Browsing by Author "Ceylan O."

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    Phenolic composition, antioxidant and enzyme inhibitory activities of acetone, methanol and water extracts of Clinopodium vulgare L. subsp. vulgare L.
    (Elsevier, 2015) Sarikurkcu C.; Ozer M.S.; Tepe B.; Dilek E.; Ceylan O.
    The aim of this study is to evaluate the antioxidant and enzyme inhibitory activities of acetone, methanol and water extracts of Clinopodium vulgare L. subsp. vulgare L. as well as its phytochemical composition. Methanol extract was found rich in of phenolic compounds (44.42. mg GAEs/g extract) whereas the highest flavonoid content was determined in the water extract (40.20. mg REs/g extract). Methanol extract was also found rich in protocatechuic acid, (+)-catechin, chlorogenic acid, caffeic acid, ferulic acid, rosmarinic acid and apigenin. Data obtained from the phosphomolybdenum assay was found in correlation with those obtained from total phenolic assay. Methanol extract exhibited the highest activity (374.86. mmol TEs/g extract). In the case of chelating effect assay, acetone extract exhibited the highest activity. As observed in many previously reported studies, water extract exhibited the highest DPPH free radical scavenging activity (81.72. mg TEs/g extract). ABTS cation scavenging assay was resulted in the superiority of methanol extract (51.45. mg TEs/g extract). It also showed the strongest reducing power in CUPRAC and FRAP assays. Acetone extract exhibited remarkable inhibitory activity on acetylcholinesterase, butyrylcholinesterase and tyrosinase, while the highest α-amylase and α-glucosidase inhibitory activities were exhibited by methanol and water extracts. Total amounts of unsaturated fatty acids were determined as 51.15%. C18:1 ω9, C18:2 ω6 and C18:3 ω3 were determined in considerable quantities (23.93, 6.18 and 5.78%, respectively). © 2015 Elsevier B.V.
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    A nationwide multicentre study in Turkey for establishing reference intervals of haematological parameters with novel use of a panel of whole blood
    (Biochemia Medica, Editorial Office, 2017) Ozarda Y.; Ichihara K.; Bakan E.; Polat H.; Ozturk N.; Baygutalp N.K.; Taneli F.; Guvenc Y.; Ormen M.; Erbayraktar Z.; Aksoy N.; Sezen H.; Demir M.; Eskandari G.; Polat G.; Mete N.; Yuksel H.; Vatansev H.; Gun F.; Akin O.; Ceylan O.; Noyan T.; Gozlukaya O.; Aliyazicioglu Y.; Kahraman S.; Dirican M.; Tuncer G.O.; Kimura S.; Eker P.
    Introduction: A nationwide multicentre study was conducted to establish well-defined reference intervals (RIs) of haematological parameters for the Turkish population in consideration of sources of variation in reference values (RVs). Materials and methods: K2-EDTA whole blood samples (total of 3363) were collected from 12 laboratories. Sera were also collected for measurements of iron, UIBC, TIBC, and ferritin for use in the latent abnormal values exclusion (LAVE) method. The blood samples were analysed within 2 hours in each laboratory using Cell Dyn and Ruby (Abbott), LH780 (Beckman Coulter), or XT-2000i (Sysmex). A panel of freshly prepared blood from 40 healthy volunteers was measured in common to assess any analyser-dependent bias in the measurements. The SD ratio (SDR) based on ANOVA was used to judge the need for partitioning RVs. RIs were computed by the parametric method with/without applying the LAVE method. Results: Analyser-dependent bias was found for basophils (Bas), MCHC, RDW and MPV from the panel test results and thus those RIs were derived for each manufacturer. RIs were determined from all volunteers’ results for WBC, neutrophils, lymphocytes, monocytes, eosinophils, MCV, MCH and platelets. Gender-specific RIs were required for RBC, haemoglobin, haematocrit, iron, UIBC and ferritin. Region-specific RIs were required for RBC, haemoglobin, haematocrit, UIBC, and TIBC. Conclusions: With the novel use of a freshly prepared blood panel, manufacturer-specific RIs’ were derived for Bas, Bas%, MCHC, RDW and MPV. Regional differences in RIs were observed among the 7 regions of Turkey, which may be attributed to nutritional or environmental factors, including altitude. © by Croatian Society of Medical Biochemistry and Laboratory Medicine.
