Person: YEGEN, BERRAK
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YEGEN
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BERRAK
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Publication Metadata only Melatonin supports alendronate in preserving bone matrix and prevents gastric inflammation in ovariectomized rats(WILEY, 2019) YEGEN, BERRAK; Gurler, Esra Bihter; Cilingir-Kaya, Ozlem Tugce; Eyuboglu, Irem Peker; Ercan, Feriha; Akkiprik, Mustafa; Reiter, Russell J.; Yegen, Berrak C.The anti-catabolic bisphosphonate alendronate is considered as the first-line medical treatment in post-menopausal osteoporosis; but several side effects, including gastric mucosal injury, are associated with its use. The aim was to elucidate whether combined treatment with melatonin plus alendronate would be more advantageous in the maintenance of bone and the prevention of gastric side effects. Under anaesthesia, female Sprague-Dawley rats underwent bilateral ovariectomy (OVX), while control group had sham surgery. Four weeks after the surgery, OVX rats were treated with saline, melatonin (25 mu g/mL/d), alendronate (70 mu g/kg/wk), melatonin + alendronate, melatonin + melatonin receptor antagonist (luzindole, 10 mu g/kg/d) or alendronate + melatonin + luzindole for 8 weeks. Rats were euthanized at the end of 12th week. Runx2 expression, apoptotic cells, and trabecular thickness were evaluated in tibiae, while gastric tissues were analysed for oxidative injury parameters. In all OVX groups, Runx2 expression was depressed. Saline-treated OVX group presented an extreme decrease in calcified area in opposition to melatonin- or alendronate-treated groups, while the bones in alendronate + melatonin-treated group were similar to those of the sham-operated group. Concomitant with the improvements examined histologically in bone tissues, quantitative TUNEL (+) cells were similarly lower in alendronate- or melatonin-treated groups. Oxidative gastric damage was increased in saline- or alendronate-treated groups, which were depressed in the presence of melatonin. Although melatonin and alendronate exerted similar supportive effects on the maintenance of bone mass, melatonin may have a more advantageous impact by protecting against OVX-induced gastric injury, which was aggravated by alendronate use. Highlights Our results demonstrate that alendronate and melatonin had similar supportive effects on the maintenance of bone mass, while melatonin prevented the gastric side effects of alendronate, making this combination an advisable therapeutic approach in the treatment of menopausal osteoporosis.Publication Metadata only Deneysel sepsis modelinde akut kardiyopulmoner ve serebral hasarda nöropeptit W'nin etkisi(2019-12-13) ATICI, ALİ EMRE; PEKER EYÜBOĞLU, İREM; YEGEN, BERRAK; AKKİPRİK, MUSTAFA; ERCAN, FERİHA; ATICI A. E., ARABACI TAMER S., levent h. n., PEKER EYÜBOĞLU İ., ERCAN F., AKKİPRİK M., YEGEN B.Giriş ve Amaç: Ciddi enfeksiyonların neden olduğu sepsis ve beraberinde görülen çoklu organ yetmezliği, yüksek morbidite ve mortalite oranıyla en önemli klinik sendromlardan biridir. Yakın zamanda tanımlanan ve nöroendokrin düzenlemelerde işlev gördüğü gösterilen nöropeptit W (NPW)’nin, deneysel sepsis modeli oluşturularak akciğer, kalp ve beyin dokularında indüklenen oksidatif hasarda olası tedavi edici etkilerini araştırmayı amaçladık. Yöntemler: Ketamin anestezisi altında, Sprague-Dawley erkek sıçanlarda sham-operasyon (n=8) yapıldı veya çekal ligasyon ve perforasyon ile sepsis oluşturuldu (n=64). Post-operatif ciltaltına 3 doz (hemen sonra, 12. ve 24. saatlerde) serum fizyolojik (SF) veya TNF-alfa inhibitörü + antibiyotik (1 mg/kg etanersept + 100 mg/kg seftriakson) veya NPW (0,1; 0,3; 1, 3 ve 10 g/kg) uygulanırken, sham-opere gruba SF enjeksiyonları yapıldı. Yirmibeşinci saatte alınan kan örneklerinde C-reaktif protein (CRP), kortikosteron ve IL-6 düzeyleri ile çıkarılan akciğer, kalp ve beyin dokularında antioksidan glutatyon, lipit peroksidasyonunu gösteren malondialdehit ile nükleer faktör kappa-B (NF- B) mRNA ekspresyon düzeyleri ölçüldü. Hematoksilen-eozin ile histopatolojik değerlendirmeler yapıldı. Verilerin analizinde ANOVA ve Student’ın t-testleri kullanıldı. Bulgular: Etanersept+antibiyotik veya NPW (1-10 g/kg) tedavili sepsis gruplarında IL6, kortikosteron ve CRP düzeyleri SF-tedavili sepsis grubuna göre düşük bulundu (p<0,05-0,001). SFsepsis grubunda beyinde ve akciğerde malondialdehit düzeylerinin arttığı (p<0,01) ve glutatyonun düştüğü (p<0,01) gözlendi. Etanersept+antibiyotik tedavisi veya NPW beyindeki bu değişiklikleri engelledi (p<0,05-0,001). Buna karşın, akciğerde sepsisle artan malondialdehit ve azalan glutatyon düzeylerine antibiyotik+etanersept etkili olmazken, NPW (0,1-0,3 g/kg) akciğerde malondialdehit düzeyini düşürdü (p<0,05-0,01). Kalp dokusunda ölçülen malondialdehit ve glutatyon düzeyleri ile tüm dokularda ölçülen NF- B ekspresyonları açısından gruplar arasında anlamlı fark bulunmadı. SF-tedavili sepsis grubunda gözlenen dejenere nöron sayısında artış, akciğerde şiddetli kanama, alveoler yapıda bozulma ve nötrofil infiltrasyonu ile kardiyomiyositlerdeki konjesyon ve orta derecede hasar gibi değişikliklerin etanersept+antibiyotik ve NPW (10 g/kg) ile hafiflediği ve histolojik yapıların neredeyse normale döndüğü izlendi. Sonuç: Sepsisin ilk 24 saatinde uygulanan NPW, doza bağımlı olarak akciğer ve beyinde oksidatif hasara karşı koruyucu etki göstermektedir.Publication Open Access Ghrelin Treatment Improves Lipid Metabolism and Hepatic Degeneration in Ovariectomized Rats(GAZI UNIV, FAC MED, 2020-01-01) YEGEN, BERRAK; Gurler, Esra Bihter; Ozbeyli, Dilek; Kaya, Ozlem Tugce Cilingir; Ercan, Feriha; Yegen, Berrak C.Objective: Metabolic disorders occurring in post-menopausal period increase the risk for development of fatty liver disease in women. Aim of the study was to evaluate possible effects of ghrelin on metabolic biomarkers and hepatic morphology in ovariectomized (OVT) rats. Methods:Under ketamine-chlorpromazine anesthesia (100 mg/kg, 0.75 mg/kg), Sprague-Dawley rats (n=12) underwent bilateral OVT, while control group had sham-surgery (n=6). Four weeks after surgery, half of OVT rats were treated intraperitonally with ghrelin (1 mg/kg/hafta) for 4 weeks, while others were not treated. Rats were euthanized by cardiac puncture at the end of 8th weeks, and serum levels of glucose, insulin, aspartate aminotransferase (AST), high-density lipoprotein (HDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), triglycerides, estradiol and progesterone were measured by an automated analyzer. Results: Increased body weights in OVT rats (p<0.001) recorded at the end of 2 months was not changed with ghrelin. Serum estradiol and progesterone levels were reduced (p<0.05) verifying altered gonadal hormone status, but insulin and glucose levels were not changed. Reduced HDL and increased LDL levels (p<0.0.5) were evident in non-treated OVX rats, while ghrelin treatment depressed LDL levels (p<0.0.5), but did not change HDL levels. However, ghrelin in OVT rats depressed triglycerides, VLDL and AST levels significantly (p<0.05). Moderate sinusoidal congestion, activated Kupffer cells and hepatocytes with ballooning degeneration