Therapeutic effect of quercetin and resveratrol in an in vitro model of Graves’ophthalmopathy

Abstract

[한글]

[영문]As the management of Graves’ ophthalmopathy is challenging and often not satisfactory, a new effective and safe treatment on intractable Graves’ ophthalmopathy is mandatory. Flavonoids, which are polyphenolic compounds with a wide distribution throughout the plant kingdom, are found to have anti-inflammatory and anti-adipogenic activities. We investigated the therapeutic effect of quercetin and resveratrol in an in vitro model of Graves’ ophthalmopathy. Primary cultures of orbital fibroblasts were treated with interleukin-1 (IL-1) β with quercetin or resveratrol in nontoxic concentrations. The inhibitory effect of quercetin and resveratrol on the IL-1β induced proinflammatory cytokine expression and the hyaluronan production by IL-1β or tumor necrosis factor (TNF)-a were determined by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) and by hyaluronan ELISA, respectively. To evaluate anti-adipogenic activities, confluent fibroblasts were subjected to differentiation protocol including peroxisome proliferator activator gammar (PPARr) agonist for 10 days, and exposed to quercetin and resveratrol during adipocyte differentiation. Differentiated cells were stained with oil red O, and the expression of PPARr and CCAAT-enhancer-binding proteins (C/EBP)a, β were determined by western blot. Quercetin attenuated IL-1β (10ng/ml) induced intercellular adhesion molecule-1 (ICAM-1), IL-6, IL-8 and cyclo-oxygenase (COX-2) mRNA expression in a dose- and time- dependent manner. Resveratrol also had a significant suppressive effect on IL-1β induced proinflammatory cytokine expressions. Hyaluronan production was only inhibited by quercetin treatment in a dose- and time-dependent manner. Treatment of both quercetin and resveratrol in the process of adipogenic differentiation inhibited lipid accumulation in the cytoplasm of cells stained with oil red O and resulted in decreased expression of adipogenesis-related factors, PPARγ and C/EBPβ in western blot analyses in a dose-dependent manner. The results suggest that quercetin and resveratrol possess significant anti-inflammatory and anti-adipogenic effects in vitro. In addition, quercetin significantly inhibited hyaluronan production. Our study results provided a basis for further study of the potential usage of quercetin and resveratrol for the treatment of Graves’ ophthalmopathy.