OBJECTIVETo investigate the effects of matrine on the cell cycle and apoptosis in human colon adenocarcinoma SW620 cells and explore the possible mechanisms.

METHODSThe effect of matrine on cell proliferation was assessed using MTT assay, and the cell cycle arrest induced by matrine was determined by flow cytometry. The changes of cell morphology were observed through optical microscope, fluorescence microscope and electron microscope, and the cell apoptosis was detected using Annexin V-FITC apoptosis assay.

RESULTSMatrine inhibited the proliferation of SW620 cells in a dose- and time-dependent manner. Compared with the control group, the matrine-treated cells showed increased cell percentage arrested in G 0/G1 phase with decreased S-phase cells. Morphologically, the SW620 cells treated with matrine exhibited cell shrinkage, cell size reduction, plasma condensation, cytoplasmic vacuolar changes, and formation of apoptotic body with also the presence of the signet-ring cells, all typical of apoptotic cells.

CONCLUSIONMatrine exposure of SW620 cells inhibits the cell proliferation, causes cell cycle arrest at G 0/G1 phase, and induces apoptosis in a dose- and time- dependent manner.