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    A comprehensive study on chemical composition, antioxidant and enzyme inhibition activities of the essential oils of Chenopodium botrys collected from three different parts of Turkey
    (Elsevier B.V., 2017) Ozer M.S.; Sarikurkcu C.; Ceylan O.; Akdeniz I.; Tepe B.
    In this study, we aimed to evaluate the chemical composition of the essential oil of Chenopodium botrys L. collected from three different parts of Turkey. Additionally, we analyzed the antioxidant activities of the oil samples by using free radical scavenging, phosphomolybdenum, ferrous ion chelating, and reducing power assays as well as their inhibitory activities on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase. According to the results of GC-FID and GC–MS analyses, twenty-seven, twenty-four, and sixteen compounds were identified representing 94.45%, 96.96%, and 94.41% of the oils, respectively. In Afyonkarahisar and Isparta samples, ledol (25.11% and 22.73%), elemol (15.25% and 24.86%), and germacrene D-4-ol (14.83% and 11.27%) were determined as the major compounds, whereas ledol (31.83%), elemol (23.70%), and eudesm-7(11)-en-4-ol (8.94%) were found as the main compounds of Konya sample. The oil of Isparta sample showed the maximum radical scavenging activity in all test systems, except superoxide anion radical scavenging assay. Phosphomolybdenum, ferrous ion chelating, and reducing power assays were resulted in the superiority of Afyonkarahisar sample. In AChE and tyrosinase inhibition assays, the essential oil of C. botrys collected from Konya showed the maximum activity (0.87 mg GALAEs/g oil and 0.82 mg KAEs/g oil, respectively). On the other hand, BChE inhibition assay was resulted in the superiority of Afyonkarahisar sample (1.02 mg GALAEs/g oil). In order to determine the contribution of oil components to the biological activity, correlation coefficients between the compounds and assays were also presented. © 2017
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    Onosma heterophyllum: Phenolic composition, enzyme inhibitory and antioxidant activities
    (Elsevier B.V., 2018) Ozer M.S.; Kirkan B.; Sarikurkcu C.; Cengiz M.; Ceylan O.; Atılgan N.; Tepe B.
    Onosma species have frequently been used for their colouring and dyeing properties in foods and medicinal preparations. The antioxidant and enzyme inhibitory activities of the ethyl acetate, methanol and water extracts of Onosma heterophyllum (Griseb.) are described. Phytochemical compositions of these extracts were also determined. The water extract showed not only remarkable antioxidant activity in all assays but also considerable inhibitory activity on tyrosinase and α-glucosidase (112.44 μmol KAEs/g dry plant and 984.36 μmol ACEs/g dry plant, respectively). The methanol extract exhibited the highest inhibitory activity on acetylcholinesterase (AChE) and α-amylase (79.18 μmol GALAEs/g dry plant and 10.42 μmol ACEs/g dry plant, respectively). Chromatographic analyses revealed that the water extract was found to be rich in phenolic and flavonoid contents. On the basis of the correlation coefficients calculated separately for all experimental parameter pairs, protocatechuic acid, p-hydroxybenzoic acid, syringic acid, p-coumaric acid and luteolin were found to be highly in correlation with the antioxidant and enzyme inhibitory activities. This study demonstrates that O. heterophyllum, contained in food preparations with various purposes for many years, could be used for the treatment of diabetes as well as its skin whitening effect. © 2017 Elsevier B.V.
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    Chemical characterization and biological activity of Onosma gigantea extracts
    (Elsevier B.V., 2018) Sarikurkcu C.; Kirkan B.; Ozer M.S.; Ceylan O.; Atilgan N.; Cengiz M.; Tepe B.
