Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Korunga Tohumundan Elde Edilen Protein ve Peptidlerin Hücresel Toksisite, Bağışıklık ve Bağırsak Geçirgenliği Üzerindeki Etkileri(2025) Güngör, Sevde Nur; Güleç, Şükrü; Büyükkileci, Ali OğuzBitkisel protein kaynaklarının fonksiyonel özellikleri, beslenme bilimi ve sürdürülebilir gıda sistemleri açısından önemli bir araştırma alanı haline gelmiştir. Bu çalışmada, korunga (Onobrychis viciifolia L.) tohumundan elde edilen protein izolatının (SSPI), insan sağlığına yönelik güvenlik profili ve bağırsak bariyer fonksiyonu üzerindeki etkileri değerlendirilmiştir. SSPI'nin sitotoksik etkisi, Caco-2 ve IEC-6 hücre hatlarında MTT yöntemiyle analiz edilmiştir. Alerjenite değerlendirmesi ise makrofaj hücre hattı (RAW 264.7) üzerinden gerçekleştirilmiş; TNF-α ve IL-6 salınımı ölçülerek immün yanıt potansiyeli belirlenmiştir. Bulgular, SSPI'nin her iki formunun da toksik veya alerjenik risk oluşturmadığını göstermiştir. Bağırsak geçirgenliği üzerine etkileri değerlendirmek amacıyla, diferansiye olmuş Caco-2 hücreleri kullanılarak transepitel bir hücre kültürü sistemi oluşturulmuştur. LPS ve sitokin kokteyli ile geçirgenlik bozulmuş, ardından sindirilmiş SSPI uygulamaları yapılmıştır. TEER ölçümleri ve sıkı bağlantı genlerinin (Occludin, ZO-1, Claudin-1) ekspresyon analizleri, SSPI'nin bariyer fonksiyonunu destekleyici yönde etkiler sağladığını ortaya koymuştur. Bu çalışma, SSPI'nin biyolojik güvenliğini ve bağırsak sağlığı açısından taşıdığı fonksiyonel potansiyeli göstererek, onu gelecekte fonksiyonel gıdalarda değerlendirmeye yönelik bilimsel bir temel sunmaktadır. Elde edilen veriler, SSPI'nin sindirim sonrası da etkili olabildiğini ve bozulmuş bağırsak geçirgenliği gibi inflamatuar durumlara karşı epitel bariyeri güçlendirebildiğini ortaya koymuştur. Bu bağlamda, SSPI yalnızca bir alternatif protein kaynağı değil, aynı zamanda bağırsak bütünlüğünü destekleyici biyoaktif bir bileşen olarak da değerlendirilme potansiyeline sahiptir. Ayrıca, bu çalışma, korunga gibi alternatif bitkisel kaynakların insan sağlığı üzerindeki etkilerini araştıran sınırlı sayıdaki çalışmalardan biri olarak literatürde önemli bir boşluğu doldurmakta ve SSPI'nin nutrasötik ve fonksiyonel ürün geliştirme süreçlerinde dikkate alınabilecek güvenli bir aday olduğunu göstermektedir.Master Thesis Application of fourier transform infrared spectroscopy and molecular techniques in the in vitro study of iron deficiency anemia(01. Izmir Institute of Technology, 2024) Dalyan, Eda; Güleç, ŞükrüBu tez özelinde ele alınacak olan hastalık modeli olan demir eksikliği anemisinin (Iron Deficiency Anemia (IDA)) sebep olduğu fizyolojik değişimleri ve moleküler düzeydeki mekanizmaları anlamak, bu noktada öncü bilgiler elde etmek ve tedavi sonuçlarının tahmin edilmesi için uygun maliyetli ve pratik olan vibrasyonel spektroskopi teknikleri kullanılmıştır. İleriki çalışmalarda anemiye yönelik tasarlanan fonksiyonel gıda & ilaç ürünlerinin anemi üzerindeki etkilerinin veya bu ürünlerin farklı parametlerinin hızlı, pratik ve uygun maliyetli bir şekilde analiz edilmesinde kullanılmak üzere, IDA üzerinde iyileştirici etkisi bilinen ve takviye olarak kullanımı yaygın olan demir formlarıyla tedavi edilen hücrelerden elde edilen spektroskopik veriler kullanılarak bir model oluşturulmuştur. Oluşturulan modelin ileriki çalışmalardaki kullanımını test etmek amacıyla geliştirilen demirin serbest formunu azaltan ve biyoyararlanımını artıran fonksiyonel bir gıda bileşeni olarak işlev görmesi amaçlanan protein-demir kompleksleri vibrasyonel spektroskopi teknikleri ile analiz edilmiştir. Elde edilen veriler oluşturulan modele entegre edilerek protein-demir kompleksinin terapötik etkisi vibrasyonel spektroskopi teknikleri kullanılarak gösterilmiştir. Vibrasyonel spektroskopi teknikleri kullanılarak gösterilen terapötik etkiler, moleküler ve genetik metotlar kullanılarak elde edilen sonuçlarla doğrulanmıştır.Master Thesis The Investigation of Intestinal Zinc and Glucose Metabolism Due To Increased Glucose Amount in Obesity(2023) Divrik, Bengisan; Güleç, Şükrü; Büyükkileci, Ali OğuzObesity