L-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes

Mika Takeshima, Ikuko Miyazaki, Shinki Murakami, Taizo Kita, Masato Asanuma

Research output: Contribution to journalArticle

9 Citations (Scopus)

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 languageEnglish
Pages (from-to)93-99
Number of pages7
JournalJournal of Clinical Biochemistry and Nutrition
Volume59
Issue number2
DOIs
Publication statusPublished - Sep 1 2016

Fingerprint

Astrocytes
Dopamine
Neurons
Glutathione
Corpus Striatum
Conditioned Culture Medium
Coculture Techniques
Neuroglia
theanine
Oxidative stress
Dopaminergic Neurons
Tea
Cell culture
Sulfhydryl Compounds
Glutamic Acid
Brain
Cell Survival
Animals
Oxidative Stress
Cell Culture Techniques

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 journalArticle

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