Imatinib mesylate induction of ROS-dependent apoptosis in melanoma B16F0 cells

Background

Imatinib mesylate (STI571), a protein tyrosine kinase inhibitor, was shown to reduce the viability of several cancer cell lines via apoptosis induction; however, the role of reactive oxygen species (ROS) in STI571-induced melanoma cell apoptosis is still undefined.

Objective

In this study, we investigated the contribution of ROS to STI571-induced apoptosis in melanoma B16F0 cells, and the apoptotic mechanism elicited by STI571 was illustrated.

Methods

Using an in vitro cell culture system, the effects of STI571 on ROS production, cell cycle progression, caspase activation, and mitochondrial functions were examined via Western blotting, a flow cytometric analysis, an enzyme activity assay, and a DNA integrity assay. In pharmacological studies, the ROS scavenger, N-acetyl cysteine (NAC), the NADPH oxidase inhibitor, dipheylene iodide (DPI), and mitogen-activated protein kinase (MAPK) inhibitors (PD98059, SP600125, and SB203580) were applied to investigate the mechanism.

Results

STI571 reduced the viability of melanoma cells B16F0, but not human skin fibroblasts WS1, via apoptosis induction. Besides, apoptosis induced by STI571 was inhibited by the addition of NAC and DPI, and an increase in the intracellular peroxide level by STI571 was identified in melanoma B16F0 cells. Activation of caspases 3 and 9 enzyme activities accompanied by disrupting the mitochondria membrane potential in according with stimulating JNK and p38 protein phosphorylation was identified in STI571-treated B16F0 cells. STI571-mediated a ROS-dependent apoptosis potentiated by JNK inhibitor SP600125 was first identified in melanoma B16F0 cells.

Conclusion

Our results support the idea that ROS-dependent apoptosis in STI571-treated melanoma cells B16F0. The combination of a JNK inhibitor with STI571 for treating melanomas is suggested for further in vivo studies.     

三氧化二砷体外抑制A375黑色素瘤细胞的生长及谷胱甘肽过氧化物酶的活力

目的:了解三氧化二砷(As2O3)对体外培养的A375黑色素瘤细胞的生长及谷胱甘肽过氧化物酶活力的影响。方法:采用四甲基偶氮唑蓝(MTT)还原法检测1.5,3.0,6.0,12.0,24.0μmol/LAs2O3与A375黑色素瘤细胞作用24,48,72h后对瘤细胞的抑制作用;测定共培养24h的A375黑色素瘤细胞所含的谷胱甘肽过氧化物酶活性。结果:各浓度As2O3对A375瘤细胞的生长均有明显的抑制作用,As2O3的浓度越高,增殖抑制作用越强;各浓度As2O3与A375黑色素瘤细胞作用24h后,瘤细胞的谷胱甘肽过氧化物酶活力均有明显的降低,分别为2.23±0.81,2.87±0.70,4.08±0.81,2.63±0.84,1.40±0.41mU/mL,在As2O3浓度为6.0μmol/L时,酶活性最高,低于此浓度或高于此浓度时,酶活力呈递减的趋势。经过统计学独立样本的t检验分析,差别有统计学意义。结论:As2O3对A375瘤细胞的生长有浓度依赖性抑制作用,AsO显著降低A375瘤细胞谷胱甘肽过氧化物酶活力。     

Protective effects of epigallocatechin gallate after UV irradiation of cultured human lens epithelial cells

PURPOSE: To evaluate the protective effects of epigallocatechin gallate (EGCG) against UV irradiation of cultured human lens epithelial cells. METHODS: We irradiated cultured human lens epithelial cells with a 30-second pulse from a UV lamp with an irradiance of 0.6 mW/cm(2). Five minutes and 1 hour after UV irradiation, we administered 0, 5, 10, 15, 25, 50, or 100 uM EGCG. The cell number was measured with a microscopic counting chamber and cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: Compared to untreated cells, the total number of cultured human lens epithelial cells was markedly higher after UV irradiation. In a dose-dependent manner, viability was also higher in EGCG-treated cells. CONCLUSIONS: EGCG increased the cell count and cell viability after UV irradiation of cultured human lens epithelial cells, indicating that EGCG can protect lens epithelium against UV damage.     

