The Vasodilatation Effects of Four Active Components in Baige Capsule and the Potential Mechanism of Them with the NMDA Receptor

The vasodilatation effects of four components in Baige capsule were investigated on isolated cerebral basilar arteries and mesenteric arteries model of rats. In order to inspect the potential mechanism, the SH-SY5Y cellular membrane chromatography (CMC) was established to specially recognize the ligand which could interact with N-methyl-D-aspartate receptor (NMDA). Frontal chromatography and competitive binding chromatography were applied to investigate the interaction of four main components in Baige capsule with this receptor. MK-801 (an antagonist of NMDA receptor) was used as the displacer, ketamine hydrochloride, puerarin, daidzein, imperatorin, and isoimperatorin was used as the ligand. The results of vasodilatation test suggested that imperatorin and isoimperatorin could effectively relax both of the cerebral basilar arteries and mesenteric arteries. The CMC study showed that imperatorin and isoimperatorin could competitively displace MK-801. The molecular docking model of the NMDA receptor indicated that imperatorin and isoimperatorin showed a similar docking behavior as MK-801. Overall, the studies demonstrated that imperatorin and isoimperatorin had obvious vasodilatation effect and might be prospective candidates as new NMDA receptor antagonists.