Evaluation of Receptor Affinity, Analgesic Activity and Cytotoxicity of a Hybrid Peptide, AWL3020

Abstract

Abstract In the present contribution we report design, synthesis and evaluation of receptor affinity, analgesic activity and cytotoxicity of a hybrid peptide, AWL3020. The peptide includes two pharmacophores, one of δ-opioid receptor (δOR) agonists and one of neurokinin-1 receptor (NK1R) antagonists. The design was motivated by the desire to obtain a compound with strong analgesic action and potential additional antiproliferative action. The compound displays high δOR affinity (IC 50 = 29.5 nM). On the other hand, it has only poor affinity for the NK1R (IC 50 = 70.28 μM). The substance shows good analgesic action which is however weaker than that of morphine. Regarding the effect on proliferation, the compound exhibits no pro-proliferative action in the assayed range. In higher concentrations, it has also cytotoxic activity. This effect is however not selective. The strongest effect of AWL3020 was found for melanoma MeW164 cell line (EC 50 = 46.27 μM in reduction of cell numbers after a few days of incubation; EC 50 = 37.78 μM in MTT assay).