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Objective: Hypericum perforatum extract (HPE), known for its antidepressant effect, has been explored in the present study for its protective role against MPTP induced neurotoxicity. Materials and Methods: Mice were treated with 20 mg/kg of MPTP, four injections i.p., at 2 h intervals within 24 h. HPE was administered at different doses of 100, 200 and 300 mg/kg (p.o) in different groups once a day for seven days and the dose on the first day was given 30 min prior to first MPTP injection. Striatal dopamine (DA) and its metabolites, antioxidant status were analysed. The behavioural changes were studied using the rotarod test, hang test and narrow beam test. Results: HPE significantly ( P Conclusion: HPE possesses significant antioxidant activity and renders neuroprotection which was more pronounced at the dose of 300 mg/kg against MPTP induced neurotoxicity.

In a double-blind, randomized, placebo-controlled trial with 375 patients the authors investigated the antidepressant efficacy and safety of 300 mg t.i.d. of hydroalcoholic Hypericum perforatum extract WS 5570.The study participants were male and female adult outpatients with mild to moderate major depression (single or recurrent episode, DSM-IV criteria). After a single-blind placebo run-in phase, the patients were randomly assigned, 186 to WS 5570 and 189 to placebo, after which they received double-blind treatment for 6 weeks. Follow-up visits were held after 1, 2, 4, and 6 weeks. The primary outcome measure was the change from baseline in the total score on the 17-item Hamilton Depression Rating Scale. In addition, analyses of responders (patients with at least a 50% reduction in Hamilton total score) and patients with remissions (patients with a total score of 6 or less on the Hamilton scale at treatment end) were carried out, and subscale/subgroup analyses were conducted. The design included an adaptive interim analysis performed after random assignment of 169 patients with options for group size adjustment or early termination.Compared to placebo, WS 5570 produced a significantly greater reduction in total score on the Hamilton depression scale and significantly more patients with treatment response or remission. It was more effective in patients with higher baseline Hamilton scores and led to global reduction of depression-related core symptoms, assessed with the melancholia subscale of the Hamilton scale. The placebo and WS 5570 groups had comparable adverse events.H. perforatum extract WS 5570 was found to be safe and more effective than placebo for the treatment of mild to moderate depression.

The single- and multiple-dose pharmacokinetics of the naphthodianthrones hypericin and pseudohypericin derived from St. John's wort (Hypericum perforatum, LI 160, Lichtwer Pharma GmbH, Berlin) were studied in 12 healthy male subjects. After a single oral dose of 300, 900, or 1800 mg of dried hypericum extract (250, 750, or 1500 micrograms hypericin and 526, 1578, or 3156 micrograms pseudohypericin), plasma levels were measured with a modified highly sensitive high-pressure liquid chromatography (HPLC) method (lower detection limit 0.1 ng/mL) up to 3 days. The median maximal plasma levels were 1.5, 4.1, and 14.2 ng/mL for hypericin and 2.7, 11.7, and 30.6 ng/mL for pseudohypericin, respectively, for the three doses given above (interim evaluation of four volunteers). The median elimination half-life times of hypericin were 24.8 to 26.5 hours, and varied for pseudohypericin from 16.3 to 36.0 hours. Ranging between 2.0 to 2.6 hours, the median lag-time of absorption was remarkably prolonged for hypericin when compared to pseudohypericin (0.3 to 1.1 hours). The areas under the curves (AUC) showed a nonlinear increase with raising dose; this effect was statistically significant for hypericin. During long-term dosing (3 x 300 mg/day), a steady-state was reached after 4 days. Mean maximal plasma level during the steady-state treatment was 8.5 ng/mL for hypericin and 5.8 ng/mL for pseudohypericin, while mean trough levels were 5.3 ng/mL for hypericin and 3.7 ng/mL for pseudohypericin. In spite of their structural similarities there are substantial pharmacokinetic differences between hypericin and pseudohypericin.