富集纯化前上样液参数影响三七皂苷类成分的研究

目的 考察富集纯化前上样液参数pH值、氯化钠浓度、时间等对三七皂苷类成分的影响.方法 用UV、TLSC分别测定3种不同上样液在不同时间段的三七总皂苷、人参皂苷Rg1、人参皂苷Rb1、三七皂苷R1的含量.结果 3种上样液放置72 h后,人参皂苷Rg1含量均增加(P＜0.01);三七皂苷R1含量均减少(P＜0.05);人参皂苷Rb含量变化无差异;pH5.5上样液和pH 7.0上样液中的总皂苷含量均增加(P＜0.05),pH5.5且含4％氯化钠的上样液中总皂苷含量无明显变化.结论 在富集纯化过程中,上样液的pH值、无机盐浓度和时间对皂苷类成分含量变化有影响.     

Triptolide inhibits rat vascular smooth muscle cell proliferation and cell cycle progression via attenuation of ERK1/2 and Rb phosphorylation

Background

Drug-eluting stents have demonstrated a substantial reduction of restenosis and currently are gaining a leading position in the intervention field. Triptolide, a purified extract from Chinese herb medicine Tripterygium wilfordii hook F, exhibits antiproliferative and pro-apoptotic function in vitro and in vivo. In the present study, we investigated effects of triptolide on in-stent restenosis in vivo and in vitro, and study the biological mechanism of this drug.

Methods

Rat aortic smooth muscle cells were cultured and treated with different concentration of triptolide (0, 1, 10, and 50 nM). For cell viability, we used trypan blue exclusion (TBE) survival assay. Flow cytometry was used to study the influence of triptolide on VSMCs cell cycle. Signal proteins were detected by western blotting analysis. Triptolide coated stents had been implanted in the iliac arteries of New Zealand rabbits. After 4 weeks, the stented iliac artery segments were processed for embedding, staining and histomorphometric analysis.

Results

Triptolide of concentration 10 nM, 50 nM significantly inhibited fetal calf serum-induced VSMC proliferation (p < 0.05). The accumulation of triptolide-treated cells at the G1/S-interphase was dose dependent. Triptolide completely blocked the cell cycle progression at 50 nM. Western blotting analysis showed decreased ERK1/2 MAP kinase phosphorylation level, significantly increased p21^cip1 expression and reduced retinoblastoma protein (pRb) phosphorylation after 24 h of triptolide treatment. 4 weeks after the surgery, the arterial wall morphology was shown that triptolide-coated stent has less neointimal vs bare metal stent.

Conclusions

Our study indicates that triptolide exert inhibitory effect on VSMC proliferation, inactivation of MAPK pathway and modulation of cell cycle proteins p21^cip1 and Rb are relating mechanisms. Triptolide drug-eluting stents attenuated neointimal formation after stent implantation in rabbit vessel. We believe that triptolide may potentially be useful in treating cardiovascular restenosis after PCI.     

Targeting Rb inactivation in cancers by synthetic lethality

The retinoblastoma protein, pRb, is a key regulator of cell proliferation, differentiation, apoptosis, as well as checkpoint and stress responses. The function of Rb is often inactivated in many types of cancers, a feature that can potentially be used to target this specific subset of cancers. However little is known about how the loss of Rb function can be exploited in cancer therapies. In this review, we overview the functions of Rb, and discuss a genetic screen that led to the finding that inactivation of TSC2 and Rb induces synergistic cell death in both Drosophila developing tissues and human cancer cells. The mechanisms for synergistic cell death involve the accumulation of cellular stress, suggesting that inactivation of TSC2 and chemotherapeutic agents that result in induction of cellular stress can potentially be combined to treat cancers harboring inactivated Rb.     

人参皂苷Rb1对小鼠T淋巴细胞体外活化、增殖及凋亡的影响

目的研究人参皂苷Rb1对小鼠T淋巴细胞体外活化及增殖的影响,并对其免疫调节作用进行初步探讨。方法分离制备小鼠淋巴结细胞悬液;以双色荧光抗体染色技术结合流式细胞术检测在刀豆蛋白A(ConA)的刺激下,人参皂苷Rb1对早期活化标志CD3/CD69和调节T淋巴细胞标志CD4/CD25表达的影响;用羧基荧光素乙酰乙酸(CFDA-SE)染色结合流式细胞术和MTT法检测在ConA的刺激下,人参皂苷Rb1对T淋巴细胞增殖的影响;DIOC/PI双染技术检测在H2O2作用下,人参皂苷Rb1对淋巴细胞凋亡进程的影响。结果终浓度为5、10、20μmol/L的人参皂苷Rb1对ConA刺激的调节T淋巴细胞CD4+/CD25+的表达具有促进作用,而CD3+/CD69+的表达明显下调(P<0.01);对ConA刺激的T淋巴细胞增殖具有明显的抑制作用(P<0.05),且呈剂量依赖性;人参皂苷Rb1显著抑制H2O2诱导的淋巴细胞的凋亡进程(P<0.05)。结论人参皂苷Rb1对小鼠淋巴细胞的体外活化及增殖均具有明显的抑制作用,是一种潜在的免疫抑制剂。     

Metabolomic strategy to study therapeutic and synergistic effects of tanshinone IIA, salvianolic acid B and ginsenoside Rb1 in myocardial ischemia rats

Aim of the study

Tanshinone IIA (T), salvianolic acid B (S) and ginsenoside Rb1 (G) are the three major active ingredients of Compound Danshen Formula (CDF) for its protective effects on myocardial ischemia (MI). In this study, we aimed to investigate therapeutic and synergistic effects of TSG (combination of T, S and G) on MI rats with metabolomic strategy.

