Department of Pharmacology and Toxicology, National Institute for Pharmaceutical Research and Development, P.M.B. 21, Abuja, Nigeria.
Asian Pac J Trop Med. 2013 Mar;6(3):169-75. doi: 10.1016/S1995-7645(13)60018-8.
To investigate the antiplasmodial activity of Phyllanthus niruri (P. niruri) methanol extract (ME) and its fractions in mice.
P. niruri methanol extract and its chloroform, ethanol and aqueous portions were tested against chloroquine-sensitive Plasmodium berghei berghei in early, established and repository models of infection using Knight and Peter's 4-day suppressive model, Ryley and Peters curative model and Peters prophylactic model respectively.
Chemosuppression of parasitaemia (37.65%-50.53 %) was elicited by 100-400 mg/kg (b.w.) of ME. At doses of 100 mg/kg b.w., the chloroform fraction (F1) significantly (P<0.01) suppressed parasitaemia by 85.29%, while ethanol and aqueous fractions (F2 and F3, respectively) elicited 67.06% and 51.18% chemosuppression. The most active fraction, F1 was selected for further antiplasmodial screening. In established infection, ME reduced parasitaemia (15.81%-62.96%) while F1 significantly (P<0.01) reduced parasitaemia (44.36%-90.48%), with effects comparable to that of chloroquine (96.48%). The prophylactic antiplasmodial activity of ME (92.50% suppression) was also significant (P<0.01) and was more effective than pyrimethamine (85.00%). Additionally, cell membrane integrity of non-parasitized erythrocytes incubated with 125-500 mg/mL F1 was maintained.
These findings indicate the antiplasmodial efficacy of P. niruri methanol extract, and the localization of this effect in its chloroform fraction.
研究叶下珠（Phyllanthus niruri）甲醇提取物（ME）及其各馏分在小鼠体内的抗疟活性。
采用 Knight 和 Peter 的 4 天抑制模型、Ryley 和 Peters 的治愈模型和 Peters 的预防模型，分别检测叶下珠甲醇提取物及其氯仿、乙醇和水部分对氯喹敏感的伯氏疟原虫（Plasmodium berghei berghei）的抗疟活性。
ME 100-400mg/kg（bw）可抑制疟原虫血症（37.65%-50.53%）。在 100mg/kg bw 的剂量下，氯仿馏分（F1）显著（P<0.01）抑制疟原虫血症 85.29%，而乙醇和水馏分（F2 和 F3）分别引起 67.06%和 51.18%的化学抑制。最活跃的馏分 F1 被选用于进一步的抗疟筛选。在已建立的感染中，ME 降低了疟原虫血症（15.81%-62.96%），而 F1 显著（P<0.01）降低了疟原虫血症（44.36%-90.48%），与氯喹的效果相当（96.48%）。ME 的预防性抗疟活性（92.50%的抑制率）也非常显著（P<0.01），比乙胺嘧啶（85.00%）更有效。此外，与 125-500mg/mL F1 孵育的未感染红细胞的细胞膜完整性得以维持。
这些发现表明叶下珠甲醇提取物具有抗疟活性，并且这种作用定位于其氯仿馏分。
