Liu Xiao-Ni, Zhang Cheng-Yu, Jin Xiu-Dong, Li Yue-Zhen, Zheng Xue-Zhi, Li Li
Department of Physiology, Mudanjiang Medical College, Mudanjiang 157011, Heilongjiang Province, China.
World J Gastroenterol. 2007 Dec 28;13(48):6506-11. doi: 10.3748/wjg.v13.i48.6506.
To investigate the inhibitory effect and possible mechanism of action of schisandrin B in SC-B on gastric cancer cells in vitro.
SC-B consisted of schisandrin B, aloe-emodin, and Astragalus polysaccharides. Exponentially growing human gastric cancer SGC-7901 cells were divided into six treatment groups: (1) control group (RPMI 1640 medium); (2) negative control group (2% DMSO); (3) positive control group (50 mg/L 5-Fluorouracil, 5-FU); (4) low-dose group (LSC, final concentration of schisandrin B, 25 mg/L); (5) moderate-dose group (MSC, final concentration of schisandrin B, 50 mg/L); (6) high-dose group (HSC, final concentration of schisandrin B, 100 mg/L). Follow-up was done at 12-48 h. An MTT (Methylthiazolyldiphenyl-tetrazolium bromide) assay was used to examine the inhibitory effect of SC-B on gastric cancer cells. The mitosis index was assessed using an inverted microscope. Flow cytometry was used to visualize the cell cycle. An RT-PCR (Reverse transcription-Polymerase chain reaction) -based assay was used to detect mRNA expression for cyclin D1 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH).
The MTT assay showed that the number of living cells in the LSC, MSC and HSC groups was significantly smaller than that in the DMSO-treated group (P < 0.05) at 12-48 h. The inhibitory rate (IR) of the LSC group was 41.15% +/- 3.86%, 59.24% +/- 5.34% and 69.93% +/- 7.81% at 12, 24 and 48 h, respectively. The IR of the MSC group was 42.82% +/- 4.94%, 62.68% +/- 7.58% and 71.79% +/- 8.12% at 12, 24 and 48 h, respectively. The IR of the HSC group was 37.50% +/- 3.21%, 40.34% +/- 2.98% and 61.99% +/- 4.88% at 12, 24 and 48 h, respectively. These results suggested that a moderate dosage had the most obvious inhibitory efficacy at 48 h. Compared to the DMSO group, the mitosis index of the LSC, MSC, HSC groups was greatly decreased (P < 0.05) at all time points. Any dose of SC-B suppressed mitosis within 12-48 h. Compared to the DMSO group, the percentage of cells in the G0/G1 phase of the MSC group was greatly increased, and that of the S + G2M phase was greatly decreased, while the percentage of cell inhibition (PCI) in the MSC group was greatly increased (P < 0.05). This suggested that SC-B could exclusively arrest cells in the G0/G1 phase. Cyclin D1 mRNA expression was lower in the MSC group than that in the DMSO group (P < 0.05).
SC-B can inhibit the proliferation and aberrant mitosis of human gastric cancer SCG-7901 cells in vitro. This inhibitory effect may be due to the down-regulation of cyclin D1 mRNA expression, which causes cell cycle arrest of gastric cancer cells.
探讨五味子乙素-芦荟大黄素-黄芪多糖复合物（SC-B）对体外培养胃癌细胞的抑制作用及其可能的作用机制。
SC-B由五味子乙素、芦荟大黄素和黄芪多糖组成。将对数生长期的人胃癌SGC-7901细胞分为6个处理组：（1）对照组（RPMI 1640培养基）；（2）阴性对照组（2%二甲基亚砜，DMSO）；（3）阳性对照组（50 mg/L 5-氟尿嘧啶，5-FU）；（4）低剂量组（LSC，五味子乙素终浓度25 mg/L）；（5）中剂量组（MSC，五味子乙素终浓度50 mg/L）；（6）高剂量组（HSC，五味子乙素终浓度100 mg/L）。于12 - 48 h进行后续观察。采用MTT（噻唑蓝）法检测SC-B对胃癌细胞的抑制作用。利用倒置显微镜评估有丝分裂指数。采用流式细胞术观察细胞周期。采用基于逆转录-聚合酶链反应（RT-PCR）的方法检测细胞周期蛋白D1（cyclin D1）和甘油醛-3-磷酸脱氢酶（GAPDH）的mRNA表达。
MTT法检测结果显示，12 - 48 h时，LSC组、MSC组和HSC组的活细胞数显著低于DMSO处理组（P < 0.05）。LSC组在12、24和48 h的抑制率分别为41.15%±3.86%、59.24%±5.34%和69.93%±7.81%。MSC组在12、24和48 h的抑制率分别为42.82%±4.94%、62.68%±7.58%和71.79%±8.12%。HSC组在12、24和48 h的抑制率分别为37.50%±3.21%、40.34%±2.98%和61.99%±4.88%。这些结果表明，中剂量在48 h时具有最明显的抑制效果。与DMSO组相比，LSC组、MSC组、HSC组在各时间点的有丝分裂指数均显著降低（P < 0.05）。任何剂量的SC-B在12 - 48 h内均能抑制有丝分裂。与DMSO组相比，MSC组G0/G1期细胞百分比显著增加，S + G2M期细胞百分比显著降低，同时MSC组细胞抑制率（PCI）显著增加（P < 0.05）。这表明SC-B可使细胞特异性阻滞于G0/G1期。MSC组cyclin D1 mRNA表达低于DMSO组（P < 0.05）。
SC-B可在体外抑制人胃癌SCG-7901细胞的增殖和异常有丝分裂。这种抑制作用可能是由于cyclin D1 mRNA表达下调，导致胃癌细胞周期阻滞。
