AB0182 Molecular mechanisms mediating antioxidant effect of epigallocatechin-3-gallate in experimental scleroderma model
Authors: A. Kocak, D. Harmancı, M. Birlik, G. Guner
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Scleroderma (SSc) is an autoimmune multisystemic connective tissue disease characterised by skin and internal organ fibrosis(.<sup>1</sup>Underlying mechanism is still unclear for SSc. Besides there is no specific treatment for SSc, various treatments may alleviate symptoms and improve the quality of life. Epigallocatechin-3-gallate (EGCG) is a phenol with antioxidant effects in many disease processes.<sup>2</sup>In this disease, oxidative stress may play a role for pathogenesis(.<sup>3–4</sup>Recent studies showed a relationship between oxidative/antioxidative markers and SSc.<sup>5</sup> <h3>Objectives</h3> The aim of this study was to investigate the antioxidant effects of epigallocatechin-3-gallate in the scleroderma process in experimental mouse model with bleomycin. <h3>Methods</h3> Thirty-two healthy female Balb-c mouse species were used and randomly divided into four groups:control, bleomycin, bleomycin +EGC, EGCG. At the end of the experiment, skin tissues were collected. Sodium dismutase enzyme (SOD) and malondialdehyde (MDA) levels have been analysed for oxidative stress. High performance liquid chromatography (HPLC) was used for MDA measurements. Colorimetric kit was used for SOD analysis. Furthermore, the ratio of phosphorylated p-38/total p-38 protein, and phosphorylated-Akt/total Akt protein and NF-kappa B were measured by western blotting. Immunohistochemistry(α-SMA), histochemistry (masson trichrome-hematoxylin and eosin) studies were also performed on FFPE skin samples. <h3>Results</h3> When the experimental and control groups were compared, the degree of fibrosis in the connective tissue of the dermis areas stained with masson trichrome decreased in the EGCG groups.SOD activity was increased in the EGCG groups compared to the positive control group, and MDA was significantly decreased in the EGCG groups. According to Western blotting results, pp-38 MAPK and NF-κB were found to decrease significantly in the EGCG groups compared with the controls. Parallel to these findings, phosphorylated Akt protein was found to increase in the EGCG groups compared with the control groups. <h3>Conclusions</h3> It has been shown that EGCG can antioxidative effect in scleroderma. <h3>References</h3> [1] Varga J, Abraham D. Systemic sclerosis: a prototypic multisystem fibrotic disorder. J Clin Invest2007;117(3):557–67. [2] White OP, Tribout H, Baron E. Protective mechanisms of green tea polyphenols in skin. Oxid Med Cell Longev2012;560682. [3] Herrick AL, Matucci Cerinic M. The emerging problem of oxidative stress and the role of antioxidants in systemic sclerosis. Clin Exp Rheumatol2001;19:4–8. [4] Lundberg AC, Akesson A, Akesson B. Dietary intake and nutritional status in patients with systemic sclerosis. Ann Rheum Dis1992;51:1143–8. [5] Kawashiri SY, Ueki Y, Terada K, Yamasaki S, Aoyagi K, Kawakami A. Improvement of plasma endothelin-1 and nitric oxide in patients with systemic sclerosis by bosentan therapy. Rheumatol Int2014;34:221–5. <h3>Acknowledgements</h3> This research carried out at Dokuz Eylul University Medicine Faculty of Research Laboratory (R-LAB). <h3>Disclosure of Interest</h3> None declared