Verma Vijay C, Gangwar Mayank, Nath Gopal
Laboratory for Gastrointestinal Infections and Molecular Diagnosis, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005 UP India.
Laboratory for Gastrointestinal Infections and Molecular Diagnosis, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005 UP India ; Department of Pharmacology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005 UP India.
J Parasit Dis. 2014 Dec;38(4):432-9. doi: 10.1007/s12639-013-0271-z. Epub 2013 Mar 8.
Characteristic ultrastructural changes were observed when protoscoleces of hydatid cysts Echinococcus granulosus was treated with extract of endophytic fungi Eupenicillium and Chaetomium sp. isolated from Azadirachta indica and Piper longum plants respectively. A sharp decrease in viability of protoscoleces was observed after 6 h of incubation with fungal extracts. The ultrastructural changes included rosteller disorganization, loss of hooks and shedding of the microtriches of scolex region. The formation of digitiform projections on tegument layer which, increased in size as prolong incubation with extract and get burst, leading to a osmoregulatory damage into tegumental layers of parasite. This osmoregulatory damages caused the loss of turgidity due to leakage of cell contents, which might be the major cause of the mortality in treated parasites. It is remarkable, since very similar type of ultrastructural changes were observed with some pyrazinoisoquinoline derivatives, as praziquantel. Our initial results indicate that extract of endophytic Eupenicillium and Chaetomium spp. are having significant anti-cestodal activity and have selective activity on tegument layer. Further chemical prospection is required through rigorous bioassay guided fractionation coupled with robust high resolution mass spectrometric analysis to get final stereo-structures responsible for the parasiticidal activity. This initial strain selection outcome will serve a platform for isolation and characterization of new drug lead that can be useful in tailoring novel, safe and effective anthelmintics.
当分别用从印楝和长蒌叶植物中分离出的内生真菌细梗青霉和毛壳菌提取物处理细粒棘球绦虫包虫囊肿的原头节时，观察到了特征性的超微结构变化。与真菌提取物孵育6小时后，观察到原头节的活力急剧下降。超微结构变化包括顶突紊乱、钩的丢失和头节区域微毛的脱落。皮层上形成指状突起，随着与提取物孵育时间的延长，其尺寸增大并破裂，导致寄生虫皮层的渗透调节损伤。这种渗透调节损伤导致细胞内容物泄漏，从而导致虫体失去膨压，这可能是经处理寄生虫死亡的主要原因。值得注意的是，在一些吡嗪异喹啉衍生物（如吡喹酮）中也观察到了非常相似的超微结构变化。我们的初步结果表明，内生细梗青霉和毛壳菌提取物具有显著的抗绦虫活性，并且对皮层具有选择性活性。需要通过严格的生物测定指导分级分离以及强大的高分辨率质谱分析进行进一步的化学勘探，以获得负责杀虫活性的最终立体结构。这一初步的菌株筛选结果将为分离和鉴定新的药物先导物提供一个平台，这些先导物可用于开发新型、安全有效的驱虫药。