is defined as an excessive accumulation of adipose tissue within the human body. The global prevalence of obesity has seen a marked increase, and our country is no exception to this trend. The pathogenesis of obesity is intricately linked to the consumption of glucose, a phenomenon in which glucose absorption plays a pivotal role via the enterocytes of the intestinal lining. In individuals with obesity, both dietary and blood glucose levels are elevated, thereby intensifying the exposure of enterocyte cells to glucose. This thesis results delved into the interactions between high-glucose-associated zinc metabolism and zinc-dependent glucose metabolism within enterocyte cells. Results revealed a correlation between elevated glucose concentrations and reduced zinc levels within the cells, coupled with the regulation of mRNA levels on zinc transporters. Additionally, observed a reduction in cellular 2-deoxy-glucose uptake upon zinc treatment. Also, indicated that zinc treatments, whether administered to the basolateral or both apical and basolateral sides of the cells, led to the regulation of mRNA levels for glucose transporters, compared to control groups. Remarkably, also observed that specific treatments involving zinc on the polarized sides of Caco-2 cells increased the efflux of glucose from these cells. In conclusion, results suggest that zinc may play a pivotal role in the development of obesity concerning glucose metabolism.Master Thesis Investigation of the biological health potency of fig stalk waste pectin for colon cancer cell growth and intestinal glucose absorption(Izmir Institute of Technology, 2022) Başer, Filiz; Güleç, Şükrü; Yemenicioğlu, AhmetHigher intake of dietary fiber is correlated with reduced obesity-related disorders such as cardiovascular diseases and diabetes, improved gut health, and protection against colorectal cancer. Pectin comes from plant cell walls and is mainly composed of galacturonic acid units branched with neutral sugars that provide bioactive and functional properties. Pectin has long been appreciated in the food industry due to its viscous structure and gelling properties. Dietary pectin as a soluble fiber is linked with cancer and metabolic health. Anti-cancer activity of pectin is promising in multiple types of cancer in humans and animals by inducing cellular apoptosis and inhibiting tumor metastasis. Soluble dietary pectin regulates blood glucose levels, sparking interest in diabetes prevention and treatment. Fig stalk waste was used as an unconventional pectin source in the present study, providing a promising green option. The health benefit of fig stalk waste pectin (FSWP) was investigated in terms of colon cancer cell growth and intestinal glucose absorption. The inhibitory effects of FSWP on colon cancer Caco-2 cells were further confirmed with cell cycle analysis and apoptotic cell death. Intestinal glucose absorption was modeled with Caco-2 enterocyte uptake and transport systems. FSWP inhibited 2-deoxyglucose uptake into Caco-2 cells and reduced glucose absorption as a food ingredient in the intestinal transport system. Taken together, FSWP has promising bioactivity against colon cancer and could be used as a functional food additive due to its inhibitory effect on intestinal glucose absorption.Master Thesis Development of Novel Pet Food Involving Drying Step(Izmir Institute of Technology, 2022) Alyamaç, Ayşegül; Güleç, ŞükrüMost of the pet parents prefer dry petfood since it is easy to portion, has longer open-shelf life and doesn`t have an unappealing smell compared to wet petfood. However, wet petfood more closely resembles the fresh meat that pets crave. It helps maintaining hydration and digestion since it includes a high water content. In the petfood industry, it is an open new area to produce dry petfood that can be easily rehydrated and turned into a wet product to provide the benefits of both dry and wet petfood. Considering current food products in the market, a pasta production line can be shown as a good example of manufacturing such products. It consists of dry powder and wet material. Having