Many species of Psephellus and Centaurea genuses have pharmacological activities including antiin... more Many species of Psephellus and Centaurea genuses have pharmacological activities including antiinflamatory, antipyretic, cytotoxic etc. Psephellus pyrrhoblepharus (Boiss.) Wagenitz (Centaurea pyrrhoblephara), an endemic plant, was collected from Elazığ, Turkey. Liver cancer is affecting millions of people all over the world. Recent days interest in use of plant-derived compounds for therapeutic purposes in cancer is increasing. So any approach to treat liver cancer is extremely valuable. We aimed to evaluate the cytotoxic potential of extracts (methanol:water 1:1, chloroform and n-hexane) of aerial parts of P. pyrrhoblepharus using human liver cancer cell (HepG2) by utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay in different concentrations (50,100,200 µg/mL) and time points (6, 12, 24 h). Regarding the cytotoxicity, cell viability was decreased following extract exposures at different time points. However, the highest cytotoxic activity was observed in 100 µg/mL concentrations of chloroform extract at 24 h. Chloroform extract of plant showed the highest cytotoxic activity in 200 µg/mL concentrations when compared to methanol:water and n-hexane extracts at 12 h. It can be suggested that used extracts of P. pyrrhoblepharus exert cytotoxic effect in HepG2 carcinoma cells in a dose-and time-dependent manner. Generally, results provide information regarding the threshold concentrations of P. pyrrhoblepharus extracts that might be used in different applications without toxicity hazards.
Glia hücreleri ve özellikle astrositler santral sinir sistemi hücre içeriğinde önemli bir orana s... more Glia hücreleri ve özellikle astrositler santral sinir sistemi hücre içeriğinde önemli bir orana sahiptir. Glutamat toksisitesine karşı nöronlardan daha dirençli olduğu bilinen glia hücreleri nöron koruyucu mekanizmalara da sahiptir. Oksidan stres, reaktif oksijen türevleri ve serbest radikal oluşumu ve bunlara bağlı organel ve hücre hasarını (akson, glia, endotel dahil) geliştirir. 1-2 günlük sıçan beyinlerinden elde edilen primer mikst glia kültürleri 14. kültür gününde kontrol (n=6), toksisite (glutamat) (n=6), toksisite+melatonin (n=6), toksisite+7-nitroindazol (n=6) veya toksisite+riluzol (n=6) olmak üzere 5 gruba ayrıldı. 20mM glutamat eklenerek toksisite oluşturulduktan sonra, 100μM melatonin, 500μM 7-nitroindazol veya 100μM riluzol kültür ortamına eklendi. 1, 6, 24 ve 48. saatlerde kültür üst sıvıları alındı. Bu örneklerde LDH ve nirtrit düzeyleri saptandı. Veriler SPSS programında multivariate ANOVA ve post hoc Bonferroni ile değerlendirildi. Multifaktöryel ANOVA sonuçlarına göre zaman [F(3,54)= 116.57, p=0.001)] ve gruplar [F(3,18)=7.993, p=.0001] anlamlı faktörler olarak belirlenmiş ve ayrıca zaman ile gruplar arası anlamlı etkileşim saptanmıştır [F(12,54)=3.664, p=0.001)]. Verilerin değerlendirilmesinde her saat için ayrı ayrı tek yönlü ANOVA kullanıldığında, bekleneceği üzere yine gruplar arası anlamlı fark bulunmuştur [1, 6, 24 ve 48 saatler için, sırasıyla: F(4,28)=7.129, p=0.001; F(4,28)= 8.493, p=0.001; F(4,28)= 6.816, p=0.001; F(4,25)= 11.822, p=0.001]. Post hoc test (Bonferroni) ile gruplar arası farklar Şekil 3ʼte gösterilmektedir. 1., 6. ve 48. saatlerde 7-nitroindazol melatoninden daha etkili olmuştur [t testi sırasıyla: p=0.028, p=0.020, p=0.001]. 24. saatte melatonin ve 7-nitroindazol arasında toksisiteyi azaltma yönünden anlamlılık bulunamamıştır. Sonuç olarak bu çalışmamızda, daha önce deneysel serbral iskemi ve omurilik zedelenmesi modellerimizde gözlemiş olduğumuz melatonin ve 7-nirtoindazolün sağladığı davranışsal koruyucu/iyileştirici etkilere (Dagci et al., 2000; Peker et al., 2000) benzer sonuçlar elde ettik. Adı geçen ajanların, özellikle 7-nitroindazolʼun nöronlar için çok değerli mekanik, metobolik ve biyolojik destek oluşturan glianın in-vitro kültüründe de hücre hasar ve ölümünü engelleyici etkiler ortaya koyduğunu gözlemledik
Purpose: The present study was conducted to determine oxidative stress and cell viability after c... more Purpose: The present study was conducted to determine oxidative stress and cell viability after contact with resin composites polymerized for different times. Methods: Disk-shaped specimens of Admira Fusion, Ceram X One Universal, Solare x and Filtek Z550 (n = 12) were prepared, and two subgroups with polymerization times of 20 and 40 s were employed. The specimens were incubated with mouse fibroblast cells for 48 and 72 h, and changes in reactive oxygen species (ROS) production and cellular viability were determined by an assay with a cell-permeable fluorescent dye, 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCF-DA), and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, respectively. Results: At 72 h, ROS production in the presence of Admira Fusion polymerized for 40 s was reduced relative to that in the presence of Admira Fusion polymerized for 20 s (P < 0.05). Cell viability was maximal in the Admira Fusion and Solare x groups and there was no difference relative to the control group at 48 h. Cell viability was higher in the Admira Fusion and Solare x groups polymerized for 40 s than for the same materials polymerized for 20 s at 72 h (P < 0.05). Conclusion: Extension of the polymerizaton time has a material-specific effect and may be used as a strategy to increase the biocompability of resin composites.