    Onosma species have traditionally been used as laxative and anthelmintic agents as well as their uses in eye, blood diseases, bronchitis, abdominal pain, strangury, thirst, itch, leucoderma, fever, wounds, burns, piles, and urinary calculi. This study examines the investigation of biological activities of ethyl acetate, methanolic, and aqueous extracts from Onosma gigantea Lam. The extracts were evaluated for the antioxidant and enzyme inhibitory activities. Phenolic compounds in the extracts were also detected by RP-HPLC-DAD. The aqueous extract showed remarkable antioxidant activity in phosphomolybdenum [134.31 μmol trolox equivalents (TEs)/g air dry matter (adm)], chelating effect [32.97 μmol ethylenediaminetetraacetic acid (disodium salt) equivalents (EDTAEs)/g adm], radical scavenging [on DPPH (32.14 μmol TEs/g adm) and ABTS (58.68 μmol TEs/g adm)], and reducing power [CUPRAC (50.23 μmol TEs/g adm) and FRAP (40.96 μmol TEs/g adm)] assays. The aqueous extract also exhibited considerable inhibitory activity of tyrosinase (10.48 μmol kojic acid equivalents/g adm) and α-glucosidase [1320.53 μmol acarbose equivalents (ACEs)/g adm]. It has been determined that the methanolic extract showed significant AChE (31.57 μmol galanthamine equivalents (GALAEs)/g adm) and α-amylase (6.75 μmol ACEs/g adm) inhibitory activity. The ethyl acetate, which contains low polarity compounds, showed the highest BChE inhibitory activity (6.87 μmol GALAEs/g adm). In general, it is found that there is a positive correlation between the phytochemical contents of the extracts and their biological activities. The results indicate that O. gigantea extracts could be considered as a novel source of bioactive agents with functional connections. © 2018 Elsevier B.V.
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    Phenolic profile, antioxidant and enzyme inhibitory potential of Onosma tauricum var. tauricum
    (Elsevier B.V., 2018) Kirkan B.; Sarikurkcu C.; Ozer M.S.; Cengiz M.; Atılgan N.; Ceylan O.; Tepe B.
    This study focused on phytochemical characterization and biological evaluation, both antioxidant and enzymatic inhibition, of ethyl acetate (OTT-EtOAc), methanol (OTT-MeOH), and water (OTT-W) extracts from Onosma tauricum var. tauricum aerial parts. The OTT-W extract was found to be the richest one in terms of its phenolic and flavonoid contents. Amounts of the phenolic and flavonoid compounds were determined as 40.88 μmol GAEs/g and 7.40 μmol REs/g dry plant (dp), respectively. The OTT-MeOH and OTT-W extracts were also found to contain significant amounts of chlorogenic acid, rosmarinic acid, p-hydroxybenzoic acid, caffeic acid, rutin, p-coumaric acid, trans-cinnamic acid, luteolin, and apigenin. The OTT-W extract showed remarkable antioxidant activity in phosphomolybdenum, ferrous ion chelating, reducing power, and radical scavenging assays. The OTT-MeOH extract exhibited inhibitory activity on acetylcholinesterase (AChE) (54.62 μmol GALAEs/g dp), while the extracts remained almost inactive on butyrylcholinesterase (BChE). The OTT-W extract also exhibited inhibitory activity on tyrosinase (90.66 μmol KAEs/g dp) and α-glucosidase (2258.87 μmol ACEs/g dp). The results suggest that especially the OTT-MeOH and OTT-W extracts can be used as a source of alternative natural products in the treatment of diseases caused by the enzymes evaluated here. © 2018 Elsevier B.V.
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    Chemical composition and biological activities of the essential oils of two endemic Nepeta species
    (Elsevier B.V., 2018) Sarikurkcu C.; Ceylan O.; Targan S.; Ćavar Zeljković S.
    The chemical composition, antioxidant activity and several enzyme inhibitions of the essential oils of two endemic Nepeta species, N. nuda subsp. glandulifera and N. cadmea were investigated for the first time. The major compounds of N. nuda subsp. glandulifera essential oil were geijerene (61.02%) and neointermedeol (6.07%). On contrary, essential oil of N. cadmea contained 70.94% of 4aβ,7α,7aβ-nepetalactone. The oil of N. nuda subsp. glandulifera revealed better activity than the oil of N. cadmea against both reducing metal ions and radicals. Moreover, both oils have relatively weak but still noticeable activity against acetylcholinesterase and butyrylcholinesterase; weak activity against α-glucosidase, but quite high activity against α-amylase. On the other hand, both essential oils showed significant activity against tyrosinase. Presented results suggest that these two endemic species have strong potential to be used in food and pharmacological industries, and therefore they should to be investigated further. © 2018 Elsevier B.V.
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    LC-MS/MS profiles and interrelationships between the enzyme inhibition activity, total phenolic content and antioxidant potential of Micromeria nervosa extracts
    (Elsevier Ltd, 2020) Sarikurkcu C.; Andrade J.C.; Ozer M.S.; de Lima Silva J.M.F.; Ceylan O.; de Sousa E.O.; Coutinho H.D.M.
