SH could enhance the rate of apoptosis in thyroid cells treated with iodine-131. (A and D) HTori-3, (B and E) BCPAP and (C and F) TPC-1 cells apoptosis analysis by flow cytometry. Quantitation of apoptotic cells in D, E and F (*P < 0.05). (H) Compare the apoptosis rate of ISH group among three cell lines(*P < 0.05). The data are presented as the mean ± standard deviation of three independent experiments. SH, sinomenine hydrochloride; I, iodine-131; ISH, co-treatment of iodine-131 and SH.