Oroxylin A is a flavonoid extracted from the root of Scutellaria baicalensis Georgi. We previously demonstrated that oroxylin A induced apoptosis in human colon cancer cells via the mitochondrial pathway. In the present study, we investigated the underlying mechanisms responsible for the mitochondrial apoptotic pathway triggered by oroxylin A. p53 regulates mitochondrial survival, mitochondrial DNA integrity, and protection from oxidative stress. We determined that oroxylin A induces p53 mitochondrial translocation and inhibits SOD2 activity. Additionally, our studies demonstrate that oroxylin A promotes the formation and mitochondrial translocation of the p53-Recql4 complex in HCT-116 cells. Finally, we showed that oroxylin A triggers cytosolic p53 activation, thereby promoting apoptosis. Mitochondrial translocation of p53 was also validated in vivo. Thus, oroxylin A induces mitochondrial translocation of p53 and leads to mitochondrial dysfunction in human colon cancer cells.
Keywords: oroxylin A; oxidative stress; p53; translocation.