Theanine

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Theanine
Systematic (IUPAC) name
2-Amino-4-(ethylcarbamoyl)butyric acid
Identifiers
CAS number 3081-61-6
ATC code  ?
PubChem 228398
ChemSpider 388498
Chemical data
Formula C7H14N2O3 
Mol. mass 174.20 g/mol
SMILES eMolecules & PubChem
Synonyms L-Theanine, N-Ethyl-L-glutamine
Physical data
Melt. point 117 °C (243 °F)
Pharmacokinetic data
Bioavailability  ?
Metabolism  ?
Half life  ?
Excretion  ?
Therapeutic considerations
Pregnancy cat.

?
Legal status

Legal
Routes Oral
Neuroscience portal

Theanine is an amino acid commonly found in tea (infusions of Camellia sinensis), and also in the basidiomycete mushroom Boletus badius.[1] In 1950 the Tea laboratory of Kyoto successfully separated theanine from Gyokuro leaf, which has the highest theanine content among all teas. Theanine is related to glutamine, and can cross the blood-brain barrier.[2] Because it can enter the brain, theanine has psychoactive properties.[3] Theanine has been shown to reduce mental and physical stress[4], may produce feelings of relaxation[5] and improves cognition and mood when taken in combination with caffeine.[6]

Theanine is speculated to produce these effects by increasing the level of gamma-aminobutyric acid (GABA) production. Theanine increases brain serotonin, dopamine, GABA levels and has micromolar affinities for AMPA, Kainate and NMDA receptors.[7] It has also been found that injecting spontaneously hypertensive mice with theanine significantly lowered levels of 5-hydroxyindoles in the brain.[8] Researchers also speculate that it may inhibit glutamic acid excitotoxicity.[7] Theanine also promotes alpha wave production in the brain.[3]

Studies on test rats have shown that even repeated, extremely high doses of theanine cause little to no harmful psychological or physical effects.[9] Theanine showed neuroprotective effects in one rat study.[10]

L-theanine may help the body's immune response to infection by boosting the disease-fighting capacity of gamma delta T cells. The study, published in 2003 by the Brigham and Women's Hospital, included a four-week trial with 11 coffee drinkers and 10 tea drinkers, who consumed 600 milliliters of coffee or black tea daily. Blood sample analysis found that the production of anti-bacterial proteins was up to five times higher in the tea-drinkers, an indicator of a stronger immune response.[11]

[edit] See also

[edit] References

  1. ^ Casimir J, Jadot J, Renard M (1960). "[Separation and characterization of N-ethyl-gamma-glutamine from Xerocomus badius.]". Biochim Biophys Acta 39: 462–8. PMID 13808157. 
  2. ^ Yokogoshi H, Kobayashi M, Mochizuki M, Terashima T (1998). "Effect of theanine, r-glutamylethylamide, on brain monoamines and striatal dopamine release in conscious rats". Neurochem Res 23 (5): 667–73. doi:10.1023/A:1022490806093. PMID 9566605. 
  3. ^ a b Gomez-Ramirez M. "The Deployment of Intersensory Selective Attention: A High-density Electrical Mapping Study of the Effects of Theanine". Clin Neuropharmacol 30 (1): 25–38. PMID 17272967. 
  4. ^ Kimura K, Ozeki M, Juneja L, Ohira H (2007). "L-Theanine reduces psychological and physiological stress responses". Biol Psychol 74 (1): 39–45. doi:10.1016/j.biopsycho.2006.06.006. PMID 16930802. 
  5. ^ Lu K, Gray M, Oliver C, Liley D, Harrison B, Bartholomeusz C, Phan K, Nathan P (2004). "The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans". Hum Psychopharmacol 19 (7): 457–65. doi:10.1002/hup.611. PMID 15378679. 
  6. ^ Haskell CF, Kennedy DO, Milne AL, Wesnes KA, Scholey AB (2008). "The effects of l-theanine, caffeine and their combination on cognition and mood". Biol Psychol 77 (2): 113–22. doi:10.1016/j.biopsycho.2007.09.008. PMID 18006208. 
  7. ^ a b Nathan P, Lu K, Gray M, Oliver C (2006). "The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent". J Herb Pharmacother 6 (2): 21–30. PMID 17182482. 
  8. ^ Yokogoshi H, Kato Y, Sagesaka YM, Takihara-Matsuura T, Kakuda T, Takeuchi N (1995). "Reduction effect of theanine on blood pressure and brain 5-hydroxyindoles in spontaneously hypertensive rats.". Biosci Biotechnol Biochem. 59 (4): 615–618. PMID 7539642. 
  9. ^ Borzelleca J, Peters D, Hall W (2006). "A 13-week dietary toxicity and toxicokinetic study with L-theanine in rats". Food Chem Toxicol 44 (7): 1158–66. doi:10.1016/j.fct.2006.03.014. PMID 16759779. 
  10. ^ Egashira N, Ishigami N, Pu F, et al (2008). "Theanine prevents memory impairment induced by repeated cerebral ischemia in rats". Phytother Res 22 (1): 65–8. doi:10.1002/ptr.2261. PMID 17705146. 
  11. ^ Kamath A, Wang L, Das H, Li L, Reinhold V, Bukowski J (2003). "Antigens in tea-beverage prime human Vgamma 2Vdelta 2 T cells in vitro and in vivo for memory and nonmemory antibacterial cytokine responses". Proc Natl Acad Sci USA 100 (10): 6009–14. doi:10.1073/pnas.1035603100. PMID 12719524. 
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