Oktay Yıldız

Prof. Oktay Yıldız

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2013 in Journal of Enzyme Inhibition and Medicinal Chemistry
Verified
Journal Article
Closed access
OYOktay Yıldız
Oktay Yıldız
FKFatma YAYLACI KARAHALİL
Fatma YAYLACI KARAHALİL
ZCZ. Can
Z. Can
Huseyin SahinHuseyin Sahin
Huseyin Sahin
SKS. Kolayli
S. Kolayli
Monoamine oxidase (MAO) inhibitors are generally used in the treatment of depressive disorders and some neurodegenerative illnesses, such as Parkinson’s disease and Alzheimer’s disease. The aim of this preliminary study was to investigate the MAO [MAO (E.C.1.4.3.4)] inhibiting effect of various apitherapeutic products, such as chestnut honey, pollen and propolis. Extracts’ MAO inhibition was measured using peroxidase-linked spectrophotometric assay in enzyme isolated from rat liver microsomes, and the values are expressed as the inhibition concentration (IC50) causing 50% inhibition of MAO. The antioxidant activity of the bee products was also determined in terms of total phenolic content (TPC) and ferric reducing/antioxidant power in aquatic extracts. All samples exhibited substantial inhibition of MAO, propolis having the highest. Inhibition was related to samples’ TPCs and antioxidant capacities. These results show that bee products possess a sedative effect and may be effective in protecting humans against depression and similar diseases.

13 February 2018 in Turkish Journal of Biochemistry
Verified
Journal Article
Closed access
PDF file
SKSevgi Kolaylı
Sevgi Kolaylı
ZCZehra Can
Zehra Can
HÇHilal Ebru Çakir
Hilal Ebru Çakir
TTTrabzon Turkey
Trabzon Turkey
OYOktay Yıldız
Oktay Yıldız
Objective: The purpose of this study was therefore to investigate various physicochemical properties, phenolic composition and antioxidant capacities of the oak honey, large quantities of which are produced in the Thrace region of Northwest Turkey. Methods: Hunter color values (Lab), optical rotation, electrical conductivity, moisture and ash were measured as physicochemical determinants. Sugar, proline content, mineral, phenolic acids, total phenolic flavonoids contents were evaluated as chemical parameters. Ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging were used as antioxidant determinants. Results: The results determined that dark-colored honeys (mean 24.95±8.35 L) have proline levels (649.82±203.90 mg/kg), total phenolic content (TPC) (67.29±13.10 mgGAE/100 g) and total flavonoid content (TFC) (10.14±4.78 mgQE/100 g), a high ratio of fructose/glucose (1.65±0.18). Rutin (11.14±8.50 μg/g), p -coumaric acid (6.97±5.80 μg/g) and protocatechuic acid (6.12±4.39 μg/g) were the major phenolic components, and quercetin was also detected in varying amounts in all samples. Potassium (2523±0.28 mg/kg), calcium (63.40±3.20 mg/kg) and magnesium (38.88±0.65 mg/kg) were the major minerals in the honeys. Conclusion: Our results showed that physicochemical properties, phenolic compounds, antioxidant capacity, sugar and mineral contents successfully distinguish the geographical origins of oak honey. These findings will contribute to a more accurate evaluation of oak honey in the literature.

16 May 2022 in European Food Research and Technology
Verified
Journal Article
Closed access
PDF file
OYOktay Yıldız
Oktay Yıldız
HGHacer Gürkan
Hacer Gürkan
DSdidem Sahingil
didem Sahingil
ADAtiye Değirmenci
Atiye Değirmenci
MKMehtap Er Kemal
Mehtap Er Kemal
AHAli Adnan Hayaloglu
Ali Adnan Hayaloglu

30 August 2021 in TURKISH JOURNAL OF BIOLOGY
Verified
Journal Article
Open access
Halil Ibrahim GülerHalil Ibrahim Güler
Halil Ibrahim Güler
FŞFulya Ay Şal
Fulya Ay Şal
ZCZehra Can
Zehra Can
YKYakup KARA
Yakup KARA
OYOktay Yıldız
Oktay Yıldız
SKSevgi Kolaylı
Sevgi Kolaylı
Propolis is a multi-functional bee product rich in polyphenols. In this study, the inhibitory effect of Anatolian propolis against SARS-coronavirus-2 (SARS-CoV-2) was investigated in vitro and in silico. Raw and commercial propolis samples were used, and both samples were found to be rich in caffeic acid, p-coumaric acid, ferulic acid, t-cinnamic acid, hesperetin, chrysin, pinocembrin, and caffeic acid phenethyl ester (CAPE) at HPLC-UV analysis. Ethanolic propolis extracts (EPE) were used in the ELISA screening test against the spike S1 protein (SARS-CoV-2): ACE-2 interaction for in vitro study. The binding energy values of these polyphenols to the SARS-CoV-2 spike and ACE-2 protein were calculated separately with a molecular docking study using the AutoDock 4.2.6 program. In addition, the pharmacokinetics and drug-likeness properties of these eight polyphenols were calculated according to the SwissADME tool. The binding energy value of pinocembrin was highest in both receptors, followed by chrysin, CAPE, and hesperetin. Based on the in silico modeling and ADME (absorption, distribution, metabolism, and excretion) behaviors of the eight polyphenols, the compounds exhibited the potential ability to act effectively as novel drugs. The findings of both studies showed that propolis has a high inhibitory potential against the Covid-19 virus. However, further studies are now needed.

15 June 2015 in Journal of Enzyme Inhibition and Medicinal Chemistry
Verified
Journal Article
Open access
SKSevgi Kolaylı
Sevgi Kolaylı
Huseyin SahinHuseyin Sahin
Huseyin Sahin
ZCZehra Can
Zehra Can
OYOktay Yıldız
Oktay Yıldız
KSKübra Sahin
Kübra Sahin
The purpose of this study was to investigate the anti-hyaluronidase activities of honeys from different botanical origins honeys in order to determine their anti-inflammatory properties. The total phenolic contents, total flavonoids and total tannin levels of six types of honey, chestnut, oak, heather, pine, buckwheat and mixed blossom, were determined. Concentration-related inhibition values were tested turbidimetrically on bovine testis hyaluronidase (BTHase) as IC50 (mg/mL). All honeys exhibited various concentration-dependent degrees of inhibition against BTHase. Inhibition values varied significantly depending on honeys' levels of phenolic contents, flavonoid and tannin. The honeys with the highest anti-hyaluronidase activity were oak, chestnut and heather. In conclusion, polyphenol-rich honeys have high anti-hyaluronidase activity, and these honeys have high protective and complementary potential against hyaluronidase-induced anti-inflammatory failures.