Acetylcholine (15 μg/mL) (Beijing Dingguo Biotech Co. Ltd, Batch NO. 9BE10120, 99% purity) was applied to produce
contraction. Then different samples dissolved in 1% DMSO were added. Atropine (5 μg/mL) (98%, Tianjin Jinyao Amino
Acid CO., Ltd, batch NO. 1004112) was employed as a positive control, and 1% DMSO was employed as a blank.