Objective:To observe the effect of Maimendong decoction on apoptosis

cell cycle and expression of epidermal growth factor receptor(EGFR) and signal transducer and activator of transcription 3 (STAT3) genes of lung a cancer cell A549 by experiments in vitro. Method:A549 cells in the logarithmic phase (2×104/mL) were selected to observe their morphological changes by inverted microscope after Maimendong decoction (0.25

2.5

25 g·L-1) effecting for 24

48

72 hours; to observe apoptosis of A549 cells effected by Maimendong decoction (2.5

25 g·L-1) for 48 hours after adding 4

6-diamidino-2-phenylindole(DAPI) staining fluid; to analyze cycles of A549 cells effected by Maimendong decoction (2.5 g·L-1) for 48 hours; to relatively quantify expression of EGFR and STAT3 genes of apoptotic cells by Real-time fluorescent quantitative (RT)-PCR technique. Result:0.25

2.5

25 g·L-1 Maimendong decoction all could inhibit the growth of A549 cell

change its appearance in different levers. After 0.25

2.5 g·L-1 Maimendong decoction impacting A549 for 48 hours

we can find that nucleus's appearance has changed

and its chromatins have gathered and been marginalized and so on

results from flow cytometer display that cells were inhibited in G0/G1 and G2/M phase

and result from RT-PCR suggest that the expression of EGFR and STAT3 genes has obviously reduced. Conclusion:Maimendong decoction can restrain the growth of a non-small cell lung cancer A549 cell line

induce its apoptosis

stagnate it in G0/G1 and G2/M phase

which may be related to reducing the expression of EGFR and STAT3 genes.