H4R antagonist 1 is a potent and highly selective histamine H4 receptor (H4R) antagonist with an IC50 of 27 nM. H4R antagonist 1 does not show any noticeable binding affinity to other subtypes of histamine receptors, H1R, H2R, and H3R[1].
The competitive binding assay against a wider panel of GPCR, ion channel, and transporters at the concentration of 10 μM reveals that H4R antagonist 1 (Compound 48) is highly selective for H4R. The inhibitory activity of H4R antagonist 1 against mouse H4R (IC50=0.29 μM) is about 10 times weaker than that for human H4R[1].
H4R antagonist 1 (Compound 48) shows significant antipruritic and anti-inflammatory efficacy in Oxazolone-induced murine model mimicking human atopic dermatitis (AD)[1]. In the [35S]GTPγS functional assay, H4R antagonist 1 shows inhibitory activity against mouse H4R with an IC50 of 0.69 μM[1].