Browsing by Author "Hacimuftuoglu, Ahmet"

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Alzheimer Hastalığının Tedavisinde Yeni Tripeptidler
(2019) Caccıatore, Ivana; Keleş, Mevlüt Sait; Kadıoğlu, Yücel; Çalık, Muhammet; Ozgeris, Bunyamin; Hacimuftuoglu, Ahmet; Turkez, Hasan
Nörodejeneratif hastalıklar duyusal, motor ve algısal fonksiyonların progresif kaybı ile kognitif ve davranışsal bozukluklarla ilişkili pek çok kronik nörolojik hastalığı kapsamaktadır. Diğer nörodejeneratif hastalıklara kıyasla Alzheimer (AH), Parkinson (PH), Huntington (HH) hastalıkları ile amyotrofik lateral skleroza (ALS) daha fazla önem verilmektedir. Özellikle, AH hipokampus ve korteksteki piramidal nöronların yanı sıra bazal ön beyindeki kolinerjik nöronların kaybı ile karakterize edilen bir nörodejeneratif hastalıktır. Etiyolojisi henüz tam olarak bilinmemekle birlikte, βamiloid (Aβ) birikimi, Tau (τ)-protein agregasyonu, hücresel yapılarda oksidatif hasarların oluşumu ve metal dishomeostasisi gibi hastalıkta belirgin roller üstlendiği gözlenen farklı bulgular mevcuttur. Üstelik, Alzheimer hastalarında Aβ-ilişkili serbest radikallerin ve sonuçta oluşan oksidatif stresin, beyinde nörodejenerasyona yol açan patojenik kaskad mekanizmasının bir bölümü olduğuna dair güçlü kanıtlar bulunmaktadır. Bu patolojinin multi-faktoriyel yapısı dikkate alındığında, tek bir hedefe yönelik ilaçların yetersiz bir strateji sunduğu açıkça görülmektedir. Diğer taraftan, tek bir hedefe yönelik ilaçlara nazaran daha yüksek terapötik etkinliği sağlamak için nörodejeneratif hastalıkların patojenik kaskadında yer alan seçilmiş moleküler hedeflere ulaşabilen multi-hedeflere yönelik ligandlara (MHYL) olan ilgi son yıllarda giderek artmıştır. Bu bağlamda mevcut projede Alzheimer hastalığının tedavisinde kullanılabilecek yeni multi-hedefli tripeptidlerin sentezlenmesi ve in vitro koşullarda biyolojik etkinliklerinin değerlendirilmesi amaçlanmıştır. Sentezleri gerçekleştirilen bu yeni tripeptidler (I) belirli beyin bölgelerinde radikaller tarafından oluşturulan oksidatif stresi engelleyebilecek, (II) metal-iyon disregülasyonuna karşı koyabilecek ve (III) Alzheimer hastalığı gibi nörodejeneratif patolojilerin ayırt edici özelliklerinden olan nöroenflamatuar prosesleri önleyebilecektir. Yeni multi-hedefli tripeptidler solüsyon faz sentetik teknikleri kullanılarak geliştirilen uygun ve innovatif stratejiler doğrultusunda sentezlenmiştir. Tüm yeni bileşikler farklı tekniklerin kullanılmasıyla detaylı olarak karakterize edilmiştir. Farmakokinetik profilleri HPLC metotları kullanılarak değerlendirilmiştir. Tüm tripeptidlerin anti-Alzheimer potansiyelleri iki farklı in vitro Alzheimer modeli kullanılarak değerlendirilmiştir. Bu bağlamda, proje kapsamında hücre canlılığı ve sitotoksisite, oksidatif değişimler, proenflamatuar yanıtlar, asetilkolinesteraz (AChE) aktivitesi ve şelatlama kapasitesi ile apoptotik ve nekrotik etkilerin belirlenmesi amacıyla SH-SY5Y ve NT2-N hücre hatlarının kullanılacağı non-genetik/toksik ve transfeksiyon modelleri üzerinde oldukça kapsamlı in vitro analizler gerçekleştirilmiştir. İlaveten, amiloid analizleri içinWestern blot, ELISA ve elektron mikroskopi teknikleri kullanılmıştır. Proje sonucunda ileri in vivo araştırmalar, faz çalışmaları ve patent alınabilirliği için oldukça ümit verici adaylar keşfedilmiştir.
