山木瓜来源化合物Griffipavixanthone调节自噬和钙离子抑制肿瘤细胞生长

目的：本文主要探索藤黄属植物山木瓜中提取的天然小分子化合物Griffipavixanthone对肿瘤自噬的影响和作用机制。方法：以宫颈癌HeLa细胞株为体外研究模型,通过共聚焦显微术,流式细胞术和蛋白免疫印迹法检测Griffipavixanthone对自噬和钙离子信号通路的影响;同时使用裸鼠荷瘤模型,探索Griffipavixanthone体内的抗肿瘤作用。结果：Griffipavixanthone浓度和时间依赖增加细胞内GFP-LC3点状结构,诱导LC3 I至LC3 II的转变,增加SQSTM1蛋白含量;同时,Griffipavixanthone显著抑制HeLa细胞生长,并且在营养缺乏情况下,可以加速细胞死亡;此外,Griffipavixanthone可以下调细胞内钙离子的浓度;最后体内实验表明Griffipavixanthone具有一定的抗肿瘤效果。结论：体内体外的研究结果表明Griffipavixanthone具有抗肿瘤作用,其作用机制可能和Griffipavixanthone抑制自噬通量和钙离子内流相关。     

HPLC法测定木薯叶中芦丁的含量

目的:建立测定木薯叶中芦丁含量的方法。方法:采用高效液相色谱法。色谱柱为Agilent ZORBAX Eclipse XDB C18(0.105006～mm0.×046.06mmgm.,m5Lμ-1m范)围,流内动与相峰为面甲积醇积-分0.1值%呈磷良酸好(1的2:线88性),关流系速(为r=10.m99L.9m9)i;n-平1,均检加测样波回长收为率35为4n1m00。.7结2%果,:R芦SD丁=的2.检3%测(浓n=度6)在。结论:本方法操作简便、准确、重复性好,可作为木薯叶中芦丁的含量测定方法。     

Novel Ampeloviruses Infecting Cassava in Central Africa and the South-West Indian Ocean Islands

Cassava is one of the most important staple crops in Africa and its production is seriously damaged by viral diseases. In this study, we identify for the first time and characterize the genome organization of novel ampeloviruses infecting cassava plants in diverse geographical locations using three high-throughput sequencing protocols [Virion-Associated Nucleotide Acid (VANA), dsRNA and total RNA], and we provide a first analysis of the diversity of these agents and of the evolutionary forces acting on them. Thirteen new Closteroviridae isolates were characterized in field-grown cassava plants from the Democratic Republic of Congo (DR Congo), Madagascar, Mayotte, and Reunion islands. The analysis of the sequences of the corresponding contigs (ranging between 10,417 and 13,752 nucleotides in length) revealed seven open reading frames. The replication-associated polyproteins have three expected functional domains: methyltransferase, helicase, and RNA-dependent RNA polymerase (RdRp). Additional open reading frames code for a small transmembrane protein, a heat-shock protein 70 homolog (HSP70h), a heat shock protein 90 homolog (HSP90h), and a major and a minor coat protein (CP and CPd respectively). Defective genomic variants were also identified in some cassava accessions originating from Madagascar and Reunion. The isolates were found to belong to two species tentatively named Manihot esculenta-associated virus 1 and 2 (MEaV-1 and MEaV-2). Phylogenetic analyses showed that MEaV-1 and MEaV-2 belong to the genus Ampelovirus, in particular to its subgroup II. MEaV-1 was found in all of the countries of study, while MEaV-2 was only detected in Madagascar and Mayotte. Recombination analysis provided evidence of intraspecies recombination occurring between the isolates from Madagascar and Mayotte. No clear association with visual symptoms in the cassava host could be identified.     

羊肚菌胞外粗多糖对S_(180)肉瘤小鼠的抑制实验

目的:考察羊肚菌胞外粗多糖对S180肉瘤小鼠的抑瘤作用,并探讨其作用机制。方法:昆明小鼠右腋皮下接种S180肉瘤,接种后随机分为模型组,羊肚菌胞外粗多糖低、中、高剂量组(0.167 g/kg,0.333 g/kg,0.667 g/kg)和放疗组5组,连续给药21 d后处死动物,剥离皮下肿瘤并称重。观察粗多糖对荷瘤小鼠一般生存状况、瘤重、胸腺指数、脾指数的影响。S180瘤块用4%多聚甲醛固定,用免疫组织化学法检测瘤组织中血管内皮生长因子(VEGF)的表达。结果:羊肚菌胞外粗多糖低、中、高剂量组的抑瘤率分别是19.94%、39.68%、41%。与模型组比较,羊肚菌胞外粗多糖中、高剂量组能抑制S180荷瘤小鼠肿瘤的生长(P0.05),提高胸腺指数(P0.05),减轻VEGF的表达(P0.05)。结论:羊肚菌胞外粗多糖对S180肉瘤生长有抑制作用,其机制可能与抑制血管内皮生长因子的表达有关。     

