Purpose:
We investigated the therapeutic effect of quercetin, a natural plant flavonoid, in an in vitro model of Graves’ ophthalmopathy, targeting the pathway of adipogenesis.
Methods:
Confluent fibroblasts were subjected to differentiation protocol including adipogenic supplements and peroxisome proliferator activator gamma (PPARγ) agonist for 10 days, and/or exposed to exogenous IL-1β (10ng/ml), H2O2 10 µM and cigarette smoke extract (CSE) 2% for the first 3 days. Quercetin was treated during 10 days of differentiation, and at day 10, cells were stained with oil red O, and the expression of PPARγ and CCAAT-enhancer-binding proteins (C/EBP) α, β proteins were determined by western blot.
Results:
Quercetin inhibited accumulation of intracytoplasmic lipid droplets stained with oil red O and resulted in decreased expression of PPARγ and C/EBPα, β proteins dose-dependently. Quercetin also inhibited the adipogenesis induced by IL-1β, low dose of H2O2 and CSE, which can mimic condition of orbital inflammation, oxidative stress and cigarette smoking in vivo.
Conclusions:
These findings provided a basis for further study of the potential usage of quercetin for the treatment of Graves’ ophthalmopathy, especially the fat-predominant type.
Keywords: orbit • inflammation • oxidation/oxidative or free radical damage