Department of Pharmaceutics & Pharmaceutical Technology, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu, Nigeria.
Asian Pac J Trop Med. 2011 Apr;4(4):283-7. doi: 10.1016/S1995-7645(11)60087-4. Epub 2011 May 29.
To investigate the antiplasmodial activity of the extracts of Phyllanthus amarus (P. amarus) on Plasmodium yoelii (P. yoelii) (a resistant malaria parasite strain used in animal studies) infection in mice.
The aqueous and ethanol extracts of the whole plant of Phyllanthus amarus was administered to Swiss albino mice at doses of 200 mg/kg/day, 400 mg/kg/day, 800 mg/kg/day and 1600 mg/kg/day and the prophylactic and chemotherapeutic effect of the extracts against P. yoelii infection in mice was investigated and compared with those of standard antimalaria drugs used in the treatment of malaria parasite infection. Acute toxicity test was carried out in mice to determine the safety of the plant extract when administered orally.
The results showed that the extracts demonstrated a dose-dependent prophylactic and chemotherapeutic activity with the aqueous extracts showing slightly higher effect than the ethanol extract. The antiplasmodial effects of the extracts were comparable to the standard prophylactic and chemotherapeutic drugs used in chloroquine resistant Plasmodium infection although the activity depended on the dose of the extract administered. The extracts showed prophylactic effect by significantly delaying the onset of infection with the suppression of 79% at a dose of 1600 mg/kg/day.
The results obtained indicate that the extracts of the whole plant of P. amarus possess repository and chemotherapeutic effects against resistant strains of P. yoelii in Swiss albino mice. The findings justify the use of the extract of P. amarus in traditional medicine practice, for the treatment of malaria infections.
研究叶下珠（Phyllanthus amarus）提取物对感染伯氏疟原虫（P. yoelii）（一种用于动物研究的抗疟寄生虫株）的小鼠的抗疟原虫活性。
给瑞士白化病小鼠灌胃给予叶下珠全草的水提物和醇提物，剂量分别为 200mg/kg/天、400mg/kg/天、800mg/kg/天和 1600mg/kg/天，并比较这些提取物对小鼠伯氏疟原虫感染的预防和化学治疗作用与用于治疗疟原虫感染的标准抗疟药物。在小鼠中进行急性毒性试验，以确定口服给予植物提取物的安全性。
结果表明，提取物表现出剂量依赖性的预防和化学治疗活性，水提物的效果略高于醇提物。提取物的抗疟原虫作用与用于氯喹耐药性疟原虫感染的标准预防和化学治疗药物相当，尽管其活性取决于给予的提取物剂量。提取物以 1600mg/kg/天的剂量显著延迟感染的发生，抑制率为 79%，表现出预防作用。
所得结果表明，叶下珠全草提取物对瑞士白化病小鼠的伯氏疟原虫抗性株具有储备和化学治疗作用。这些发现证明了在传统医学实践中使用叶下珠提取物治疗疟疾感染的合理性。
