molecular mechanisms of luteolin induced growth inhibition and apoptosis of human osteosarcoma cells

luteolin is a flavone in medicinal plants as well as some vegetables and spices. it is a natural anti-oxidant with less pro-oxidant potential but apparently with a better safety profile. the purpose of this study was to investigate the molecular mechanism of luteolin-mediated apoptosis of mg-63 human osteosarcoma cells. mtt assay kit was employed to evaluate the effects of luteolin on mg-63 cells proliferation. then, we performed annexin v-fitc/pi to analyze the apoptotic rate of the cells. furthermore, the inhibitory effects of luteolin on the expressions of bcl-2, bax, caspase-3 and survivin were detected by western blotting. as expected, luteolin (0.5, 2.5, 12.5 µg/ml) inhibited the growth of mg-63 cells by inhibiting cell proliferation and inducing cell apoptosis. western blotting demonstrated that luteolin (0.5, 2.5, 12.5 µg/ml) inhibited the expressions of bcl-2, caspase-3 and survivin, and promoted the expression of bax in mg-63 cells with a concentration dependent way. luteolin can inhibit osteosarcoma cell proliferation and induce apoptosis effectively in a dose dependent manner through down-regulating the expression of bcl-2, caspase-3 and survivin proteins levels and up-regulating the expression of bax protein level. these findings indicated that luteolin may be used as a novel herbal medicine for the treatment of osteosarcoma.