Establishment of H1R-SNAP-tag/CMC and screening for anti-allergic active ingredients targeting H1R.

In this study, a novel cell membrane chromatography (CMC) model was developed to discover Histamine H1 receptors (H1R) targeted anti-allergic drugs for specific screening and ligand-receptor interaction analysis by SNAP-tagged H1R fusion protein conjugation and BG-modified silica gel. Allergic diseases (ADs) are prevalent pathological conditions arising from immune dysregulation, which significantly compromise patient quality of life across multiple domains, while traditional Chinese medicines (TCMs) are widely used to treat ADs. H1R plays a pivotal role in the pathogenesis of allergic diseases and acts as an attractive target for therapeutic intervention. Although antihistamines are the first-line therapy for ADs, their clinical utility is limited by side effects. Consequently, a novel screening method for active components targeting H1R in TCMs is crucial for the research and discovery of novel anti-allergic lead compounds. In the current study, the H1R-SNAP-tag cell membrane chromatography (H1R-SNAP-tag/CMC) column was prepared with outstanding specificity, selectivity, and reproducibility by chemically immobilizing H1R overexpression cell membranes to the BG-silica gel (BG-SiO2) using the SNAP-tag technology. The H1R-SNAP-tag/CMC-HPLC-MS system was investigated using the H1R antagonist Clemastine fumarate and the results showed that the system was a reliable model for screening potential anti-allergic compounds from TCMs. From an Iris tectorum Maxim. (I. tectorum) extract, six H1R-binding compounds were identified: tectoridin, iristectorin A, iridin, tectorigenin, irigenin, and irisflorentin. Frontal analysis and molecular docking confirmed their affinity for H1R, while subsequent in vivo and in vitro pharmacological assays preliminarily validated their anti-allergic efficacy.