LEYLA GÜVEN

Dr. LEYLA GÜVEN

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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11 February 2023 in Molecules
Verified
Journal Article
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HKHasan Karageçili
Hasan Karageçili
Mustafa Abdullah YILMAZMustafa Abdullah YILMAZ
Mustafa Abdullah YILMAZ
AEAdem Ertürk
Adem Ertürk
HKHatice Kızıltaş
Hatice Kızıltaş
LGLEYLA GÜVEN
LEYLA GÜVEN
Ilhami GulcinIlhami Gulcin
Ilhami Gulcin
Propolis is a complex natural compound that honeybees obtain from plants and contributes to hive safety. It is rich in phenolic and flavonoid compounds, which contain antioxidant, antimicrobial, and anticancer properties. In this study, the chemical composition and antioxidant activities of propolis were investigated; ABTS•+, DPPH• and DMPD•+ were prepared using radical scavenging antioxidant methods. The phenolic and flavonoid contents of propolis were 53 mg of gallic acid equivalent (GAE)/g and 170.164 mg of quercetin equivalent (QE)/g, respectively. The ferric ion (Fe3+) reduction, CUPRAC and FRAP reduction capacities were also studied. The antioxidant and reducing capacities of propolis were compared with those of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and Trolox reference standards. The half maximal inhibition concentration (IC50) values of propolis for ABTS•+, DPPH• and DMPD•+ scavenging activities were found to be 8.15, 20.55 and 86.64 μg/mL, respectively. Propolis extract demonstrated IC50 values of 3.7, 3.4 and 19.6 μg/mL against α-glycosidase, acetylcholinesterase (AChE) and carbonic anhydrase II (hCA II) enzyme, respectively. These enzymes’ inhibition was associated with diabetes, Alzheimer’s disease (AD) and glaucoma. The reducing power, antioxidant activity and enzyme inhibition capacity of propolis extract were comparable to those demonstrated by the standards. Twenty-eight phenolic compounds, including acacetin, caffeic acid, p-coumaric acid, naringenin, chrysin, quinic acid, quercetin, and ferulic acid, were determined by LC-MS/MS to be major organic compounds in propolis. The polyphenolic antioxidant-rich content of the ethanol extract of propolis appears to be a natural product that can be used in the treatment of diabetes, AD, glaucoma, epilepsy, and cancerous diseases.

11 September 2022 in Molecules
Verified
Journal Article
Open access
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LDLokman Durmaz
Lokman Durmaz
HKHatice Kızıltaş
Hatice Kızıltaş
LGLEYLA GÜVEN
LEYLA GÜVEN
HKHasan Karageçili
Hasan Karageçili
SASaleh Alwasel
Saleh Alwasel
Ilhami GulcinIlhami Gulcin
Ilhami Gulcin
Magnofluorine, a secondary metabolite commonly found in various plants, has pharmacological potential; however, its antioxidant and enzyme inhibition effects have not been investigated. We investigated the antioxidant potential of Magnofluorine using bioanalytical assays with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD•+), and 1,1-diphenyl-2-picrylhydrazyl (DPPH•) scavenging abilities and K3[Fe(CN)6] and Cu2+ reduction abilities. Further, we compared the effects of Magnofluorine and butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-Tocopherol, and Trolox as positive antioxidant controls. According to the analysis results, Magnofluorine removed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with an IC50 value of 10.58 μg/mL. The IC50 values of BHA, BHT, Trolox, and α-Tocopherol were 10.10 μg/mL, 25.95 μg/mL, 7.059 μg/mL, and 11.31 μg/mL, respectively. Our results indicated that the DPPH· scavenging effect of Magnofluorine was similar to that of BHA, close to that of Trolox, and better than that of BHT and α-tocopherol. The inhibition effect of Magnofluorine was examined against enzymes, such as acetylcholinesterase (AChE), α-glycosidase, butyrylcholinesterase (BChE), and human carbonic anhydrase II (hCA II), which are linked to global disorders, such as diabetes, Alzheimer’s disease (AD), and glaucoma. Magnofluorine inhibited these metabolic enzymes with Ki values of 10.251.94, 5.991.79, 25.411.10, and 30.563.36 nM, respectively. Thus, Magnofluorine, which has been proven to be an antioxidant, antidiabetic, and anticholinergic in our study, can treat glaucoma. In addition, molecular docking was performed to understand the interactions between Magnofluorine and target enzymes BChE (D: 6T9P), hCA II (A:3HS4), AChE (B:4EY7), and α-glycosidase (C:5NN8). The results suggest that Magnofluorine may be an important compound in the transition from natural sources to industrial applications, especially new drugs.

