Pharmacokinetics of theanine enantiomers in rats
| Autor: | Walter H. Hsu, Manmeet S. Gill, Meera J. Desai, Daniel W. Armstrong |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Pharmacology
Male Chemistry Reabsorption Organic Chemistry Stereoisomerism Absorption (skin) Theanine Catalysis Intestinal absorption Mass Spectrometry Analytical Chemistry Rats Excretion Rats Sprague-Dawley Route of administration chemistry.chemical_compound Pharmacokinetics Glutamates Oral administration Drug Discovery Animals Spectroscopy Chromatography Liquid |
| Zdroj: | Chirality. 17(3) |
| ISSN: | 0899-0042 |
| Popis: | Theanine, first discovered in tea, is a chiral nonproteinic amino acid that has been reported to have cardiovascular, neurological, and oncological effects. It is being considered as a therapeutic/medicinal agent and additive in consumer products. The present study evaluated the pharmacokinetics of D-theanine, L-theanine, and D,L-theanine in plasma and urine using LC-ESI/MS in rats after oral (p.o.) and intraperitoneal (i.p.) administration. Oral administration data indicated that gut absorption of d-theanine was far less than that of L-theanine. However, after i.p. administration, plasma theanine concentrations of L- and D-theanine were similar. This indicated that D- and L-theanine may exhibit a competitive effect with respect to intestinal absorption. Regardless of the route of administration, p.o. or i.p., the presence of the other enantiomer always decreased theanine plasma concentrations, indicating D,L-theanine competition with respect to urinary reabsorption. Data on urinary concentrations of D-theanine suggested that the D-isomer may be eliminated with minimal metabolism. L-Theanine appeared to be preferentially reabsorbed and metabolized by the kidney while D-theanine was preferentially excreted. Clearly, the bioequivalencies of D,L-theanine and its enantiomers were found to be quite different from one another. Consequently, the efficacy of commercial theanine products containing D-theanine, L-theanine, or D,L-theanine may be quite different. |
| Databáze: | OpenAIRE |
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