RESUMO
Objective To investigate the effects and mechanism of huoxuexiaoying tablet on experimental goiter of rats. Methods The rats were randomly divided into six groups: the control, the model control group, huoxuexiaoying tablet at different doses,and the sodium levothyroxine group ( Euthyrox group) . Except for the rats in the control,the rats in other groups were given with propylthiouracil (20 mg·kg-1 ·d-1 ) by intragastric ( i. g. ) administration every day for 60 days. Meanwhile, some rats were treated with huoxuexiaoying tablet at low (4. 4 g·kg-1·d-1),middle (8. 8 g·kg-1·d-1) and high dose (17. 6 g·kg-1 ·d-1 ) orally,and those in the Euthyrox group were given with 7. 8μg·kg-1 ·d-1 Euthyrox by i. g. administration. The rats in the control group were administrated with the same volume of saline (N. S). After 60 days of treatment,the rats were sacrificed,the organ indexes of thyroid and pituitary and the levels of free triiodothyronine ( FT3 )、free thyroxin ( FT4 ) and thyroid stimulating hormone(TSH) in serum,were tested. The expression of basic fibroblast growth factor(bFGF),transforming growth factor-β( TGF-β) and B-cell lymphoma 2 gene ( Bcl-2 ) were examined by immunofluorescence. Results Compared with the model,organ indexes of thyroid were significantly reduced by huoxuexiaoying tablet at three doses (P0. 05). The levels of FT3 and FT4 were in a elevating trend,but TSH decreased with no significance (P>0. 05). The morphological structure of thyroid was greatly improved by huoxuexiaoying tablet in comparison with the model. In which the gland dilated,thyroid follicular restored to moderate size,epithelia were cubic or flattened and follicular cavity filled with abundant glial. The expression of bFGF and Bcl-2 decreased significantly (P<0. 01) while TGF-β expression increased notably (P<0. 01). Conclusion Huoxuexiaoying tablet has a great anti-goiter effect,the mechanism of which may be related to promoting thyroid cells apoptosis and inhibiting thyroid cells proliferation.