Antiproliferative, Genotoxic and Oxidant Activities of Cyclosativene in Rat Neuron and Neuroblastoma Cell Lines
(Inst Bioloska Istrazivanja Sinisa Stankovic, 2014) Togar, Basak; Turkez, Hasan; Geyikoglu, Fatime; Hacimuftuoglu, Ahmet; Tatar, Abdulgani
Cyclosativene (CSV) is a tetracyclic sesquiterpene found in the essential oils of Centaurea cineraria (Asteraceae) and Abies magnifica A. Murray (Pinaceae) plants. To the best of our knowledge, its cytotoxic, genotoxic and oxidant effects have never been studied on any cell lines. Therefore, we aimed to investigate the in vitro antiproliferative and/or cytotoxic properties, antioxidant/oxidant activity and genotoxic damage potential of CSV in healthy neurons and N2a neuroblastoma (N2a-NB) cell cultures. After treatment with 10-400 mu g/ml of CSV for 24 h, cell proliferation was measured by the MTT (3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The antioxidant activity was assessed by the total antioxidant capacity (TAC) and total oxidative stress (TOS) assays. To evaluate the level of DNA damage, single cell gel alkaline electrophoresis (SCGE) was used. The MTT assay showed that the application of CSV significantly reduced cell viability in both cell types. CSV treatments at higher doses led to decreases of TAC levels and increases of TOS levels in neuron and N2a-NB cells. The mean values of the total scores of cells showing DNA damage were not found to be significantly different from the control values in both cells. In conclusion, this study suggests that CSV has weak anticancer potential.
Astrocyte/Neuron Ratio and Its Importance on Glutamate Toxicity: An in Vitro Voltammetric Study
(Springer, 2016) Hacimuftuoglu, Ahmet; Tatar, Abdulgani; Cetin, Damla; Taspinar, Numan; Saruhan, Fatih; Okkay, Ufuk; Suleyman, Halis
The purpose of this study was to clarify the relationship between neuron cells and astrocyte cells in regulating glutamate toxicity on the 10th and 20th day in vitro. A mixed primary culture system from newborn rats that contain cerebral cortex neurons cells was employed to investigate the glutamate toxicity. All cultures were incubated with various glutamate concentrations, then viability tests and histological analyses were performed. The activities of glutamate transporters were determined by using in vitro voltammetry technique. Viable cell number was decreased significantly on the 10th day at 10(-7) M and at 10(-6) M glutamate applications, however, viable cell number was not decreased at 20th day. Astrocyte number was increased nearly six times on the 20th day as compared to the 10th day. The peak point of glutamate reuptake capacity was about 2 x 10(-4) M on the 10th day and 10(-3) M on the 20th day. According to our results, we suggested that astrocyte age was important to maintain neuronal survival against glutamate toxicity. Thus, we revealed activation or a trigger point of glutamate transporters on astrocytes due to time since more glutamate was taken up by astrocytes when glutamate transporters on the astrocyte were triggered with high exogenous glutamate concentrations. In conclusion, the present investigation is the first voltammetric study on the reuptake parameters of glutamate in vitro.
Boric Acid Impedes Glioblastoma Growth in a Rat Model: Insights from Multi-Approach Analysis
(Humana Press Inc, 2025) Turkez, Hasan; Alper, Fatih; Bayram, Cemil; Baba, Cem; Yildiz, Edanur; Saracoglu, Melik; Hacimuftuoglu, Ahmet
Limited advancements in managing malignant brain tumors have resulted in poor prognoses for glioblastoma (GBM) patients. Standard treatment involves surgery, radiotherapy, and chemotherapy, which lack specificity and damage healthy brain tissue. Boron-containing compounds, such as boric acid (BA), exhibit diverse biological effects, including anticancer properties. This study aimed to examine whether boron supplementation, as BA, can inhibit glioblastoma growth in a xenograft animal model. Using MRI-based tumor size measurement, survival rates, hematological, clinical biochemistry analyses, and genotoxicity parameters, we assessed the impact of BA. Histopathological, immunohistochemical, and immunofluorescence examinations were also conducted. All BA doses (3.25, 6.5, and 13 mg kg-1 b.w.) extended survival compared to GBM controls after 14 days, with a dose-dependent anti-GBM effect observed in MRI analyses. BA treatment improved hematological (WBC and PLT counts) and biochemical parameters (LDL-C, CREA, and ALP). Histopathological examination revealed a significant reduction in tumor diameter with 6.5 and 13 mg kg-1 BA. Immunohistochemical and immunofluorescence staining showed modulation of intracytoplasmic Ki67, cytoplasmic CMPK2, and GFAP expressions in tumor cells post-BA treatment. Additionally, BA did not increase micronuclei formations, indicating its non-genotoxic nature. In conclusion, targeting tumor suppressor networks with boron demonstrates significant therapeutic potential for GBM treatment.
