L-theanine promotes nitric oxide production in endothelial cells through eNOS phosphorylation.
J Nutr Biochem
; 24(3): 595-605, 2013 Mar.
Article
en En
| MEDLINE
| ID: mdl-22819553
ABSTRACT
Consumption of tea (Camellia sinensis) improves vascular function and is linked to lowering the risk of cardiovascular disease. Endothelial nitric oxide is the key regulator of vascular functions in endothelium. In this study, we establish that l-theanine, a non-protein amino-acid found in tea, promotes nitric oxide (NO) production in endothelial cells. l-theanine potentiated NO production in endothelial cells was evaluated using Griess reaction, NO sensitive electrode and a NO specific fluorescent probe (4-amino-5-methylamino-2',7'-difluororescein diacetate). l-Theanine induced NO production was partially attenuated in presence of l-NAME or l-NIO and completely abolished using eNOS siRNA. eNOS activation was Ca(2+) and Akt independent, as assessed by fluo-4AM and immunoblotting experiments, respectively and was associated with phosphorylation of eNOS Ser 1177. eNOS phosphorylation was inhibited in the presence of ERK1/2 inhibitor, PD-98059 and partially inhibited by PI3K inhibitor, LY-294002 and Wortmanin suggesting PI3K-ERK1/2 dependent pathway. Increased NO production was associated with vasodilation in ex ovo (chorioallantoic membrane) model. These results demonstrated that l-theanine administration in vitro activated ERK/eNOS resulting in enhanced NO production and thereby vasodilation in the artery. The results of our experiments are suggestive of l-theanine mediated vascular health benefits of tea.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Extractos Vegetales
/
Células Endoteliales
/
Óxido Nítrico Sintasa de Tipo III
/
Glutamatos
/
Óxido Nítrico
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
J Nutr Biochem
Asunto de la revista:
BIOQUIMICA
/
CIENCIAS DA NUTRICAO
Año:
2013
Tipo del documento:
Article
País de afiliación:
India