The experimental and clinical pharmacology of St John's Wort (Hypericum perforatum L.)

Abstract

Hypericum (St John's Wort) is a plant that has been used for centuries as a medicinal herb. Pre-clinical animals studies suggest that hypericum is effective in three major biochemical systems relevant for antidepressant activity, namely the inhibition of the synaptic re-uptake system for serotonin (5-HT), noradrenaline (NA) and dopamine (DA). It is the only antidepressant capable of inhibiting the re-uptake of 5-HT, NA and DA with similar potencies. The potencies for monoamine re-inhibition and chronic changes in receptors are also consistent with changes seen with known antidepressants. Behavioral studies suggest that hypericum is active in pre-clinical animal models of depression with comparable effects to known antidepressants. Supporting the pre-clinical pharmacology and efficacy, many clinical studies have shown that hypericum has superior efficacy compared to placebo and comparable efficacy to standard antidepressants in the treatment of mild-to-moderate depression. The advantage of hypericum over other antidepressants may result from its favorable side-effect profile. Although pre-clinical and short-term clinical studies demonstrate antidepressant activity, the lack of long-term use and efficacy, and the heterogeneity of patients, interventions, extract preparations from previous clinical studies suggests that more careful and controlled studies are needed to determine the long-term efficacy of hypericum in mild-to-moderate depression.

St. John's Wort reduces neuropathic pain through a hypericin-mediated inhibition of the protein kinase C γ and ɛ activity

“…SJW interacts with the monoaminergic system through different mechanisms: the MAO-inhibitory properties of SJW were mainly due to hypericin [17,18] whereas the inhibition of serotonin, dopamine and noradrenaline synaptosomal uptake is related to the presence of hyperforin [19][20][21][22]. It has therefore been suggested that SJW may induce antidepressant activity through a mechanism similar to TCAs [23]. This evidence may suggest that similar to TCAs, SJW can also relieve neuropathic pain.…”

Hyperforin-Containing Extracts of St John's Wort Fail to Alter Gene Transcription in Brain Areas Involved in HPA Axis Control in a Long-Term Treatment Regimen in Rats

“…In fact, the active constituents are not fully known. The pharmacological activity of SJW extracts has recently been reviewed (Butterweck, 2003;Greeson et al, 2001;Nathan, 1999). Reports about the antidepressant activity of SJW extracts and their constituents both in vivo and in vitro have been published (Baureithel et al, 1997;Butterweck et al, 1997Butterweck et al, , 1998Butterweck et al, , 2000Butterweck et al, , 2001aButterweck et al, , b, 2002Calapai et al, 1999;Chatterjee et al, 1996Chatterjee et al, , 1998aDi Matteo et al, 2000;Franklin and Cowen, 2001;Gobbi et al, 1999Gobbi et al, , 2001Müller et al, 1997Müller et al, , 1998Müller et al, , 2001Simmen et al, 1999Simmen et al, , 2001Singer et al, 1999;Wonnemann et al, 2001).…”

St John's wort (Hypericum perforatum L.): a review of its chemistry, pharmacology and clinical properties

“…Several pharmacological activities, including antidepressant, antiviral, and antibacterial effects, have been documented for extracts of St John's wort and\or its constituents (Bombardelli & Morazzoni 1995 ;American Herbal Pharmacopeia 1997 ;Chatterjee 1998a ;Schulz et al 1998 ;Nathan 1999 ;Mills & Bone 2000).…”