Department of Environmental Sciences, International Islamic University, Islamabad, 44000, Pakistan.
Parasitol Res. 2013 Mar;112(3):1179-88. doi: 10.1007/s00436-012-3249-3. Epub 2013 Jan 10.
Acanthamoeba is an opportunistic protozoan pathogen and known to be one of the most ubiquitous organisms, play a vital role in ecosystem, and recognized to cause blinding keratitis and rare but fatal granulomatous encephalitis involving the central nervous system with a very poor prognosis. This is due to limited availability of effective anti-Acanthamoeba drugs. The objective of the present study was to determine the efficacy of methanolic plants crude extracts on the viability and biological properties of Acanthamoeba castellanii (T4 genotype) and its cytotoxic effects on human corneal epithelial cells (HCEC). Using HCEC, it was observed that Acanthamoeba exhibited binding (>90 %) and cytotoxicity (>80 %) to host cells. However, plant crude extracts remarkably inhibited more than 70 and 60 % of Acanthamoeba binding and cytotoxicity to HCEC, respectively. It was further established that crude extracts (ranging from 0.1 to 1.5 mg/ml) exhibited amoebicidal effects, i.e., >50 % of trophozoites were killed/reduced at maximum dose (1.5 mg/ml) within 1 h incubation. However, the residual subpopulation remained static over longer incubations. Furthermore, growth assay demonstrated crude extracts inhibited >50 % Acanthamoeba numbers up to 7 days. Our results confirmed that plant crude extracts has inhibitory effects on Acanthamoeba growth and viability. Overall, these findings revealed that tested plant extracts is inhibitory to Acanthamoeba properties associated with pathogenesis. To the best of our knowledge, our findings demonstrated for the first time that selected methanol plant crude extracts exhibits inhibitory effects on biological properties of Acanthamoeba without any toxic effects on HCEC cells in vitro.
棘阿米巴是一种机会性原生动物病原体，已知是最普遍存在的生物之一，在生态系统中发挥着重要作用，并被认为会导致致盲性角膜炎和罕见但致命的累及中枢神经系统的肉芽肿性脑炎，预后极差。这是由于有效的抗棘阿米巴药物有限。本研究的目的是确定甲醇植物粗提取物对棘阿米巴 castellanii（T4 基因型）的活力和生物学特性的疗效及其对人角膜上皮细胞（HCEC）的细胞毒性作用。使用 HCEC，观察到棘阿米巴对宿主细胞表现出结合（>90%）和细胞毒性（>80%）。然而，植物粗提取物显著抑制了超过 70%和 60%的棘阿米巴与 HCEC 的结合和细胞毒性。进一步证实，粗提取物（范围为 0.1 至 1.5 mg/ml）表现出杀阿米巴作用，即在 1 小时孵育内，最大剂量（1.5 mg/ml）下，超过 50%的滋养体被杀死/减少。然而，剩余的亚群在更长的孵育时间内保持静止。此外，生长测定表明，粗提取物抑制超过 50%的棘阿米巴数量长达 7 天。我们的结果证实，植物粗提取物对棘阿米巴的生长和活力具有抑制作用。总的来说，这些发现表明，测试的植物提取物对与发病机制相关的棘阿米巴生长和活力具有抑制作用。据我们所知，我们的研究结果首次表明，所选甲醇植物粗提取物在体外对 HCEC 细胞没有任何毒性作用的情况下，对棘阿米巴的生物学特性具有抑制作用。
