Physical Sciences and Mathematics Commons^™

Capsaicin Is A Negative Allosteric Modulator Of The 5-Ht3 Receptor, Eslam El Nebrisi, Tatiana Prytkova, Dietrich Ernst Lorke, Luke Howarth, Asma Hassan Alzaabi, Keun-Hang Susan Yang, Frank Christopher Howarth, Murat Oz

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In this study, effects of capsaicin, an active ingredient of the capsicum plant, were investigated on human 5-hydroxytryptamine type 3 (5-HT₃) receptors. Capsaicin reversibly inhibited serotonin (5-HT)-induced currents recorded by two-electrode voltage clamp method in Xenopus oocytes. The inhibition was time- and concentration-dependent with an IC₅₀ = 62 μM. The effect of capsaicin was not altered in the presence of capsazepine, and by intracellular BAPTA injections or trans-membrane potential changes. In radio-ligand binding studies, capsaicin did not change the specific binding of the 5-HT₃ antagonist [³H]GR65630, indicating that it is a noncompetitive inhibitor of …