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 mesence- phalic 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 com- pounds. 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 neuroprotec- tion against oxidative stress-induced neuronal damage by humoral molecules released from astrocytes, probably including glutathione.
| Original language | English |
|---|---|
| Pages (from-to) | 93-99 |
| Number of pages | 7 |
| Journal | Journal of Clinical Biochemistry and Nutrition |
| Volume | 59 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Sep 1 2016 |
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Keywords
- Astrocyte
- Dopamine
- Glutathione
- L-theanine
- Neuroprotection
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Nutrition and Dietetics
- Clinical Biochemistry
Cite this
L-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes. / Takeshima, Mika; Miyazaki, Ikuko; Murakami, Shinki; Kita, Taizo; Asanuma, Masato.
In: Journal of Clinical Biochemistry and Nutrition, Vol. 59, No. 2, 01.09.2016, p. 93-99.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - L-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes
AU - Takeshima, Mika
AU - Miyazaki, Ikuko
AU - Murakami, Shinki
AU - Kita, Taizo
AU - Asanuma, Masato
PY - 2016/9/1
Y1 - 2016/9/1
N2 - 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 mesence- phalic 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 com- pounds. 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 neuroprotec- tion against oxidative stress-induced neuronal damage by humoral molecules released from astrocytes, probably including glutathione.
AB - 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 mesence- phalic 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 com- pounds. 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 neuroprotec- tion against oxidative stress-induced neuronal damage by humoral molecules released from astrocytes, probably including glutathione.
KW - Astrocyte
KW - Dopamine
KW - Glutathione
KW - L-theanine
KW - Neuroprotection
UR - http://www.scopus.com/inward/record.url?scp=84988911452&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84988911452&partnerID=8YFLogxK
U2 - 10.3164/jcbn.16-15
DO - 10.3164/jcbn.16-15
M3 - Article
AN - SCOPUS:84988911452
VL - 59
SP - 93
EP - 99
JO - Journal of Clinical Biochemistry and Nutrition
JF - Journal of Clinical Biochemistry and Nutrition
SN - 0912-0009
IS - 2
ER -