Research ReportNovaeguinoside II inhibits cell proliferation and induces apoptosis of human brain glioblastoma U87MG cells through the mitochondrial pathway

Novaeguinoside II is one of the newly found asterosaponins, which are a kind of steroidal glycosides extracted from starfish with an anti-tumor effect. In this study, we investigated the bioactivity of novaeguinoside II on human U87MG glioblastoma cells. The results showed that novaeguinoside II significantly suppresses U87MG cell proliferation in a time- and concentration-dependent manner. Flow cytometric analysis of DNA in U87MG cells showed that novaeguinoside II induces the prominent appearance of an S phase peak in the cell cycle that is suggestive of apoptosis that is identical to the result of an annexin V/PI assay. Fluorescence and electron microscopy revealed apoptotic change of U87MG cells. The electrophoresis of DNA showed a typical “ladder” that is consistent with apoptotic DNA fragmentation. Cytofluorometry showed a decreased mitochondrial transmembrane potential in novaeguinoside II-treated U87MG cells. Western blot showed that novaeguinoside II increased the expression of cytochrome-c and caspase-3 protein. The novel findings suggest that novaeguinoside II can induce apoptosis of U87MG cells by a mitochondrial apoptotic pathway.

Research Highlights►Novaeguinoside II induced apoptosis specific DNA cleavage in U87MG cells. ►Novaeguinoside II induced the release of cytochrome-c and the activation of caspase-3. ►Novaeguinoside II induced apoptosis by increasing the release of cytochrome-c and caspase 3.