was observed in non-treated OVT rats, while significant improvements were present in livers of ghrelin-treated rats. Conclusion: In conclusion, mild dyslipidemia and hepatic degeneration in early post-menopausal period appear to be attenuated by ghrelin treatment, and require further investigation.Publication Metadata only Oxytocin ameliorates oxidative colonic inflammation by a neutrophil-dependent mechanism(ELSEVIER SCIENCE INC, 2005) YEGEN, BERRAK; Iseri, SO; Sener, G; Saglam, B; Gedik, N; Ercan, F; Yegen, BCOxytocin (OT), a nonapeptide produced in the paraventricular and the supraoptical nuclei in the hypothalamus has a wide range of effects in the body. However, the role of OT on the gastrointestinal (GI) tract has to be settled. OT may participate in the regulation of motility, secretion, blood flow, cell turnover and release of neurotransmitters and/or peptides in the GI tract, possesses antisecretory and antiulcer effects, facilitates wound healing and is involved in the modulation of immune and inflammatory processes. The present work was conducted to assess the possible therapeutic effects of OT against the acetic acid-induced colonic injury in the rat. Methods: Colitis was induced by intracolonic administration of acetic acid (5%) in Sprague-Dawley rats (200-250 g). Either saline or OT (0.5 mg/kg) was injected subcutaneously, immediately after the induction of colitis and repeated two times a day for 4 days. On the 4th day, rats were decapitated and distal 8 cm of the colon were removed for the macroscopic and microscopic damage scoring, determination of tissue wet weight index (Wl), malondialdehyde (NIDA) levels, an end product of lipid peroxidation; glutathione (GSH) levels, a key antioxidant; and myeloperoxidase (MPO) activity, as an indirect index of neutrophil infiltration. Colonic collagen content, as a fibrosis marker was also determined. Lactate deydrogenase (LDH) and tumor necrosis factor-alpha (TNF-alpha) levels were assayed in serum samples. In the acetic acid-induced colitis, macroscopic and microscopic damage scores, WI, MDA and MPO levels were significantly increased, while GSH levels were decreased when compared to control group (p < 0.05-<0.001). Treatment with OT abolished the colitis-induced elevations in damage scores, WI, MDA and MPO levels and restored the GSH levels (p<0.05-0.001). Similarly. acetic acid increased the collagen content of colonic tissues and OT-treatment reduced this value to the level of the control group. Serum LDH and TNF-a levels were also elevated in the acetic acid-induced colitis group as compared to control group, while this increase was significantly decreased by OT treatment. The results suggest that OT, which improves the antioxidative state of the colonic tissue and ameliorates oxidative colonic injury via a neutrophil-dependent mechanism, requires further investigation as a potential therapeutic agent in colonic inflammation. (C) 2004, Elsevier Inc. All rights reserved.Publication Metadata only Melatonin protects against oxidative organ injury in a rat model of sepsis(SPRINGER, 2005) YEGEN, BERRAK; Sener, G; Toklu, H; Kapucu, C; Ercan, F; Erkanli, G; Kacmaz, A; Tilki, M; Yegen, BCPurpose. Based on the potent antioxidant effects of melatonin, we investigated the putative protective role of melatonin against sepsis-induced oxidative organ damage in rats. Methods. Sepsis was induced by cecal ligation and puncture (CLP) in Wistar albino rats. Animals subjected to CLP and sham-operated control rats were given saline or melatonin 10 mg/kg intraperitoneally 30 min before and 6 h after the operation. The rats