ABSTRACT
Several steps in the pathogenesis of a
Plasmodium falciparum
infection depend on interactions of parasite surface proteins with negatively charged sugars on the surface of host cells such as sialate residues or glycosaminoglycans. For these reasons, our previous studies examining agents that interfere with heparan sulfate-protein binding during amyloidogenesis suggested that short-chain aliphatic polysulfonates may prove useful as antimalarial agents. A series of related polysulfonates were synthesized and assessed both in tissue culture with the asexual stages of
P. falciparum
in human red blood cells and in vivo by use of
Plasmodium berghei
infections in mice. Poly(vinylsulfonate sodium salt) (molecular weight range, 1,500 to 3,000) proved effective in interfering with
P. falciparum
merozoite entry into human red blood cells and significantly delaying the increase in the level of
P. berghei
parasitemia in mice. The concept that anionic molecules that mimic large polysaccharide structures may have antimalarial properties has been suggested and examined previously. Our results suggest that related anionic agents [poly(vinylsulfonate sodium salt)-like molecules] orders of magnitude smaller than those previously considered may prove useful in abrogating merozoite entry into erythrocytes and may potentially block sporozoite entry into liver cells. Structure-activity studies conducted to enhance these properties may provide compounds with scope for significant further analysis and development.
摘要
恶性疟原虫发病机制的几个步骤
恶性疟原虫
感染的几个步骤取决于寄生虫表面蛋白与宿主细胞表面带负电荷的
糖类(如
硅酸盐残基或糖胺聚糖)之间的相互作用。基于这些原因,我们之前对干扰淀粉样蛋白生成过程中
硫酸肝素与蛋白质结合的药物进行了研究,结果表明短链脂肪族多
磺酸盐可能被证明是有用的
抗疟药物。我们合成了一系列相关的多
磺酸盐,并在组织培养过程中对无性阶段的恶性疟原虫进行了评估。
恶性疟原虫
的组织培养中进行了评估,并在体内使用
疟原虫
感染小鼠。聚
乙烯基磺酸钠盐(分子量范围为 1,500 至 3,000)被证明能有效地干扰恶性疟原虫。
恶性疟原虫
子虫进入人体红细胞,并显著延缓小鼠体内恶性疟原虫
疟原虫
小鼠寄生虫血症
水平的增加。模拟大型
多糖结构的阴离子分子可能具有抗疟特性的概念在以前就已提出并进行过研究。我们的研究结果表明,相关的阴离子制剂[聚
乙烯磺酸钠盐类分子]比以前考虑的那些分子小很多,可能会被证明有助于阻止子虫进入红细胞,并有可能阻止孢子虫进入肝细胞。为提高这些特性而进行的结构-活性研究可能会为化合物提供进一步分析和开发的重要空间。