Computational Identification of Potential Antiviral Agents Against Monkeypox Virus
(2025) Aydemir, Dr. Murat; Hacimuftuoglu, Ahmet; Arslan, Mehmet Enes; Turkez, Hasan; Akbaba, Yusuf; Selvitopi, Harun; Selvitopi, Zulkuf
This study introduces a drug repurposing approach for monkeypox virus using molecular docking and molecular dynamics (MD) simulations to screen clinically approved drugs for other diseases. Potential candidates were analyzed with AutoDock software in two categories: (1) DNA polymerase inhibitors and (2) RNA polymerase inhibitors. Docking analysis identified seven promising compounds—five DNA polymerase and two RNA polymerase inhibitors—showing strong affinity toward monkeypox targets. MD simulations further confirmed their binding stability. Among them, etravirine (−8.04 kcal/mol) and valaciclovir (−7.57 kcal/mol) exhibited the highest affinity to DNA polymerase active sites at residues ASP347 and ASP462. Moreover, emetine dihydrochloride (−7.17 kcal/mol) demonstrated the strongest binding to the catalytic site of RNA polymerase. Consequently, etravirine and emetine dihydrochloride are proposed as potential therapeutics against monkeypox. Since these compounds are already approved by the U.S. Food and Drug Administration (FDA) for other viral infections, extensive safety testing and high development costs can be avoided, making this repurposing strategy an efficient and cost-effective option for managing monkeypox infection.
Cytotoxic and Cytogenetic Effects of α-Copaene on Rat Neuron and N2a Neuroblastoma Cell Lines
(Springer, 2014) Turkez, Hasan; Togar, Basak; Tatar, Abdulgani; Geyikoglu, Fatime; Hacimuftuoglu, Ahmet
Alpha-copaene (alpha-COP), a tricyclic sesquiterpene, is present in several essential oils of medicinal and aromatic plants and has antioxidant and antigenotoxic features. Its cytotoxic, cytogenetic and oxidative effects have not been investigated in neuron and N2a neuroblastoma (NB) cell cultures. Therefore, we aimed to describe in vitro: (i) cytotoxic properties by 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenlytetrazolium bromide test; (ii) antioxidant/oxidant activity by total antioxidant capacity (TAC) and total oxidative status (TOS) analysis; and (iii) genotoxic damage potential by single cell gel electrophoresis - of alpha-COP in healthy neuron and N2a-NB cell cultures for the first time. Significant (P < 0.05) decrease in cell proliferation were observed in cultured primary rat neurons starting with the concentration of 150 mg/L and in N2a-NB cells starting with 100 mg/L. In addition, 25 mg/L of alpha-COP treatment caused increase of TAC levels and alpha-COP treatments at higher doses led to increase of TOS levels in neuron N2a-NB cell cultures. Moreover, none of the tested concentrations of alpha-COP have shown a genotoxic effect on both cell lines. Our findings clearly demonstrate that alpha-COP exhibited mild cytotoxic effects on N2a-NB cell line. In conclusion, alpha-COP may have potential as an anticancer agent, which needs to be further studied.
Cytotoxicity and Genotoxicity of Zingiberene on Different Neuron Cell Lines in Vitro
(Springer, 2015) Togar, Basak; Turkez, Hasan; Tatar, Abdulgani; Hacimuftuoglu, Ahmet; Geyikoglu, Fatime
The main objective of this study is to investigate the cytotoxic, genotoxic and antioxidant properties of zingiberene (ZBN) in an in vitro rat brain cell culture study. The cytotoxic effect was determined against the rat neuron and N2a neuroblastoma (N2a-NB) cell lines using the 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while the antioxidant activity was assessed using the total antioxidant capacity (TAC) and total oxidative stress (TOS) assays. The effects on DNA damage were also evaluated in this study by the single cell gel electrophoresis assay. The results indicated that ZBN has an anti-proliferative activity suppressing the proliferation of N2a-NB cells at concentrations over 50 mg L-1 and neuron cells at concentrations over 150 mg L-1. In addition, ZBN treatments at higher doses (10-400 mg L-1) led to increases of TOS levels in N2a-NB cell cultures. However 25 mg L-1 of ZBN treatment caused increases of TAC levels in cultured neuron and N2a-NB cell cultures while ZBN at doses of 10-400 mg L-1 did not increase the number of total damage score in both cell lines. This study clearly indicates that ZBN has a significant potential to be used as a natural anticancer agent in cultured N2a-NBs.
