冬凌草甲素通过激活caspase诱导HeLa细胞凋亡

目的　研究冬凌草甲素诱导人子宫颈癌HeLa细胞凋亡的作用机制。方法　采用形态学观察、DNA凝胶电泳及LDH法。结果　冬凌草甲素能显著诱导HeLa细胞发生凋亡 ,其作用呈明显的量效关系和时间依赖性。形态学观察可见凋亡小体的形成 ,琼脂糖凝胶电泳可见凋亡典型的DNA梯带 ;caspase家族抑制剂 ,caspase 1和 3抑制剂能抑制冬凌草甲素诱导HeLa细胞的凋亡 ,6 8 7μmol·L-1冬凌草甲素作用HeLa细胞 12h使caspase 3的活力提高 2倍。 结论　适宜浓度以下 ,冬凌草甲素 (6 8 7μmol·L-1)诱导HeLa细胞凋亡具有浓度与时间依赖性 ,大剂量 (137 4 μmol·L-1)时 ,冬凌草甲素诱导HeLa细胞坏死的程度强于凋亡 ,且通过激活caspase途径诱导HeLa细胞凋亡。     

冬凌草甲素对Raji细胞的增殖抑制作用及其机制

目的探讨冬凌草甲素对B淋巴细胞白血病细胞株Raji细胞的增殖抑制作用及其机制。方法以不同浓度的冬凌草甲素作用于体外培养的Raji细胞，MTT法检测细胞生长抑制率，应用流式细胞仪、Hoechst 33258荧光染色法观察细胞凋亡，TRAP-PCR-ELISA法检测细胞凋亡前后的端粒酶活性。结果冬凌草甲素可显著降低Raji细胞的端粒酶活性，抑制细胞的生长，诱导细胞发生凋亡，并呈现出明显的剂量-效应与时间-效应关系。结论冬凌草甲素对B淋巴细胞白血病具有明显的体外抗白血病作用，降低细胞端粒酶活性，诱导细胞发生凋亡，可能是其重要作用机制。     

冬凌草甲素作用PI3K/AKT通路诱导HeLa细胞凋亡

【目的】研究冬凌草甲素诱导HeLa细胞凋亡的作用及其机制。【方法】MTT法测定冬凌草甲素对HeLa细胞的生长抑制实验,Hoechst 33342荧光染色等观察细胞核形态学变化;LDH法研究细胞死亡的途径。流式细胞仪检测细胞的凋亡,免疫印迹实验检测相关蛋白的表达。【结果】25μmol/L以上的冬凌草甲素对宫颈癌HeLa细胞具有明显的生长抑制作用,并能诱导细胞发生凋亡,随着药物浓度的增加和作用时间的延长,细胞的生长抑制率及细胞凋亡率均明显升高,冬凌草甲素抑制细胞生长及诱导细胞发生凋亡的过程中,细胞端粒酶Akt、FKHRL、GSK3表达水平及活性显著降低。【结论】冬凌草甲素能够通过诱导人子宫颈癌HeLa细胞发生凋亡而发挥抑制HeLa细胞生长作用,抑制Akt和GSK3的活性是冬凌草甲素体外诱导人子宫颈癌HeLa细胞发生凋亡的重要作用机制之一。     

冬凌草甲素通过诱导人宫颈癌HeLa细胞自噬下调凋亡的机制

研究冬凌草甲素通过诱导人宫颈癌HeLa细胞自噬拮抗凋亡的机制。MTT法测定冬凌草甲素对HeLa细胞的细胞毒作用。通过相差显微镜观察细胞形态学变化，用琼脂糖凝胶电泳检测DNA片段化，用流式细胞仪检测细胞自噬和凋亡水平，用Western blotting检测分析药物对蛋白质表达的影响。冬凌草甲素明显抑制HeLa细胞的增殖，诱导HeLa细胞凋亡，同时诱导HeLa细胞发生自噬。Western blotting检测结果表明，冬凌草甲素作用24 h后，促凋亡蛋白Bax、细胞色素c和控制Bax活力的去乙酰化酶SIRT-1的表达明显改变。冬凌草甲素(64 μmol·L^-1)诱导的自噬通过影响SIRT-1和线粒体途径蛋白的表达下调凋亡。     

冬凌草甲素对肝癌HepG2细胞株体外放射增敏作用

目的观察冬凌草甲素对肝癌细胞株体外的放射增敏作用。方法对肝癌细胞系（HepG2）进行克隆形成实验。照射前用1.804、3.608、5.412、7.216、18.040μmol/L冬凌草甲素处理HepG2细胞6～72h,然后分别给予0、1、2、3、4、5、6Gy的^60Co照射,观察细胞存活率,计算放射增敏比（SER）。并运用常规照射剂量2Gy时的放射增敏比（SERSF2）作为评价指标。结果冬凌草甲素可提高HepG2细胞的放射敏感性,并呈时间、浓度依赖关系。照射前用1.804μmol/L冬凌草甲素处理HepG2细胞6～72h,在6、12和24h未观察到放射增敏作用,放射增敏作用仅在48和72h出现。当高浓度冬凌草甲素（18.040μmol/L）处理HepG2细胞6、12和24h,各时间点均可见放射增敏效应。结论冬凌草甲素可能是一种肝癌放射增敏剂。     

