In vitro effects & the related molecular mechanism of galangin & quercetin on human gastric cancer cell line (SGC-7901)

Natural flavonoids are proven to be powerful against various cancers,but few studies have investigated the potential effects of two flavonoids galangin and quercetin on a human gastric cancer cell line (sgc-7901). in vitro growth inhibition and apoptosis of the two flavonoids on the sgc-7901 cells as well as potential mechanism about apoptosis induction are reported in the present study. the assaying results showed that the two flavonoids at 40-200 μmol/l for 24-72 hours conferred lower cell viability of 14.1-90.3% in dose-and time-dependent manner,and at 160 μmol/l for 24-48 hours enhanced the proportion of apoptotic cells into 13.3-27.4% and 40.6-65.6%,respectively. galangin was more powerful than quercetin to inhibit cell growth,induce apoptosis and decrease mitochondrial membrane potential (mmp). oligonucleotide micro array,real-time rt-pcr and western-blot analyses revealed expression changes of the genes and proteins in the treated cells,clarifying a mechanism related to apoptosis induction. the two flavonoids activated caspase-8,which cleaved bid into tbid; simultaneously,bax transferred from cytosol into mitochondria to decrease mmp; consequentially,cytochrome c released from mitochondria activated caspase-9,and then caspase-9 activated caspase-3,which executed the apoptosis. that is,the apoptosis occurred via a mitochondrial pathway involving caspase-8/bid/bax activation.