抗疟中草药筛选及其有效部位研究

目的:为寻找新的有效抗疟药物提供实验依据。方法:建立伯氏疟原虫鼠疟实验模型,比较常山复方、金牛草、山豆根、鹅不食草、常山、仙鹤草、青蒿等药物的50%醇提取物抗疟活性,比较抗疟活性最强醇提取物中不同萃取部位对疟原虫的抑制效果。结果:常山复方的50%醇提取物疟原虫抑制率为83.46%,高于青蒿药材的67.33%,抗疟效果比较差异具有统计学意义(P<0.05);常山复方的50%醇提取物乙酸乙酯萃取部位对疟原虫的抑制率达93.78%,与青蒿素的95.92%接近。结论:常山复方乙酸乙酯萃取物具有显著的抗疟活性,可作为抗击疟疾的候选药物。

Expression analysis of reactive oxygen species detoxifying enzyme genes in Anopheles stephensi during Plasmodium berghei midgut invasion

Objective:To investigate the involvement of reactive oxygen species detoxification system in Anopheles stephensi during Plasmodium berghei midgut invasion.Methods:Eight key reactive oxygen species metabolizing enzymes were cloned and characterized,and their expression was monitored in parasite-infected mosquitoes.Results:Superoxide anion detoxifying superoxide dismutases(Fe/Mn SOD,Cu/Zn SOD 2,Cu/Zn SOD 3A,and Cu/Zn SOD 3B)depicted varied expression patterns.Fe/Mn SOD expression declined,whereas Cu/Zn SOD expression was elevated in the infected mosquitoes.Peroxidases,catalase and glutathione peroxidase showed lack of induction in expression during the Plasmodium berghei infection.Further,expression of thioredoxin reductase increased in the infected mosquitoes,whereas gluthathione S-transferase levels decreased markedly.Conclusions:Detoxification enzymes may play a role in modulating host immunity and parasite transmission.

麦胚系统真核表达小鼠伯氏疟原虫TIP样蛋白的实验研究

目的体外真核表达小鼠伯氏疟原虫TIP样蛋白(PbTIP)胞外域重组蛋白。方法合成PbTIP胞外域DNA片段,克隆入真核表达载体pEU-E01-His-TEV-MCS,采用CFS真核无细胞蛋白表达系统(麦胚系统),在体外表达可溶性PbTIP胞外域重组蛋白,SDS-PAGE凝胶电泳和Western-blot检测并鉴定目的蛋白表达情况。结果获得了可溶性表达的PbTIP胞外域重组蛋白,分子量约70 000 Mr,与预期相符,目的蛋白浓度约为0.1 mg/ml。结论采用麦胚系统在体外获得了较高浓度的可溶性PbTIP胞外域重组蛋白,不但为后续的PbTIP胞外域功能研究打下了良好的基础,也为众多疟原虫未知蛋白的功能研究提供了新的方法。