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L-theanine promotes nitric oxide production in endothelial cells through eNOS phosphorylation.
- Source :
-
The Journal of nutritional biochemistry [J Nutr Biochem] 2013 Mar; Vol. 24 (3), pp. 595-605. Date of Electronic Publication: 2012 Jul 21. - Publication Year :
- 2013
-
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.<br /> (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Subjects :
- Apoptosis drug effects
Calcium analysis
Calcium metabolism
Cell Line
Cell Survival drug effects
Chromones pharmacology
Endothelial Cells metabolism
Endothelium, Vascular cytology
Endothelium, Vascular drug effects
Flavonoids pharmacology
Humans
Mitogen-Activated Protein Kinase 1 antagonists & inhibitors
Mitogen-Activated Protein Kinase 1 genetics
Mitogen-Activated Protein Kinase 1 metabolism
Mitogen-Activated Protein Kinase 3 antagonists & inhibitors
Mitogen-Activated Protein Kinase 3 genetics
Mitogen-Activated Protein Kinase 3 metabolism
Morpholines pharmacology
NG-Nitroarginine Methyl Ester metabolism
Nitric Oxide Synthase Type III metabolism
Ornithine analogs & derivatives
Ornithine metabolism
Phosphatidylinositol 3-Kinases genetics
Phosphatidylinositol 3-Kinases metabolism
Phosphorylation
Proto-Oncogene Proteins c-akt genetics
Proto-Oncogene Proteins c-akt metabolism
Signal Transduction
Tea chemistry
Vasodilation drug effects
Endothelial Cells drug effects
Glutamates pharmacology
Nitric Oxide biosynthesis
Nitric Oxide Synthase Type III genetics
Plant Extracts pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 1873-4847
- Volume :
- 24
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- The Journal of nutritional biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 22819553
- Full Text :
- https://doi.org/10.1016/j.jnutbio.2012.02.016