Spinal cord injury (SCI) leads to vascular damage and disruption of blood-spinal cord barrier whi... more Spinal cord injury (SCI) leads to vascular damage and disruption of blood-spinal cord barrier which participates in secondary nerve injury. Epidermal growth factor (EGF) is an endogenous protein which regulates cell proliferation, growth and differention. Previous studies reported that EGF exerts neuroprotective effect in spinal cord after SCI. However, the molecular mechanisms underlying EGFmediated protection in different regions of nervous system have not shown yet. In this study, we aimed to examine possible anti-apoptotic and protective roles of EGF not only in spinal cord but also in brain following SCI. Twenty-eight adult rats were divided into four groups of seven animals each as follows: sham, trauma (SCI), SCI + EGF and SCI + methylprednisolone (MP) groups. The functional neurological deficits due to the SCI were assessed by behavioral analysis using the Basso, Beattie and Bresnahan (BBB) open-field locomotor test. The alterations in pro-/anti-apoptotic protein levels and antioxidant enzyme activities were measured in spinal cord and frontal cortex. In our study, EGF promoted locomotor recovery and motor neuron survival of SCI rats. EGF treatment significantly decreased Bax and increased Bcl-2 protein expressions both in spinal cord and brain when compared to SCI group. Moreover, antioxidant enzyme activities including catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were increased following EGF treatment similar to MP treatment. Our experiment also suggests that alteration of the ratio of Bcl-2 to Bax may result from decreased apoptosis following EGF treatment. As a conclusion, these results show, for the first time, that administration of EGF exerts its protection via regulating apoptotic and oxidative pathways in response to spinal cord injury in different regions of central nervous system.
ObjectiveThe aim of this in vitro study is to evaluate the effects of resveratrol (RES) addition ... more ObjectiveThe aim of this in vitro study is to evaluate the effects of resveratrol (RES) addition on the cytotoxicity and microtensile bond strength (μTBS) of different adhesives.Materials and methodsFive self-etching adhesives (G-aenial Bond-GC, Optibond All in One-Kerr, Gluma Self Etch-Kulzer, Clearfil S3 Bond-Kuraray, and Nova Compo-B Plus-Imicryl) were tested. They were applied to L-929 cell culture by the extract method. In the test groups, 0.5 μM RES (Sigma-Aldrich) was added into the medium. Cell viability was assessed by MTT assay after 24 h. Human extracted third molars were used for μTBS test (n = 7). The adhesives with or without 0.5 μM RES addition were applied on dentin surfaces. A composite build-up was constructed. Then, the specimens were sectioned into multiple beams with the non-trimming version of the microtensile test and subjected to microtensile forces. Statistical analysis was performed using ANOVA and post hoc Tukey test (p ˂ 0.05).ResultsThe extracts of all adhesives decreased the cell viability. However, RES addition increased the cell viability in all groups (p ˂ 0.05). RES addition did not cause any decrease in μTBS values of the adhesives compared to baseline. Optibond All in One showed the highest μTBS after RES addition. It was followed by Clerafil S3 Bond and Nova Compo-B Plus. No difference was determined between the Optibond All in One and Clearfil S3 Bond. There was difference between Optibond All in One and Nova Compo-B Plus (p ˂ 0.05).ConclusionRES addition may improve the biocompatibility without causing negative influence on μTBS of the adhesives.Clinical relevanceRES addition has clinical applicable potential to overcome the adverse biocompatibility of adhesives.
Study Design: Experimental animal study investigating the efficacy of C-terminal domain of tetanu... more Study Design: Experimental animal study investigating the efficacy of C-terminal domain of tetanus toxin application as neuroprotective effects on rat brain in a model of spinal cord injury. Objective: The aim of the present study was to investigate the possible role of C-terminal domain of tetanus toxin (Hc-TeTx) on cell death mechanisms including apoptosis and autophagy following SCI. Summary of Background Data: Traumatic spinal cord injury (SCI) can lead to posttraumatic inflammation, oxidative stress, motor neuron apoptosis, necrosis and autophagy of tissue. To promote and enhance recovery after SCI, recent development of devices and therapeutic interventions are needed. Methods: Twenty-eight adult rats were divided into four groups (n=7 each) as follows: sham, trauma (SCI), SCI+Hc-TeTx and SCI+methylprednisolone groups. The functional neurological deficits due to the SCI were assessed by behavioral analysis using the BBB open-field locomotor test. The alterations in pro-/anti-apoptotic and autophagy related-protein levels were measured by western blotting technique. Results: In this study, Hc-TeTx promotes locomotor recovery and motor neuron survival of SCI rats. Hc-TeTx also decreased expression of bax, bad, bak, cleaved caspase-3, Ask1 and autophagy-related proteins including Atg5 and LC3II in brain. Our study provides an evidence that cell death mechanisms play critical roles in SCI and that the non-toxic peptides including Hc-TeTx may exert protective effect and decrease cell death following SCI. Conclusion: Our preliminary findings suggest a possible therapeutic agent to improve survival after spinal cord trauma, but further analysis are still needed to evaluate the difference between acute and chronic injuries.
