Objective: To observe the effects of Tonglian decoction (TD) of morphology

the growth cycle and nuclear factor-kappa B (NF-κB) signaling pathway

and to discuss the inhibiting mechanisms on gastric cancer cell proliferation in gastric carcinoma cell line MGC803. Method: MGC803 cell line was seeded in 96-well micro-plate with 1×104 cells in each well

and cultured with DMEM containing 5% fetal bovine serum (FBS)

and maintained in the incubator at 37 ℃ with 5% CO2 in humidified atmosphere. After cell adherence for 24 h

TD of different concentrations was administrated from 25-800 mg·L-1 with common ration of two

while Fluorouracil from 10-160 mg·L-1 as positive control group. 48 hours' administration was followed by observation on cell morphology by inverted microscope

and cell proliferation determined by MTT assay. The half maximum inhibition rates (IC50) of TD and fluorouracil were calculated by curve fitting method. After 48 hours' administration of TD and Fluorouracil at 48 h IC50 concentration

flow cytometry (FCM) was employed for cell cycle determination

and western blot for protien expression of inhibitor kappa B kinase β (IKKβ)

NF-κB and phosph-NF-κB. Result: 48 h IC50 of TD is 192.74 mg·L-1

and that of Fluorouracil is 23.61 mg·L-1. Compared with control group

TD can significantly affect G2 phase of cell cycle in cell line MGC803

and Fluorouracil G1 phase (P<0.05);TD and fluorouracil could significantly decrease protein expression of IKKβ and NF-κB. Conclusion: TD has inhibition effect on cell line MGC803

which is related to inhibiting cells in G2 phase

and down-regulating protein expression of IKKβ and NF-κB.