Browsing by Author "Ozbilgin, Ahmet"

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Antileishmanial Activity of Selected Turkish Medicinal Plants
(PHARMACOTHERAPY GROUP, 2014-01-01) Ozbilgin, Ahmet; Durmuskahya, Cenk; Kayalar, Husniye; Ertabaklar, Hatice; Gunduz, Cumhur; Ural, Ipek Ostan; Zeyrek, Fadile; Kurt, Ozgur; Cavus, Ibrahim; Balcioglu, Cuneyt; Toz, Seray Ozensoy; Ozbel, Yusuf
Purpose: To determine the in vitro and in vivo anti-leishmanial activities of extracts obtained from Centaurea calolepis, Phlomis lycia, Eryngium thorifolium, Origanum sipyleum and Galium incanum ssp. centrale. Methods: To estimate the cytotoxicity of plant extracts, WST-1 assay was used. Parasite inhibition in the presence of plant extracts (25 - 500 mu g/ml) in comparision with control group and reference group (glucantime, 25 mu g/ml) at 12 - 72 h were determined in vitro on L. tropica promastigotes. The in vivo leishmanicidal activity of the extracts was evaluated against L. tropica-infected mice with glucantime as reference drug. Results: The chloroform extract of Galium incanum ssp. centrale showed the highest cytotoxicity with IC50 value of 0.0316 +/- 0.005 mu g/ml. In vitro parasite inhibition by the plant extracts ranged between 16.7 +/- 0.01 \% and 100 +/- 0.00 \% at 25 mu g/ml concentration. The methanol extract of Eryngium thorifolium possessed the highest activity on promastigotes of L. tropica with 100 \% inhibition at 25 mu g/ml. The water and chloroform extracts of C. calolepis and water and methanol extracts of E. thorifolium at a dose of 100 mg/kg reduced parasitaemia in L. tropica infected mice. Conclusion: Parasite viability results suggest that the methanol extract of Eryngium thorifolium, regarded as non-cytotoxic, is a promising candidate drug for treating L. tropica infection.
Determination of Antimony Resistance Mechanism of Leishmania tropica Causing Cutaneous Leishmaniasis in Turkey
(ANKARA MICROBIOLOGY SOC, 2020-01-01) Ozbilgin, Ahmet; Zeyrek, Fadile Yildiz; Guray, Melda Zeynep; Culha, Gulnaz; Akyar, Isin; Harman, Mehmet; Ozbel, Yusuf; Ertabaklar, Hatice; Cavus, Ibrahim; Gunduz, Cumhur
World Health Organization reported that approximately one billion people are at risk in endemic areas, one million cases of cutaneous leishmaniasis (CL) and approximately 300,000 cases of visceral leishmaniasis (VL) were reported per year in the last five years. The number of deaths due to VL is reported to be approximately 20,000 per year. Approximately 2500 cases/year have been reported as CL, caused by Leishmania tropica and Leishmania infantum, in Turkey. The significant increase observed in many cities mainly in the provinces of Mediterranean and Aegean regions in cases and foci in recent years, suggests that there may be an increase in this infections in the following years as well. In Turkey, the causative agent of CL is L.tropica and meglumine antimoniate is used in the treatment of CL. We aimed to determine antimony resistance genes specific for L.tropica by comparing the gene and protein expressions of antimony-resistant and non-resistant L.tropica strains. Ltropica isolates obtained from 3 CL patients without antimonate resistance from Aegean, Mediterranean and Southeastern regions of Turkey were provided to transform into 3 resistant isolates against meglumine antimony in the laboratory conditions. Gene expression alterations by microarray method
Diversity of Leishmania Strains Isolated from Cutaneous Leishmaniasis Patients in Turkey and its Reflection to Clinics in Mice Model
(ANKARA MICROBIOLOGY SOC, 2020-01-01) Ozbilgin, Ahmet; Culha, Gulnaz; Guray, Melda Zeynep; Zeyrek, Fadile Yildiz; Akyar, Isin; Toz, Seray; Ural, Ipek Ostan; Kurt, Ozgur; Kocagoz, Tanil; Cavus, Ibrahim; Gunduz, Cumhur
Although asexual reproduction has been attributed to Leishmania species, genetic exchange has recently been demonstrated, which helped emerging of hybrid isolates. Situated on the crossroads between three continents, Leishmania hybrids may be present in Turkey. In Turkey, visceral leishmaniasis caused by Leishmania infantum is less common, while cutaneous leishmaniasis (CL) caused by Leishmania tropica and L.infantum could reach 2500 reported cases a year. Our aim was to investigate genetic variability of local Leishmania species and presence of hybrid Leishmania strains in Turkey. Twenty CL patients from Sanliurfa and Hatay, where only L.tropica and both L.tropica and L.infantum cause CL, respectively, were registered equally. All isolates were assessed with real-time polymerase chain reaction (Rt-PCR), isoenzyme analysis, gene sequencing, two-dimensional gel electrophoresis (2D-PAGE) and MALDI-TOF/TOF-MS followed by in vivo analyses on mouse model. Identification of differentially expressed proteins was performed. These proteins were confirmed by sequence analysis. All isolates from Sanliurfa were found to be L.tropica which caused cutaneous infection in mice. However, one of 10 isolates from Hatay was found as Leishmania major which caused cutaneous infection. Five isolates were found as L.tropica with Rt-PCR and gene sequencing, one of which had one different protein from the reference L.tropica strain and caused cutaneous infection. Four of the five isolates had five different proteins compared to reference strain and caused both cutaneous and visceral infections. Remaining four isolates showed double melting curves in Rt-PCR, which were concordant with L.tropica and L.infantum. Their sequencing and isoenzyme analyses indicated them as L.infantum. They had six different proteins compared to reference L.infantum strain and caused cutaneous and visceral infections. It is concluded that the isolates with different proteins were hybrid Leishmania species. In the present study, outcomes of the proteomics, genomics, clinical manifestations and tissue tropism on animal models were evaluated together for the first time. In addition to L. tropica and L.infantum, L.major was identified as a causative agent for CL and hybrids of Linfantum/tropica were also shown to be present.