去甲基斑蝥素(Norcantharidin, NCTD)是斑蝥素的化學領衍生物，而斑蝥素則是由乾燥的斑蝥蟲體中純化而得。本實驗使用MTT方法以去甲基斑蝥素分別對8種腫瘤細胞林（人類大勝直腸癌細胞株HCT-15、小細胞肺癌細胞株H1688、非小加胞肺無細胞株A549、具有雖激素接受器的乳癌細胞株MCF-7、不具雖激素接受器的乳癌細胞株Hs-578T、雄激素不教感陸前到腺癌細胞林PC-3及DU-145、肝癌細胞林C3a）及人類正常成纖維細胞進行細胞毒性及生長抑制試驗其IC50值分別爲21.1±1.96、573.6±3.68、26.7±4.92、27.1±9.20、20.7±0.37、6.5±0.87、20.9±0.85、18.4±1.28、6.9±0.92、1.56±8.16及86.0±1.50μg/ml。以成纖維細胞林的IC50作爲選擇指標，得出前列線癌細胞株(PC-3)的選擇指標最佳，其次是肝癌細胞株C3a、大腸直腸癌細胞株HCT-15，以下依次爲不具雌激素接受器的乳癌細胞株Hs-578T及雄激素不敏感性前到線癌細胞株DU-145，顯示NCTD具有成爲前列腺癌、肝癌、大腸直腸癌新一代抗癌藥物的潛力。

Recently, it has been reported that norcatharidin has growth-inhibiting effect on various malignant tumor cells. The present study used MTT test to investigate the cytotoxic effects of norcatharidin on various human malignant tumor cell lines. Normal skin fibroblasts were used as the control. Norcatharidin showed dose-dependent cytotoxic effects on various malignant tumor cells. The IC50 value of norcatharidin was 86±1.50μg/ml for normal human fibroblast, 21.1±1.96μg/ml for colorectal carcinoma cells HCT-15, 26.7±4.92μg/ml for non-small cell lung cancer cells A549, 57.6±3.68μg/ml for small cell lung cancer cells H1688, 27.1±9.20μg/ml for breast cancer cells MCF-7, 20.7±0.37μg/ml for breast cancer cells Hs-578T, 6.5±0.87μg/ml for prostate cancer cells PC-3, 18.4±1.28μg/ml for hepatoma cells C3a and 20.9±0.85μg/ml for prostate cancer cells DU-145. The results demonstrated that norcantharidin might be a promising novel agent for the treatment of various cancers, especially the prostate and colorectal cancers and hepatoma.