St. John's Wort: Basics
Hyperforin vs. Hypericin
Scientists used to think the active constituent in St. Johnís Wort (SJW) was only due to Hypericin and its inhibitory effects on the monoamine oxidase enzymes. However, recent studies have shown that SJW may owe its main effects on depression through Hyperforin. A brief chemical description of Hypericin and Hyperforin follows for those interested in learning more about how they work.
Hypericin is a fluorescent red pigment classified as a dianthrone - its chemical structure consists of an unusually complex eight-ringed aromatic structure - and is similar chemically to Pseudohypericin.1 It is able to pass through the blood-brain barrier and may inhibit the action of the enzyme dopamine Ŗ-hydroxylase, which is required in converting dopamine to norepinephrine. As a result of this enzyme inhibition, this may lead to increased dopamine levels - thus possibly decreasing norepinephrine and epinephrine.
Although many St. Johnís Wort extracts are still standardized for hypericin, increasing research shows that hypericin may play little or no role in the mood-related effects of St. Johnís Wort. Rather, it seems likely that hyperforin is the primary (but probably not the only) active constituent.
Hyperforin is derived from phloroglucinol which is expanded into a bicyclo-[3,3,1]-nonaendionol, substituted with several lipophilic isoprene chains.2 Based on recent independently published clinical research, Hyperforin is now thought to be the main active factor in St. Johnís Wort that has beneficial effects on anxiety and depression.3 Hyperforin has strong reuptake inhibitor effects on all four of the mood neurochemicals (serotonin, norepinephrine, dopamine and GABA). It is also believed that Hyperforin may be actually responsible for inducing the P450 liver enzymes, which may increase the metabolism of other drugs in the body. As a result of the P450 liver enzymes activation, St. Johnís Wort does have some herbal-drug interactions that need to be monitored by your doctor.