Phytochemicals genistein and capsaicin modulate Kv2.1 channel gating

Pharmacol Rep. 2017 Dec;69(6):1145-1153. doi: 10.1016/j.pharep.2017.05.018. Epub 2017 Jun 3.

Abstract

Background: Phytochemicals are a large group of plant-derived compounds that have a broad range of pharmacological effects. Some of these effects are derived from their action on transport proteins, including ion channels. The present study investigates the effects of the phytochemicals genistein and capsaicin on voltage-gated potassium Kv2.1 channels.

Methods: The whole-cell patch clamp technique was used to explore the regulation of Kv2.1 channels expressed in HEK293 cells by genistein and capsaicin.

Results: Both phytochemicals had a profound effect on the gating properties of Kv2.1 channels; the voltage dependence of activation and inactivation was shifted to hyperpolarized potentials, the closed-state inactivation was accelerated, and the recovery from inactivation was delayed. Moreover, genistein and capsaicin inhibited Kv2.1 currents in a concentration dependent manner.

Conclusion: This study effectively demonstrated the inhibitory effects of genistein and capsaicin on Kv2.1 channels. As Kv2.1 channels play a prominent role in glucose-stimulated insulin secretion, our findings contribute to our understanding of the putative mechanism by which these phytochemicals exert their reported hypoglycemic effects.

Keywords: Capsaicin; Gating; Genistein; Kv2.1 channels; Phytochemicals.

MeSH terms

  • Capsaicin / administration & dosage
  • Capsaicin / pharmacology*
  • Dose-Response Relationship, Drug
  • Genistein / administration & dosage
  • Genistein / pharmacology*
  • HEK293 Cells
  • Humans
  • Hypoglycemic Agents / administration & dosage
  • Hypoglycemic Agents / pharmacology
  • Patch-Clamp Techniques
  • Potassium Channel Blockers / administration & dosage
  • Potassium Channel Blockers / pharmacology
  • Shab Potassium Channels / antagonists & inhibitors*
  • Shab Potassium Channels / metabolism

Substances

  • Hypoglycemic Agents
  • KCNB1 protein, human
  • Potassium Channel Blockers
  • Shab Potassium Channels
  • Genistein
  • Capsaicin