Quercertin per se did not affect redox homeostasis but increased the time of hemolysis and decrea... more Quercertin per se did not affect redox homeostasis but increased the time of hemolysis and decreased TBARs levels. Following the EE the Q group displayed a higher GSH/GSSG ratio and a less pronounced increase in TBARs, compared to placebo group. Moreover, we found that GPx enzyme activity were induced after EE only in Q group, while any significant modification of this parameter was detected in placebo group. In conclusion, the Q supplementation may be used as a countermeasure against oxidative stress inducing, in erythrocytes, a cellular adaptation allowing subjects to better cope with the oxidative stress induced by an acute exercise.
molecular etiology of HCC are limited. The Nrf2 signaling pathway can protect cells from a variet... more molecular etiology of HCC are limited. The Nrf2 signaling pathway can protect cells from a variety of toxicants and carcinogens by increasing the expression of a number of cytoprotective genes.The idea of using G. lucidum for cancer treatment is based on numerous laboratory and preclinical studies with cancer and immune cells as well as animal models demonstrating various biological activities in vitro and in vivo. The aim of our study is to evaluate the potential antioxidant role of G. lucidum in HCC. For this purpose, analysis of Nrf2 levels and cell cycle arrest were done. The most effective concentration of G. lucidum were found at 1/5 dilution. The changes in cytoplasmic/nuclear Nrf2 protein levels following G. lucidum extracts (1:5 or 1:10) treatments for 24, 48 or 72 h were observed. 1/10 and 1/5 diluted of G. lucidum induced G0/G1 cell cycle arrest in HCC. Consistently, the cells distributed in S phase were significantly reduced.In conclusion, our findings suggest that G. lucidum has a potential as an anticancer agent and. our data support the importance of the clarification of the molecular mechanisms of phytochemicals-induced Nrf2 activation.
In vivo performance of different scaffolds for dental pulp stem cells induced for odontogenic dif... more In vivo performance of different scaffolds for dental pulp stem cells induced for odontogenic differentiation Abstract: This study was designed to determine the in vivo performance of three different materials as scaffolds for dental pulp stem cells (DPSC) undergoing induced odontogenic differentiation. An odontogenic medium modified by the addition of recombinant human bone morphogenetic protein 2 was used in the experimental groups to induce differentiation. Mesenchymal stem cell medium was used in the control groups. DPSC were transplanted onto the backs of mice via three scaffolds: copolymer of L-lactide and DL-lactide (PLDL), copolymer of DL-lactide (PDL) and hydroxyapatite tricalcium phosphate (HA/TCP). The expression levels of dentin sialo-phosphoprotein (DSPP), dentin matrix protein-1 (DMP1), enamelysin/matrix metalloproteinase 20 (MMP20) and phosphate-regulating gene with homologies to endopeptidases on X chromosome (PHEX) were analysed using RT-PCR. The expressions in the experimental groups were compared to those in the control groups. The transcript expressions at 6 and 12 weeks were significantly different for all scaffolds (p < 0.05), except for the expression of DSPP in the PLDL group with regard to the time variable. Although there was a decrease in the expression of enamelysin/MMP20 in PLDL and HA/TCP at 12 weeks, all other expressions increased and reached their highest level at 12 weeks. The highest DSPP expression was in the PDL group (p < 0.05). The highest expression of DMP1 was detected in the HA/TCP group (p < 0.05). The highest expression of PHEX was in the PLDL group (p < 0.05). Consequently, PLDL and PDL seemed to be promising scaffold candidates for odontogenic regeneration at least as HA-TCP, when they were applied with the DPSC induced for odontogenic differentiation.
Celal Bayar Üniversitesi Fen Bilimleri Dergisi, 2016
Bir dental implant tedavisinin başarısında cerrahi teknik, implant materyali ve implant dizaynı g... more Bir dental implant tedavisinin başarısında cerrahi teknik, implant materyali ve implant dizaynı gibi faktörlerin yanı sıra, implant materyalinin yüzey özelliklerinin de önemli olduğu bilinmektedir. Son yıllarda yapılan çalışmalar iyon implantasyonunun dental implantların yüzey modifikasyonu açısından iyi bir aday olduğunu göstermiştir._Bu çalışmada, MEVVA iyon implantasyon teknolojisi kullanılarak, metal+gaz hibrit iyon implantasyonu yapılmış yüzeylerin osteoblast hücre tutunmasına etkisi incelenmiştir. Bu amaçla, iyon implante edilecek materyal olarak son yıllarda dental implant materyali olarak en çok kullanılan titanyum (ISO 5832-2 Grade 4) seçilmiştir. Titanyum yüzeylere implante edilecek metal element olarak yüksek biyouyumluluğu ile bilinen zirkonyum ve zirkonyum ile eş zamanlı implante edilen gaz elementi olarakta titanyum yüzeylerin pasivasyonunu arttırmak için oksijen kullanılmıştır. Osteoblast hücre tutunmaları in vitro ortamda gerçekleştirilerek yüzey pürüzlülüğünün ve iyon implantasyon işleminin osteoblast hücre tutunmaları üzerine etkisi karşılaştırılmalı olarak incelenmiştir. Sonuç olarak pürüzlü ve iyon implante edilmiş yüzeylerde hücrelerin daha iyi tutunduğu görülmüştür.
Conference of the Society-for-Free-Radical-Research-Europe (SFRR-E) -- JUN 08-11, 2016 -- Budapes... more Conference of the Society-for-Free-Radical-Research-Europe (SFRR-E) -- JUN 08-11, 2016 -- Budapest, HUNGARYWOS: 000377617900124Soc Free Rad Res Europ
Increased concentration of manganese (Mn) in the brain is known to be associated with excitotoxic... more Increased concentration of manganese (Mn) in the brain is known to be associated with excitotoxicity and neuroinflammation. Vinpocetine, an alkaloid derived from the plant Vinca minor L., basically shows its effect via phosphodiesterase inhibition and voltage-dependent Na(+) channels. Vasoactive intestinal peptide (VIP) has gastrointestinal, vasomotor, muscular, and neuroprotective effects. The aim of this study was to examine the potential protective effects of vinpocetine and VIP against Mn toxicity in NE-4C neural stem cells (NSCs). VIP treatment at 1 μM and vinpocetine treatment at 2 μM concentrations were sufficient to yield maximum protection, and these concentrations were adopted in the following experiments. In this study, Mn treatment significantly increased lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS) production, and triggered cell death in NE-4C cultures. However, significant reduction in LDH release was observed following vinpocetine or VIP treatments when compared with control. Similar to these findings, vinpocetine or VIP treatments significantly reduced membrane degradation induced by Mn (p &lt; 0.001). Moreover, vinpocetine attenuated Mn-induced decrease of mitochondrial membrane potential. Similarly, proapoptotic protein bax and ROS production significantly decreased in cells after incubation with vinpocetine (p = 0.01) or VIP in the presence of Mn (p &lt; 0.001). Our study provides the evidence that both vinpocetine and VIP may exert protective effects via modulating oxidative stress and apoptosis in Mn-induced neurodegeneration in NE-4C cells.
