Inhibition kinetics of certain enzymes in the nervous tissue of vector snail Lymnaea acuminata by active molluscicidal components of Sapindus mukorossi and Terminalia chebula

Effect of active molluscicidal components of Sapindus mukorossi and Terminalia chebula on the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activity in the nervous tissue of freshwater snail Lymnaea acuminata were studied. In vivo and in vitro exposure of saponin (active component of S. mukorossi pericarp) and tannic acid (active component of T. chebula) significantly inhibited the AChE, ACP and ALP activity in the nervous tissue of L. acuminata. The inhibition kinetics of these enzymes indicate that saponin and tannic acid caused competitive and competitive–non-competitive inhibition of AChE, respectively. Saponin also caused competitive and competitive–non-competitive inhibition of ACP and ALP, respectively, whereas tannic acid caused competitive–non-competitive inhibition of ACP and ALP. Thus the inhibition of AChE, ACP and ALP by saponin and tannic acid in the nervous tissue of L. acuminata may be the cause of molluscicidal activity of S. mukorossi and T. chebula.

Graphical abstractHistogram showing in vivo effect of 24 h exposure to sublethal concentration (40% and 80% of 24 h LC50) of saponin and tannic acid on the acetylcholinesterase activity in the nervous tissue of Lymnaea acuminata.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Saponin and tannic acid inhibits AChE, ACP and ALP activities in the nervous tissue of Lymnaea acuminata. ► Plant molluscicides control fascioliasis in an ecofriendly way. ► Thus, Sapindus mukorossi and Terminalia chebula. can be used for the effective control of fascioliasis.