were killed 16 h after the operation and the biochemical changes were investigated in the liver, kidney, heart, lung, diaphragm, and brain tissues by examining malondialdehyde (MDA) and glutathione (GSH) levels, and myeloperoxidase (MPO) activity. We also examined the tissues microscopically. Results. Sepsis resulted in a significant decrease in GSH levels and a significant increase in MDA levels and MPO activity (P < 0.05-P < 0.001) showing oxidative damage, which was confirmed by histological examination. Melatonin clearly reversed these oxidant responses and the microscopic damage, demonstrating its protective effects against sepsis-induced oxidative organ injury. Conclusion. The increase in MDA levels and MPO activity and the concomitant decrease in GSH levels demonstrate the role of oxidative mechanisms in sepsis-induced tissue damage. Melatonin, by its free radical scavenging and antioxidant properties, ameliorated oxidative organ injury. Thus, supplementing antiseptic shock treatment with melatonin may be beneficial in the clinical setting.Publication Open Access Neuropeptide w alleviates hepatorenal oxidative damage in sepsis-induced rats(2020-05-01) ATICI, ALİ EMRE; PEKER EYÜBOĞLU, İREM; ERCAN, FERİHA; AKKİPRİK, MUSTAFA; YEGEN, BERRAK; ATICI A. E., ARABACI TAMER S., levent h. n., PEKER EYÜBOĞLU İ., ERCAN F., AKKİPRİK M., YEGEN B.Background: Despite modern surgical, medical and intensive care treatments, sepsis is still one of the most frequent causes of morbidity and mortality due to multiple life-threatening organ dysfunctions. We aimed to investigate the possible protective effect of neuropeptide W (NPW), a novel peptide effective in regulating neuroendocrine functions, against sepsisinduced hepatorenal damage. Methods: In male Sprague-Dawley rats (200–250 g), sepsis was induced by cecal ligation and puncture under ketamine anesthesia (n=48). Immediately after surgery, saline or TNF-alpha inhibitor (etanercept; 1 mg/kg) plus antibiotic (ceftriaxon; 100 mg/kg) (ET+C) or NPW (0.1, 0.3, 1 or 3 mg/kg) was given subcutaneously, and repeated at 12th and 24th hours, while sham-operated control group (n=8) received three saline injections within twenty-four hours. Rats were decapitated at the 25th hour of surgery and C-reactive protein (CRP), corticosterone and IL-6 levels were measured in serum samples. Kidney and liver samples were obtained for the measurement of myeloperoxidase activity (MPO), malondialdehyde and glutathione levels and nuclear factor kappa-B (NF-kB) mRNA expression levels. Histopathological evaluations were performed in hematoxylin-eosin-stained samples. ANOVA and Student's t-tests were used for data analysis. Results: Elevated serum levels of IL-6, corticosterone and CRP (p<0.05-0.01) in saline-treated sepsis group, as compared to controls, were depressed in the ET+C- (p<0.05) or NPW- (p<0.05-0.001) treated groups. Hepatic malondialdehyde and MPO levels, which were increased in salinetreated sepsis group (p<0.05 and p<0.001), were decreased by ET+C- (p<0.01) or NPW (p<0.05-0.001) treatments. Similarly, increased renal malondialdehyde level was depressed by NPW (p<0.05), but not by ET+C; while none of the treatments had an inhibitory effect on renal MPO. In contrast to replenished renal glutathione levels by all treatments, hepatic glutathione content was not changed by any of the treatments. Hepatic and renal NF-kB mRNA expressions were similar in all groups. Severe hepatocyte degeneration, sinusoidal congestion and inflammatory cell infiltration were observed in saline-treated sepsis group, while parenchymal degeneration, congestion and