Caffeic acid esters activate TREK-1 potassium channels and inhibit depolarization-dependent secretion

Area of Science:

• Pharmacology
• Neuroscience
• Cell Biology

Background:

• TREK-1 K+ channels are crucial for maintaining resting membrane potential in bovine adrenal fasciculata cells.
• Corticotropin inhibits TREK-1 channels, leading to depolarization, calcium influx, and cortisol secretion.

Purpose of the Study:

• To investigate the effect of caffeic acid derivatives on TREK-1 K+ channel activity.
• To explore the therapeutic potential of these derivatives in modulating cellular electrical activity.

Main Methods:

• Whole-cell and single-channel patch-clamp recordings were performed on bovine adrenal fasciculata cells.
• Structure/activity relationship studies were conducted on various caffeic acid esters.
• The effect of Cinnamyl 1-3,4-dihydroxy-alpha-cyanocinnamate (CDC) on corticotropin-stimulated cortisol secretion was assessed.

Main Results:

• Caffeic acid derivatives, including CDC and CAPE, were found to significantly enhance TREK-1 K+ channel activity.
• CDC activated TREK-1 channels at concentrations of 5-10 microM, independent of lipoxygenase inhibition.
• CDC reversed corticotropin-induced membrane depolarization and inhibited cortisol secretion by activating TREK-1 channels.

Conclusions:

• Selected caffeic acid derivatives are novel openers of TREK-1 background K+ channels.
• These compounds stabilize the resting membrane potential, counteracting depolarization and calcium entry.
• Caffeic acid derivatives show potential as neuroprotective and cardioprotective agents.