Determination of alpha-mangostin in rat plasma by HPLC-MS and its application to pharmacokinetic studies
Garcinia mangostana L. (Clusiaceae) is a plant that originates from Southeast Asia and has been used traditionally to treat diarrhea, dysentery, inflammation, skin disorders, and wounds. Products manufactured from G. mangostana are increasingly popular as a botanical dietary supplement in the United States, because of their potent antioxidant properties. The xanthone α-mangostin is one of the major bioactive secondary metabolites in mangosteen. Until now, studies on the disposition, absorption, bioavailability, and metabolism of α-mangostin are limited. In the present study, a HPLC-MS assay has been established for the determination of α-mangostin in rat plasma, with bergamottin as internal standard. The recovery percentage of α-mangostin from the plasma samples was 93.19%. The calibration curve was linear over the range of 20–2000ng/ml. The total run time was 8min. The intra- and inter-assay variability was less than 9.32% and 9.87%, respectively. The accuracies determined at the concentrations of 70, 850 and 1800ng/ml for α-mangostin were within +15%. The validated method, which is rapid, simple, and precise, was used successfully to support pharmacokinetic studies in rats after oral and intravenous (i.v.) injection. Non-compartmental analysis suggested a short half-life of 4 minutes and a low oral bioavailability of only 4.24% for α-mangostin. Further investigations are in preparation to link the pharmacokinetics of α-mangostin with the threshold of its reported antitumorigenic or antiproliferative effects.