中文摘要：

目的探讨左旋紫草素诱导雄激素非依赖型前列腺癌PC3细胞凋亡的作用及其可能机制。方法实验分为对照组（只加DMSO）、不同浓度的左旋紫草素组（2、4、8、16、32μmol／L），作用PC3细胞24h后收集细胞，应用MTT法检测各组细胞生长抑制率并计算左旋紫草素半数有效抑制浓度ICsoμmol／L左旋紫草素作用PC3细胞0、6、12、24、48、72h后收集细胞，用MTF法计算各时间点细胞生长抑制率。PC3细胞加入8Ixmol／L的左旋紫草素，分别培养0、12、24、48h后收集细胞，流式细胞仪检测各时间点细胞凋亡率。8μmol／L浓度的左旋紫草素作用PC3细胞0、6、12、24、48、72h后收集细胞，荧光分光光度计检测caspases3的活性。将PC3细胞分为对照组（DMSO）、z．DEVD．fmk（caspase3抑制剂，20Iμmol／L）、z—IETD—fmk（caspase9抑制剂，20μmol／L）和z．LEHD—fmk（caspase8抑制剂，20μmol／L）组，各组加入抑制剂1h后加入左旋紫草素，24h后收集细胞，MTT法计算各组细胞生长抑制率。结果左旋紫草素能抑制PC3细胞的增殖，作用24h后随浓度的升高，细胞生长抑制率逐渐增加，ICso为（7．91±0．73）μmol／L。8μmol／L左旋紫草素作用PC3细胞0、6、12、24、48、72h后，随着时间的延长，细胞生长抑制率逐渐升高。左旋紫草素8μmol／L作用12、24、48h后，PC3细胞的凋亡率分别为（5．73±0．82）％、（19．15±1．14）％、（32．68±1．03）％，与0h时（0．98±0．34）％比明显升高（均P〈0．05）。左旋紫草素8p,mol／L作用PC3细胞后，caspase3活性6h时开始升高，在24h达高峰，其后开始下降。caspase3、caspase9、caspase8抑制剂均可明显逆转左旋紫草素对PC3细胞增殖的抑制作用，与DMSO对照组比较，细胞生长抑制率由（50．63±O．99）％分别降至（25．30±0．58）％、（30．81±0．35）％、（39．64±1．19）％（均P〈O．05）。结论左旋紫草?

英文摘要：

Objective To explore the effect and mechanism of shikonin induced apoptosis androgen-independent prostate cancer PC3 cells. Methods The PC3 cells were treated with DMSO （control group） and different concentrations of shikonin （2, 4, 8, 16 and 32 μmol/L） for harvesting at 24 hours. This entailed measurement of growth inhibitory rate and calculation of effective semi inhibitory concentration （ICs0） of shikonin by using MTT technique. Following treatment with 8 μmol/L shikonin, the PC3 cells were harvested at hours 0, 6, 12, 24, 48 and 72, thus allowing for computation of the respective growth inhibitory rate by using MTT technique. Flow cytometer was employed to determine the cell apoptosis rate at hours 0, 12, 24 and 48 following treatment with 8 μmol/L shikonin. And the fluorescent spectrometer was applied to assay the easpase3 activity by harvesting the PC3 cells at hours 0, 6, 12, 24, 48 and 72. The PC3 cellsincubated with DMSO （control group）, z-DEVD-fmk （caspase3 inhibitor, 20 μmol/L） , z-IETD-fmk （caspase9 inhibitor, 20 μmol/L） and z-LEHD-fmk （caspase8 inhibitor, 20 μmol/L） for 1 h were added with shikonin for subsequent harvesting at hour 24, which allowed calculation of growth inhibitory rate by using MTF technique. Results Shikonin inhibited PC3 cell proliferation. An increase in the concentration of shikonin was associated with a higher growth inhibitory rate at hour 24 [ICs0：（7.91 ± 0.73） μmol/L]. Following treatment with 8 μmol/L shikonin at hours 0, 6, 12, 24, 48 and 72, there was an increase in the growth inhibitory rate with the time. Treatment of 8 μmol/L shikonin resulted in an increased apoptosis rate at hours 12 [ （5.73±0.82）%], 24 [ （19.15±1.14）% ] and 48 [ （32.68± 1.03）% ] compared with that at hour 0 [ （0.98 ± 0.34） %, all P〈0.05 ]. Following treatment with 8 μmol/L shikomin, the caspase3 activity of PC3 cells that increased at hour 6 and culminated at hour 24 followed by a gradual reduction thereafter. Compared with DMSO, cas