Browsing by Author "Beydemir, Sukru"

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Antioxidant and Antiradical Properties of Selected Flavonoids and Phenolic Compounds
(Hindawi Ltd, 2017) Huyut, Zubeyir; Beydemir, Sukru; Gulcin, Ilhami
Phenolic compounds and flavonoids are known by their antioxidant properties and one of the most important sources for humans is the diet. Due to the harmful effects of synthetic antioxidants such as BHA and BHT, natural novel antioxidants have become the focus of attention for protecting foods and beverages and reducing oxidative stress in vivo. In the current study, we investigated the total antioxidant, metal chelating, Fe3+ and Cu2+ reduction, and free radical scavenging activities of some phenolic and flavonoid compounds including malvin, oenin, ID-8, silychristin, callistephin, pelargonin, 3,4-dihydroxy-5-methoxybenzoic acid, 2,4,6-trihydroxybenzaldehyde, and arachidonoyl dopamine. The antioxidant properties of these compounds at different concentrations (10-30 mu g/mL) were compared with those of reference antioxidants such as BHA, BHT, alpha-tocopherol, and trolox. Each substance showed dose-dependent antioxidant activity. Furthermore, oenin, malvin, arachidonoyl dopamine, callistephin, silychristin, and 3,4-dihydroxy-5-methoxybenzoic acid exhibited more effective antioxidant activity than that observed for the reference antioxidants. These results suggest that these novel compounds may function to protect foods and medicines and to reduce oxidative stress in vivo.
The Effects of Some Cephalosporins on Acetylcholinesterase and Glutathione S-Transferase: an in Vivo and in Vitro Study
(Taylor & Francis Ltd, 2019) Turkan, Fikret; Huyut, Zubeyir; Demir, Yeliz; Ertas, Fatma; Beydemir, Sukru
Background: Glutathione S-transferase (GST) and acetylcholinesterase (AChE) are important enzymes in the metabolism. GSTs are primarily available in phase II metabolism. AChE is vital for neurodegenerative disorders. Subjects and methods: The in vitro and in vivo effects of cefoperazone sodium (CFP), cefuroxime (CXM), and cefazolin (CZO) were investigated on GST and AChE activity in the present study. GST was purified using Glutathione-Agarose affinity chromatography. Results: K-i constants of CFP, CXM, and CZO were 0.1392 +/- 0.02, 1.5179 +/- 0.33, and 1.006 +/- 0.11 mM for GST and 0.3010 +/- 0.07, 0.3561 +/- 0.09, and 0.3844 +/- 0.04 mM, for AChE, respectively. The most effective inhibitor was CFP for both enzymes in in vitro. CZO (50 mg/kg), CXM (25 mg/kg), and CFP (100 mg/kg) inhibit in vivo GST and AChE activities. CXM had the most effective in vivo inhibition on AChE and GST. Conclusions: CZO, CXM, and CFP are effective AChE and GST inhibitors in both in vitro and in vivo.
Inhibition Properties of Some Flavonoids on Carbonic Anhydrase I and Ii Isoenzymes Purified From Human Erythrocytes
(Wiley, 2017) Huyut, Zubeyir; Beydemir, Sukru; Gulcin, Ilhami
Carbonic anhydrases (CAs, E.C.4.2.1.1) play a critical role in many important physiological events and treatment of some diseases. Flavonoids or phenolic compounds have been discovered as novel CAs inhibitors instead of the traditional sulfonamides, with different binding to CAs, pro-drug activities, and new inhibition mechanisms. Here, we investigated the inhibition effects of some flavonoids including malvin, callistephin, oenin, pelargonin, silychristin, and 1-(4-methoxyphenyl)-2-methyl-3-nitro-1-H-indol-6-ol (ID-8) against hCA I and II, which purified from human erythrocytes by affinity column chromatography. Both hCA isoenzymes were inhibited by flavonoids, with IC50 and K-i values in the range of 2.34nM to 346.5M and 51.01-99.55M for hCA I and 86.60-750.00M for hCA II, respectively. These results showed that flavonoids especially malvin and oenin effectively inhibited hCA I and II isoenzymes. Hence, they may be used as an effective CA inhibitor in medical applications for treatment of certain diseases such as glaucoma, in the future.
Inhibitory Effects of Some Phenolic Compounds on the Activities of Carbonic Anhydrase: From in Vivo To Ex Vivo
(Taylor & Francis Ltd, 2016) Huyut, Zubeyir; Beydemir, Sukru; Gulcin, Ilhami
Carbonic anhydrase (CA) inhibitors have been used for more than 60 years for therapeutic purposes in many diseases table such as in medications against antiglaucoma and as diuretics. Phenolic compounds are a new class of CA inhibitor. In our study, we tested the effects of arachidonoyl dopamine, 2,4,6-trihydroxybenzaldehyde and 3,4-dihydroxy-5-methoxybenzoic acid on esterase and the CO2-hydratase activities of CA I and II isozymes purified from in vivo to ex vivo. The K-i values of arachidonoyl dopamine, 2,4,6-trihydroxybenzaldehyde and 3,4-dihydroxy-5-methoxybenzoic acid were 203.80, 1170.00 and 910.00 mu M, respectively for hCA I and 75.25, 354.00 and 1510.00 mu M, respectively for hCA II. Additionally, IC50 values from in vivo studies were found to be in the range of 173.25-1360.0 mu M for CA I and II, respectively, using CO2-hydratase activity methods. These results demonstrated that phenolic compounds used in in vivo studies could be used in different biomedical applications to inhibit approximately 30% of the CO2-hydratase activity of the total CA enzyme of rat erythrocytes.