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

Abstract

Hypericum perforatum (St John's wort) is a well known medicinal plant used in many pharmaceutical formulations 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. At the molecular level, it was proven that long-term human administration of St John's wort may result in diminished clinical effectiveness or increased dosage requirements for all CYP 3A4 substrates [4]. In addition, short term administration does not alter most of the circulating androgens, except for the 5 -reduced androgens [5]. KeywordsDaily treatment with either Hypericum extract (or hypericin alone) for 14 days significantly decreased plasma ACTH and corticosterone levels, but does not affect the plasma prolactin or LH levels [6]. Ze117 extract (low hyperforin content), does not interact with the pharmacokinetics of the hormonal components of the low-dose oral contraceptive [3,7]. The procedures and protocol design are in accordance with the ethical guidelines and regulations of the European Union. In this study we have used 1, respectively 3 months old RAP mice of both sexes. Each group was subdivided into a control subgroup and a test subgroup, treated daily for a month. The control subgroup received hydro-alcoholic mixture (5% alcohol) and the test group received Hyperici herba hydro-alcoholic extract. The body weight was monitored at specific intervals 0, 1, 2, 4, and 12 weeks.The Hyperici Herba extract was provided by Bionorica Company (Germany) and their HPLC analysis indicates a content of 0.19% hypericin, 0.25% pseudohypericin and 3.4% hyperforin. During one month oral administration, a daily total dose of 1500 mg/kg Hyperici was administered in 3 hits. Solubilisation was done in a mixture of 5% ethylic alcohol, 2% sucrose and deionized water (MilliQ). In order to increase the solubility, the extract was sonicated for 2 hours with a Soniprep 150 (Sanyo, Gallenkamp PLC, UK). In order to reduce photodamage effects, the whole solution was prepared at the beginning of the experiment, and maintained in dark conditions at 2-4 °C. The animals were sacrified at 24 hours after the last oral dose.The body temperature was measured with a digital thermometer (LCD Digital, Prima Long) intra-anal at 0, 1, 2, 3 and 4-hours after the dosage administration. In the control group, the animals received daily a mixture of 5% ethylic alcohol, 2% sucrose and deionized water (MilliQ), a...