    The objective of this study was to quantify the phenolic compounds and to evaluate and compare the biological activities of the ethyl acetate (EtOAc), methanolic (MeOH) and aqueous extracts from the Micromeria nervosa aerial parts, based on their antioxidant activity and enzymatic inhibition. Total phenolic and flavonoid contents were calculated and individual compo3unds were detected using LC-ESI-MS/MS. The antioxidant activity was determined using six different assays while enzymatic activity was determined by α-amylase and tyrosinase enzyme inhibition. The main phenolic constituents detected in the extracts were rosmarinic acid. In the antioxidant assays the aqueous extract was shown to be more efficient than the others. The EtOAc and MeOH extracts presented higher inhibitory activity with respect to α-amylase and tyrosinase. Regardless of the solvent, the results suggest M. nervosa aerial extracts present a biological potential due to their antioxidant activity and enzymatic inhibition. © 2020 Elsevier Ltd
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    Phenolic composition and biological activities of Turkish endemic plant: Stachys cretica subsp. kutahyensis
    (Elsevier B.V., 2021) Benabderrahim M.A.; Sarikurkcu C.; Elfalleh W.; Ozer M.S.; Ceylan O.
    Stachys cretica L. subsp. kutahyensis is a Turkish endemic plant specie and used in flock medicine against many diseases. To our knowledge, no data are available on the chemical composition and the biological activities of this plant. In this study, the phytochemical composition, the enzyme inhibition and antioxidant activity of this specie were assessed. The Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC–ESI–MS) analysis allowed the determination of 26 phenolic compounds with predominance of chlorogenic acid and verbascoside. The concentration of phenolic acids and flavonoid compounds significantly changed according to solvent used (water and methanol). From five different methods used, the antioxidant activity was important and significantly different between extracts for ferrous ion chelating and ABTS assays where the aqueous extract expressed higher antioxidant activity. However, interesting enzyme inhibition activities were observed for the extracts of S. cretica subsp. kutahyensis using α-amylase and tyrosinase. The highest α-amylase and tyrosinase inhibition activities were recorded with the methanol extract. The results confirm that S. cretica subsp. kutahyensis could be used as valuable new natural source with beneficial biological properties for food and pharmacology applications. © 2020 SAAB
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    Onosma demirizii: Chemical composition, antioxidant and enzyme inhibitory activity
    (John Wiley and Sons Inc, 2024) Ozer M.S.; Karan R.C.; Ceylan O.; Sarikurkcu C.; Sihoglu Tepe A.; Aboul-Soud M.A.M.; Ghneim H.K.
    The primary objectives of the present work were to determine the chemical composition, antioxidant potential and enzyme inhibitory activity of three extracts derived from Onosma demirizii (Boraginaceae), including methanol, water and ethyl acetate, and to chemically characterize the phytochemicals underlying this activity. A rapid, reproducible, simple, and sensitive method, which had been previously validated, was employed to identify 31 phenolics based on liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The conducted analysis of LC-ESI-MS/MS indicated that the methanol extract of O. demirizii was the richest in terms of both flavonoids and phenolics (42.75 mg GAEs/g extract and 59.90 mg QEs/g extract, respectively). The compounds with greatest abundance in methanol extract were hesperidin (177957 mg/g extract), chlorogenic acid (31815 mg/g extract), hyperoside (10199 mg/g extract), rosmarinic acid (8857 mg/g extract) and pinoresinol (2502 mg/g extract). Moreover, methanol extract exhibited the greatest activity in all antioxidant assays except for ferrous ion-chelating assay. The EC50/IC50 values of the extract in CUPRAC and FRAP reducing power, phosphomolybdenum, DPPH and ABTS radical scavenging assays were determined to be 0.85, 1.47, 0.47, 1.78, and 1.67 mg/mL, respectively. However, the ferrous ion-chelating assay was superior for water extract (1.07 mg/mL). Contrary to the results obtained from the assays of antioxidant activity, ethyl acetate extract was observed to be effective in enzymatic inhibition tests. The extract exhibited the highest activity against AChE and BChE (IC50 values 1.04 and 1.47 mg/mL, respectively). These extracts and compounds can be useful for the management of human diseases that are linked to oxidative stress. © 2024 Wiley-VCH GmbH.