Kupffer cell activation were mild in ET+Cand NPW-treated sepsis groups. Similarly, severe degeneration of renal corpuscles and tubules with glomerular and interstitial congestion in the saline-treated sepsis group was replaced by moderate glomerular and interstitial vascular congestion and mild tubular congestion in both NPW- and ET+C-treated groups. Conclusion: NPW, applied during the first 24 hours of sepsis, exerted a dose-dependent protective effect against hepatorenal damage, which appears to involve an inhibitorPublication Open Access Cerrahi menopoz oluşturulmuş sıçanların karaciğer ve böbrek dokularında oksidan/antioksidan dengenin korunmasında egzersizin ve östrojenin yararlı etkileri(2022-09-01) YÜKSEL, MERAL; ERCAN, FERİHA; YILDIRIM, ALPER; YEGEN, BERRAK; Tamer S. A. , Levent N., Yüksel M., Ercan F., Yıldırım A., Yegen B.Amaç: Bu çalışmanın amacı cerrahi olarak menopoz oluşturulan sıçanların böbrek ve karaciğerlerinde gözlenen histopatolojik ve fonksiyonel değişiklikleri ve östrojen veya egzersizin ya da östrojen-egzersiz kombinasyonunun oksidan hasar üzerine etkilerini araştırmaktır.Materyal ve Metot: Anestezi altında Sprague Dawley dişi sıçanlara (n=32) bilateral overiektomi uygulandı ve tüm sıçanlar rastgele olarak iki gruba ayrıldı. Sıçanların yarısına normal içme suyu, diğer yarısının içme sularına östrojen (1mg/kg/gün) eklendi. İki hafta sonra gruplar kendi içlerinde sedanter ve egzersiz (5 gün/hafta, 30 daki-ka, 8 hafta) gruplarına ayrıldı. Deney protokolünün sonun-da serum, karaciğer ve böbrek örnekleri biyokimyasal ve histopatolojik incelemeler için alındı. Femurda da histopa-tolojik değerlendirme yapıldı.Bulgular: Cerrahi olarak menopoz oluşturulan sıçan-larda östrojenin böbrek dokusunda nötrofil infiltrasyonunu ve reaktif oksijen türlerinin üretimini baskılayarak koruyu-cu etki gösterdiği, kemik kütlesinde hafif düzeyde artışa neden olduğu, ancak karaciğerin antioksidan glutatyon düzeyinde azalmaya yol açtığı belirlenmiştir. Buna karşın, östrojen uygulaması menopozda yapılan egzersiz nedeniy-le karaciğerde oluşan oksidan stresi engellemiştir. Egzer-sizle veya egzersize östrojen tedavisinin eklenmesiyle böbrek fonksiyonları önemli ölçüde etkilenmezken, kemik yapısında tek başına östrojene kıyasla daha olumlu deği-şiklikler gözlenmiştir.Sonuç: Östrojen replasmanı kemik dokusundaki olum-lu etkilerinin yanı sıra karaciğer ve böbrekte oksidan stresi azaltmakta ve özellikle karaciğerde egzersize bağlı gelişen oksidan stresi baskılayarak koruyucu etki göstermektedir.Publication Metadata only L-Carnitine ameliorates methotrexate-induced oxidative organ injury and inhibits leukocyte death(SPRINGER, 2006) YEGEN, BERRAK; Sener, G; Eksioglu-Demiralp, E; Cetiner, M; Ercan, F; Sirvanci, S; Gedik, N; Yegen, BCMethotrexate (MTX), a folic acid antagonist widely used for the treatment of a variety of tumors and inflammatory diseases, affects normal tissues that have a high rate of proliferation, including the hematopoietic cells of the bone marrow and the gastrointestinal mucosal cells. To elucidate the role of free radicals and leukocytes in MTX-induced oxidative organ damage and the putative protective effect of L-carnitine (L-Car), Wistar albino rats were administered a single dose of MTX (20 mg/kg) followed by either saline or L-Car (500 mg/kg) for 5 days. After decapitation of the rats, trunk blood was obtained, and the ileum, liver, and kidney were removed for histological examination and for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and collagen content. Our results showed that MTX administration increased the MDA and MPO activities and