Publications (2)7.64 Total impact
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Article: Cigarette-Smoke-Extract-Induced Adipogenesis in Graves' Orbital Fibroblasts Is Inhibited by Quercetin via Reduction in Oxidative Stress.
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ABSTRACT: Cigarette smoking is known to aggravate Graves' orbitopathy (GO) severity by enhancing adipogenesis. We investigated the effect of quercetin, an antioxidant, on adipocyte differentiation induced by cigarette smoke extract (CSE) in primary cultured orbital fibroblasts (OFs) from GO patients. Freshly prepared CSE was added to the cells and H2O2 was used as a positive control. Intracellular reactive oxygen species (ROS) generation and adipogenesis were measured. The expressions of proteins peroxisome proliferator-activated receptor (PPAR) γ, CCAAT-enhancer-binding proteins (C/EBP) α and β, and heme oxygenase-1 (HO-1), an antioxidant enzyme , were examined during adipogenic differentiation. In result, CSE and H2O2 dose-dependently stimulated intracellular ROS production in normal and Graves' OFs. The effect of 2% CSE was similar to that of 10 μM H2O2; both concentrations were noncytotoxic and were used throughout the experiment. Quercetin pretreatment reduced the ROS generation stimulated by either CSE or H2O2 in preadipocyte OFs. CSE and H2O2 stimulated adipocyte differentiation in cultured OFs. The addition of quercetin (50 or 100 μM) suppressed adipogenesis. Quercetin also suppressed ROS generation in differentiating OFs during adipogenesis stimulated by CSE and H2O2. Additionally, the expressions of PPARγ, C/EBPα, and C/EBPβ proteins were reduced in the quercetin-treated OFs. Quercetin also reduced the CSE- and H2O2-induced upregulation of ROS and HO-1 protein in differentiated OFs and preadipocyte OFs. As shown in this study, quercetin inhibited adipogenesis by reducing ROS in vitro, supporting the use of quercetin in the treatment of GO.Journal of Endocrinology 11/2012; · 3.55 Impact Factor -
Article: Quercetin inhibits IL-1β-induced inflammation, hyaluronan production and adipogenesis in orbital fibroblasts from Graves' orbitopathy.
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ABSTRACT: Management of Graves' orbitopathy (GO) is challenging, as no reliable, specific, and safe medical therapeutic agents have yet been developed. We investigated the effect of quercetin in primary cultured orbital fibroblasts from GO, targeting pathways of inflammation, aberrant accumulation of extracellular matrix macromolecules, and adipose tissue expansion. Quercetin significantly attenuated intercellular adhesion molecule-1 (ICAM-1), interleukin (IL) -6, IL-8, and cyclooxygenase (COX) -2 mRNA expression, and inhibited IL-1β-induced increases in ICAM-1, IL-6, and IL-8 mRNA. Increased hyaluronan production induced by IL-1β or tumor necrosis factor-α was suppressed by quercetin in a dose- and time-dependent manner. Treatment with noncytotoxic doses of quercetin inhibited accumulation of intracytoplasmic lipid droplets and resulted in a dose-dependent decrease in expression of peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein (C/EBP) α, and C/EBPβ proteins. In conclusion, inhibition of inflammation, hyaluronan production, and adipogenesis by the natural plant product quercetin in vitro provides the basis for further study of its potential use in the treatment of GO.PLoS ONE 01/2011; 6(10):e26261. · 4.09 Impact Factor
