ABSTRACT
Three plant oils from the plants Spearmint, Basil and Camphor were tested for their molluscicidal activity against Biomaphalaria alexandrina snails. Spearmint oil was more toxic than the other two oils against B. alexandrina. Its Lc50 was 42 ppm; meanwhile the values were 500 and 560 ppm for Basil and Camphor, respectively. Spearmint oil, also, showed a more deleterious effect against both miracidia and cercariae of S. mansoni than the other two oils, all of them were killed after 15 min of exposure to 70 ppm. The present results indicated that the alterations in total protein concentrations in tissues of treated snails were not significantly different from that of control ones. It was noticed, also, that the increase in the activity of ALT enzyme and the decrease in that of AlkP enzyme in tissues of treated snails were not significantly different than that of control snails. However, Spearmint oil at 32 and 42 ppm significantly decreased the activities of AST and ACP activities in snail's tissues in comparison with control ones. The electrophoretic [SDS-PAGE] pattern of tissue soluble proteins extracted from treated and controls B. alexandrina snails showed different plant oils effects on the synthesis of protein within snails yielded a complex pattern of polypeptides ranging in molecular weight between 14.7 to 304.6 KDa. Some bands were present in treated snails especially at Camphor oil and at 500ppm of Basil oil. At least, three bands were absent from tissues of snails treated with 42ppm of Spearmint oil in comparison with control group. The molecular weights of these bands are 14.9, 15.7 and 17.0 KDa. It was, also observed that total number of bands in snails treated with Basil or Camphor oil was more [15-17 bands] than that of control group [13 bands]