Effect of alkaloids and saponins of plant origin on biomphalaria alexandrina snails

ABSTRACT

Lactate dehydrogenase [LDH] [E.C. 1.1.1.28] and glycogen of Biomphalaria alexandrina, the speceific molluscan intermediate host for Schistosoma mansoni, were measured in snails treated with alkaloids extracted from peganum harmala seeds and saponins extracted from luffa cylindrica seeds. Biochemical and histochemical investigations revealed marked depletion in glycogen. Biochemically, LDH activity increased significantly in the lacltate producing direction. This was confirmed histochemically by an inhibition of the enzyme in the pyruvate producing direction in the hepatopancreas and headfoot muscles. The effects were more pronounced in alkaloid treated snails than those treated with saponins. The results indicate an inhibitory effect of both alkaloids and saponins on the aerobic respiration of B. alexandrina. This in turn could inhibit the host-parasite association and hence combat schistosomiasis. Disturbance of the aerobic pathway and stimulation of anaerobia metabolism may lead to glycogen depletion in the host which is the most important prerequiste for the developing parasite