Ahmet Özkaya
Fırat University
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Featured researches published by Ahmet Özkaya.
Journal of Chemistry | 2013
Ahmet Özkaya; Harun Ciftci; Ökkeş Yilmaz; Ahmet Zafer Tel; Erol Cil; B. Sitki Cevrimli
The levels of fat-soluble vitamin, trace element and fatty acid of Vitex agnus-castus L., Juniperus oxycedrus L., and Papaver somniferum L. seeds in Turkey were determined by using HPLC, ICP-OES, and GC, respectively. In the Vitex agnus-castus L., Juniperus oxycedrus L., and Papaver somniferum L. seeds, linoleic acid (18 : 2) was determined with the highest level rates (%54.11, %28.03, and %72.14, resp.). In the Vitex agnus-castus L. seeds, R-tocopherol, α-tocopherol, and K1 levels were determined as 9.70 μg/g, 18.20 μg/g, and 24.79 μg/g, respectively; In the Juniperus oxycedrus L. seeds, R-tocopherol, α-tocopherol, and K1 were determined as 18.50 μg/g, 0.84 μg/g, and 5.00 μg/g, respectively, and in the Papaver somniferum L. seeds, R-tocopherol, α-tocopherol, K1, and D2 levels were determined as 43.25 μg/g, 122.05 μg/g, 12.01 μg/g, and 0.62 μg/g, respectively. In the Vitex agnus-castus L., Juniperus oxycedrus L., and Papaver somniferum L. seeds, nickel (Ni), zinc (Zn), and iron (Fe) were determined with the trace element level rates (4.42 mg/kg, 10.43 mg/kg, 3.71 mg/kg for Ni, 7.00 mg/kg, 7.70 mg/kg, and 24 mg/kg for Zn and 93.73 mg/kg, 187.95 mg/kg, and 149.64 mg/kg for Fe, resp.). These parameters in seeds are very important for human life.
Journal of Intercultural Ethnopharmacology | 2017
Ahmet Özkaya; Zafer Sahin; Ahmet O Gorgulu; Abdurrauf Yüce; Sait Çelik
Background: Hydrogen peroxide (H2O2) is an oxidant agent and this molecule naturally occurs in the body as a product of aerobic metabolism. Geraniol is a plant-derived natural antioxidant. The aim of this study was to determine the role of geraniol on hepatic fatty acids alterations following H2O2-induced oxidative stress in male rats. Methods: After randomization, male Wistar rats were divided into four groups (n = 7 each group). Geraniol (50 mg/kg, dissolved in corn oil) and H2O2 (16 mg/kg, dissolved in distilled water) were administered by an intraperitoneal injection. Administrations were performed during 30 days with 1-day interval. Results: Administration of H2O2 resulted with a significant increase in malondialdehyde (MDA) and a significant decrease in glutathione (GSH) peroxidase glutathione level; geraniol restored its effects on liver. However, hepatic catalase (CAT) activities were significantly higher in H2O2, geraniol, and geraniol+H2O2 groups than control group. The ratio of hepatic total saturated fatty acids increased in H2O2-treated animals compared with control. In addition, hepatic total unsaturated fatty acids reduced in H2O2 group compared with control. The percentages of both hepatic total saturated and unsaturated fatty acids were not different between geraniol+H2O2 and control groups. Conclusions: H2O2-induced oxidative stress may affect fatty acid composition in liver and body. Geraniol can partly restore oxidative hepatic damage because it cannot completely reverse the H2O2-induced increase in hepatic CAT activities. Moreover, this natural compound can regulate hepatic total saturated and unsaturated fatty acids percentages against H2O2-induced alterations.
Journal of basic and clinical physiology and pharmacology | 2017
Zafer Sahin; Ahmet Özkaya; Ökkeş Yilmaz; Abdurrauf Yüce; Mehmet Gunes
Abstract Background: We have investigated the effects of α-lipoic acid (LA), a powerful antioxidant, on the fatty acid (FA) profiles, aluminum accumulation, antioxidant activity and some minerals such as zinc, copper and iron against aluminum chloride (AlCl3)-induced oxidative stress in rat liver. Methods: Twenty-eight male Wistar rats were divided into four groups as control, LA, AlCl3 and LA+AlCl3. For 30 days, LA was intraperitoneally administrated (50 mg/kg) and AlCl3 was given via orogastric gavage (1600 ppm) every other day. Results: AlCl3-treated animals exhibited higher hepatic malondialdehyde concentration and lower glutathione peroxidase and catalase activity, whereas these alterations were restored by the LA supplementation. Total saturated FA of the AlCl3-treated group was higher than the LA supplementation groups. Moreover, total unsaturated FA level of the LA+AlCl3 group was higher than the AlCl3-treated group. Hepatic zinc level of the AlCl3-treated group was lower than the control group, whereas it was higher in the LA and the LA+AlCl3 groups. Hepatic copper levels did not significantly change in the experimental groups. Iron level was lower in the LA and LA+AlCl3 groups compared with the AlCl3-treated group. Moreover, the liver Al concentration was found to be lower in the LA and LA+AlCl3 groups compared to the AlCl3 group. Conclusions: These results indicate that AlCl3 treatment can induce oxidative stress in the liver. LA supplementation has a beneficial effect on the AlCl3-induced alterations such as high lipid peroxidation, Al accumulation, FA profile ratios and mineral concentrations.
The Turkish Journal of Pharmaceutical Sciences | 2017
Müslüm Kuzu; Ahmet Özkaya; Zafer Şahin; Üzeyir Dağ; Veysel Çomaklı; Ramazan Demirdağ
Objectives: Carbonic anhydrase (CA) enzyme catalyses the reversible reactions of CO2 with water and takes part in metabolically important events such as systemic acid-base regulation and respiration. In this study, in vivo effects of lead, which is a heavy metal and to which living beings are exposed by different ways, with naringenin, a flavanone, were investigated. Materials and Methods: For this purpose, four different rat groups were established and one of them was chosen as the control group. The other three groups were given lead, naringenin and lead+naringenin substances to analyze the changes in the CA enzyme of rat erythrocytes. Results: The research findings showed that the enzyme activity in the control group was higher than that in the other groups. The naringenin group showed the highest inhibition effect, while the lead group showed the lowest inhibition. Conclusion: Therefore, it can be said that naringenin is a strong inhibitor of the CA enzyme.
Journal of Biochemistry and Molecular Biology | 2002
Sait Çelik; Ahmet Özkaya
Cell Biochemistry and Function | 2006
Sait Çelik; Hatice Akarçay; Ökkeş Yilmaz; Ahmet Özkaya
Kafkas Universitesi Veteriner Fakultesi Dergisi | 2010
Ahmet Özkaya; Abdurrauf Yüce
Turkish Journal of Biochemistry-turk Biyokimya Dergisi | 2013
Ahmet Özkaya; Harun Ciftci; Alpaslan Dayangac; Bekir Sıtkı Çevrimli; Ali Olcucu; Sait Çelik
Archive | 2013
Husamettin Vatansev; Harun Ciftci; Ahmet Özkaya; Bahadir Ozturk; Nurcan Evliyaoglu; Aysel Kiyici
Journal of Animal and Veterinary Advances | 2011
Alpaslan Dayangac; Muammer Bahşi; Ahmet Özkaya; Ökkeş Yilmaz