Abstract: The H1R antagonists are used in the treatment of several allergic conditions,such as rhinoconjunctivitis,urticaria and atopic dermatitis.Here we reported a label-free cell phenotypic profiling model for high throughput screening of H1R antagonists.Resonant waveguide grating enabled dynamic mass redistribution (DMR) assay was used to characterize the endogenous H1R in A431 cell using known agonists and antagonists.To further identify potential natural products as H1R antagonists,32 natural products were screened using label-free DMR assay.Results showed that label-free DMR assay was suitable for high throughput screening of H1R antagonists;Among 32 compounds,two lactone compounds which isolated from Smallanthus sonchifolius were found to be more potent antagonist in DMR assay.These results suggested that label-free DMR assay might represent a new approach for the discovery of H1R antagonists.

Key words: histamine, H1 receptor, antagonist, screening