Trimyristin, an active molluscicidal component of Myristica fragrans Houtt, significantly inhibits acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activities in the nervous tissue of Lymnaea acuminata. IC50s of Trimyristin against AChE, ACP, and ALP are 0.11, 0.16 and 0.18 mM, respectively.