Abstract: AIM: To explore the effect of diclofenac on theProliferation inleukemia K562 cells and the synergism with adriomycin(ADM).METHODS: Cell viability and cell cycle were determined by MTT assay and flow cytometry.K562 cells were separately treated with different dosages of diclofenac,or ADM,or diclofenac+ADM in vitro.RESULTS: The cellProliferation was inhibited significantly by the diclofenac.Thelarge the dosage,the stronger the action.ADM(25 mg·L^-1)alone inhibited the growth of K562 cells,but this effect strengthened when diclofenac was added.Diclofenac or ADM alone elicited apoptotic changes,but ADMPlus diclofenac obviously enhanced the number of apoptotic cells from 13.3 %±1.0 % to 68.0 %±3.6 %.After exposure to different concentrations of diclofenac(with orwithout ADM)for 48h,K562 cells were accumulated in G₀/G₁Phase,and the cell number decreased in SPhase.CONCLUSION: Diclofenac inhibits theProliferation and elicits apoptosis on the K562 cells.Diclofenac combined with ADM appears to interact in a synergistic manner.

Key words: pharmacology, diclofenac, leukemia, adriomycin, synergism, apoptosis