To investigate the effect and molecular mechanism of total flavonoids of three species of Hippophae (TFH) on proliferation and migration of lung cancer cells A549,the cells were pretreated with different concentrations of total flavonoids of Hippophae tibetana (TFHt),H. rhamnoides subsp. sinensis (TFHr) and H. neurocarpa (TFHn).MTT assay was adopted to detect the effect of different concentrations of the TFH on the relative cell viability.The colony formation assay and soft agar assay was used to observe the colony formation ability.Annexin V-FITC/PI double stainings by flow-cytometry was performed to detect the apoptosis rate of A549 cells pretreated by the TFH.From the above results,it was found that the TFHt had the best anticancer effect.In order to preliminarily explore the effect of the TFHt on invasion and migration,the wound healing and transwell assay were used to analysis in A549 cells.Western blot was used to study the expression of MMP9,E-cadherin and other related proteins.The ability of cell invasion and migration were detected in knockdown of E-cadherin and then pretreated with the TFH.The results showed that the three species of TFH could inhibit the growth in A549 cells pretreated for 48 hours,which was ordered as TFHt,TFHr,TFHn.Compared with control group,the cell invasion and migration were both significantly decreased in experimental group pretreated by the TFHt (P<0.05).The expressions of MMP9,MMP2,TGF-β and N-cadherin were significantly weakened,while the expression of E-cadherin was markedly enhanced in the experimental group.We found that knockdown of E-cadherin in A549 cells and the TFHt can reverse the expression of E-cadherin,which increased the migration.The TFHt have obvious advantages in inhibiting the proliferation and reducing the invasion and migration ability of lung cancer A549 cells,which may be related to the down regulating the expression of MMP9 by TGF-β and inhibiting EMT of lung cancer.