Dioscin protects against diabetic nephropathy by inhibiting renal inflammation through TLR4/NF-κB pathway in mice

Diabetic nephropathy (DN) is a chronic kidney disease caused by the long-term loss of renal function, which occurs in 20% - 40% of all diabetes and is also the primary cause of end-stage renal diseases. DN is related with other lethal diseases, particularly cardiovascular diseases, leading to an increased risk of death. Therefore, an effective treatment for DN is required. Here we tested the protective effect of dioscin in a mouse model of streptozocin (STZ)-induced DN. First, STZ was intraperitoneally injected into C57BL/6 J mice and TLR4^-/- mice respectively, on a daily basis for 5 days to induce diabetes. Dioscin was then orally administered into diabetic mice daily for 8 weeks. Our results show that STZ injection effectively induced diabetes in mice as indicated by the increased blood glucose levels in C57BL/6 J mice, whereas it did not cause diabetes in TLR4^-/- mice. Dioscin significantly ameliorated STZ-induced renal damage via reducing inflammatory responses in diabetic mice and antagonizing the activation of TLR4/NF-κB pathway and the production of inflammatory cytokines. In conclusion, our study highlights the potential of dioscin as a novel approach to treat DN in diabetic patients.     

Cytotoxicity of dioscin in human gastric carcinoma cells through death receptor and mitochondrial pathways

In the present study, the antiproliferative effect of dioscin on human gastric carcinoma SGC‐7901 cells was confirmed by 3‐(4, 5‐dimethylthiahiazo‐zyl)‐2, 5‐dip‐henytetrazolium bromide and flow cytometry assays. Through acridine orange–ethidium bromide double fluorescent staining, apoptotic morphology of the cells was observed. Radioimmunoassays showed that the tumor necrosis factor (TNF)‐α concentration in cells treated with dioscin significantly increased compared with untreated cells. Several proteins and mRNA related to the mitochondrial and death receptor pathways were investigated. We found that the expression of Bid, bcl‐2 and bcl‐xl was markedly downregulated, and the expression of Bak and Bax was upregulated. In addition, cytochrome c was released from the mitochondria into the cytosol, which indicates activation of the mitrochondrial pathway by dioscin. Furthermore, upregulation of Fas, FasL (Fas ligand), TNF‐α, TNF receptor‐1, TNF receptor‐associated factor 1 and Fas‐associated protein with death domain demonstrated involvement of the death receptor pathway. Increased mRNA expression of p53 was also found in dioscin‐treated SGC‐7901 cells, and the activation of caspase‐3 and ?8 was also observed. Consequently, this study clarifies the mechanism underlying the anticancer effect of dioscin, and also indicates that dioscin may be a potential drug treatment for human gastric cancer. Copyright © 2012 John Wiley & Sons, Ltd.     

Antitumor effects of dioscin in A431 cells via adjusting ATM/p53-mediated cell apoptosis,DNA damage and migration

Skin cancer is the deadliest type of malignant disease and causes primary mortality worldwide. Dioscin, which exists in medicinal plants, has potent anticancer effects. However, its effects on skin cancer remain unknown. In the present study, the activity and mechanism of dioscin on the human skin cancer A431 cell line were investigated, MTT, colony formation, Transwell, wound-healing, TUNEL, Comet, immunofluorescence and western blot assays were used to assess the effects of dioscin on A431 cells. The results of MTT, colony formation, Transwell and wound-healing assays revealed that dioscin suppressed proliferation, colony formation and invasion of the cancer cells. TUNEL and comet assays demonstrated that dioscin exhibited significant effects on cell apoptosis and DNA damage. Investigations into the mechanism revealed that the expression levels of phosphorylated Ataxia telangiectasia-mutated (ATM) were considerably activated by dioscin, which significantly upregulated the expression levels of p53 to activate mitochondrial apoptosis signaling. Furthermore, the expression levels of BAX, cleaved caspase-3/9 and cleaved poly (ADP-ribose) polymerase were upregulated, and the expression levels of BCL-2 were downregulated by dioscin. Additionally, dioscin markedly downregulated the expression levels of matrix metalloproteinase 2 (MMP2), MMP9, RHO and cdc42, which are all associated with tumor invasion. In addition, p53-small interfering RNA transfection experiments indicated that dioscin exhibited excellent activity against skin cancer in vitro by decreasing p53 expression. Overall, the present results suggested that dioscin inhibited skin cancer cell proliferation via adjusting ATM/p53-mediated cell apoptosis, migration and DNA damage, which should be considered as a potential option for future treatments of skin cancer.     

蚤休薯蓣皂苷联合顺铂抑制小鼠移植瘤生长及转移

目的 探讨蚤休薯蓣皂苷(RD)联合顺铂对小鼠Lewis肺癌皮下移植瘤生长与转移的抑制作用。方法 40只C₅₇BL小鼠皮下接种Lewis肺癌细胞建立肺腺癌移植瘤模型,随机均分成对照组、RD组、顺铂组及RD联合顺铂组,从接种后第4 天开始给予生理盐水或相应药物干预,于接种后第29 天处死,通过免疫组化检测皮下移植瘤组织CD34表达,荧光实时定量PCR检测皮下移植瘤组织血管内皮生长因子(VEGF) mRNA表达,Western blotting测定皮下移植瘤组织 VEGF、Bcl-2、Bax蛋白表达。结果 RD联合顺铂组抑瘤率、肺表面结节转移抑制率高于RD组与顺铂组(P<0.01),Q值为1.01;RD联合顺铂组上述指标改善程度优于单独用药组(P<0.01),但RD组与顺铂组相比,差异无显著性(P>0.05)。结论 RD联合顺铂对小鼠Lewis肺癌皮下移植瘤生长与转移有相加抑制作用,其机制可能与拮抗肿瘤血管生成和诱导肿瘤细胞凋亡有关。     