Materials and methods

MI model were induced in Sprague-Dawley rats by left anterior descending coronary artery ligation. MI rats were respectively administrated T, S, G, TSG and CDF. Plasma was analyzed by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Partial least squares discriminate analysis (PLS-DA) models were built to evaluate the therapeutic and synergistic effects of TSG at whole level. 22 MI biomarkers in rat plasma were also investigated to explain that.

Results

TSG brings nearly equal therapeutic effects on MI as CDF and it plays more stable regulated action on those 22 identified metabolites than single compound.

Conclusions

Overall, there were few methods for the study of synergistic effects of Chinese medicine. Our results suggested that metabolomics offers a new idea for Chinese medicine research.     

Effects of carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone on the growth inhibition in human pulmonary adenocarcinoma Calu-6 cells

Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) is an uncoupler of mitochondrial oxidative phosphorylation in eukaryotic cells. Here, we evaluated the in vitro effects of FCCP on the growth of Calu-6 lung cancer cells. FCCP inhibited the growth of Calu-6 cells with an IC₅₀ of approximately 6.64 ± 1.84 μM at 72 h, as shown by MTT. DNA flow cytometric analysis indicated that FCCP induced G1 phase arrest below 20 μM of FCCP. Treatment with FCCP decreased the level of CDKs and cyclines in relation to G1 phase. In addition, FCCP not only increased the p27 level but also enhanced its binding with CDK4, which was associated with hypophosphorylation of Rb protein. While transfection of p27 siRNA inhibited G1 phase arrest in FCCP-treated cells, it did not enhance Rb phosphorylation. FCCP also efficiently induced apoptosis. The apoptotic process was accompanied with an increase in sub-G1 cells, annexin V staining cells, mitochondria membrane potential (MMP) loss and cleavage of PARP protein. All of the caspase inhibitors (caspase-3, -8, -9 and pan-caspase inhibitor) markedly rescued the Calu-6 cells from FCCP-induced cell death. However, knock down of p27 protein intensified FCCP-induced cell death. Moreover, FCCP induced the depletion of GSH content in Calu-6 cells, which was prevented by all of the caspase inhibitors. In summary, our results demonstrated that FCCP inhibits the growth of Calu-6 cells in vitro. The growth inhibitory effect of FCCP might be mediated by cell cycle arrest and apoptosis via decrease of CDKs and caspase activation, respectively. These findings now provide a better elucidation of the mechanisms involved in FCCP-induced growth inhibition in lung cancer.     

Estrogens decrease gamma-ray-induced senescence and maintain cell cycle progression in breast cancer cells independently of p53

PURPOSE: Sequential administration of radiotherapy and endocrine therapy is considered to be a standard adjuvant treatment of breast cancer. Recent clinical reports suggest that radiotherapy could be more efficient in association with endocrine therapy. The aim of this study was to evaluate the estrogen effects on irradiated breast cancer cells (IR-cells). METHODS AND MATERIALS: Using functional genomic analysis, we examined the effects of 17-beta-estradiol (E(2), a natural estrogen) on MCF-7 breast cancer cells. RESULTS: Our results showed that E(2) sustained the growth of IR-cells. Specifically, estrogens prevented cell cycle blockade induced by gamma-rays, and no modification of apoptotic rate was detected. In IR-cells we observed the induction of genes involved in premature senescence and cell cycle progression and investigated the effects of E(2) on the p53/p21(waf1/cip1)/Rb pathways. We found that E(2) did not affect p53 activation but it decreased cyclin E binding to p21(waf1/cip1) and sustained downstream Rb hyperphosphorylation by functional inactivation of p21(waf1/cip1). We suggest that Rb inactivation could decrease senescence and allow cell cycle progression in IR-cells. CONCLUSION: These results may help to elucidate the molecular mechanism underlying the maintenance of breast cancer cell growth by E(2) after irradiation-induced damage. They also offer clinicians a rational basis for the sequential administration of ionizing radiation and endocrine therapies.     

Curcumin induces the degradation of cyclin E expression through ubiquitin-dependent pathway and up-regulates cyclin-dependent kinase inhibitors p21 and p27 in multiple human tumor cell lines

Curcumin, a well-known chemopreventive agent, has been shown to suppress the proliferation of a wide variety of tumor cells through a mechanism that is not fully understood. Cyclin E, a proto-oncogene that is overexpressed in many human cancers, mediates the G(1) to S transition, is a potential target of curcumin. We demonstrate in this report a dose- and time-dependent down-regulation of expression of cyclin E by curcumin that correlates with the decrease in the proliferation of human prostate and breast cancer cells. The suppression of cyclin E expression was not cell type dependent as down-regulation occurred in estrogen-positive and -negative breast cancer cells, androgen-dependent and -independent prostate cancer cells, leukemia and lymphoma cells, head and neck carcinoma cells, and lung cancer cells. Curcumin-induced down-regulation of cyclin E was reversed by proteasome inhibitors, lactacystin and N-acetyl-L-leucyl-L-leucyl-L-norleucinal, suggesting the role of ubiquitin-dependent proteasomal pathway. We found that curcumin enhanced the expression of tumor cyclin-dependent kinase (CDK) inhibitors p21 and p27 as well as tumor suppressor protein p53 but suppressed the expression of retinoblastoma protein. Curcumin also induced the accumulation of the cells in G1 phase of the cell cycle. Overall, our results suggest that proteasome-mediated down-regulation of cyclin E and up-regulation of CDK inhibitors may contribute to the antiproliferative effects of curcumin against various tumors.