Synergistic Anti-Cancer Effects of Icariin and Temozolomide in Glioblastoma.

Glioblastoma is an aggressive malignancy, which is associated with poor prognosis. Temozolomide (TMZ) has been showed to be an effective chemotherapeutic agent for glioblastoma treatment; however, the response rate is not satisfactory. Icariin is a natural compound with anti-cancer activity against a variety of cancers. This study is designed to determine whether icariin could potentiate the antitumor activity of TMZ in glioblastoma. Cell proliferation and apoptosis were measured using MTT assay and flow cytometry, respectively. Expression of apoptosis and proliferation-related molecules was detected by Western blotting while NF-κB activity was detected by ELISA. Icariin dose-dependently inhibited proliferation and induced apoptosis in tested glioblastoma cell lines. Icariin enhanced the anti-tumor activity of TMZ in vitro. The anti-tumor activity of icariin and the enhanced anti-tumor activity of TMZ by icariin correlated with suppression of NF-κB activity. Our results showed that icariin exhibited anti-tumor activity and potentiated the anti-tumor activity of TMZ in glioblastoma, at least in part, by inhibiting NF-κB activity. Although more studies including clinical trials are needed, this study provides insight for using icariin as a chemosensitizing agent in clinic settings.