Enhanced Antitumor Effects of Interferon-Stimulating DNA and Magnetic Hyperthermia in a Breast Cancer Rat Model
(Elsevier, 2025) Solak, Kubra; Mavi, Ahmet; Taghizadehghalehjoughi, Ali; Yildirim, Serkan; Genc, Sidika; Hacimuftuoglu, Ahmet
This study examined the targeted delivery of interferon-stimulating DNA (ISD) by magnetic nanoparticles (MNPs) against breast cancer in a rat model. We synthesized Fe3O4 MNPs and modified their surface with silica and polyethyleneimine (Fe3O4@SiO2@PEI) for biocompatibility and water dispersibility. A folic acid-linked polyethyleneimine (PEI-FA) was synthesized to enhance the targeted delivery of ISD to the breast cancer cells. The ISD-loaded Fe3O4@SiO2@PEI MNPs at low concentrations significantly affected breast cancer cells by contributing to reduced oxidative stress, triggering a pathway to stimulate interferon-beta production. However, they did not affect non-tumorigenic MCF-10A cells. Furthermore, treating ISD-loaded MNPs significantly decreased the quantity of tumor cells in a rat model of breast cancer. Magnetic hyperthermia (MHT) improved the therapeutic efficacy by elevating the temperature of ISD-loaded MNPs over 40 degrees C under an alternating current magnetic field. In the rat model, there was an over 5-fold difference in tumor mass between the untreated groups and those treated with ISD and MHT. We observed that apoptosis, inflammation, and DNA damage markers were significantly changed in the tumor tissues of the rats. Despite the low amount of material (max 2 mu g ISD) and short exposure to the magnetic field (1 h), the treatment results demonstrated encouraging outcomes.
Guaiazulene Biochemical Activity and Cytotoxic and Genotoxic Eff Ects on Rat Neuron and N2a Neuroblastom Cells
(Ejmanager LLC, 2015) Togar, Basak; Turkez, Hasan; Hacimuftuoglu, Ahmet; Tatar, Abdulgani; Geyikoglu, Fatime
Aim: Neuroblastoma (NB) cells are often used in cancer researches such as glioblastoma cells since they have the potential of high mitotic activity, nuclear pleomorphism, and tumor necrosis. Guaiazulene (GYZ 1,4-dimethyl-7-isopropylazulene) is present in several essential oils of medicinal and aromatic plants. Many studies have reported the cytotoxic effect of GYZ; however, there are no studies that compare such effects between cancer cell lines and normal human cells after treatment with GYZ. Materials and Methods: In this study, we aimed to describe in vitro antiproliferative and/or cytotoxic properties (by 3-[4,5 dimetylthiazol -2-yl]-2,5 diphenlytetrazolium bromide [MTT] test), oxidative effects (by total antioxidant capacity [TAC] and total oxidative stress [TOS] analysis) and genotoxic damage potentials (by single cell gel electrophoresis) of GYZ. Result: The results indicated that GYZ have anti-proliferative activity suppressing the proliferation of neuron and N2a-NB cells at high doses. In addition, GYZ treatments at higher doses led to decreases of TAC levels and increases of TOS levels in neuron and N2a-NB cells. On the other hand, the mean values of the total scores of cells showing DNA damage were not found different from the control values. Conclusion: From this study, it is observed that GYZ has in vitro cytotoxic activity against neuron and N2a-NB cells.
The in Vitro Protective Effect of Salicylic Acid Against Paclitaxel and Cisplatin-Induced Neurotoxicity
(Springer, 2016) Cetin, Damla; Hacimuftuoglu, Ahmet; Tatar, Abdulgani; Turkez, Hasan; Togar, Basak
Paclitaxel (PAC) and cisplatin (CIS) are two established chemotherapeutic drugs used in combination for the treatment of various solid tumors. However, the usage of PAC and CIS are limited because of the incidence of their moderate or severe neurotoxic side effects. In this study, we aimed to assess the protective role of salicylic acid (SA) against neurotoxicity caused by PAC and CIS. For this purpose, newborn Sprague Dawley rats were decapitated in sterile atmosphere and primary cortex neuron cultures were established. On the 10th day SA was added into culture plates. PAC and CIS were added on the 12th day. The cytotoxicity was determined by using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Oxidative alterations were assessed using total antioxidant capacity and total oxidative stress assays in rat primary neuron cell cultures. It was shown that both concentrations of PAC and CIS treatments caused neurotoxicity. Although SA decreased the neurotoxicity by CIS and PAC, it was more effective against the toxicity caused by CIS rather than the toxicity caused by PAC. In conclusion it was clearly revealed that SA decreased the neurotoxic effect of CIS and PAC in vitro.
