Falade Mofolusho O, Komoni Favour, Nwuba Roseangela I
Cellular Parasitology Programme, Department of Zoology, University of Ibadan, Ibadan, Nigeria.
Drug Res (Stuttg). 2018 Apr;68(4):232-237. doi: 10.1055/s-0043-120759. Epub 2017 Nov 30.
Enhanced antimalarial activity of plant extracts used for treatment of malaria in endemic areas is attributed to partial immunity gained by prior infection. This suggests synergy between immunity and extract activity in treatment. Testing this hypothesis, rodent malaria was used to determine efficacy of Lophira alata leaf extracts in treating malaria in prior infected mice. One round of P. berghei infection and Pyrimethamine drug-cure was used to establish partial immunity in mice. Previously Exposed Mice (PEM) and Previously Unexposed Mice (PUM) mice challenged with P. berghei were used to determine influence of partial antimalarial immunity on efficacy of L. alata leaf extracts, administered alone or in combination with Artesunate (ART) in malaria treatment. There was a significant reduction in parasitemia in PEM when compared to PUM animals (P<0.001) irrespective of treatment regimen. Administration of L. alata combined with ART significantly reduced parasitemia (P<0.0032) and prolonged (P=0.0109) survival than when L. alata was administered alone in infected mice. These findings suggest that the action of L. alata in treating malaria infections in a murine model is enhanced by prior exposure to the malaria parasite. Thus the requirements of using plants in treating malaria in endemic populations may differ for those used in western systems, where trials are carried out with non-immune cohorts. Combining artemisinin derivatives and medicinal plants in malaria exposed populations may provide an alternative control measure in endemic regions and may justify the continued use of these plants by indigenous populations in treating malaria.
在疟疾流行地区，用于治疗疟疾的植物提取物抗疟活性增强归因于先前感染所获得的部分免疫力。这表明在治疗中免疫力与提取物活性之间存在协同作用。为验证这一假设，利用啮齿动物疟疾模型来确定翅苹婆叶提取物对先前感染疟疾的小鼠的治疗效果。用一轮伯氏疟原虫感染及乙胺嘧啶药物治愈来使小鼠建立部分免疫力。用感染伯氏疟原虫的先前暴露小鼠（PEM）和先前未暴露小鼠（PUM）来确定部分抗疟免疫力对翅苹婆叶提取物单独给药或与青蒿琥酯（ART）联合用于疟疾治疗效果的影响。无论治疗方案如何，与PUM动物相比，PEM动物的寄生虫血症显著降低（P<0.001）。在感染小鼠中，翅苹婆与ART联合给药比单独给予翅苹婆能显著降低寄生虫血症（P<0.0032）并延长生存期（P=0.0109）。这些发现表明，先前接触疟原虫可增强翅苹婆在小鼠模型中治疗疟疾感染的作用。因此，在疟疾流行人群中使用植物治疗疟疾的要求可能与西方系统中不同，西方系统的试验是在非免疫人群中进行的。在疟疾暴露人群中联合使用青蒿素衍生物和药用植物可能为流行地区提供一种替代控制措施，也可能证明当地人群持续使用这些植物治疗疟疾是合理的。
