Simultaneous liquid chromatography- tandem mass spectrometry method to quantify epicatechin and procyanidin B2 in rat plasma after oral administration of Trichilia catigua (catuaba) extract and its application to a pharmacokinetic study

Trichilia catigua A. Juss., Meliaceae, known as catuaba in Brazil, is traditionally used for the treatment of stress, sexual impotence and memory deficits. To our knowledge, there is no analytical method described in literature for simultaneous quantification of catuaba extract marker substances in biological matrices. The aim of this study was to develop and validate a bioanalytical method by LC–MS/MS to quantify epicatechin and procyanidin B2 in rat plasma after administration of standardized extract of T. catigua. Chromatographic separation was achieved with a C18 column, methanol and 0.1% aqueous formic acid at a flow rate of 0.25 ml/min. Detection was performed using electrospray ionization in negative mode. The lower limits of quantification were 5 ng/ml and 12.5 ng/ml for procyanidin B2 and epicatechin, respectively. Intra- and inter-day assays variability were less than 15%. The extraction recovery was 104% for epicatechin and 74% for procyanidin B2 using one-step liquid–liquid extraction with ethyl acetate. Epicatechin and PB2 were detected in plasma up to 300 min after oral administration of 400 mg/kg of standardized extract of T. catigua in rats. This rapid and sensitive method for the analysis of the epicatechin and procyanidin B2 in rat plasma can be applied to pharmacokinetic studies.

Keywords:
Analytical validation; Epicatechin; Procyanidin B2; LC–MS/MS; Pharmacokinetics.