The aim of this study was to evaluate whether medium modification improves the odontogenic differ... more The aim of this study was to evaluate whether medium modification improves the odontogenic differentiation of human dental pulp stem cells (DPSC) in vitro and in vivo. DPSC isolated from human impacted third molar teeth were analysed for clusters of differentiation with flow cytometry. Odontogenic differentiation was stimulated by medium modification with the addition of bone morphogenetic protein 2 (BMP2). The expression of dentin sialophosphoprotein, dentin matrix protein 1, enamelysin/matrix metalloproteinase 20 and the phosphate-regulating gene with homologies to endopeptidases on the X chromosome of the cells were analysed with RT-PCR at 7, 14 and 21 days. Then, DPSC were transplanted on the back of immunocompromised mice via a hydroxyapatite tricalcium phosphate scaffold, and the structure of the formed tissue was investigated. The cells were identified as mesenchymal stem cells with a 98.3% CD73 and CD90 double-positive cell rate. The increase in mineralization capacity and expression of human enamel-dentin specific transcripts proportional to the culture period were determined after differentiation. Six weeks after transplantation, an osteo-dentin matrix was formed in the group in which odontogenic differentiation was stimulated, and the odontogenic characteristics of the matrix were confirmed by histological examination and RT-PCR analysis. Odontogenic differentiation of the isolated and characterized human DPSC was improved with medium modification by the addition of BMP2 in vitro and in vivo. The defined medium and applied technique have a potential use for forming reparative dentin in the future, but the effects of the method should be investigated in long-term studies.
Systemic kainic acid (KA) administration to rats triggers wet dog shakes (WDS) followed by epilep... more Systemic kainic acid (KA) administration to rats triggers wet dog shakes (WDS) followed by epileptic seizures. Although WDS are often associated with the occurrence of seizures, we have recently shown that following nitric oxide (NO) synthesis inhibition, the number of WDS decreased; subsequently the onset of seizure activity was shortened, and the number of convulsions was increased. Somatostatin (SS), whose release appears to be controlled by NO, inhibits seizure activity. There are sex differences in seizure susceptibility as well as in SS and NO activities in brain. The present study was undertaken to assess the effect of octreotide (OC), a stable SS analogue, on KA-induced WDS and seizures in rats, with emphasis on possible sex differences. WDS and seizures were induced by KA in male and female (proestrus) Sprague Dawley rats; OC or saline was injected 30 min before KA and the behavior was monitored for 120 min after KA. Octreotide increased the number of WDS and decreased the number of convulsions; this effect was more pronounced in males. Onset of KA-induced seizure activity was earlier in females than males; however, there was no effect of OC on seizure latency. Seizure activity started after the termination of WDS. These results show OC has opposite effects on WDS and convulsions, in that it stimulates the former and inhibits the latter. These results support our previous findings that WDS and seizure activity involve separate mechanisms and suggest that WDS may have an inhibitory effect on limbic seizures.
Resveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and c... more Resveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and cancer and exhibit neuroprotective effects. In this study, we examined the neuroprotective and antioxidant effects of resveratrol against hydrogen peroxide in embryonic neural stem cells. Hydrogen peroxide treatment alone increased catalase and glutathione peroxidase activities but did not change superoxide dismutase levels compared with hydrogen peroxide + resveratrol treatment. Nitric oxide synthase activity and concomitant nitric oxide levels increased in response to hydrogen peroxide treatment. Conversely, resveratrol treatment decreased nitric oxide synthase activity and nitric oxide levels. Resveratrol also attenuated hydrogen peroxide-induced nuclear or mitochondrial DNA damage. We propose that resveratrol may be a promising agent for protecting embryonic neural stem cells because of its potential to decrease oxidative stress by inducing higher activity of antioxidant enzymes, decr...
N-methyl-d-aspartate (NMDA) receptors are major pharmacological targets to prevent or reduce the ... more N-methyl-d-aspartate (NMDA) receptors are major pharmacological targets to prevent or reduce the progression of neurodegenerative diseases. Successful therapy with NMDA receptor antagonists in humans has been limited by the severe side effects of complete receptor blockade. The aim of the present study was to investigate the possible protective effects of tideglusib against NMDA receptor overactivation in neural stem cells. We measured the alteration in membrane integrity, free radical generation, intracellular Ca(2+) accumulation, mitochondrial membrane potential (MMP)/mitochondrial morphology and glycogen synthase kinase-3 (α/β isoforms and phospho-GSK-3α/β) protein expression levels following treatments. NMDA treatment, with or without d-serine, significantly increased LDH leakage and triggered cell death in neural stem cells. Reactive oxygen species (ROS) formation and intracellular Ca(2+) levels were increased following NMDA receptor overactivation. The significant reduction in MMP was found in NMDA/d-serine-treated cells. Tideglusib significantly decreased ROS production and membrane degradation, but did not change intracellular Ca(2+) levels following NMDA receptor activation. Both in the presence or in the absence of NMDA/d-serine, tideglusib increased MMP and the levels of phospho-GSK-3β in NSCs. Moreover, GW9662 (a peroxisome-proliferator-activated receptor gamma (PPARγ) antagonist) treatment significantly inhibited the protective effect of tideglusib in NMDA/d-serine-treated cells. Our study provides the evidence that GSK-3β and PPARγ may be directly involved in pathways leading to NMDA receptor-induced cell death and that the inhibitors including tideglusib may exert neuroprotective effect against these receptor overactivation.
