Artemisinin and the Derivatives Play Novel Role in Treatment for Graves’ Orbitopathy as Conventional Antimalarials

Context: Graves’ orbitopathy (GO) an autoimmune disease in orbit, characterized with proptosis due to excessive proliferation, adipogenesis, fibrosis and hyaluronan secretion of orbital fibroblasts (OFs). OFs is potential to be a target for proptosis. But there are few effective therapies. Objectives: Our present purpose was to evaluate the effects of artemisinin (ARS) and the derivatives dihydroartemisinin (DHA), artesunate (ART) on OFs from GO patients in vitro. Design/Setting/Participants: OFs isolated from patients with GO (n = 10) were allowed to proliferate in the proliferation medium (PM); differentiate into adipocytes in the differentiation medium (DM) or differentiate into myofibroblast stimulated by TGF-β (10ng/ml); or produce hyaluronan stimulated by IL-1β (5ng/ml). Different dosages of ARS and the derivatives were administered in the above conditions. Main Outcome Measures: CCK-8 was used to assessed cell viability of OFs, EdU incorporation and flow cytometry were conducted to assess cellular proliferation. Adipogenesis was determined by Western blot and Oil Red O staining. Hyaluronan was quantified by ELISA. Fibrosis was assessed using Western blot. Results: ARS in concentrations lower than 100 μM, DHA < 20 μM and ART < 10 μM are nontoxic for OFs. Cellular proliferation of GO-OFs was halted by ARS and its derivatives at the maximum nontoxic dosage. ARS and its derivatives exerted an inhibitory action on adipogenesis of OFs in a concentration-dependent manner. Moreover, hyaluronan secretion was obviously decreased by ARS and its derivatives. Intriguingly, fibrosis markers were also decreased by the antimalarias in a dosage-dependent way. Conclusions: We elucidated the efficacies of ARS and its derivatives on proliferation, adipogenesis, fibrosis and hyaluronan production of OFs, supporting that ARS-based antimalarials play potential role as a novel therapy for GO from a perspective of in-vitro study.