The Bis(1,2,3,4-tetrahydroisoquinoline) Alkaloids Cepharanthine and Berbamine Are Ligands of SK Channels

Cepharanthine and berbamine, both alkaloids with structural similarities to known SK channel blockers, were evaluated for their affinity to SK2 and SK3 channels. The study found that cepharanthine has K_i values of 1,318 μM for SK2 and 1,091 μM for SK3, while berbamine shows stronger affinities with K_i values of 0,284 μM for SK2 and 0,679 μM for SK3. These affinities align with the concentrations at which these alkaloids are therapeutically active, suggesting a potential role of SK channels in their pharmaceutical effects and warranting further investigation into this interaction.