Yang Ping, Yu Ting-xi, Ma Run-di, Yu Li-jian, Su Wei-ming, Shao Hai-yan, Liao Ming-neng, Huang Lai-zhen
Guangdong Provincial Key Laboratory of Marine Pharmacy, Zhanjiang Ocean University, Zhangjiang 524025, P. R. China.
Ai Zheng. 2002 Apr;21(4):346-50.
BACKGROUND & OBJECTIVE: Tubeimoside, which is composed of tubeimoside I (79%) and II (21%), was isolated from the tubers of Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae), a traditional Chinese medicine, "Tu-Bei-Mu". This study was designed to investigate the anti-tumor mechanism of tubeimoside.
Growth inhibition was measured by MTT assay. Induction of cell cycle arrest and apoptosis was determined by flow cytometry, fluorescence and electron microscopy, and gel electrophoresis of fragmented DNA.
Tubeimoside display strong growth inhibitory effect in a dose- and time-dependant manner against HeLa cells with estimated IC50 values of 20.0, 18.8, and 8.8 mumol/L after 24, 48, and 72 h of treatment with tubeimoside. The flow cytometry profiles revealed that treatment with tubeimoside (5 h; 15, 30, 35 mumol/L) led to a dose-dependant shift from 9.80% up to 21.90%, and 27.00% in percentage of cells with a G2/M-like DNA content. On the other hand, treatment with tubeimoside (12 h, 15, 30, 35 mumol/L) led to a time-dependant shift from 8.20% up to 21.40%, 31.15%, and 34.55%, respectively. Exposure of HeLa cells to 40 mumol/L of tubeimoside induced nuclear shrinkage, chromation condensation and margination against nuclear envelope, subdiploid peak, and DNA fragmentation, characteristic as seen in apoptotic cells.
Induction of cell cycle arrest and apoptosis may play an important role in the anti-tumor effect of tubeimoside.
土贝母苷由土贝母苷甲（79%）和土贝母苷乙（21%）组成，从传统中药“土贝母”（葫芦科植物土贝母的块茎）中分离得到。本研究旨在探讨土贝母苷的抗肿瘤机制。
采用MTT法检测生长抑制情况。通过流式细胞术、荧光和电子显微镜以及DNA片段化凝胶电泳来确定细胞周期阻滞和凋亡的诱导情况。
土贝母苷对HeLa细胞显示出强烈的剂量和时间依赖性生长抑制作用，土贝母苷处理24、48和72小时后，估计IC50值分别为20.0、18.8和8.8μmol/L。流式细胞术分析表明，用土贝母苷（5小时；15、30、35μmol/L）处理导致具有G2/M样DNA含量的细胞百分比从9.80%剂量依赖性地转移至21.90%和27.00%。另一方面，用土贝母苷（12小时，15、30、35μmol/L）处理分别导致具有G2/M样DNA含量的细胞百分比从8.20%时间依赖性地转移至21.40%、31.15%和34.55%。将HeLa细胞暴露于40μmol/L土贝母苷会诱导核固缩、染色质凝聚并边缘化至核膜、亚二倍体峰和DNA片段化，这些是凋亡细胞的特征。
诱导细胞周期阻滞和凋亡可能在土贝母苷的抗肿瘤作用中起重要作用。
