OBJECTIVETo investigate the effect of baicalin on insulinoma cell line and the molecular mechanism involved.

METHODSLight microscope, MTT assay, flow cytometry, gene analysis and Western Blot were applied to investigate the effects of baicalin on the cell proliferation, the cell cycle and the involved molecular mechanism.

RESULTSAfter treatment with baicalin, the number of cells in mitotic stage and the survival rate of cells obviously decreased, and cell proliferation was inhibited in a drug concentration- and acting time-dependent manner, with the appearance of apoptotic insulinoma cells. During the apoptotic process, the activity of caspase-3 was elevated by baicalin in a time-dependent manner; with the increase of the concentration of baicalin, the number of cells in S-phase obviously decreased from 38.2% to 9.4%, while the percentage of cells in G0/G1 phase increased from 56.4% to 85.9%, indicating cells were arrested in G1-phase. Meanwhile, the activity of cyclin gene promoter obviously declined, and the expression of cyclin reduced remarkably.

CONCLUSIONBaicalin could induce apoptosis of insulinoma cells, which might be correlated with the activity of caspase-3, and inhibiting proliferation of insulinoma cells in a concentration- and time-dependent manner, in which the action of baicalin in down-regulating the gene transcription and expression of cyclin may play an important role.