Quercetin inhibits the 5-hydroxytryptamine type 3 receptor-mediated ion current by interacting with pre-transmembrane domain I.
Mol Cells
; 20(1): 69-73, 2005 Aug 31.
Article
em En
| MEDLINE
| ID: mdl-16258243
ABSTRACT
The flavonoid, quercetin, is a low molecular weight substance found in apple, tomato and other fruit. Besides its antioxidative effect, quercetin, like other flavonoids, has a wide range of neuropharmacological actions including analgesia, and motility, sleep, anticonvulsant, sedative and anxiolytic effects. In the present study, we investigated its effect on mouse 5-hydroxytryptamine type 3 (5-HT3A) receptor channel activity, which is involved in pain transmission, analgesia, vomiting, and mood disorders. The 5-HT3A receptor was expressed in Xenopus oocytes, and the current was measured with the two-electrode voltage clamp technique. In oocytes injected with 5-HT3A receptor cRNA, quercetin inhibited the 5-HT-induced inward peak current (I(5-HT)) with an IC50 of 64.7 +/- 2.2 microM. Inhibition was competitive and voltage-independent. Point mutations of pre-transmembrane domain 1 (pre-TM1) such as R222T and R222A, but not R222D, R222E and R222K, abolished inhibition, indicating that quercetin interacts with the pre-TM1 of the 5-HT3A receptor.
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Base de dados:
MEDLINE
Assunto principal:
Quercetina
/
Estrutura Terciária de Proteína
/
Antagonistas do Receptor 5-HT3 de Serotonina
/
Potenciais da Membrana
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article