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.