A new diterpene from the stems of Manihot esculenta

A new diterpene, named yucalexin P-23 (1), together with three known compounds, yucalexin P-15 (2), protocatechuic acid (3), and catalpinic acid (4), was isolated from the stems of Manihot esculenta. Their structures were determined by means of physicochemical evidence and spectral analysis. Compounds 3 and 4 exhibited antimicrobial activity.     

商陆皂甙甲抑制小鼠巨噬细胞和抗体生成

商陆皂甙甲(EsA)体外在0.01～10μmol·L^-1范围内,对小鼠腹腔巨噬细胞吞噬中性红和LPS诱导的巨噬细胞合成及释放白介素1都呈明显的抑制作用。体内给药2.5～5mg·kg^-1可显著减少绵羊红细胞致敏的小鼠血清溶血素的含量。提示EsA的抗炎作用可能主要通过抑制巨噬细胞的吞噬和分泌功能。EsA间接作用于B细胞,抑制抗体生成。     

斑鸠菊果实中总黄酮的提取工艺研究

目的：优选斑鸠菊果实中总黄酮的最佳提取工艺。方法：采用分光光度法,通过单因素实验考察乙醇浓度、提取次数、提取时间以及液料比对斑鸠菊果实中总黄酮提取率的影响。结果：最佳提取条件为乙醇浓度70%、提取4次,每次1 h、料液比为1:20。结论：采用最佳提取条件,得到的斑鸠菊果实中总黄酮含量为103.55 mg·g^-1。     

酶解法制备可口革囊星虫抗菌物质的研究

目的 确定可口革囊星虫体壁中抗菌物质的最佳酶解工艺。方法 以可口革囊星虫体壁为原料,利用筛选出的木瓜蛋白酶酶解可口革囊星虫体壁蛋白,获得含可口革囊星虫体壁的酶解产物,并用抑菌圈法比较不同条件下酶解产物对大肠埃希菌活性的影响。在单因素试验的基础上,应用四因素三水平正交设计分析法,探讨酶解温度、pH值、酶解时间、加酶量及底物浓度对酶解产物抑菌活性的影响。结论 木瓜蛋白酶最适合水解可口革囊星虫体壁制备抗菌物质,其最佳工艺条件为：底物浓度为4g/L、加酶量为4000U/g、温度为55℃、pH值为8.0的条件下酶解4h,获得平均抑菌圈大小为(15.78±0.5)mm。     

羊肚菌对小鼠胃排空的影响

分别以正常、新斯的明负荷、肾上腺素负荷小鼠为实验研究模型,采用改良酚红含量测定法,探索羊肚茵对小鼠胃排空的影响.结果表明,羊肚菌提取液1次性ig给药6g·kg-1可非常显著促进正常小鼠的胃排空(p＜0.01);对新斯的明负荷小鼠引起的胃排空亢进有显著的拮抗作用(p＜0.01);对肾上腺素负荷小鼠引起的胃排空抑制没有明显影响(P＞0.05).     

A voltage-dependent K+ channel controlling the membrane potential in frog oocytes

Full-grown frog ovarian oocytes (Rana esculenta), were voltage clamped with a conventional two-microelectrode system. Depolarizations from a holding potential of –60 mV produced slowly developing outward currents. Two-step clamp experiments showed that, in Ringer's solution, this current has a reversal potential at about –84 mV. Substitution of either sodium or chloride with impermeant ions in the external solution did not alter significantly the activation of the current nor its reversal potential. Increasing the potassium ions concentration caused a shift on the reversal potential in the positive direction with a slope of about 48 mV per decade. The presence of TEA ions (50 mM) in the external solution partially reduced the current. It is concluded that the membrane of full-grown frog ovarian oocytes possesses voltage-dependent ionic channels permeated mainly by potassium. They appear to play an important role in the control of membrane potential.