Determination of hyperforin, hypericin, and pseudohypericin in human plasma using high-performance liquid chromatography analysis with fluorescence and ultraviolet detection

Hyperforin, hypericin and pseudohypericin are the main ingredients of St. J ohn's wort extract, which is available over the counter for treatment of mi ld to moderate depression. To facilitate clinical studies we developed two sensitive HPLC methods for determination of hypericin/pseudohypericin and h yperforin, respectively, in human plasma samples. The achieved limits of qu antitation of 0.25 ng/ml for hypericin and pseudohypericin and 10 ng/ml for hyperforin were low enough to allow determination of pharmacokinetic param eters of the substances. Following Liquid-liquid extraction of human plasma the samples were separated by isocratic reversed-phase HLPC and analyzed u sing fluorimetric detection for hypericin/pseudohypericin and UV detection for hyperforin. (C) 2001 Elsevier Science B.V. All rights reserved.