柚皮苷半合成N-苯亚甲基柚皮素腙及细胞活性

从丰富易得的柚皮苷(Naringin)1出发,通过酸水解得到了柚皮素2.以柚皮素为先导化合物,通过4-位羰基与水合肼作用合成了中间体柚皮素腙3,进而与各种不同类型的醛缩合,合成了14个新型N-苯亚甲基柚皮素腙及类似物(4a~4n).MTT蛋白染色法体外抑制肿瘤增值活性测试显示化合物4c、4d、4h、4j、4n对胃癌细胞SGC-7901有一定的抑制作用.     

In fl uence of the extraction parameters on the cytotoxicity test results of Mg materials

Recently more and more researchers query the predictability of cytotoxicity results of biomedical Mg alloys obtained according to ISO 10993 due to significant difference between in vitro and in vivo corrosion. This study aimed to observe the influence of different extraction parameters(time, volume/surface ratio and medium composition) on cytotoxicity results and illustrate whether more predictable results could be obtained by adjusting the extraction parameters. The results showed that longer extraction time and smaller extraction volume/surface ratio improve the sensitivity of screening Mg materials by making inferior Mg materials release relatively more ions to the extract; and more predictable results could not be obtained by the way of simply adding bovine serum albumin(BSA) into the extraction medium to the same level in vivo or simply using fetal bovine serum(FBS) directly as extraction medium, since BSA and FBS accelerated the corrosion of Mg materials during extraction and they affected the cells’ health states during the test. In order to get more predictable results, in our opinions, it is necessary to establish a database of primary cells’ hazards(metal ions, p H and H2gas) tolerance and a set of in vitro corrosion test with high similarity in vivo, which is very difficult to realize now however.     

d-Ribosylated Tau forms globular aggregates with high cytotoxicity

Although the glycation of Tau that is involved in paired helical filament formation in Alzheimer’s disease has been widely studied, little attention has been paid to the role of d-ribose in the glycation of Tau. Here, we show that Tau is rapidly glycated in the presence of d-ribose, resulting in oligomerization and polymerization. Glycated derivatives appeared after 24 h incubation. Western blotting indicated the formation of advanced glycation end-products (AGEs) during initial stages of glycation. Thioflavin T-positive (ThT-positive) aggregations that appeared from day 4 indicated the globular-like features. Atomic force microscopy revealed that the surface morphology of ribosylated Tau40 was globular-like. Kinetic studies suggested that d-ribosylated Tau is slowly oligomerized and rapidly polymerized with ThT-positive features. Moreover, d-ribosylated Tau aggregates were highly toxic to SHSY5Y cells and resulted in both apoptosis and necrosis. This work has demonstrated that d-ribose reacted with Tau protein rapidly, producing ThT-positive aggregations which had high cytotoxicity. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Hydrothermal synthesis of pyrrhotite (Fex-1S) nanoplates and their antibacterial, cytotoxic activity study

The aim of this study was to synthesize and characterize Fe_(x-1)S 2D-nanostructures with pyrrhotite phase,as well as to explore their biological(antibacterial and cytotoxic)properties,namely the expression of reactive oxygen species(ROS)in the exposure of cells and bacteria.Based on hydrothermal synthesis,the characterization of asprepared 2D-nanostructures was performed by XRD,SEM,EDS,and TEM,in which the single-crystalline pyrrhotite phased Fe_(x-1)S nanoplate morphology was observed.The antibacterial activities of Fe_(x-1)S nanoplates against human pathogenic strains such as Staphylococcus aureus,Escherichia coli,and Enterococcus faecalis were tested.Minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)were determined following the broth microdilution method.Cytotoxicity and expression of intracellular ROS of pyrrhotite nanoplates on Human Gingival Fibroblast(HGF),Human Pulp Cells(HPC)and Human Osteoblast(HBC)were calculated.Cell viability was determined by the MTT method.All experiments were performed of three independent experiments and data were analyzed by Kruskal-Wallis and Mann-Whitney tests,also Pearson′s Correlation was performed.The nanoplates exhibited good bactericidal effect.All types of cells tested showed slight cytotoxicity.It was found that intracellular ROS is produced when cells and bacteria tested are exposed to pyrrhotite nanoplates in presence of both air and peroxide hydrogen.ROS production levels were higher in the bacteria than the cells exposed to these nanoplates.     

IL-2联合银耳多糖激活的脾细胞对体外肿瘤细胞杀伤作用的研究

目的研究淋巴因子IL-2联合银耳多糖(Tremella Polysaccharide TP)共同激活的小鼠脾细胞对肿瘤细胞的体外杀伤作用.方法用甲基-3氢胸腺嘧啶核苷标记肿瘤细胞H22,B16,p815,将标记的靶细胞悬液调至1×105/mL,分别以效靶比40∶1,20∶1和10∶1加入效应细胞,混匀后置37℃5%CO2培养箱内培养2h,2h后用γ-闪烁记数仪对上述细胞悬液进行检测.结果 2种效应细胞对B16杀伤作用最强,H22次之,p815最弱,TP-LAK细胞的作用较之LAK细胞更强(P<0.05),且效靶比越高,杀伤作用越强.结论 IL-2激活脾LAK细胞是有效的抗肿瘤细胞,IL-2与银耳多糖在活化脾细胞提高抗肿瘤方面具有协同作用.     

Hela细胞MTT试验作为眼刺激替代试验的研究

目的探讨Hela细胞MTT试验(Hela-MTT)是否可作为家兔眼刺激试验(Draize test)的一种替代方法。方法用该方法对22种化妆品的眼刺激性进行检测,并与1999年卫生部颁布的《化妆品卫生规范》和新颁布的《化妆品卫生规范》(2002版)测定的眼刺激试验最大平均值(MASold和MASnew)分别进行相关性比较。结果Hela-MTT和MASold、MASnew的相关系数分别为-0.811、-0.639。结论Hela-MTT可作为替代方法用于眼刺激性的评价,是比较有潜力的眼刺激替代试验方法。     

小叶女贞叶片提取物药用活性研究

对小叶女贞叶片提取物进行体外抗菌、细胞毒性以及抗氧化药用活性研究,结果表明,小叶女贞叶片提取物对铜绿假单胞菌PAO1具有较强的抑制作用,最小抑制浓度(MIC)为8.0 mg/mL;对人肝癌细胞BEL-7404体外增殖具有显著的抑制作用,浓度在0.6 mg/mL时,抑制率达94.2％;同时具有较强的DPPH自由基清除能力,浓度为15.1 μg/mL时,清除率为85.9％.活性跟踪测试表明,小叶女贞叶片提取物干柱层析得到的各组分中,低极性组分Fr.1为活性部分.     

磺化铝酞菁对胃腺癌细胞MGc—803的体外光动力杀伤实验

近年来血卟啉衍生物（ＨｅｍａｔｏｐｏｒｐｈｙｒｉｎＤｅｒｉｖａｔｉｖｅ,ＨＰＤ）在基础医学与临床上对癌细胞的较强杀伤作用研究已取得了不少进展,但它不易从血清中制备,在肝脏有太多积聚,对体表皮肤有光毒反应等缺点,同时它的主吸收峰在紫光波段（４０５ｎｍ）...