Osmoregulatory and tegumental ultrastructural damages to protoscoleces of hydatid cysts Echinococcus granulosus induced by fungal endophytes

J Parasit Dis. 2014 Dec;38(4):432-9. doi: 10.1007/s12639-013-0271-z. Epub 2013 Mar 8.

Abstract

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.

Keywords: Anti-cestodal activity; Endophytic fungi; Eupenicillium sp; Hydatid cysts; SEM.