The effect of Annona squamosa, Lawsonia inermis and their combination with
other herbal molluscicides were studied on different enzyme activity in the
nervous tissue of Lymnaea acuminata. Twenty-Four hour in vivo exposure to 40%
and 80% of 24 h LC50 of plant derived molluscicides and their combination with
other molluscicides such as Cedrus deodara, Azadirachta indica oil, Allium
sativum, Polianthes tuberosa bulb and oleoresin of Zingiber officinale and
acetogenins caused a significant reduction in the activity of acetylcholinesterase,
cytochrome oxidase and Na+/K+ ATPase in the nervous tissue of L. acuminata.
Combination of C. deodara with A. squamosa or L. inermis inhibited the
acetylcholinesterase activity in the nervous tissue up to 60% and 58.70% of
control, respectively. Acetogenin was more effective against Na+/K+ ATPase and
cytochrome oxidase. Inhibition of these enzymes even at lower concentrations of
plant derived molluscicides present in binary mixture with respect to their single
treatment inhibit the enzyme activity nearly up to same level.