Fragrances in oolong tea that enhance the response of GABA(A) receptors

• Published in: Bioscience, biotechnology, and biochemistry Vol. 68; no. 9; pp. 1842 - 1848
• Main Authors: Hossain, S.J. (Yamaguchi Univ. (Japan)), Aoshima, H, Koda, H, Kiso, Y
• Format: Journal Article
• Language: English
• Published: 01.09.2004
• Subjects: BIOLOGICAL RESPONSE MODIFIERS; FROGS; GABA; HORMONE RECEPTORS; LACTONES; NEUROLEPTICS; SLEEP; SMELL; TEA
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.68.1842

We electrophysiologically investigated the effect of some fragrant compounds in oolong tea on the response of ionotropic gamma-aminobutyric acid (GABA) receptors (GABA sub(A) receptors) which were expressed in Xenopus oocytes. Of the tested fragrances in oolong tea, cisjasmone, jasmine lactone, linalool oxide and methyl jasmonate significantly potentiated the response. Among these, cis-jasmone and methyl jasmonate potently potentiated the response, having a respective dissociation constant of the compound (K sub(p)) and maximum potentiation (V sub(m)) of 0.49 mM and 322% for cis-jasmone, and 0.84 mM and 450% for methyl jasmonate. Inhalation of 0.1% cis-jasmone or methyl jasmonate significantly increased the sleeping time of mice induced by pentobarbital, suggesting that these fragrant compounds were absorbed by the brain and thereby potentiated the GABA sub(A) receptor response. Both of these compounds may therefore have a tranquillizing effect on the brain.