collagen content and decreased GSH levels in all tissues, while these alterations were reversed in L-Car-treated group. The elevated serum TNF-alpha level observed following MTX treatment was depressed with L-Car. The oxidative burst of neutrophils stimulated by Annexin V was reduced in the saline-treated MTX group, while L-Car abolished this inhibition. Similarly, flow cytometric measurements revealed that leukocyte apoptosis was increased in MTX-treated animals, while L-Car reversed these effects. Severe degeneration of the intestinal mucosa, liver parenchyma, and glomerular and tubular epithelium observed in the saline-treated MTX group was improved by L-Car treatment. These results suggest that L-Car, possibly via its free radical scavenging and antioxidant properties, ameliorates MTX-induced oxidative organ injury and inhibits leukocyte apoptosis. Thus, supplementation with L-Carnitine as an adjuvant therapy may be promising in alleviating the systemic side-effects of chemotherapeutics.Publication Open Access Nikotinin Sıçan Pankreatit_x000D_ Modelindeki Hafifletici Etkisinde_x000D_ Vagusun Rolünün Araştırılması(2021-04-01) YEGEN, BERRAK; Meltem KOLGAZİ;Zozan GÜLEKEN;Bircan KOLBAŞI;Canberk Sami BAŞIBÜYÜK;Feriha ERCAN;Berrak Çağlayan YEĞENNikotinin birçok farklı dokuda anti-inflamatuvar etkilere sahip olduğu ve bu etkileri kolinerjik anti-inflamatuvar yolağı aktive_x000D_ ederek gerçekleştirdiği gösterilmiştir. Çalışmada akut pankreatit modelinde nikotin tedavisinin etkilerini ve bu etkilerin_x000D_ kolinerjik yolla ilişkisini araştırmak amaçlanmıştır. Wistar albino sıçanların pankreas-safra ortak kanalı bağlanırken (PSKB),bir_x000D_ gruba da yalancı-cerrahi (YC) uygulandı. PSKB sıçanlara vagal aferent denervasyon (perivagal kapsaisin; 10mg/ml) veya_x000D_ trunkal vagotomi uygulandı ya da vagusları sağlam bırakıldı. PSKB grupları cerrahi sonrası ikiye ayrılarak 4 gün boyunca_x000D_ intraperitoneal nikotin (1 mg/kg/gün) ya da serum fizyolojik verildi. Dördüncü günde dekapitasyonu takiben, serumda tümör_x000D_ nekroz faktör (TNF)-∝ ve interlökin (IL)-10 ölçümü, akciğer, karaciğer ve pankreas dokularında miyeloperoksidaz aktivitesi_x000D_ (MPO), malondialdehit (MDA), glutatyon (GSH) ölçümleri ve histolojik inceleme yapıldı. TNF-∝ düzeyi PSKB grubunda YC_x000D_ grubuna göre belirgin şekilde daha yüksekken, nikotin tedavisi alanlarda belirgin şekilde daha düşüktü. IL-10 düzeyi ise SF_x000D_ tedavisi almış PSKB grubunda YC grubuna göre daha düşüktü ve nikotin tedavisi ile arttığı gözlendi.YC grubuna göre PSKB_x000D_ grubunun pankreas, karaciğer ve akciğer dokularında mikroskopik hasar, MDA, MPO düzeyleri artarken GSH düzeyleri azaldı._x000D_ Nikotin tedavisi ile karaciğer ve pankreas dokularındaki hasar, MDA, MPO düzeyleri azaldı ve GSH miktarları korundu. Vagal_x000D_ aferent denervasyon ya da trunkal vagotomi yapılması nikotinin bu koruyucu etkilerini değiştirmedi. Sonuçlar, nikotinin_x000D_ pankreatit hasarına karşı koruyucu etkilerini vagal yoldan bağımsız olarak, doğrudan immün hücreler üzerindeki ∝7nAChR_x000D_ aktivasyonu ile nötrofil infiltrasyonunu ve pro-inflamatuvar sitokinleri inhibe ederek gerçekleştirdiğini ortaya koymaktadır._x000D_ _x000D_ Anahtar Kelimeler: pankreatit, nikotin, vagus, inflamasyon, pankreatik kanal bağlamaPublication Metadata only Investigation of biphosphonate and melatonin combine treatment on bone formation/resorption rate and morphology in a rat model of osteoporosis(2016-09-01) PEKER EYÜBOĞLU, İREM; YEGEN, BERRAK; AKKİPRİK, MUSTAFA; ERCAN, FERİHA; GÜRLER E. B., PEKER EYÜBOĞLU İ., çilingir kaya ö. T., AKKİPRİK M., ERCAN F., YEGEN B.