Objective: To study the effect of mussaendoside U on M cholinergic innervation organs (ileum smooth muscle

pupil and salivary gland). Method: ①Muscle contraction force information was obtained using muscle force measuring device in vitro. Atropine was added to bath to achieve a final concentration of 10 mg·L-1

or mussaendoside U was added in bath to achieve a final concentration of 100

50

25 mg·L-1 respectively. After 10 min

acetylcholine bromide was cumulatively added to observed the effect of drug on contraction force of muscle induced by different final concentration of acetylcholine bromide. The experiment was repeated for 10 times. ②Mice were divided into normal group and 5 model groups

with 10 mice in each group. Model group received intraperitoneal injection of pilocarpine once at a dose of 20 mg·kg-1to make M cholinergic nerve excitement model. After 15 min

modeled mice received intravenous injection of atropine at a dose of 2.5 mg·kg-1

or mussaendoside U at a dose of 10

5

2.5 mg·kg-1

and received telecarbon suspension ig at the same time. Telecarbon propulsion rate at intestine was measured after 30 min. ③Methods of mice grouping

modeling and treatment were identical with those in above.Pupil diameter and salivary gland secretion were measured respectively 15

60

240 min after administration. Result: Mussaendoside U reduced contraction force of intestine smooth muscle;dose-effect curve between acetylcholine bromide and muscle contraction force was shifted to right;telecarbon propulsion rate at intestine in mussaendoside U (5 mg·kg-1) group was (64.20±10.14)%

lower than that in model group;pupil diameters were (2.5±0.19)

(2.2±0.18)

(2.1±0.40) mm respectively 15

60

240 min after administration

bigger than those in model group;salivary gland secretion was (102.3±13.6)

(90.2±20.5)

(68.0±21.5) mg

lower than those in model group (P<0.05). Conclusion: Mussaendoside U may inhibit M cholinergic nerve excitement as a kind of anticholinergic drug.