Many species of Psephellus and Centaurea genuses have pharmacological activities including antiin... more Many species of Psephellus and Centaurea genuses have pharmacological activities including antiinflamatory, antipyretic, cytotoxic etc. Psephellus pyrrhoblepharus (Boiss.) Wagenitz (Centaurea pyrrhoblephara), an endemic plant, was collected from Elazığ, Turkey. Liver cancer is affecting millions of people all over the world. Recent days interest in use of plant-derived compounds for therapeutic purposes in cancer is increasing. So any approach to treat liver cancer is extremely valuable. We aimed to evaluate the cytotoxic potential of extracts (methanol:water 1:1, chloroform and n-hexane) of aerial parts of P. pyrrhoblepharus using human liver cancer cell (HepG2) by utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay in different concentrations (50,100,200 µg/mL) and time points (6, 12, 24 h). Regarding the cytotoxicity, cell viability was decreased following extract exposures at different time points. However, the highest cytotoxic activity was observed in 100 µg/mL concentrations of chloroform extract at 24 h. Chloroform extract of plant showed the highest cytotoxic activity in 200 µg/mL concentrations when compared to methanol:water and n-hexane extracts at 12 h. It can be suggested that used extracts of P. pyrrhoblepharus exert cytotoxic effect in HepG2 carcinoma cells in a dose-and time-dependent manner. Generally, results provide information regarding the threshold concentrations of P. pyrrhoblepharus extracts that might be used in different applications without toxicity hazards.
Glia hücreleri ve özellikle astrositler santral sinir sistemi hücre içeriğinde önemli bir orana s... more Glia hücreleri ve özellikle astrositler santral sinir sistemi hücre içeriğinde önemli bir orana sahiptir. Glutamat toksisitesine karşı nöronlardan daha dirençli olduğu bilinen glia hücreleri nöron koruyucu mekanizmalara da sahiptir. Oksidan stres, reaktif oksijen türevleri ve serbest radikal oluşumu ve bunlara bağlı organel ve hücre hasarını (akson, glia, endotel dahil) geliştirir. 1-2 günlük sıçan beyinlerinden elde edilen primer mikst glia kültürleri 14. kültür gününde kontrol (n=6), toksisite (glutamat) (n=6), toksisite+melatonin (n=6), toksisite+7-nitroindazol (n=6) veya toksisite+riluzol (n=6) olmak üzere 5 gruba ayrıldı. 20mM glutamat eklenerek toksisite oluşturulduktan sonra, 100μM melatonin, 500μM 7-nitroindazol veya 100μM riluzol kültür ortamına eklendi. 1, 6, 24 ve 48. saatlerde kültür üst sıvıları alındı. Bu örneklerde LDH ve nirtrit düzeyleri saptandı. Veriler SPSS programında multivariate ANOVA ve post hoc Bonferroni ile değerlendirildi. Multifaktöryel ANOVA sonuçlarına göre zaman [F(3,54)= 116.57, p=0.001)] ve gruplar [F(3,18)=7.993, p=.0001] anlamlı faktörler olarak belirlenmiş ve ayrıca zaman ile gruplar arası anlamlı etkileşim saptanmıştır [F(12,54)=3.664, p=0.001)]. Verilerin değerlendirilmesinde her saat için ayrı ayrı tek yönlü ANOVA kullanıldığında, bekleneceği üzere yine gruplar arası anlamlı fark bulunmuştur [1, 6, 24 ve 48 saatler için, sırasıyla: F(4,28)=7.129, p=0.001; F(4,28)= 8.493, p=0.001; F(4,28)= 6.816, p=0.001; F(4,25)= 11.822, p=0.001]. Post hoc test (Bonferroni) ile gruplar arası farklar Şekil 3ʼte gösterilmektedir. 1., 6. ve 48. saatlerde 7-nitroindazol melatoninden daha etkili olmuştur [t testi sırasıyla: p=0.028, p=0.020, p=0.001]. 24. saatte melatonin ve 7-nitroindazol arasında toksisiteyi azaltma yönünden anlamlılık bulunamamıştır. Sonuç olarak bu çalışmamızda, daha önce deneysel serbral iskemi ve omurilik zedelenmesi modellerimizde gözlemiş olduğumuz melatonin ve 7-nirtoindazolün sağladığı davranışsal koruyucu/iyileştirici etkilere (Dagci et al., 2000; Peker et al., 2000) benzer sonuçlar elde ettik. Adı geçen ajanların, özellikle 7-nitroindazolʼun nöronlar için çok değerli mekanik, metobolik ve biyolojik destek oluşturan glianın in-vitro kültüründe de hücre hasar ve ölümünü engelleyici etkiler ortaya koyduğunu gözlemledik
Purpose: The present study was conducted to determine oxidative stress and cell viability after c... more Purpose: The present study was conducted to determine oxidative stress and cell viability after contact with resin composites polymerized for different times. Methods: Disk-shaped specimens of Admira Fusion, Ceram X One Universal, Solare x and Filtek Z550 (n = 12) were prepared, and two subgroups with polymerization times of 20 and 40 s were employed. The specimens were incubated with mouse fibroblast cells for 48 and 72 h, and changes in reactive oxygen species (ROS) production and cellular viability were determined by an assay with a cell-permeable fluorescent dye, 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCF-DA), and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, respectively. Results: At 72 h, ROS production in the presence of Admira Fusion polymerized for 40 s was reduced relative to that in the presence of Admira Fusion polymerized for 20 s (P < 0.05). Cell viability was maximal in the Admira Fusion and Solare x groups and there was no difference relative to the control group at 48 h. Cell viability was higher in the Admira Fusion and Solare x groups polymerized for 40 s than for the same materials polymerized for 20 s at 72 h (P < 0.05). Conclusion: Extension of the polymerizaton time has a material-specific effect and may be used as a strategy to increase the biocompability of resin composites.
