Evaluation of oils from the plants mentha sativa,] ocimum basilicum and cinnamomum camphor on survival, hepatic enzymes activities and protein electrophoresis of biomphalaria Alexandrina snails

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]

Effect of the plants Thevetia peruviana and Alstonia scholaris [family: apocynaceae] on acetylcholinesterase activity of lymnaea acuminata snails

The aquatic snail Lymnaea acuminata is a vector of the liver flukes Fasciola hepatica and Fasciola gigantica, which cause endemic fascioliasis in cattle and livestock of Eastern India. Very low concentration of the aqueous and partially purified extracts of lattices of Thevetia peruviana and Alstonia scholaris [Family-Apocynaceae] can kill these snails. The latices of both plants had strong in vivo and in vitro inhibitory effects on the acetylcholinesterase [AChE] of Lymnaea acuminata. These plants could potentially use in snail control. Their reversible action and low toxicity to fishes would be an added advantage in their use. It is possible that at this level of molluscicidal activity, the tested extracts from the plants Thevetia peruviana and Alstonia scholaris will have a future use in control of fascioliasis

Comparative studies on different small intestinal oligosaccharidase activities in some vertebrates and invertebrates like molluscs.

Oligosaccharidase activities of the small intestinal mucosal homogenates were measured in vertebrates viz fish, toad, garden-lizard (calotes), pigeon, rat and some invertebrates viz, molluscsa. Maximum activities of the enzymes Lactase, Sucrase and Maltase were found in the mammalian species rat, whereas much less activities were found in the non-mammalian vertebrates among which toad shows the highest values and garden lizard the lowest. Among the invertebrates Pila globosa shows higher values of all the enzymes than Achatina fulica. The results obtained have been discussed in the lights of phylogeny and diet habits.