Pingmu decoction enhances apoptosis of orbital adipocytes derived from patients with Graves' ophthalmophathy.

Graves' ophthalmopathy (GO), an autoimmune disease, has been demonstrated to result from an increased volume of orbital contents, including adipose, connective and extraocular muscle tissues. In our previous study, we showed that Pingmu decoction is capable of alleviating GO progression. In this study, to further investigate the underlying mechanism(s), we examined the effects of Pingmu decoction-containing serum on the proliferation and apoptosis of preadipocytes and adipocytes derived from the orbital adipose tissue of GO patients. Our data demonstrate for the first time that Pingmu decoction-containing serum significantly reduces preadipocyte proliferation and increases adipocyte apoptosis as measured by MTT assay and Annexin V/FITC staining, respectively. Moreover, Pingmu decoction elevated the levels of cleaved caspase-3, 8 and 9 and decreased the levels of cell cycle-related genes compared to those of the control. In addition, cell cycle arrest at the G0/G1 phase was observed following Pingmu decoction treatment. This study shows a mechanism by which Pingmu decoction serves as an effective GO medicine by downregulating preadipocyte proliferation and increasing adipocyte apoptosis.