Melatoninin Mcf-7 Hücre Kültüründeki Apoptoz Aktivasyonunun ve Sitotoksisitesinin Polimeraz Zincir Reaksiyonu (PCR), Mtt Hücre Canlılık Testi ve İmmunsitokimya Yöntemleriyle Araştırılması
(2024) Ozbek, Ahmet; Gedikli, Semin; Hacimuftuoglu, Ahmet; Şahin, Elvan; Tatar, Abdulgani; Kara, Adem
Amaç: Dünyada ve Türkiye’de en sık görülen kanser türlerinden biri olan meme kanseri, kanser nedenli ölüm oranları arasında ilk sıralarda yer almaktadır. Bu nedenle bu hastalığın tedavisine yönelik yeni araştırmalar yapılmaktadır. Bu çalışmada, güçlü bir antioksidan olan melatoninin kanserle olan ilişkisinin ve kanser hastalığının tedavisi yönündeki katkısının araştırılması amaçlanmıştır. Gereç ve Yöntemler: Çalışmamızda, melatoninin sitotoksik dozlarını ve IC50 değerini belirleyebilmek için MCF-7 hücre hattına 10 nM–100.000 nM aralığında melatonin konsantrasyonları uygulandı. Melatonin uygulamasının ardından hücre canlılığı analizi yapıldı ve melatonin için etkin dozlar belirlendi. MCF-7 hücreleri, 5 konsantrasyon (10, 100, 1000, 10.000 ve 100.000 nM) melatonin dozu ile 24 saat inkübasyon işlemine tabi tutuldu. Tüm gruplarda melatoninin sitotoksisitesi, toplam antioksidan kapasite ve toplam oksidan düzeyi, apoptotik aktivite (Bax ve p53 immünopozitifliği) ve p53 gen ekspresyon düzeyleri incelendi. Bulgular: Yirmi dört saatlik inkübasyon sonunda MCF-7 hücrelerine uygulanan melatoninin hücre proliferasyonunu inhibe ederek sitotoksik etki yaptığı (p<0.05), p53 gen ekspresyonunu ve Bax protein sentezini artırdığı tespit edildi. İmmünsitokimyasal boyamada Bax ve p53 immünpozitifliğinin arttığı belirlendi. Ayrıca melatonin tedavisi TAS’ı artırıp TOS’u azalttı. Sonuç: Bu etkiler, melatoninin p53 gen ekspresyonu ve Bax proteinindeki artışa bağlı olarak apoptoz aktivasyonunu indüklediğini ve dolayısıyla kanser tedavisinde kullanılabilecek yardımcı bir ajan olabileceğini göstermektedir.
Neuroprotective Effects of Farnesene Against Hydrogen Peroxide-Induced Neurotoxicity in Vitro
(Springer/Plenum Publishers, 2014) Turkez, Hasan; Sozio, Piera; Geyikoglu, Fatime; Tatar, Abdulgani; Hacimuftuoglu, Ahmet; Di Stefano, Antonio
Oxidative stress is highly damaging to cellular macromolecules and is also considered a main cause of the loss and impairment of neurons in several neurodegenerative disorders. Recent reports indicate that farnesene (FNS), an acyclic sesquiterpene, has antioxidant properties. However, little is known about the effects of FNS on oxidative stress-induced neurotoxicity. We used hydrogen peroxide (H2O2) exposure for 6 h to model oxidative stress. Therefore, this experimental design allowed us to explore the neuroprotective potential of different FNS isomers (alpha-FNS and beta-FNS) and their mixture (Mix-FNS) in H2O2-induced toxicity in newborn rat cerebral cortex cell cultures for the first time. For this aim, both MTT and lactate dehydrogenase assays were carried out to evaluate cell viability. Total antioxidant capacity (TAC) and total oxidative stress (TOS) parameters were used to assess oxidative alterations. In addition to determining of 8-hydroxy-2-deoxyguanosine (8-OH-dG) levels in vitro, the comet assay was also performed for measuring the resistance of neuronal DNA to H2O2-induced challenge. Our results showed that survival and TAC levels of the cells decreased, while TOS, 8-OH-dG levels and the mean values of the total scores of cells showing DNA damage (comet assay) increased in the group treated with H2O2 alone. But pretreatment of FNS suppressed the cytotoxicity, genotoxicity and oxidative stress, which were increased by H2O2 in clear type of isomers and applied concentration-dependent manners. The order of antioxidant effectiveness for modulating H2O2-induced oxidative stress-based neurotoxicity and genotoxicity is as beta-FNS > Mix-FNS > alpha-FNS.