Gender-Differences in Mice Hypericin Plasma Levels Upon Long-Term Hypericum Administration

Hypericum perforatum (St John's wort) is a well known medicinal plant used in many pharmaceutical formula- tions and its main active compound is hypericin. The purpose of our study was to examine the plasma level of hypericin upon long term mice treatment with Hyperici herba extract. A reversible hyperthermia was recorded upon 2 hours of the extract administration, both in males and females. Hypericin plasma levels in mice were evaluated by HPLC analysis. In 1-month old mice, no significant gender differences in the hypericin plasma level were recorded. By contrast, at the age of 3-months, hypericin plasma levels are significantly more elevated in females (93 ± 7 ng/ml; n = 8, p < 0.05) than in males (32 ± 3 ng/ml; n = 9). In conclusion, gender specific precautions must be considered when Hypericum is prescribed in human patients.