Background
A number of commercial stains have been used to assess the viability of protoscolices ( defined as the capacity of being alive ) that develop in hydatid cysts, the infective stage of the tapeworm Echinococcus granulosus (s.l). There has been a remarkable increase of interest in natural product research over the past few decades for application of these products in a diversity of fields. Hibiscus sabdariffa L. (Malvaceae) is a flowering plant widely cultivated in the Sudan. Aqueous extracts from plant calyces have characteristic brilliant red colouration due to the presence of anthocyanins, an important group of water-soluble plant pigments. Lawsonia inermis L. (Lythraceae), commonly called "Henna" or "Mehndi ", is famous for having dyeing properties due to the presence of lawsone, a red-orange pigment extracted from plant leaves. Objective was to assess the viability of protoscolices of camel origin following exposure to aqueous extracts of H. sabdariffa calyces or L. inermis leaves taking advantage of the kinetically distinct molecular transfer systems of the Echinococcus protoscolex for uptake of materials across the tegument (external body covering).Results
Viable protoscolices are capable of exclusion of plant pigment obtained from either H. sabdariffa or L. inermis whereas dead protoscolices uptake the pigment in both occasions. Performance is comparable to eosin.Conclusions
It is suggested that extracts of both plants can be used effectively as a cheap and a readily available natural material for assessment of viability of protoscolices. Regarding the remarkable diversity of functions of the tapeworm tegument, it is proposed that the Echinococcus protoscolex can be employed as an experimental model in studies concerned with tapeworm natural protective responses in hostile environments, for instance upon exposure to antiparasitic drugs or host's body defences.