Title:Quercetin is a Useful Medicinal Compound Showing Various Actions Including Control of Blood Pressure, Neurite Elongation and Epithelial Ion Transport
Volume: 25
Issue: 37
Author(s): Yoshinori Marunaka*, Naomi Niisato, Hiroaki Miyazaki, Ken-Ichi Nakajima, Akiyuki Taruno, Hongxin Sun, Rie Marunaka, Motoki Okui, Toshiro Yamamoto, Narisato Kanamura, Haruka Kogiso, Yukiko Ikeuchi, Makiko Kashio, Shigekuni Hosogi and Takashi Nakahari
Affiliation:
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566,Japan
Keywords:
Flavonoid, Na+-K+-2Cl- cotransporter, ENaC, neurite, Cl-, tubulin, GTPase.
Abstract: Quercetin has multiple potential to control various cell function keeping our body condition
healthy. In this review article, we describe the molecular mechanism on how quercetin exerts its action
on blood pressure, neurite elongation and epithelial ion transport based from a viewpoint of cytosolic
Cl- environments, which is recently recognized as an important signaling factor in various types of cells.
Recent studies show various roles of cytosolic Cl- in regulation of blood pressure and neurite elongation,
and prevention from bacterial and viral infection. We have found the stimulatory action of quercetin
on Cl- transporter, Na+-K+-2Cl- cotransporter 1 (NKCC1; an isoform of NKCC), which has been
recognized as one of the most interesting, fundamental actions of quercetin. In this review article, based
on this stimulatory action of quercetin on NKCC1, we introduce the molecular mechanism of quercetin
on: 1) blood pressure, 2) neurite elongation, and 3) epithelial Cl- secretion including tight junction forming
in epithelial tissues. 1) Quercetin induces elevation of the cytosolic Cl- concentration via activation
of NKCC1, leading to anti-hypertensive action by diminishing expression of epithelial Na+ channel
(ENaC), a key ion channel involved in renal Na+ reabsorption, while quercetin has no effects on the
blood pressure with normal salt intake. 2) Quercetin also has stimulatory effects on neurite elongation
by elevating the cytosolic Cl- concentration via activation of NKCC1 due to tubulin polymerization
facilitated through Cl--induced inhibition of GTPase. 3) Further, in lung airway epithelia quercetin
stimulates Cl- secretion by increasing the driving force for Cl- secretion via elevation of the cytosolic Cl-
concentration: this leads to water secretion, participating in prevention of our body from bacterial and
viral infection. In addition to transcellular ion transport, quercetin regulates tight junction function via
enhancement of tight junction integrity by modulating expression and assembling tight junction-forming
proteins. Based on these observations, it is concluded that quercetin is a useful medicinal compound
keeping our body to be in healthy condition.
