Pharmacokinetic study in mice of galphimine-A, an anxiolytic compound from Galphimia glauca

The aim of this study was to obtain pharmacokinetic data for the anxiolytic compound galphimine-A (G-A) from Galphimia glauca. G-A is the most abundant anxiolytic compound in this plant, while Galphimine-E (G-E) is the most abundant galphimine, but inactive. G-E was transformed chemically into G-A. The pharmacokinetic study was carried out in ICR mice, which were orally administered a single 200 mg/kg dose of G-A. Samples of blood and brain were taken at different times after administration of G-A. Previously, we established the validation of methods for determining the concentration of G-A. The G-A was detected in plasma 5 min after oral administration, and its concentration reached 2.47 μg/mL. Data from concentration-time curves allowed us to establish the main pharmacokinetic parameters in two models: one- and/or two-compartment. C(max) values were 3.33 and 3.42 μg/mL respectively, likewise AUC(0→1440 min) were 1,951.58 and 1,824.95 μg/mL·min. The G-A in brain tissue was noted to cross the blood-brain barrier, reaching C(max) 2.74 μg/mL, T(max) 81.6 min, and then drop gradually to 0.32 μg/mL detected at 24 h. The presence of G-A in brain tissue, confirmed that this anxiolytic compound can access the target organ and acts directly on the CNS.