L-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes
Year: 2016
Type: article
Abstract: l-Theanine (γ-glutamylethylamide), a component of green tea, is considered to have regulatory and neuroprotective roles in the brain. The present study was designed to determine the effect of l-theanine on excess dopamine-induced neurotoxicity in both cell culture and animal experiments. The primary cultured mesencephalic neurons or co-cultures of mesencephalic neurons and striatal astrocytes were pretreated with l-theanine for 72 h, and then treated with excess dopamine for further 24 h. The cell viability of dopamine neurons and levels of glutathione were evaluated. Excess dopamine-induced neurotoxicity was significantly attenuated by 72 h preincubation with l-theanine in neuron-astrocyte co-cultures but not in neuron-rich cultures. Exposure to l-theanine increased the levels of glutathione in both astrocytes and glial conditioned medium. The glial conditioned medium from l-theanine-pretreated striatal astrocytes attenuated dopamine-induced neurotoxicity and quinoprotein formation in mesencephalic neurons. In addition, replacement of l-glutamate with l-theanine in an in vitro cell-free glutathione-synthesis system produced glutathione-like thiol compounds. Furthermore, l-theanine administration (4 mg/kg, p.o.) for 14 days significantly increased glutathione levels in the striatum of mice. The results suggest that l-theanine provides neuroprotection against oxidative stress-induced neuronal damage by humoral molecules released from astrocytes, probably including glutathione.
DOI: 10.3164/jcbn.16-15
Institutions: Okayama University, Kyushu Nutrition Welfare University
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
Awards: A novel therapeutic strategy for Parkinson's disease by activation of dopamine quinone-sensing molecules in astroglia, Basic study of a measurement of the autonomic nerve balance by the food intake and its food function evaluation, G5622707743, Studies of rotenone-induced dopaminergic neurodegeneration focusing on brain region-specific astrocyte dysfunction., Systemic neurodegeneration and involvement of astroglial cells in Parkinson's disease., Studies on mechanism of rotenone-induced neurodegeneration in central and peripheral nervous systems and involvement of neuron-astrocyte interaction.
OpenAlex ID: W2460913867