this analogy in mind, a novel textured wet petfood development was investigated. A Microwave vacuum dryer is used as a novel drying technology in petfood industry. In laboratory trials, die plates of different sizes were tested and the effect of surface area on rehydration was investigated. In pilot plant trials, different raw materials were tested and their effect on the process and on the rehydration time were evaluated. Results showed that the increase in the surface area had a significant effect on the rehydration time. Also, it was observed that the use of blood plasma powder affected the formulation positively and the rehydration negatively. The products made by using poultry meal which were cooled twice after cooking, showed the highest efficiency by causing the least formation of fines during cutting.Master Thesis Extraction of Phytochemicals From Scolymus Hispanicus and Determination of Potential Health Effects(Izmir Institute of Technology, 2017) Ahmad, Bilal; Büyükkileci, Ali Oğuz; Güleç, ŞükrüGolden thistle (Scolymus hispanicus) is an edible medicinal plant growing in Turkey. It has been in use since decades for the treatment of various disorders by local folks. In the past the extracts from the root barks of S. hispanicus were in use in the form of a medicine for the removal of kidney stones. Its root barks are the only eaten part and the root internal and aerial parts are considered as residues. The effect of harvesting time and plant maturity on phytochemicals composition of this plant have not been studied before. Besides that, in previous studies only the edible part was analyzed for bioactive constituents and the residues (aerial parts and root internal parts) have not been analyzed before. In this study, various phytochemicals and total antioxidant activities in the ethanol extracts of aerial parts, root barks and root internal tissues of S. hispanicus harvested from November 2016 to July 2017 were measured. The dominant phytochemicals were different in the roots and the aerial parts, whereas phytochemicals were influenced differently by the harvesting time. Total phenol contents and total antioxidant activities were higher in the aerial parts than the root parts, while total triterpenoid contents were higher in root barks and root internal tissues. Thin Layer Chromatography (TLC) analysis showed that there were not any free triterpenoids in the extracts, however there were glycosides, which may have contained triterpenoids. The crude extracts of S. hispanicus showed cytotoxic effects on Caco-2 cells growth. The results suggested that these extracts might have potential preventative effects on colon cancer.Master Thesis Testing of Antidiabetic Features of Formulated Food Products in Enterocyte Cell Culture Model(Izmir Institute of Technology, 2017) Pilatin, Gözde; Güleç, ŞükrüIn recent years, there has been an increasing interest in designing low calorie functional foods that might have health benefit against development of obesity and T2D. However, researches on developing low calorie foods in Turkey are quite insufficient. Even if the products are developed, in vitro and in vivo approaches to design low calorie foods are not carried out properly. Thus, we aimed to test diabetic features of newly formulated low calorie and no-added sugar containing cake, almond paste and pudding in intestinal cell culture system. Cake, almond paste and pudding were developed by “Egepak Gıda ve Ambalaj San.” and same type foods were chosen from market to use as reference. We modeled human carbohydrates digestive systems in test tube and relative glucose efflux were measured from rat enterocyte cells that were grown on bicameral cell culture system. Bioaccessibility of glucose was found at least 61%, 89% and 64% lower in cake, almond paste and pudding respectively relative to references. The levels of cellular glucose efflux were significantly lower from 30min (for cake 1.9 fold; for almond paste 4.3; for pudding 3.3 fold) to 120 min (for cake 2.2 fold; for almond paste 3.7 fold) to 180 min (for pudding 2.0 fold) in products than their references. To the