Spinal cord injury (SCI) leads to vascular damage and disruption of blood-spinal cord barrier whi... more Spinal cord injury (SCI) leads to vascular damage and disruption of blood-spinal cord barrier which participates in secondary nerve injury. Epidermal growth factor (EGF) is an endogenous protein which regulates cell proliferation, growth and differention. Previous studies reported that EGF exerts neuroprotective effect in spinal cord after SCI. However, the molecular mechanisms underlying EGFmediated protection in different regions of nervous system have not shown yet. In this study, we aimed to examine possible anti-apoptotic and protective roles of EGF not only in spinal cord but also in brain following SCI. Twenty-eight adult rats were divided into four groups of seven animals each as follows: sham, trauma (SCI), SCI + EGF and SCI + methylprednisolone (MP) groups. The functional neurological deficits due to the SCI were assessed by behavioral analysis using the Basso, Beattie and Bresnahan (BBB) open-field locomotor test. The alterations in pro-/anti-apoptotic protein levels and antioxidant enzyme activities were measured in spinal cord and frontal cortex. In our study, EGF promoted locomotor recovery and motor neuron survival of SCI rats. EGF treatment significantly decreased Bax and increased Bcl-2 protein expressions both in spinal cord and brain when compared to SCI group. Moreover, antioxidant enzyme activities including catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were increased following EGF treatment similar to MP treatment. Our experiment also suggests that alteration of the ratio of Bcl-2 to Bax may result from decreased apoptosis following EGF treatment. As a conclusion, these results show, for the first time, that administration of EGF exerts its protection via regulating apoptotic and oxidative pathways in response to spinal cord injury in different regions of central nervous system.
ObjectiveThe aim of this in vitro study is to evaluate the effects of resveratrol (RES) addition ... more ObjectiveThe aim of this in vitro study is to evaluate the effects of resveratrol (RES) addition on the cytotoxicity and microtensile bond strength (μTBS) of different adhesives.Materials and methodsFive self-etching adhesives (G-aenial Bond-GC, Optibond All in One-Kerr, Gluma Self Etch-Kulzer, Clearfil S3 Bond-Kuraray, and Nova Compo-B Plus-Imicryl) were tested. They were applied to L-929 cell culture by the extract method. In the test groups, 0.5 μM RES (Sigma-Aldrich) was added into the medium. Cell viability was assessed by MTT assay after 24 h. Human extracted third molars were used for μTBS test (n = 7). The adhesives with or without 0.5 μM RES addition were applied on dentin surfaces. A composite build-up was constructed. Then, the specimens were sectioned into multiple beams with the non-trimming version of the microtensile test and subjected to microtensile forces. Statistical analysis was performed using ANOVA and post hoc Tukey test (p ˂ 0.05).ResultsThe extracts of all adhesives decreased the cell viability. However, RES addition increased the cell viability in all groups (p ˂ 0.05). RES addition did not cause any decrease in μTBS values of the adhesives compared to baseline. Optibond All in One showed the highest μTBS after RES addition. It was followed by Clerafil S3 Bond and Nova Compo-B Plus. No difference was determined between the Optibond All in One and Clearfil S3 Bond. There was difference between Optibond All in One and Nova Compo-B Plus (p ˂ 0.05).ConclusionRES addition may improve the biocompatibility without causing negative influence on μTBS of the adhesives.Clinical relevanceRES addition has clinical applicable potential to overcome the adverse biocompatibility of adhesives.
Study Design: Experimental animal study investigating the efficacy of C-terminal domain of tetanu... more Study Design: Experimental animal study investigating the efficacy of C-terminal domain of tetanus toxin application as neuroprotective effects on rat brain in a model of spinal cord injury. Objective: The aim of the present study was to investigate the possible role of C-terminal domain of tetanus toxin (Hc-TeTx) on cell death mechanisms including apoptosis and autophagy following SCI. Summary of Background Data: Traumatic spinal cord injury (SCI) can lead to posttraumatic inflammation, oxidative stress, motor neuron apoptosis, necrosis and autophagy of tissue. To promote and enhance recovery after SCI, recent development of devices and therapeutic interventions are needed. Methods: Twenty-eight adult rats were divided into four groups (n=7 each) as follows: sham, trauma (SCI), SCI+Hc-TeTx and SCI+methylprednisolone groups. The functional neurological deficits due to the SCI were assessed by behavioral analysis using the BBB open-field locomotor test. The alterations in pro-/anti-apoptotic and autophagy related-protein levels were measured by western blotting technique. Results: In this study, Hc-TeTx promotes locomotor recovery and motor neuron survival of SCI rats. Hc-TeTx also decreased expression of bax, bad, bak, cleaved caspase-3, Ask1 and autophagy-related proteins including Atg5 and LC3II in brain. Our study provides an evidence that cell death mechanisms play critical roles in SCI and that the non-toxic peptides including Hc-TeTx may exert protective effect and decrease cell death following SCI. Conclusion: Our preliminary findings suggest a possible therapeutic agent to improve survival after spinal cord trauma, but further analysis are still needed to evaluate the difference between acute and chronic injuries.
