惡性神經膠母細胞瘤(GBM)是最常見的成人原發性腦瘤，因GBM 細胞對凋亡有很強的抗性，所以GBM 的病人經過積極的治療後，復發率仍高。復發性的GBM 細胞內的促凋亡分子如 Bak、Bax、Bid、Noxa 及 PUMA 等含量低於正常細胞，若能開發促進這類促凋亡分子之表現量，將有助於GBM 的治療。本研究擬探討五爪金英萃取物是否能透過增加促凋亡分子表現，來對GBM 細胞產生抑癌作用。U373 細胞經不同濃度之五爪金英萃取物處理24 小時後，對細胞有明顯之毒殺效應，其半致死劑量約為 9-10 μg/ml。以西方點墨法檢測U373 細胞的procaspase 3、活化的caspase 3 及促凋亡分子PUMA 之表現量，均能被五
爪金英萃取物顯著促進。由結果可推論，五爪金英萃取物促使高凋亡抗性的 U373 細胞，能使其鈍化凋亡
機制，重新敏感化。

Glioblastoma (GBM) is the most common malignant brain tumor in adults. The poor prognosis for GBM patients is strongly correlated to apoptosis resistance and recurrence. The recurrent GBMs have been known to associate with lower level of Bak, Bax, Bid, Noxa and PUMA, revealing the upregulation of proapoptotic molecules may be a beneficial strategy in GBM therapy. In this study, we wanted to investigate whether Tithonia diversifolia extract (TD) sensitized GBM-U373 cells to death by upregulating proapoptotic molecules expression. We tested the inhibitory effect on tumorigenesis of TD using GBM cell line U373 characterized with high apoptosis resistance. Our results showed that TD substantially inhibited cell viability with IC50 values of approximately 9~10 μg/mL. Furthermore, TD induced a substantial increase of apoptosis-related proteins including procaspase 3, cleavaged caspase 3 and PUMA in U373 cells. These results suggested that TD had potential to sensitize apoptotic mechanism in GBM cell line with high resistance.