Berberine induces cell cycle arrest and apoptosis in human gastric carcinoma SNU-5 cell line

AIM:To investigate the relationship between theinhibited growth (cytotoxic activity) of berberine andapoptotic pathway with its molecular mechanism ofaction.METHODS:The in vitro cytotoxic techniques werecomplemented by cell cycle analysis and determinationof sub-G1for apoptosis in human gastric carcinomaSNU-5 cells.Percentage of viable cells,cell cycle,andsub-G1group (apoptosis) were examined and determinedby the flow cytometric methods.The associated proteinsfor cell cycle arrest and apoptosis were examined byWestern blotting.RESULTS:For SNU-5 cell line,the IC (50) was found tobe 48 μmol/L of berberine.In SNU-5 cells treated with25-200 μmol/L berberine,G2/M cell cycle arrest wasobserved which was associated with a marked incrementof the expression of p53,Wee1 and CDk1 proteins anddecreased cyclin B.A concentration-dependent decreaseof cells in G0/G1phase and an increase in G2/M phasewere detected.In addition,apoptosis detected as sub-Gocell population in cell cycle measurement was proved in25-200 μmol/L berberine-treated cells by monitoring theapoptotic pathway.Apoptosis was identified by sub-G0cell population,and upregulation of Bax,downregulation of Bcl-2,release of Ca(2+),decreased the mitochondrialmembrane potential and then led to the release ofmitochondrial cytochrome C into the cytoplasm andcaused the activation of caspase-3,and finally led to theoccurrence of apoptosis.CONCLUSION:Berberine induces p53 expression andleads to the decrease of the mitochondrial membranepotential,Cytochrome C release and activation ofcaspase-3 for the induction of apoptosis.