Quercertin per se did not affect redox homeostasis but increased the time of hemolysis and decrea... more Quercertin per se did not affect redox homeostasis but increased the time of hemolysis and decreased TBARs levels. Following the EE the Q group displayed a higher GSH/GSSG ratio and a less pronounced increase in TBARs, compared to placebo group. Moreover, we found that GPx enzyme activity were induced after EE only in Q group, while any significant modification of this parameter was detected in placebo group. In conclusion, the Q supplementation may be used as a countermeasure against oxidative stress inducing, in erythrocytes, a cellular adaptation allowing subjects to better cope with the oxidative stress induced by an acute exercise.
molecular etiology of HCC are limited. The Nrf2 signaling pathway can protect cells from a variet... more molecular etiology of HCC are limited. The Nrf2 signaling pathway can protect cells from a variety of toxicants and carcinogens by increasing the expression of a number of cytoprotective genes.The idea of using G. lucidum for cancer treatment is based on numerous laboratory and preclinical studies with cancer and immune cells as well as animal models demonstrating various biological activities in vitro and in vivo. The aim of our study is to evaluate the potential antioxidant role of G. lucidum in HCC. For this purpose, analysis of Nrf2 levels and cell cycle arrest were done. The most effective concentration of G. lucidum were found at 1/5 dilution. The changes in cytoplasmic/nuclear Nrf2 protein levels following G. lucidum extracts (1:5 or 1:10) treatments for 24, 48 or 72 h were observed. 1/10 and 1/5 diluted of G. lucidum induced G0/G1 cell cycle arrest in HCC. Consistently, the cells distributed in S phase were significantly reduced.In conclusion, our findings suggest that G. lucidum has a potential as an anticancer agent and. our data support the importance of the clarification of the molecular mechanisms of phytochemicals-induced Nrf2 activation.
In vivo performance of different scaffolds for dental pulp stem cells induced for odontogenic dif... more In vivo performance of different scaffolds for dental pulp stem cells induced for odontogenic differentiation Abstract: This study was designed to determine the in vivo performance of three different materials as scaffolds for dental pulp stem cells (DPSC) undergoing induced odontogenic differentiation. An odontogenic medium modified by the addition of recombinant human bone morphogenetic protein 2 was used in the experimental groups to induce differentiation. Mesenchymal stem cell medium was used in the control groups. DPSC were transplanted onto the backs of mice via three scaffolds: copolymer of L-lactide and DL-lactide (PLDL), copolymer of DL-lactide (PDL) and hydroxyapatite tricalcium phosphate (HA/TCP). The expression levels of dentin sialo-phosphoprotein (DSPP), dentin matrix protein-1 (DMP1), enamelysin/matrix metalloproteinase 20 (MMP20) and phosphate-regulating gene with homologies to endopeptidases on X chromosome (PHEX) were analysed using RT-PCR. The expressions in the experimental groups were compared to those in the control groups. The transcript expressions at 6 and 12 weeks were significantly different for all scaffolds (p < 0.05), except for the expression of DSPP in the PLDL group with regard to the time variable. Although there was a decrease in the expression of enamelysin/MMP20 in PLDL and HA/TCP at 12 weeks, all other expressions increased and reached their highest level at 12 weeks. The highest DSPP expression was in the PDL group (p < 0.05). The highest expression of DMP1 was detected in the HA/TCP group (p < 0.05). The highest expression of PHEX was in the PLDL group (p < 0.05). Consequently, PLDL and PDL seemed to be promising scaffold candidates for odontogenic regeneration at least as HA-TCP, when they were applied with the DPSC induced for odontogenic differentiation.
Celal Bayar Üniversitesi Fen Bilimleri Dergisi, 2016
Bir dental implant tedavisinin başarısında cerrahi teknik, implant materyali ve implant dizaynı g... more Bir dental implant tedavisinin başarısında cerrahi teknik, implant materyali ve implant dizaynı gibi faktörlerin yanı sıra, implant materyalinin yüzey özelliklerinin de önemli olduğu bilinmektedir. Son yıllarda yapılan çalışmalar iyon implantasyonunun dental implantların yüzey modifikasyonu açısından iyi bir aday olduğunu göstermiştir._Bu çalışmada, MEVVA iyon implantasyon teknolojisi kullanılarak, metal+gaz hibrit iyon implantasyonu yapılmış yüzeylerin osteoblast hücre tutunmasına etkisi incelenmiştir. Bu amaçla, iyon implante edilecek materyal olarak son yıllarda dental implant materyali olarak en çok kullanılan titanyum (ISO 5832-2 Grade 4) seçilmiştir. Titanyum yüzeylere implante edilecek metal element olarak yüksek biyouyumluluğu ile bilinen zirkonyum ve zirkonyum ile eş zamanlı implante edilen gaz elementi olarakta titanyum yüzeylerin pasivasyonunu arttırmak için oksijen kullanılmıştır. Osteoblast hücre tutunmaları in vitro ortamda gerçekleştirilerek yüzey pürüzlülüğünün ve iyon implantasyon işleminin osteoblast hücre tutunmaları üzerine etkisi karşılaştırılmalı olarak incelenmiştir. Sonuç olarak pürüzlü ve iyon implante edilmiş yüzeylerde hücrelerin daha iyi tutunduğu görülmüştür.
Conference of the Society-for-Free-Radical-Research-Europe (SFRR-E) -- JUN 08-11, 2016 -- Budapes... more Conference of the Society-for-Free-Radical-Research-Europe (SFRR-E) -- JUN 08-11, 2016 -- Budapest, HUNGARYWOS: 000377617900124Soc Free Rad Res Europ
Increased concentration of manganese (Mn) in the brain is known to be associated with excitotoxic... more Increased concentration of manganese (Mn) in the brain is known to be associated with excitotoxicity and neuroinflammation. Vinpocetine, an alkaloid derived from the plant Vinca minor L., basically shows its effect via phosphodiesterase inhibition and voltage-dependent Na(+) channels. Vasoactive intestinal peptide (VIP) has gastrointestinal, vasomotor, muscular, and neuroprotective effects. The aim of this study was to examine the potential protective effects of vinpocetine and VIP against Mn toxicity in NE-4C neural stem cells (NSCs). VIP treatment at 1 μM and vinpocetine treatment at 2 μM concentrations were sufficient to yield maximum protection, and these concentrations were adopted in the following experiments. In this study, Mn treatment significantly increased lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS) production, and triggered cell death in NE-4C cultures. However, significant reduction in LDH release was observed following vinpocetine or VIP treatments when compared with control. Similar to these findings, vinpocetine or VIP treatments significantly reduced membrane degradation induced by Mn (p &lt; 0.001). Moreover, vinpocetine attenuated Mn-induced decrease of mitochondrial membrane potential. Similarly, proapoptotic protein bax and ROS production significantly decreased in cells after incubation with vinpocetine (p = 0.01) or VIP in the presence of Mn (p &lt; 0.001). Our study provides the evidence that both vinpocetine and VIP may exert protective effects via modulating oxidative stress and apoptosis in Mn-induced neurodegeneration in NE-4C cells.