Dioscin Ameliorates Hyperuricemia-Induced Atherosclerosis by Modulating of Cholesterol Metabolism through FXR-Signaling Pathway

Hyperuricemia is one of the independent risk factors for atherosclerotic cardiovascular disease. Herein, we investigate the association between uric acid and cholesterol metabolism and the effect of dioscin on the prevention of hyperuricemia-induced atherosclerosis. In the potassium oxonate-treated ApoE^{−/−−/−} mice, atherosclerosis was accelerated along with elevated serum cholesterol levels in the hyperuricemic state, which can be ameliorated by dioscin. Together with the in vitro assays, we found that the effect of dioscin was at least partially through the regulation of the farnesoid X receptor (FXR) -small heterodimer partner (SHP) -7α-hydroxylase (CYP7A1) signaling pathway in the liver. Tigogenin (a metabolite of dioscin) suppressed FXR activation and increased CYP7A1, resulting in an increased conversion rate of cholesterols into bile acids. Further clinical study revealed that treatment with a dioscin-enriched preparation decreased serum cholesterol levels in individuals with hyperuricemia. In summary, this study demonstrated a slowdown effect of dioscin on the progression of hyperuricemia-induced atherosclerosis.     

基于UPLC指纹图谱结合化学计量学评价不同产地盾叶薯蓣药材质量

目的 建立盾叶薯蓣Dioscorea zingiberensis的UPLC指纹图谱,分析不同产地盾叶薯蓣质量特征的共有性和差异性,为盾叶薯蓣药材的质量评价提供科学依据.方法 采用色谱柱InfinityLab Poroshell 120 EC-C18(150 mmX2.1 mm,2.7 μm),以乙腈(B)-水(A)为流...     

薯蓣皂苷含药血清抗氧化损伤致心肌细胞凋亡的研究

 目的 采用血清药理学方法探讨薯蓣皂苷含药血清对氧化损伤心肌细胞凋亡的作用及其机制。方法 以血清药理学方法采集含药血清。培养原代乳鼠心肌细胞,建立氧化损伤模型,以含药血清进行干预, MTT法检测细胞存活率。Hoechst33258荧光染色法观察药物作用后心肌细胞形态学变化。caspase-3活性测定方法探讨薯蓣皂苷抗凋亡途径。Western blot方法测定薯蓣皂苷对Bcl-2及Bax蛋白表达的影响。结果 MTT法作用结果显示,将原始收集血清稀释为相当于灌胃0.4、 0.8、1.2 g（生药）·kg^-1浓度时,相对于H₂O₂单纯损伤组和空白血清组心肌细胞有较高的存活率（P     

HPLC—ELSD法测定盾叶薯蓣中薯蓣皂苷的含量

目的:建立盾叶薯蓣中薯蓣皂苷的含量测定方法。方法:采用高效液相色谱-蒸发光散射检测法(HPLC—ELSD),Allti-ma C_(18)色谱柱(4.6 mm×250 mm,5μm),流动相乙腈-水(52:48),流速1.0 mL·min~(-1);蒸发光散射检测器参数:漂移管温度40℃,气压3.5 kPa。结果:薯蓣皂苷在0.24～4.80μg(r=0.9995)范围内线性关系良好,平均回收率为97.9%(RSD=1.1%,n=6)。结论:该方法简便、快速、灵敏、准确、重现性好,可作为盾叶薯蓣的质量控制方法。     

聚氧乙烯-马来酸酐聚合物改性纤维素酶催化酸水解盾叶薯蓣薯蓣皂苷元的研究

目的提高纤维素酶在催化过程中的稳定性，并考察聚氧乙烯-马来酸酐聚合物改性纤维素酶在盾叶薯蓣薯蓣皂苷转化为薯蓣皂苷元过程中的可行性。方法采用聚氧乙烯-马来酸酐共聚物对纤维素酶进行化学改性，并以相对酶活考察改性酶的稳定性。以薯蓣皂苷元的提取率和熔点为指标，比较了纤维素酶和改性酶的辅助催化作用。对改性酶催化所得薯蓣皂苷元产品进行元素分析和HPLC分析。结果改性酶在高温下的活力衰减速率减小，在50℃pH4．8的醋酸-醋酸钠缓冲溶液中放置100min，保持了初始酶活的69．4％。改性酶辅助催化盾叶薯蓣中薯蓣皂苷的转化时，较未改性酶的效果好，所得薯蓣皂苷元产品提取率为97．6％以上，为白色或乳白色，熔点为200-203℃，元素分析结果为H：77．96％，O：10．11％，HPLC法测定的质量分数高达96．03％。结论聚氧乙烯-马来酸酐聚合物改性纤维素酶在较高温度下能够保持较高的催化活性，可以更有效地促进盾叶薯蓣薯蓣皂苷向薯蓣皂苷元的转化．     

莴笋花化学成分的研究

目的：研究莴笋花Ｃostus lacerus的化学成分,方法采用硅胶柱层析分离,Sephadex LH-20柱纯化,分得１０个化合物：通过波谱技术和化学降解进行８个化合物的结构鉴定。结果它们分别为：二十八烷（Ⅰ）,β－谷甾醇（Ⅱ）,薯蓣皂苷元（Ⅲ）,胡萝卜苷（Ⅳ）,薯次苷Ｂ（Ⅴ）,薯蓣次苷Ａ（Ⅵ）,薯蓣皂甙（Ⅶ）,纤维薯蓣皂苷（Ⅷ）。结论：化合物Ⅰ,Ⅱ,Ⅲ和Ⅴ为首次从该植物中分得。