Effect of different se supplementation on biomphalaria alexandrina snails: the intermediate host of echistosomiasis

ABSTRACT

A possible method of controlling the parasitic disease schistosomiasis is to kill the intermediate host using the toxic selenium dioxide on the snails Biomphalaria alexandrina. Selenium dioxide [SeO[2]] has therefore been given to the snails in a soluble form in water Se-H[2]O] or in food attractant pellets [Se-P] in order to study the mode of action of selenium on the snails. In this study, transaminases [ALT and AST], lactate dehydrogenase [LDH], adenosine deaminase, AMP deaminase, alkaline phosphatase [ALP] and 5'-nucleotidase [5'-Nu] activities in snail homogenates have been measured., The application of Se in form of food attractant pellets showed a much greater effect on snails ALP and 5'-Nu activities than its applications directly in water. However LDH activity was affected when snails were incubated in water containing SeO[2] more than feeding the animals food attractant pellets containing Se. In general the highest effect of Se on the snails was found in the activity of 5-nucleotidase. The present studies show that selenium supplemented to the snails in food attractant pellets could be a possible method for controlling the snails. However the toxicity of the food pellets needs to be improved