Determination of Caffeine and its Metabolites in Saliva and Urine as a Measure of CYP1A2 Metabolic Activity

Title:Determination of Caffeine and its Metabolites in Saliva and Urine as a Measure of CYP1A2 Metabolic Activity

Volume: 12 Issue: 4

Author(s): Miroslav Turjap, Ondrej Zendulka, Zdenek Glatz, Stanislav Brejcha, Ales Madr and Jan Jurica

Affiliation:

Keywords: Caffeine, CYP1A2, saliva, urine, phenotyping, metabolic ratio.

Abstract: Objective: The aim of this work was to develop a new, simple, rapid, sensitive and reproducible RP-HPLC method for the determination of caffeine, 1,7 dimethylxanthine, 1,7-dimethyluric acid, 5- acetylamino-6-formylamino-3-methyluracil, 5-acetylamino-6-amino-3-methyluracil, 1-methylxanthine, and 1-methyluric acid in human urine and saliva as a method of determining the metabolic activity of the human enzyme CYP1A2.

Methods: A Luna C18(2) (150 x 4.6 mm i.d.) analytical column was used for the separation. The mobile phase consisted of sodium acetate trihydrate (pH 5.0) and methanol 85:15 (v/v). The flow rate was maintained at 0.8 mL/min. The absorbance of the eluent was monitored at 263 nm (5-acetylamino-6-amino-3- methyluracil), 285 nm (5-acetylamino-6-formylamino-3-methyluracil, 1,7-dimethyluric acid, 1- methyluric acid), 272 nm (caffeine, 1,7 dimethylxanthine) and 268 nm (1-methylxanthine). Acetaminophen as an internal standard was used to ensure the precision and accuracy of this method, and it was monitored at 245 nm.

Results: All compounds, including the internal standard, were eluted within 18 min. Analytes were extracted by liquid-liquid extraction. Limits of quantitation varied from 7.2 to 74.2 µg/L for individual analytes in saliva and from 8.4 to 82.4 µg/L in urine.

Conslusion: This method may become a useful alternative to urine caffeine metabolic ratio measurement with respect to CYP1A2 metabolic activity assessment in clinical practice.

Cite this article as:

Turjap Miroslav, Zendulka Ondrej, Glatz Zdenek, Brejcha Stanislav, Madr Ales and Jurica Jan, Determination of Caffeine and its Metabolites in Saliva and Urine as a Measure of CYP1A2 Metabolic Activity, Current Pharmaceutical Analysis 2016; 12 (4) . https://dx.doi.org/10.2174/1573412912666151119212608