best of our knowledge, this is the first exemplary study in Turkey to develop newly formulated foods by analyzing their diabetic features in in vitro model of human intestine system.Master Thesis Xylan Degradation Mechanism of Human Intestinal Bacteria(Izmir Institute of Technology, 2017) Polat, Nüket; Büyükkileci, Ali Oğuz; Güleç, ŞükrüXylan is the second most abundant plant cell wall polysaccharide after cellulose. The xylan rich lignocellulosic material obtained from agriculture, forestry and industrial wastes provides cost effective raw materials. The degradation of xylan in the human body is an important process contributing to the continuation of the microbial communities living in the human colonic ecosystem. Due to its complex, long chain structure and the various chemical bonds it contains, xylan hydrolysis requires different enzymatic activities. Bacteria that live in the colon and are useful for human health, such as Bifidobacterium and Lactobacillus species can not perform xylan utilization. However, several types of xylan are utilized by the Bacteroides species, which have the second largest density in the colon. In this study, different Bifidabacterium and Bacteriodes species were investigated for their ability to degrade beechwood xylan and corncob xylan. Bifidabacterium and Bacteriodes were cultured together in tubes containing xylan as the sole carbon source. It was observed that; the B. animalis subsp. lactis, which does not have the ability to use the xylan, could grow when cultured on xylan-containing medium with Bacteroides species. These showed that, the xylan in the media was degraded into xylooligosaccharides by the Bacteroides species and the XOS formed was used as a carbon source by both species. The short chain fatty acid and lactic and succinic acid production profiles of co-cultures were different than the mono cultures, indicating a positive effect of co-culturing. This study showed that xylan is a potential prebiotic carbohydrate, which can selectively stimulate the growth of beneficial bacteria in the colon, as a result of possible cross feeding of different bacteria residing in the colon.Master Thesis Investigation of the Molecular and Genetic Response in Enterocytes of Duodenum During Elevated Intracellular Glucose Level(Izmir Institute of Technology, 2016) Boztepe, Tuğçe; Güleç, Şükrü; Seyrantepe, VolkanGlucose is one of the nutritional factor that involves in developing of obesity and type 2 diabetes in human. The studies indicated that enterocyte cells on intestine might play a role in dietary glucose sensing during obesity. Obese people are consumed high amount of dietary glucose and enterocyte cells consequently are exposed to high glucose. Thus, we aimed to find relevant physiological pathways and genome-wide mRNA expression profiles that can be regulated by glucose in fully differentiated human intestinal epithelial (CaCo-2). The cells were maintained two different glucose levels (5.5mM for control, 25mM for high glucose) at least three passages. The cells were grown on transwell system for 21 days to mimic human intestine system. Transepithelial electrical resistances (TEER) were measured to control monolayer formation and polarization. RNA isolation was performed and whole genome mRNA expression profile were determined following gene ontology analysis to find affected molecular pathways. Compared to control relative glucose level was found high in basolateral side of CaCo-2 cells that were under high glucose condition without effecting TEER. GLUT2, SGLT1, GLUT5 mRNA levels were significantly reduced during elevated glucose levels which is consistent with literature. Significant fold change analysis showed that 351 genes upregulated and 468 genes under high glucose condition. We found high glucose significantly leads changes of molecular pathways (downregulated; glycolysis and gluconeogenesis, adherens junction, fructose/mannose metabolism, pentose phosphate pathway and upregulated; protein export). These results provide us better understanding and open new window for glucose metabolism of enterocytes during obesity.