28 April 2023 in Pharmaceuticals
Verified
Journal Article
Open access
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LGLEYLA GÜVEN
LEYLA GÜVEN
AEAdem Erturk
Adem Erturk
FMFatma Demirkaya Miloglu
Fatma Demirkaya Miloglu
SASaleh Alwasel
Saleh Alwasel
Ilhami GulcinIlhami Gulcin
Ilhami Gulcin
Astragalus species are traditionally used for diabetes, ulcers, leukemia, wounds, stomachaches, sore throats, abdominal pain, and toothaches. Although the preventive effects of Astragalus species against diseases are known, there is no record of the therapeutic effects of Astragalus alopecurus. In this study, we aimed to evaluate the in vitro antiglaucoma, antidiabetic, anti-Alzheimer’s disease, and antioxidant activities of the methanolic (MEAA) and water (WEAA) extracts of the aerial part of A. alopecurus. Additionally, its phenolic compound profiles were analyzed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). MEAA and WEAA were evaluated for their inhibition ability on α-glycosidase, α-amylase, acetylcholinesterase (AChE), and human carbonic anhydrase II (hCA II) enzymes. The phenolic compounds of MEAA were analyzed by LC-MS/MS. Furthermore, total phenolic and flavonoid contents were determined. In this context, the antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), N,N-dimethyl-p-phenylene diamine (DMPD), ferric reducing antioxidant power (FRAP), cupric ions (Cu2+) reducing antioxidant capacity (CUPRAC), ferric ions (Fe3+) reducing, and ferrous ions (Fe2+) chelating methods. MEAA and WEAA had IC50 values of 9.07 and 2.24 μg/mL for α-glycosidase, 693.15 and 346.58 μg/mL for α-amylase, 1.99 and 2.45 μg/mL for AChE, and 147.7 and 171.7 μg/mL for hCA II. While the total phenolic amounts in MEAA and WEAA were 16.00 and 18.50 μg gallic acid equivalent (GAE)/mg extract, the total flavonoid contents in both extracts were calculated as 66.23 and 33.115 μg quercetin equivalent (QE)/mg, respectively. MEAA and WEAA showed, respectively, variable activities on DPPH radical scavenging (IC50: 99.02 and 115.53 μg/mL), ABTS radical scavenging (IC50: 32.21 and 30.22 µg/mL), DMPD radical scavenging (IC50: 231.05 and 65.22 μg/mL), and Fe2+ chelating (IC50: 46.21 and 33.01 μg/mL). MEAA and WEAA reducing abilities were, respectively, Fe3+ reducing (λ700: 0.308 and 0.284), FRAP (λ593: 0.284 and 0.284), and CUPRAC (λ450: 0.163 and 0.137). A total of 35 phenolics were scanned, and 10 phenolic compounds were determined by LC-MS/MS analysis. LC-MS/MS revealed that MEAA mainly contained isorhamnetin, fumaric acid, and rosmarinic acid derivatives. This is the first report indicating that MEAA and WEAA have α-glycosidase, α-amylase, AChE, hCA II inhibition abilities, and antioxidant activities. These results demonstrate the potential of Astragalus species through antioxidant properties and enzyme inhibitor ability traditionally used in medicine. This work provides the foundation for further research into the establishment of novel therapeutics for diabetes, glaucoma, and Alzheimer’s disease.

1 January 2016 in South African Journal of Botany
Verified
Journal Article
Open access
Fatma Sezer Senol DenizFatma Sezer Senol Deniz
Fatma Sezer Senol Deniz
IOIlkay Erdogan Orhan
Ilkay Erdogan Orhan
UOUfuk Ozgen
Ufuk Ozgen
GRGulin Renda
Gulin Renda
GBGokhan Bulut
Gokhan Bulut
NSNazim Sekeroglu
Nazim Sekeroglu

25 March 2024 in Records of Natural Products
Verified
Journal Article
Closed access
LGLEYLA GÜVEN
LEYLA GÜVEN
AEAdem Ertürk
Adem Ertürk
Mustafa Abdullah YILMAZMustafa Abdullah YILMAZ
Mustafa Abdullah YILMAZ
SASaleh Alwasel
Saleh Alwasel
Ilhami GulcinIlhami Gulcin
Ilhami Gulcin
Alchemilla species (Rosaceae) are popularly known as ‘Lady’s Mantle, Lion’s claw’ and are used for medicinal purposes as diuretic, laxative, tonic, and wound healing agents. Bioactivities and phenolic content of Alchemilla pseudocartalinica Juz. species have yet to be investigated. Our research focused on assessing the antioxidant characteristics of A. pseudocartalinica methanol (MEAP) and water extracts (WEAP), as well as their inhibitory effects on acetylcholinesterase (AChE), α-glycosidase (α-gly), and human carbonic anhydrase II (hCA II) enzymes. Additionally, we conducted chemical characterization using UPLC-MS/MS and investigated the correlation between major phenolic compounds and enzymes through molecular docking analysis. To assess the antioxidant activities of the MEAP and WEAP, six test systems were employed, including DPPH, ABTS, DMPD, FRAP, CUPRAC, and Fe3+ reducing assays. The outcome showed that the methanol extract of the plant generally has stronger antioxidant activity. In addition, UPLC-MS/MS analysis indicated, miquelianin (44.095 mg/g), quinic acid (17.054 mg/g), and ellagic acid (6.492 mg/g) were significant in the methanol extract. A molecular docking study revealed a significant affinity for binding between the hCAII enzyme and quinic acid, miquelianin, and AChE/α-gly enzymes. A. pseudocatalinica methanol and water extracts have high antioxidant activity and good inhibition effect against AChE, α-glycosidase, and hCA II enzymes.

9 January 2024 in South African Journal of Botany
Verified
Journal Article
Open access
LGLEYLA GÜVEN
LEYLA GÜVEN
HCHasan Can
Hasan Can
AEAdem Ertürk
Adem Ertürk
FMFatma Demirkaya Miloğlu
Fatma Demirkaya Miloğlu
MKMehmet Koca
Mehmet Koca
Ilhami GulcinIlhami Gulcin
Ilhami Gulcin