羟丙基-β-环糊精对冬凌草二萜类成分的包合作用

目的研究羟丙基-β-环糊精(HPCD)在溶液中对冬凌草二萜类成分的包合作用。方法采用相溶解度法进行研究。结果在水溶液中,冬凌草甲素的浓度随HPCD浓度的增加而呈线性增加,为典型的AL型相溶解度图。在不同pH值、不同温度、不同离子强度等条件下计算包合表观稳定常数。包合过程的热力学参数为:ΔH=17.31 kJ.mol-1,ΔS=39.57 J.mol-1,且不同温度条件下的ΔG均小于零。结论羟丙基β环糊精可以提高冬凌草甲素的溶解度。HPCD与冬凌草甲素形成摩尔比为1∶1的包合物,包合过程为吸热过程,而且是自发进行。     

Oridonin induces apoptosis in human oral cancer cells via phosphorylation of histone H2AX

Oridonin, a natural diterpenoid purified from Rabdosia rubescens, has displayed beneficial biological activities, including anti‐proliferation and anti‐angiogenesis effects, in various types of cancers. However, the anti‐cancer potential of oridonin and its mechanism in oral cancer have never previously been studied. In this study, we assessed the role of oridonin as an inducer of apoptosis in HSC‐3 and HSC‐4 human oral cancer cells. Our results showed that oridonin reduces the viability of human oral cancer cells and significantly increases the expression of γH2AX, a well‐known marker of DNA damage. 4′,6‐Diamidino‐2‐phenylindole (DAPI) staining and western blotting showed that oridonin causes nuclear condensation and fragmentation, and induces cleavage of poly(ADP‐ribose) polymerase (PARP). Moreover, oridonin‐induced γH2AX accumulation was partially abrogated by Z‐VAD, a pan‐caspase inhibitor. Taken together, our results suggest that oridonin can effectively induce apoptosis by augmenting the expression of γH2AX in response to DNA damage and might be a promising anti‐cancer drug candidate for the treatment of oral cancer.     

Combination of oridonin and TRAIL induces apoptosis in uveal melanoma cells by upregulating DR5

AIM: To investigate the inhibitory effect of the combined use of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and oridonin on choroidal melanoma cell lines, and to explore its underlying mechanism. METHODS: MUM-2B and C918 cells were treated with different concentrations of TRAIL and oridonin, and MTT assay used to evaluate the inhibition rate of the two compounds on cells. Then, the cell cycle distribution and apoptosis were detected by flow cytometry, and changes in apoptosis-related proteins such as death receptor 5 (DR5), a-caspase-3, and x-linked inhibitor of apoptosis protein (XIAP) were detected by Western blot. MUM-2B cells were transfected with si-DR5, which interfered with the expression of the DR5 gene. MTT and Western blot assay were used to detect cell activity and apoptosis-related proteins. RESULTS: When TRAIL and oridonin were simultaneously administered to the MUM-2B cells, the apoptosis rate was significantly higher than that by the two drugs individually. However, the effect of combined use of TRAIL and oridonin on C918 cells was not significantly different from that used alone. Cell cycle analysis showed that TRAIL and oridonin could induce G2/M arrest in MUM-2B cells. The Western blot results showed that the protein expression levels of the DR5, a-caspase-3, and BAX increased, while the expression levels of the anti-apoptosis-related proteins XIAP and BCL-2 were suppressed when TRAIL and oridonin simultaneously administered to MUM-2B cells. Interfering the expression of DR5 gene in MUM-2B cells could reverse the inhibitory effect of oridonin and TRAIL on the proliferation and apoptosis induction of MUM-2B cells. CONCLUSION: The inhibitory effects of oridonin and TRAIL on MUM-2B cells are significantly enhanced when they were administered as a combined treatment, which may ascribe to up-regulation of DR5.     

冬凌草甲素的提取工艺研究

目的 采用近红外光谱(NIR)技术对冬凌草中冬凌草甲素的提取工艺进行研究。方法 采用柱色谱法分离冬凌草甲素，应用NIR技术寻找最佳工艺条件。结果 此工艺所得冬凌草甲素纯度较高，且样品与对照品的HPLC峰保留时间相同，NMR和IR图谱相同。结论 本法洗脱速度快，安全、成本低、方便，并且重现性好。