Browsing by Author "Vatansever S.H."

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    Evaluation of the relationship between inducible nitric oxide synthase (iNOS) activity and effects of melatonin in experimental osteoporosis in the rat
    (2006) Oktem G.; Uslu S.; Vatansever S.H.; Aktug H.; Yurtseven M.E.; Uysal A.
    Inducible nitric oxide synthase (iNOS) plays a critical role in the pathogenesis of osteoporosis. iNOS generates nitric oxide (NO), a free radical contributing to the imbalance between bone formation and resorption caused by estrogen depletion. Melatonin is the major product of the pineal gland which is known to diminish iNOS expression and NO production significantly. The aim of this study was to determine the distribution of iNOS and the amount of apoptotic cells after melatonin treatment in ovariectomized rats. Since previous studies have shown that constitution of bone formation is primarily sustained in nucleus pulposus and epiphyseal cartilage, experiments were carried out on nucleus pulposus and epiphyseal cartilage; additional quantitation of osteoblasts and osteoclasts were evaluated on vertebral area as well. Vertebral sections of ovariectomized rats were obtained from formalin-fixed and parafin-embedded blocks. iNOS expression and quantitation of apoptotic cells in nucleus pulposus and epiphyseal cartilage were evaluated using indirect immunoperoxidase and TUNEL techniques, respectively. The number of osteoclasts and osteoblasts in trabecular bone was determined using histomorphometry. Ovariectomy increased iNOS expression and the number of apoptotic cells in nucleus pulposus and epiphyseal cartilage, whereas a 4-week treatment with melatonin (10 mg/kg/day) resulted in the reduction of both effects. These data indicate that there is strong influence of melatonin application on expression of iNOS, apoptosis, osteoclast and osteoblast numbers after ovariectomy. In conclusion, melatonin besides its usual use as an antiaging hormone, may also be an effective hormone in treatment of bone changes in estrogen deficiency states. © Springer-Verlag 2006.
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    The distribution of apoptosis and related proteins in ovarian endometriosis
    (2009) Vatansever S.H.; Inan S.V.; Giray G.S.; Sayhan S.; Ozbilgi K.M.; Sanci M.
    [No abstract available]
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    Expression of nitric oxide synthase in primary and recurrent pterygium; [Primer ve tekrarlayan pteryjiumlarda nitrik oksid sentaz ekspresyonu]
    (2012) Emre S.; Vatansever S.H.; Türköz E.; Kayikçioǧlu O.R.
    Purpose: The aim of this study was to investigate the expression of different nitric oxide synthases (NOSs) in primary and recurrent pterygia and to investigate the probable role of any nitric oxide synthase on pterygium recurrence. Materials and Method: Specimens of 40 primary pterygia and 10 recurrent pterygia excised during pterygium surgery were included in the study. Also, 15 normal conjunctiva of medial limbus obtained from patients free of pterygia and removed during other ophthalmologic surgeries formed the control group. Specimens were stained with hematoxylin and eosin for general histological and morphologic evaluation. The distribution of n-NOS, e-NOS and i-NOS were analyzed using indirect immunoperoxidase staining. Results: Histological evaluation of specimens revealed that the epithelium in primary and recurrent pterygia groups was thicker compared to that in the control group. Immunohistochemical analysis revealed that in both primary pterygium and control groups, immunoreactivity was positive for all NOSs in both epithelium and connective tissue. For recurrent pterygium group, NOS immunoreactivity could be detected moderately for n-NOS in the epithelium and weakly for e-NOS in both epithelium and connective tissue. However, in recurrent pterygium samples, i-NOS immunoreactivity was lacking in both epithelium and connective tissue. Discussion: These data are the first to demonstrate that NOS expression may differ between primary and recurrent pterygia. Meanwhile, continuous expression of n-NOS with suppression of i-NOS and e-NOS may be an important step in the recurrence process of pterygia.
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    The cytotoxic and antiproliferative effect of Polygala saponin XLIV on the human colorectal carcinoma cell line
    (Walter de Gruyter GmbH, 2025) Becer E.; Hanoğlu A.; Ünlü A.; Aydın Z.U.; Dönmez A.A.; Jurt S.; Vatansever S.H.; Çalış İ.
    Objectives: Saponins are secondary metabolites naturally found in plants with diverse pharmacological properties such as anticancer. This research aimed to explore the anti-cancer properties of Polygalasaponin XLIV (PS-XLIV) in a human colorectal carcinoma cell line derived from Polygala vulgaris roots. Methods: HCT166 cells were treated with different PS-XLIV concentrations and incubated for 24 and 48 h. We used immunocytochemistry to investigate PS-XLIV’s anti-cancer properties, employing antibodies targeting WNT3A, WNT11, STAT3, β-catenin, and Ki-67. The IC50 value of PS-XLIV was 80 μg/mL in HCT116 cells. WNT11, STAT3, β-catenin, and Ki-67. Immunoreactivities significantly decreased in PS-XLIV-treated HCT116 cells than in control group cells. Results: After PS-XLIV treatment, the epithelial morphology of cells was protected; however, the number of cells was less than that of the control group cells. While WNT3A immunoreactivity was similar in both groups, WNT11 and β-catenin immunoreactivities were decreased after PS-XLIV application. In addition, the PS-XLIV treated group exhibited significantly weaker Ki-67 immunoreactivity, STAT3 immunoreactivty was moderated after PS-XLIV application. Conclusions: For the first time, the anticancer effects of PS-XLIV isolated from P. vulgaris on HCT116 cells were shown. The anticancer effect may involve PS-XLIV reducing WNT11, β-catenin, STAT3, and Ki-67 activation pathways in HCT116 cells. © 2024 the author(s)