal fluid. The homotetrameric structure of TTR enables the simultaneous binding of two thyroid hormones per molecule. Each TTR subunit provides a single cysteine residue (Cys10), which is frequently affected by oxidative post‐translational modifications. As Cys10 is part of the thyroid hormone‐binding channel within the TTR molecule, PTM of Cys10 may influence the binding of thyroid hormones. Therefore, we analysed the effects of Cys10 modification with sulphonic acid, cysteine, cysteinylglycine and glutathione on binding of triiodothyronine (T3) by molecular modelling. Furthermore, we determined the PTM pattern of TTR in serum of patients with thyroid disease by immunoprecipitation and mass spectrometry to evaluate this association in vivo. The in silico assays demonstrated that oxidative PTM of TTR resulted in substantial reorganization of the intramolecular interactions and also affected the binding of T3 in a chemotype‐ and site‐specific manner with S‐glutathionylation as the most potent modulator of T3 binding. These findings were supported by the in vivo results, which indicated thyroid function‐specific patterns of TTR with a substantial decrease in S‐sulphonated, S‐cysteinylglycinated and S‐glutathionylated TTR in hypothyroid patients. In conclusion, this study provides evidence that oxidative modifications of Cys10 seem to affect binding of T3 to TTR probably because of the introduction of a sterical hindrance and induction of conformational changes. As oxidative modifications can be dynamically regulated, this may represent a sensitive mechanism to adjust thyroid hormone availability. 相似文献
24.
Fadime Atalay Fehmi Odabasoglu Mesut Halici Ahmet Cakir Elif Cadirci Ali Aslan Ozlem Aydin Berktas Cavit Kazaz 《化学与生物多样性》2015,12(11):1756-1767
Two lichen metabolites, rhizonaldehyde ( 1 ) and rhizonyl alcohol ( 2 ), were isolated from the acetone extract of Lobaria pulmonaria by chromatographic methods, and their chemical structures were determined by UV/VIS, IR, and 1D‐ and 2D‐NMR spectroscopic methods. The gastroprotective and in vivo antioxidant activities of extracts of L. pulmonaria and its metabolites, 1 and 2 , were investigated in indomethacin‐induced ulcer models in rats. The gastric lesions were significantly reduced by acetone, hexane, and CHCl3 extracts, with 75.3–41.5% inhibition. Rhizonyl alcohol ( 2 ) significantly reduced the gastric lesions with an inhibition rate of 84.6–42.8%, whereas rhizonaldehyde ( 1 ) significantly increased the gastric lesions. Antioxidant parameters and myeloperoxidase activities were also evaluated in the gastric tissues of the rats. Indomethacin caused oxidative stress, which resulted in lipid peroxidation in gastric tissues by decreasing the levels of the antioxidants as compared to healthy rat tissues. In contrast to indomethacin, all extracts and rhizonyl alcohol ( 2 ) caused a significant decrease in lipid peroxidation levels and an increase in antioxidant parameters, superoxide dismutase, glutathione peroxidase, and glutathione‐S‐transferase, and reduced glutathione in gastric tissues. The administration of rhizonyl alcohol ( 2 ) also resulted in a decrease in gastric myeloperoxidase activity increased by indomethacin. The gastroprotective effect of rhizonyl alcohol ( 2 ) can be attributed to its antioxidant properties and its suppressing effect on neutrophil infiltration into gastric tissues. 相似文献
25.
Systemic cladosporiosis is described in 25 merino sheep from a flock consisting 250 animals. The fungal pneumonia appeared
after an intensive antibiotic treatment, because of a respiratory system disorder. The pen of the flock was humid and crowded,
and animals had signs of respiratory distress, coughing, fever and anorexia. All of the ill animals died, and necropsy was
performed on 10 sheep. The lesions were characterized by a multifocal pyogranulomatous pneumonia and an abomasitis. Severe
hemorrhages were observed in the lungs. At the histopathological examination, severe vasculitis with thrombosis was observed
in various organs, especially in the lungs and abomasums, suggestive for a hematogenous dissemination of the infection in
these organs. Numerous PAS-positive fungal elements were seen in the pyogranulomatous foci. Dark green fungal colonies were
seen in the blood agar and Sabouraud dextrose agar that were identified as Cladosporium cladosporioides. This report highlights that phaeohyphomycosis can cause a severe systemic and fatal disease in merino sheep under insufficient
management conditions. 相似文献
26.