Mycelia extracts of fungal strains isolated from Cordyceps sinensis differently enhance the function of RAW 264.7 macrophages

Ethnopharmacological relevance

Cordyceps sinensis, an entomogenous fungus used in traditional Chinese medicine with multiple pharmacological activities. However, its usage has been limited due to the high price and short supply. Isolate of fungi strains from natural Cordyceps sinensis to achieve a large-scale production by fermentation is an alternative choice. The aim of this study was to investigate and compare the effects of mycelia extracts of different fungal stains isolated from natural Cordyceps sinensis on macrophage functions in vitro.

Materials and methods

Macrophages' proliferation, phagocytosis, nitric oxide (NO) production, cytokines secretion, iNOS, NF-κ$\mathrm{\kappa }$B p65 activation and translocation were investigated by the MTT assay, flow cytometry assay, Griess reagent method, ELISA, western blot and immunostaining assay, respectively.

Results

The results showed that the effects of cultured Cordyceps mycelia of different fungal strains isolated from natural Cordyceps sinensis on macrophages greatly variant. Among 17 Cordyceps aqueous extracts, only five extracts (UM01, QH11, BNQM, GNCC and DCXC) could significantly increase cell proliferation and NO production of RAW 264.7 mouse macrophages. Moreover, the five extracts, especially UM01 and QH11, significantly enhanced phagocytosis and promoted cytokines release of macrophages. Polysaccharides in cultured UM01 mycelia were found to be the main immune stimulating compounds.

Conclusions

The variation of biological effects of fermented mycelia of different fungal strains from natural Cordyceps sinensis may be derived from their chemical diversity, especially polysaccharides, which need further study in future.     

Scientific evidence for traditional claim of anti-obesity activity of Tecomella undulata bark

Ethnopharmacological relevance

The bark of Tecomella undulata is traditionally claimed in the treatment of various disease ailments including obesity and cancer. Till now there are no studies about anti-obesity activity of Tecomella undulata bark.

Aim of the study

The present study was aimed to establish a scientific evidence for anti-obesity efficiency of ethyl acetate extract of Tecomella undulata bark (EATUB). Further to standardize the active fractions of EATUB using different biomarkers.

Materials and methods

We investigated activity of EATUB fractions (F1–F7) using 3T3-L1 fibroblasts. Further, F1-mediated effects were characterized by determining mRNA and protein levels of SIRT1, one of the key targets for the treatment of obesity, using semi-quantitative RT-PCR (sqRT-PCR) and western blot analysis. The consequences of modulation of SIRT1 on mRNA and protein levels of various adipogenesis mediators like PPARγ, C/EBPα, E2F1, leptin, adiponectin and LPL were also studied. In vivo studies were performed using High Fat Diet (HFD) obese mice.

Results

Our data showed that compared to controls, preadipocytes and adipocytes incubated with F1 exhibited a significant decrease in adipogenesis and lipogenesis. In addition, sqRT-PCR and western blot analysis showed significant increase in SIRT1 and adiponectin levels and decrease in PPARγ, C/EBPα, E2F1, leptin and LPL levels in preadipocytes and adipocytes. In vivo studies of F1 in HFD induced obese mice showed significant improvement in lipid profile and glucose levels. The bioactive fraction (F1) was determined to possess 4.95% of ferulic acid.

Conclusion

Thus, our findings signified the beneficial effects of Tecomella undulata bark in pharmacologic interventions related to obesity and metabolic disorders. Ferulic acid and rutin are being reported and quantified for the first time from the bark of Tecomella undulata.     

Engineered peptides for the development of actively tumor targeted liposomal carriers of doxorubicin

Chemotherapy is still the treatment of choice for many types of cancer; but its effectiveness is hampered by dose limiting toxicity. Properly designed delivery systems can overcome this shortcoming by reducing the non-specific distribution and toxicity of chemotherapeutics in healthy organs and at the same time increasing drug concentrations at tumor tissue. In this study, we developed stealth liposomal formulations of doxorubicin (DOX) having a novel stable engineered peptide ligand, namely p18-4, that binds specifically to breast cancer cell line MDA-MB-435 on its surface. The coupling of p18-4 to liposomes was carried out through conventional, post insertion and post conjugation techniques and prepared liposomes were characterized for their size and level of peptide modification. The p18-4 decorated liposomal DOX formulations were then evaluated for their cellular uptake as well as cytotoxicity against the human breast cancer MDA-MB-435 cells. In this context, the effect of coupling technique on the uptake and cytotoxicity of p18-4 liposomal DOX in MDA-MB-435 cells was evaluated. The conventional and post conjugation methods of peptide incorporation were found to be more reliable for the preparation of p18-4 decorated liposomes for active DOX targeting to MDA-MB-435 cells. p18-4 decoration of liposomes by these methods did not have a notable effect on the size of prepared liposomes and DOX release, but increased the uptake and cytotoxicity of encapsulated DOX in MDA-MB-435 cells. The results show a potential for p18-4 decorated liposomes prepared by conventional and post conjugation method for tumor targeted delivery of DOX in breast tumor models.     

