Screening of target compounds from Fructus Piperis using high α_1A adrenoreceptor expression cell membrane chromatography online coupled with high performance liquid chromatography tandem mass spectrometry

Benign prostatic hyperplasia (BPH) is a common disease in elderly men. The main treatment for BPH is α-adrenergic antagonists and 5α-reductase inhibitors. In this study, a two-dimensional (2D) α_1A cell membrane chromatography (CMC) online liquid chromatography/mass spectrometry system was built. Fructus Piperis, a traditional Chinese medicine and food homolog, was assayed with this 2D system. Piperine was identified as the active compound acting on α_1A receptors. A competitive binding assay and molecular docking assay were performed to investigate the binding sites and the affinity of piperine for the α_1A receptor. The results of the competitive binding assay (dissociation equilibrium constant of tamsulosin was 1.43×10^-6M and piperine was 2.13×10^-6M) and molecular docking assay (total score for tamsulosin binding with the α_1A receptor was 6.9719, and for piperine it was 4.4891) corresponded with the retention time of tamsulosin and piperine on the α_1A/CMC column.