Germacrone inhibits the proliferation of glioma cells by promoting apoptosis and inducing cell cycle arrest.

Germacrone is one of the major bioactive components of the traditional Chinese Medicinal plant Curcuma aromatica Salisb. and has been shown to possess anti-tumor properties. In the present study, the anti-proliferative effect of germacrone on human glioma cells and the molecular mechanism underlying its cytotoxicity were investigated. Treatment of the U87 and U251 human glioma cell lines with germacrone inhibited the cell proliferation in a dose- and time-dependent manner as assessed by MTT assay, while significantly lower effects were observed on normal human astrocytes. Flow cytometric analysis and DNA fragmentation revealed that germacrone promoted apoptosis of glioma cells, associated with an increased expression of p53 and bax and decreased expression of bcl-2. Furthermore, flow cytometric cell cycle analysis revealed that germacrone induced G1 phase arrest, associated with an obvious decrease in the expression of cyclin D1 and CDK2 and an increased expression of p21. In conclusion, the present study suggested that germacrone may be a novel potent chemopreventive drug candidate for gliomas via regulating the expression of proteins associated with apoptosis and G1 cell cycle arrest.