Hyoscyamine Hyoscyamine (Daturine) is an AChR inhibitor with IC50 of 7.5 nM.
In vitro
L-hyoscyamine increases the turnover number of GTPase activity from 0.19 min-1 to 2.11 min-1 in the steady-state kinetic measurements. R-(+)-hyoscyamine results in displacement of [3H]NMS binding to the muscarinic acetylcholine receptor subtypes (m1-m5) with pKi value of 8.67, 8.51, 7.46, 8.56 and 8.53, respectively. Hyoscyamine prevents the agonist-induced stimulation of cAMP production with EC50 of 7.8 nM in CHO cells. S-(-)-hyoscyamine enhances the forskolin-stimulated synthesis of cyclic AMP in rat cardiac (both atrial and ventricular) membranes by up to 24%.
In vivo
L-hyoscyamine (20 mg/kg) prolongs migrating myoelectric complex (MMC) cycle length from 17.6 min to 29.0 min in conscious rats.
Cell Data
cell lines：Calu-6, PC-3, MDA-MA-231, SKOV-3, SW620, A549, A431, B16-F10(AP3) and Lewis Lung cells
