Yazar "Ciftci, Mehmet" seçeneğine göre listele

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    Activation and inhibition effects of some natural products on human cytosolic CAI and CAII
    (Springer Birkhauser, 2019) Adem, Sevki; Akkemik, Ebru; Aksit, Huseyin; Guller, Pinar; Tufekci, Ali Riza; Demirtas, Ibrahim; Ciftci, Mehmet
    Carbonic anhydrases (CAs) play a significant function in diverse pathological and physiological processes. Their inhibitors and activators are suitable molecules to use as a drug in the treatment of different disease. In the present study, seven natural compounds, namely didymin, retusin isoquercitrin, silymarin, verbascoside, teucroside, and 3'-O-methylhypolaetin 7-O-[6'-O-acetyl-beta-D-allopyranosyl-(1 -> 2)]-6 ''-O-acetyl-beta-D-glucopyranoside were isolated from Mentha spicata, Sideritis libanotica linearis, Platanus orientalis, Teucrium chamaedrys subsp. chamaedrys, and Silybum marianum. The influences of compounds on the carbonic anhydrase I(hCAI) and II(hCAII) purified from human erythrocytes were tested. Five phenolic compounds acted as an inhibitor on the activity of hCAI, and IC50 values were computed between 18.16 and 172.5 mu M. Isozyme hCAII is only inhibited by silymarin with an IC50 value of 43.12 mu M. This isoenzyme was effectively activated by five natural compounds with AC(50) values in the range of 2.98-18.53 mu M. To understand the binding patterns of molecules that show activation effect against hCAII, molecular docking was done using Leadit 2.3.2 software, and calculated between -19.05 and -14.42 (kJ/mol) binding energies. Both in vitro and in silico results demonstrated that the best activators against hCAII were teucroside and isoquercitrin, with AC(50) values of 2.98 and 3.17 mu M, and binding energies -19.05 and -18.01 (kJ/mol), respectively. According to the ADME results, retusin demonstrated physicochemical and pharmacokinetic properties specific to the drug candidates.
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    Effect of astaxanthin and aluminum chloride on erythrocyte G6PD and 6PGD enzyme activities in vivo and on erythrocyte G6PD in vitro in rats
    (Wiley, 2017) Temel, Yusuf; Bengu, Aydin Sukru; Akkoyun, Hurrem Turan; Akkoyun, Mahire; Ciftci, Mehmet
    In this study, we investigated the effect of astaxanthin (Ast) and aluminum (Al) on the erythrocyte glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) enzymes activities in vivo and on G6PD enzyme in vitro in rats. For in vitro studies, G6PD enzyme was purified from rat erythrocyte by using 2,5-ADP-Sepharose 4B affinity gel. The effects of Ast and Al3+ ion were investigated on the purified enzyme. It was determined that Ast increased the enzyme activity, whereas Al3+ inhibited the enzyme activity noncompetitively (IC50 values; 0.679mM, K-i values 1.32mM). For in vivo studies, the rats were divided into the groups: control (Cont.), Al, Ast, and Al+Ast. The last three groups were compared with the control group. In Al group, a significant degree of inhibition was observed in the activity of G6PD and 6PGD enzymes when compared with the control group (P<0.05), whereas there was an increase in the activities of G6PD and 6PGD enzymes in Ast and Al+Ast groups (P<0.05).
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    Inhibitory properties of some heavy metals on carbonic anhydrase I and II isozymes activities purified from Van Lake fish (Chalcalburnus Tarichi) gill
    (Springer, 2018) Kuzu, Muslum; Comakli, Veysel; Akkemik, Ebru; Ciftci, Mehmet; Kufrevioglu, Omer Irfan
    In this study, CA I and II isoenzymes were purified from Van Lake fish gills by using Sepharose-4B-L-tyrosine-sulfanilamide affinity chromatography and to determine the effects of some metals on the enzyme activities. For purified CA I isoenzyme, yield, specific activity, and purification fold were obtained as 42.07%, 4948.12 EU/mg protein, and 116.61 and for CA II isoenzyme, 7%, 1798.56 EU/mg protein, and 42.38 respectively. Activity of CA was determined by measuring CO2-hydratase activity. Purity control was checked by SDS-PAGE. In vitro inhibitory effect of Cu2+, Ag+, Cd2+, Ni2+ metal ions, and arsenic (V) oxide were also examined for both isozymes activities. Whereas Cu2+, Ag+, Cd2+, and Ni2+ ions showed inhibitory effects on both isozymes, arsenic (V) oxide showed activation effect. IC50 values were calculated by drawing activity %-[I] graphs for metal ions exhibiting inhibitory effects. IC50 values were determined as 3.39, 6.38, 13.52, and 206 mu M for CA I isozyme and 6.16, 20.29, 46, and 223 mu M for CA II isozyme respectively.
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    The effect of astaxanthin and cadmium on rat erythrocyte G6PD, 6PGD, GR, and TrxR enzymes activities in vivo and on rat erythrocyte 6PGD enzyme activity in vitro
    (Wiley, 2018) Akkoyun, Mahire Bayramoglu; Bengu, A. Sukru; Temel, Yusuf; Akkoyun, H. Turan; Ekin, Suat; Ciftci, Mehmet
    In this study, the effects of astaxanthin (AST) that belongs to carotenoid family and cadmium (Cd), which is an important heavy metal, on rat erythrocyte G6PD, 6PGD, GR, and TrxR enzyme activities in vivo and on rat erythrocyte 6PGD enzyme activity in vitro were studied. In in vitro studies, 6PGD enzyme was purified from rat erythrocytes with 2',5'-ADP Sepharose4B affinity chromatography. Results showed inhibition of enzyme by Cd at IC50; 346.5 mu M value and increase of 6PGD enzyme activity by AST. In vivo studies showed an increase in G6PD, 6PGD. and GR enzyme activities (P > 0.05) and no chance in TrxR enzyme activity by AST. Cd ion inhibited GbPD, 6PGD, and GR enzyme activities (P < 0.05) and also decreased TrxR enzyme activity (P > 0.05). AST + Cd group G6PD enzyme activity was statistically low compared with control group (P < 0.05). 6PGD and TrxR enzyme activities decreased without statistical significance (P > 0.05); however, GR enzyme activity increased statistically significantly (P < 0.05).