Molecular Simulations of the Inhibition of Active Components in Traditional ChineseMedicine on the Thromboxane A2 Receptor

Abstract

Some natural products from traditional Chinese medicine (TCM) such as flavones and resveratrol have been reported to have thromboxane A2 receptor (TP) inhibiting activity. We investigated a possible inhibition mechanism by a homology model of TP, which was built based on the crystal structure of squid rhodopsin. After that, docking methods were used to investigate the binding modes of resveratrol and apigenin in the active pocket of TP. Furthermore, a three. dimensional pharmacophore model was generated for screening other potential natural TP inhibitors. The results indicate that resveratrol and apigenin bind to the active site of TP similar to the way that thromboxane A2 binds to Ser201, Leu198, Arg295, and Thr298. The former three key residues can form hydrogen bonds with the inhibitors. The pharmacophore model consisted of seven features and a set of volume spheres, which has been proven to be efficient in identifying compounds with high TP inhibition activity. In this way, a set of potential TP inhibitors were screened from a natural product database. Some of them were reported to have platelet aggregation inhibiting activities. This research indicates that TP could be an important target of TCM drugs with blood circulation activation effects.