The aim of this study was to evaluate whether medium modification improves the odontogenic differ... more The aim of this study was to evaluate whether medium modification improves the odontogenic differentiation of human dental pulp stem cells (DPSC) in vitro and in vivo. DPSC isolated from human impacted third molar teeth were analysed for clusters of differentiation with flow cytometry. Odontogenic differentiation was stimulated by medium modification with the addition of bone morphogenetic protein 2 (BMP2). The expression of dentin sialophosphoprotein, dentin matrix protein 1, enamelysin/matrix metalloproteinase 20 and the phosphate-regulating gene with homologies to endopeptidases on the X chromosome of the cells were analysed with RT-PCR at 7, 14 and 21 days. Then, DPSC were transplanted on the back of immunocompromised mice via a hydroxyapatite tricalcium phosphate scaffold, and the structure of the formed tissue was investigated. The cells were identified as mesenchymal stem cells with a 98.3% CD73 and CD90 double-positive cell rate. The increase in mineralization capacity and expression of human enamel-dentin specific transcripts proportional to the culture period were determined after differentiation. Six weeks after transplantation, an osteo-dentin matrix was formed in the group in which odontogenic differentiation was stimulated, and the odontogenic characteristics of the matrix were confirmed by histological examination and RT-PCR analysis. Odontogenic differentiation of the isolated and characterized human DPSC was improved with medium modification by the addition of BMP2 in vitro and in vivo. The defined medium and applied technique have a potential use for forming reparative dentin in the future, but the effects of the method should be investigated in long-term studies.
Systemic kainic acid (KA) administration to rats triggers wet dog shakes (WDS) followed by epilep... more Systemic kainic acid (KA) administration to rats triggers wet dog shakes (WDS) followed by epileptic seizures. Although WDS are often associated with the occurrence of seizures, we have recently shown that following nitric oxide (NO) synthesis inhibition, the number of WDS decreased; subsequently the onset of seizure activity was shortened, and the number of convulsions was increased. Somatostatin (SS), whose release appears to be controlled by NO, inhibits seizure activity. There are sex differences in seizure susceptibility as well as in SS and NO activities in brain. The present study was undertaken to assess the effect of octreotide (OC), a stable SS analogue, on KA-induced WDS and seizures in rats, with emphasis on possible sex differences. WDS and seizures were induced by KA in male and female (proestrus) Sprague Dawley rats; OC or saline was injected 30 min before KA and the behavior was monitored for 120 min after KA. Octreotide increased the number of WDS and decreased the number of convulsions; this effect was more pronounced in males. Onset of KA-induced seizure activity was earlier in females than males; however, there was no effect of OC on seizure latency. Seizure activity started after the termination of WDS. These results show OC has opposite effects on WDS and convulsions, in that it stimulates the former and inhibits the latter. These results support our previous findings that WDS and seizure activity involve separate mechanisms and suggest that WDS may have an inhibitory effect on limbic seizures.
Resveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and c... more Resveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and cancer and exhibit neuroprotective effects. In this study, we examined the neuroprotective and antioxidant effects of resveratrol against hydrogen peroxide in embryonic neural stem cells. Hydrogen peroxide treatment alone increased catalase and glutathione peroxidase activities but did not change superoxide dismutase levels compared with hydrogen peroxide + resveratrol treatment. Nitric oxide synthase activity and concomitant nitric oxide levels increased in response to hydrogen peroxide treatment. Conversely, resveratrol treatment decreased nitric oxide synthase activity and nitric oxide levels. Resveratrol also attenuated hydrogen peroxide-induced nuclear or mitochondrial DNA damage. We propose that resveratrol may be a promising agent for protecting embryonic neural stem cells because of its potential to decrease oxidative stress by inducing higher activity of antioxidant enzymes, decr...
N-methyl-d-aspartate (NMDA) receptors are major pharmacological targets to prevent or reduce the ... more N-methyl-d-aspartate (NMDA) receptors are major pharmacological targets to prevent or reduce the progression of neurodegenerative diseases. Successful therapy with NMDA receptor antagonists in humans has been limited by the severe side effects of complete receptor blockade. The aim of the present study was to investigate the possible protective effects of tideglusib against NMDA receptor overactivation in neural stem cells. We measured the alteration in membrane integrity, free radical generation, intracellular Ca(2+) accumulation, mitochondrial membrane potential (MMP)/mitochondrial morphology and glycogen synthase kinase-3 (α/β isoforms and phospho-GSK-3α/β) protein expression levels following treatments. NMDA treatment, with or without d-serine, significantly increased LDH leakage and triggered cell death in neural stem cells. Reactive oxygen species (ROS) formation and intracellular Ca(2+) levels were increased following NMDA receptor overactivation. The significant reduction in MMP was found in NMDA/d-serine-treated cells. Tideglusib significantly decreased ROS production and membrane degradation, but did not change intracellular Ca(2+) levels following NMDA receptor activation. Both in the presence or in the absence of NMDA/d-serine, tideglusib increased MMP and the levels of phospho-GSK-3β in NSCs. Moreover, GW9662 (a peroxisome-proliferator-activated receptor gamma (PPARγ) antagonist) treatment significantly inhibited the protective effect of tideglusib in NMDA/d-serine-treated cells. Our study provides the evidence that GSK-3β and PPARγ may be directly involved in pathways leading to NMDA receptor-induced cell death and that the inhibitors including tideglusib may exert neuroprotective effect against these receptor overactivation.
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Papers by Taner Dagci