Browsing by Author "Yilmaz, Osman"

Now showing 1 - 4 of 4

Citation - WoS: 6
Citation - Scopus: 5
Antioxidant Effect of Epigallocatechin-3 in a Bleomycin-Induced Scleroderma Model
(Turkish League Against Rheumatism, 2019) Kocak, Ayse; Harmancı, Duygu; Cavdar, Zahide; Ural, Cemre; Birlik, Merih; Sarioglu, Sulen; Yilmaz, Osman; Akdoğan, Gül
Objectives: This study aims to evaluate the antioxidant effects of epigallocatechin-3-gallate (EGCG) in a bleomycin (BLM)-induced scleroderma model. Materials and methods: Thirty-two healthy female Balb-c mice (6-8-week-old; weighing 22 +/- 5 g) were used in this study. The mice were randomly divided into four groups: control (n=8), BLM (n=8), BLM+EGCG (n=8), and EGCG (n=8). Skin tissue specimens were collected at the end of the experiments. Histopathological examinations of skin tissues were performed. Skin samples were assessed for total superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The phosphorylation of p-38 mitogen-activated protein kinase and Akt protein (the serine-threonine protein kinase encoded by the AKT), as well as the nuclear factor-kappa B (NF-kappa B) levels, were analyzed by western blotting. Results: Epigallocatechin-3-gallate-treated groups were observed to have reduced connective tissue fibrosis in the dermis area using Masson's trichrome staining method. Pp-38 and NF-kappa B were found to decrease significantly in the BLM + EGCG group compared with the BLM group. Parallel to these findings, phosphorylated Akt protein was found to increase in the BLM + EGCG group compared with the BLM group. SOD activity was increased in the EGCG group and content of MDA level was decreased in EGCG groups. Conclusion: The results of the present study demonstrated that EGCG represses pp-38 and NF-kappa B signaling pathways, exerting a protective effect for scleroderma through its anti-oxidative role.
Citation - WoS: 2
Citation - Scopus: 4
Effects of Epigallocatechin-3 (egcg) on a Scleroderma Model of Fibrosis
(Walter De Gruyter Gmbh, 2018) Kocak, Ayse; Harmancı, Duygu; Birlik, Merih; Sarioglu, Sulen; Yilmaz, Osman; Cavdar, Zahide; Akdoğan, Gül
Objective: The aim of the present study was to evaluate the potential protective effects of epigallocatechin-3-gallate (EGCG) on fibrosis in bleomycin induced scleroderma model. Materials and methods: Thirty-two healthy female Balb-c mice with the average body weight of 22 +/- 5 g were used in this study. The mice were randomly divided into four groups as control (n=8), Bleomycin (n=8), Bleomycin+ EGCG (n =8) and EGCG (n =8). Skin tissue samples were collected to quantify matrix metalloproteinases (MMP-1, MMP-8, MMP-13), p-SMAD 2/3 and SMAD 2/3 in protein homogenates by western blotting. TGF-beta 1 expression was determined by real-time PCR. Immunohistopathological and histopathological examinations of skin tissues were also done. Results: When measured with Masson Trichrome, EGCG treatment was found to decrease fibrosis in connective tissue compared to the BLM injected control. EGCG was decreased dermal fibrosis. Bleomycin + EGCG group showed a significant reduction in fibrosis at the dermal surface area using hematoxylin measurements compared with the BLM group. MMP-1, MMP-8 protein levels were increased and p-SMAD 2/3 protein level was decreased. TGF-beta mRNA expression was decreased in the EGCG + BLM group compared with the BLM group. Conclusion: These results suggest an antifibrotic role for EGCG.
Citation - WoS: 11
Citation - Scopus: 12
Protective Effects of Alpha-Lipoic Acid on Bleomycin-Induced Skin Fibrosis Through the Repression of Nadph Oxidase 4 and Tgf-Beta 1/Smad3 Signaling Pathways
(Sage Publications Ltd, 2022) Kocak, Ayse; Ural, Cemre; Harmancı, Duygu; Oktan, Mehmet Asi; Afagh, Aysan; Sarioglu, Sulen; Yilmaz, Osman; Akdoğan, Gül
The aim of this study was to determine the protective effects of alpha-lipoic acid (ALA), which is known as a powerful antioxidant, and the possible related molecular mechanisms that mediate its favorable action on skin fibrosis in the bleomycin (BLM)-induced scleroderma (SSc) model in mice. The experimental design was established with four groups of eight mice: Control, ALA (100 mg/kg), BLM (5 mu g/kg), and BLM + ALA group. BLM was administered via subcutaneous (sc) once a day while ALA was injected intraperitoneally (ip) twice a week for 21 days. Histopathological and biochemical analyses showed that ALA significantly reduced BLM-induced dermal thickness, inflammation score, and mRNA expression of tumor necrosis factor-alpha (TNF-alpha) in the skin. Besides, the mRNA expressions of the subunits of NADPH oxidase, which are Nox4 and p22phox, were found to be significantly induced in the BLM group. However, ALA significantly reduced their mRNA expression, which were in parallel to its decreasing effect on serum total oxidant status (TOS) level. Moreover, it was found that ALA downregulated the mRNA expressions of alpha-smooth muscle actin (alpha-SMA), collagen type I and fibronectin in the skin tissue of the BLM group. Additionally, it was shown that ALA reduced significantly the TGF-beta 1 and p-Smad3 protein expressions in the BLM + ALA group. On the other hand, ALA did not exhibit any significant effect on the p38 mitogen-activated kinase (MAPK) activation induced by BLM. All these findings point out that ALA may be a promising treatment for the attenuation of skin fibrosis in SSc patients.
Citation - WoS: 16
Citation - Scopus: 18
The Role of Resveratrol on Full - Thickness Uterine Wound Healing in Rats
(Elsevier Taiwan, 2017) Sayin, Oya; Micili, Serap Cilaker; Goker, Asli; Kamaci, Gonca; Ergur, Bekir Ugur; Yilmaz, Osman; Akdoğan, Gül
Objective: Healing of the uterus after cesarean section and myomectomy operation is clinically important. In this study, we aimed to investigate the effects of resveratrol (3,5,4'-o-trihydroxystilbene) on the wound healing process of the uterus in rats treated with resveratrol following full thickness injury of the uterus. Materials and methods: Twenty-one female wistar albino rats were divided randomly into three groups (1) control group with no intervention (2) injury group with uterine full thickness injury (3) resveratrol group with uterine full thickness injury and treated with resveratrol. Resveratrol was injected by oral gavage at the doses of 0.5 mg/kg/day for 30 days following uterine full thickness injury. Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) distributions were assessed using the immunohistochemical methods in tissue and ELISA methods in the tissue homogenate. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were evaluated with colorimetric method and malondialdehyde (MDA) levels also were measured using high performance liquid chromatography in the tissue homogenate. The effects of resveratrol on the uterine histology also were evaluated histologically with the light microscopy. Results: Histological evaluation and immunohistochemical evaluations showed that treatment with a resveratrol significantly increased the thickness of the uterine wall and VEGF expression and decreased expression PDGF during wound healing. Biochemically, GPx and SOD activities were increased significantly after treatment with resveratrol. Additionally, resveratrol administration decreased MDA levels. Conclusion: These results showed that the antioxidant effects of resveratrol has been shown to have a positive influence on wound healing of the uterus. (C) 2017 Taiwan Association of Obstetrics & Gynecology. Publishing services by Elsevier B.V.