The pharmacokinetic properties of pure γ-mangostin in rats in comparison to mangosteen extract

α- and γ-mangostin are the major bioactive compounds in Garcinia mangostana L. (mangosteen) extracts. Previously, we reported the pharmacokinetic (PK) properties of α-mangostin in rats. The purpose of this study was to compare the PK properties of γ-mangostin in rats if administered as pure compound or as mangosteen extract. The absolute bioavailability of γ-mangostin was determined by giving male Sprague Dawley rats 2mg/kg γ-mangostin intravenously (i.v.) or 20mg/kg orally. 160mg/kg of the mangosteen extract were administered which contained a α- and γ-mangostin dose equal to 20mg/kg and 4.5mg/kg of pure the compound. Plasma samples were collected in both PK studies and compound concentrations were measured by LC-MS/MS. The PK of γ-mangostin after i.v. administration followed a two-compartment body model. The half-life of the distribution phase was 2.40min and that of the elimination phase was 1.52 hr. After oral administration, both α- and γ-mangostin underwent an intensive first-pass metabolism and both compounds were conjugated rapidly after oral administration. When given as extract the absorption of α- and γ-mangostin was not increased, but the metabolism was affected through changes in the elimination of the conjugates from two phases to one phase. In conclusion, since food supplements contain mangosteen extracts, further investigations are necessary to link the pharmacokinetics of free active compounds with the in vivo activity of mangosteen extracts.