Inhibition of intracellular Ca2+ mobilization and potassium channels activation are involved in the vasorelaxation induced by 7-hydroxycoumarin

Eur J Pharmacol. 2020 Nov 15:887:173525. doi: 10.1016/j.ejphar.2020.173525. Epub 2020 Sep 1.

Abstract

Coumarins exhibit a wide variety of biological effects, including activities in the cardiovascular system and the aim of this study was to evaluate the vascular therapeutic potential of 7-Hydroxicoumarin (7-HC). The vascular effects induced by 7-HC (0.001 μM-300 μM), were investigated by in vitro approaches using isometric tension measurements in rat superior mesenteric arteries and by in silico assays using Ligand-based analysis. Our results suggest that the vasorelaxant effect of 7-HC seems to rely on potassium channels, notably through large conductance Ca2+-activated K+ (BKCa) channels activation. In fact, 7-HC (300 μM) significantly reduced CaCl2-induced contraction as well as the reduction of intracellular calcium mobilization. However, the relaxation induced by 7-HC was independent of store-operated calcium entry (SOCE). Moreover, in silico analysis suggests that potassium channels have a common binding pocket, where 7-HC may bind and hint that its binding profile is more similar to quinine's than verapamil's. These results are compatible with the inhibition of Ca2+ release from intracellular stores, which is prompted by phenylephrine and caffeine. Taken together, these results demonstrate a therapeutic potential of 7-HC on the cardiovascular system, making it a promising lead compound for the development of drugs useful in the treatment of cardiovascular diseases.

Keywords: 7-Hydroxycoumarin; Docking; FTMap; K(+) channels; Vasorelaxation.

MeSH terms

  • Animals
  • Calcium Signaling / drug effects*
  • Calcium Signaling / physiology
  • Cell Line
  • Dose-Response Relationship, Drug
  • Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / agonists*
  • Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / chemistry
  • Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / physiology
  • Male
  • Mesenteric Arteries / drug effects*
  • Mesenteric Arteries / physiology
  • Organ Culture Techniques
  • Protein Structure, Secondary
  • Rats
  • Rats, Wistar
  • Umbelliferones / pharmacology*
  • Vasodilation / drug effects*
  • Vasodilation / physiology
  • Vasodilator Agents / pharmacology*

Substances

  • Kcnma1 protein, rat
  • Large-Conductance Calcium-Activated Potassium Channel alpha Subunits
  • Umbelliferones
  • Vasodilator Agents
  • 7-hydroxycoumarin