不同菱角壳提取物抑制肺癌A549细胞生长的研究

目的 研究不同菱壳水和乙醇提取物的抗癌活性.方法 采用Folin比色法测定不同品种菱壳提取物中多酚的含量,通过MTT法测定二角菱壳、四角菱壳的水提取物、醇提取物对肺癌A549细胞生长抑制作用.结果 四角菱壳多酚含量高于二角菱壳,醇提物多酚含量高于水提物;二角菱壳醇提取物对肺癌A549细胞的抑制率高于水提物,差异具有统计学意义(P＜0.01);四角菱壳水提物对抑制率高于二角菱壳水提物肺癌A549细胞的生长,差异具有统计学意义(P＜0.01).结论 菱角壳提取物对肺癌A549细胞生长具有较强的抑制作用,且菱角壳的醇提取物优于水提取物,四菱角壳优于二角菱壳.     

Novel ginsenosides 25-OH-PPD and 25-OCH3-PPD as experimental therapy for pancreatic cancer: anticancer activity and mechanisms of action

We recently isolated and characterized two novel ginsenosides, 25-OH-PPD and 25-OCH₃-PPD. We investigated whether these ginsenosides could represent safe and effective therapeutic agents for pancreatic cancer. In vitro and in vivo studies demonstrated that both compounds inhibited proliferation, caused cell cycle arrest, and induced apoptosis. They also both inhibited the growth of xenograft tumors without any host toxicity. Preliminary investigations into the mechanisms of action of the compounds suggest that their effects may be partially mediated by their inhibition of the MDM2 oncogene and related pathways. The data presented here support further evaluation of the ginsenosides for pancreatic cancer therapy.     

高压芒刺静电场对体外培养小鼠Lewis肺癌细胞的生物效应

目的：探讨高压芒刺静电场对小鼠Lewis肺癌细胞的作用情况及肿瘤细胞的药物敏感性变化。 方法：采用MTT法检测体外培养的小鼠Lewis肺癌细胞单纯电场辐照组、单纯卡铂作用组、电场和卡铂联合作用组及对照组的A值,根据细胞相对死亡率判断细胞活性。 结果：单纯电场作用组与对照组相比,电压≤1.5 kV时,刺激细胞生长,当电压1.5 kV时,细胞活性提高至132.7%(P<0.05);而电压>1.5 kV时,抑制细胞生长;2.5 kV时抑制效果最佳,细胞活性仅为对照组的71.7%(P<0.05)。电场和卡铂联合作用组与对照组和单纯卡铂作用组相比,能更有效地抑制小鼠Lewis肺癌细胞生长,细胞活性是对照组的57.8%(P<0.01)。 结论：高压芒刺静电场对肿瘤细胞有直接的抑制作用,同时不同程度地提高肿瘤细胞对某些 化疗药物的敏感性。     

电针及生物活性物质对大鼠多形核细胞杀菌功能的影响

用改良的四氮唑硝基蓝（ＮＢＴ）还原法观察了电针以及生物活性物质（ＢＡＳ）包括５－羟色胺（５－ＨＴ）、血管活性肠肽（ＶＩＰ）、生长抑素（ＳＯＭ）和Ｐ物质（ＳＰ）对大鼠多形核白细胞（ＰＭＮ）杀菌功能的影响。结果表明：电针及ＢＡＳ均能增强大鼠ＰＭＮ的杀菌功能（Ｐ＜０．０１）；ＢＡＳ对大鼠ＰＭＮ的杀菌功能具有双向调节效应。纳洛酮可阻抑电针对ＰＭＮ杀菌功能的提高（Ｐ＞０．０５）；可被ＢＡＳ所翻转。电针的镇痛效应和ＮＢＴ阳性细胞提高效应之间存在着明显的正相关（Ｐ＜０．０１）。