Zeynep Ermis Karaali Seyma Sozen Melis Yurdum Canan Cacina Bahar Toptas Ozlem Gok Bedia Agachan 《Molecular biology reports》2010,37(7):3615-3619
Inflammation is a crucial component of coronary atherosclerosis and myocardial infarction (MI). Chemokine receptors are important
modulators of inflammation. Polymorphisms in genes coding for chemokine receptors, CCR2 and CCR5, have been studied as genetic markers of coronary artery
disease. In the present study, we investigated whether genetic variants of CCR2-V64I and CCR5-delta32 chemokine receptors
have any effect on the development of myocardial infarction. A total of 146 MI patients and 202 control subjects were genotyped
for CCR2 and CCR5. CCR2-V64I genotypes were not significantly different between patients with MI and controls (P > 0.05). CCR5-delta32 genotype distribution in cases was significantly different from that of controls (P = 0.042). The CCR5-delta32 wt/deletion genotype frequencies for controls and cases were 0.10 and 0.19, respectively and individuals
with CCR5-delta32 wt/deletion genotype had a 2.13-fold increased risk of myocardial infarction (P = 0.0013). Individuals carrying the CCR5-delta32 heterozygote or homozygous variant genotype (deletion/deletion + wt/deletion)
had a 1.96-fold increased risk of myocardial infarction compared with the wild-type genotype (wt/wt) (p: 0.016). In conclusion,
our data have suggested that genetic variant of CCR5 might be associated with the development of MI. Further larger sample
size studies are required to confirm our findings. 相似文献
27.
Ozlem Osmanagaoglu Fadime Kiran Haluk Ataoglu 《Probiotics and antimicrobial proteins》2010,2(3):162-174
This study was conducted to evaluate the probiotic properties of Pediococcus pentosaceus OZF isolated from human breast milk. The results obtained so far suggest that the strain is resistant to low pH, bile salt, pepsin and pancreatin, so it could survive while passing through the upper part of the gastrointestinal tract and reveal its potential probiotic action on host organism. The strain was non-pathogenic (γ-hemolytic), produced anti-Listerial bacteriocin, exhibited a strong autoaggregating phenotype (85.71%) and demonstrated 6.26 and 12.99% coaggregation with Salmonella enterica serotype Typhimurium SL 1344 and Escherichia coli LMG 3083 (ETEC), respectively. The degree of adhesion of Ped. pentosaceus OZF to the human Caco-2 cell line was investigated and when compared to the adhesion of pathogenic strains tested, it was shown to inhibit the growth of human enterotoxigenic E. coli LMG 3083 (ETEC) and of Salm. Typhimurium SL 1344. Ped. pentosaceus OZF seems to adhere to human intestinal cells via mechanisms that involve different combinations of carbohydrate and lipid factors on the bacteria and eukaryotic cell surface. The percentage of adhesion to n-hexadecane was 34% showing that the surface was rather hydrophilic. Higher affinity displayed by Ped. pentosaceus OZF for chloroform demonstrates the basic property of a cell, which may be due to the presence of carboxylic groups on the cell surface. 相似文献
28.
Ozlem Bakir Boga Ahmet Bugra Ortaakarsu Beyzanur Kadırustaoglu Esabi Basaran Kurbanoglu 《化学与生物多样性》2023,20(3):e202201142
In this study, total phenolic and flavonoid analyses of flower, leaf, and stem aqueous extracts of C. orientalis were performed. Total phenolic contents of C. orientalis extracts ranged from 12.2±0.06 to 19.0±0.07 mg GAE/g extract. Total flavonoid values range between 2.0±0.11 and 6.6±0.19 mg CE/g extract. Urease, collagenase, tyrosinase, and α-glucosidase inhibition activities were determined in vitro and the relationship between them was examined. IC50 results for all enzymes were obtained between 0.18 and 3.53 μg/mL. The aqueous extract of the plant C. orientalis showed potent cytotoxic effects against the human colon cancer cell lines DLD-1. As the extract concentration increases, cell death increases. The main fatty acid composition by GC/MS analysis is erucic acid (36.5 %). The potential binding modes of the fatty acids in the plant extract to the enzymes and possible inhibition mechanisms were determined by molecular docking calculation. 相似文献
29.
Journal of Molecular Modeling - Weak interactions of graphene surface with reactive molecular impurities are the subject of many studies since noncovalent functionalization of surface via molecular... 相似文献
30.
Altindag O Gur A Calgan N Soran N Celik H Selek S 《Redox report : communications in free radical research》2007,12(3):134-138
We aimed to evaluate the association of serum paraoxonase and arylesterase activities and oxidative/antioxidative status in patients with fibromyalgia. Forty-two patients with fibromyalgia and 53 healthy controls were included in the study. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. Oxidative and antioxidative status were evaluated by measuring serum lipid hydroperoxide (LOOH) levels, total antioxidant status (TAS) and free sulfhydryl groups (-SH = total thiol). Lipid parameters were determined by routine laboratory methods. Serum paraoxonase and arylesterase activities, and TAS were lower in patients with fibromyalgia than in controls (P < 0.001, for all), and the -SH level was also lower in the patient group (P = 0.03). LOOH levels were higher in the patient group than in controls (P = 0.01). Our results suggest that patients with fibromyalgia were exposed to oxidative stress, and paraoxonase and arylesterase activities were decreased in these patients. Patients with fibromyalgia might be prone to development of atherosclerosis with reduced paraoxonase and arylesterase activities. 相似文献