Abstract
We investigated the molecular mechanism underlying the neuroprotective effect of theanine, a green tea component, using primary cultured rat cortical neurons, focusing on group I metabotropic glutamate receptors (mGluRs). Theanine and a group I mGluR agonist, DHPG, inhibited the delayed death of neurons caused by brief exposure to glutamate, and this effect of theanine was abolished by group I mGluR antagonists. Although the administration of glutamate alone decreased the neuronal expression of phospholipase C (PLC)-beta1 and -gamma1, which are linked to group I mGluRs, their expression was equal to the control levels on cotreatment with theanine. Treatment with theanine or DHPG alone for 5-7 days resulted in increased expression of PLC-beta1 and -gamma1, and the action of theanine was completely abolished by group I mGluR antagonists. These findings indicate that group I mGluRs might be involved in neuroprotective effect of theanine by increasing the expression levels of PLC-beta1 and -gamma1.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Animals
-
Apoptosis / drug effects
-
Cell Survival / drug effects
-
Cells, Cultured
-
Cerebral Cortex / cytology
-
Cerebral Cortex / drug effects
-
Cerebral Cortex / embryology
-
Cerebral Cortex / metabolism
-
Dose-Response Relationship, Drug
-
Glutamates / pharmacology*
-
Glutamic Acid / pharmacology
-
Isoenzymes / metabolism
-
Methoxyhydroxyphenylglycol / analogs & derivatives*
-
Methoxyhydroxyphenylglycol / pharmacology
-
Neurons / cytology
-
Neurons / drug effects*
-
Neurons / metabolism*
-
Neuroprotective Agents / pharmacology*
-
Phospholipase C beta
-
Phospholipase C gamma
-
Rats
-
Receptors, Metabotropic Glutamate / antagonists & inhibitors*
-
Receptors, Metabotropic Glutamate / metabolism*
-
Type C Phospholipases / metabolism
Substances
-
Glutamates
-
Isoenzymes
-
Neuroprotective Agents
-
Receptors, Metabotropic Glutamate
-
Glutamic Acid
-
Methoxyhydroxyphenylglycol
-
theanine
-
Type C Phospholipases
-
Phospholipase C beta
-
Plcb1 protein, rat
-
Phospholipase C gamma
-
3,4-dihydroxyphenylglycol