Hypericum perforatum is a perennial shrub with numerous bright yellow flowers, known to the Greeks from at least the time of Dioskorides, and of widespread occurrence. It has been extensively used through the centuries for a wide variety of ailments, including burns and wounds, depression, kidney problems, nervous disorders, neuralgia, for its anti-bacterial and anti-inflammatory action, and during the Middle Ages to ward off witchcraft and evil spirits. Its main active constituents are dianthrone derivatives like hypericin and pseudohypericin; flavonoids and tannins like hyperoside, quercetin, rutin, catechin; xanthrones, monoterpenes and sesquiterpenes, and phytosterols like beta-sitosterol and others.
- Anti-depressant. The xanthrones and hypericin of the herb have been shown to inhibit monoamine oxidase (MAO) enzymes types A and B, which are known to degrade mood-elevating neurotransmitters like serotonin and norepinephrine in the brain. MAO inhibitor application is the standard treatment for depression. And the application of hypericin in a clinical trial showed improvement of symptoms like anxiety, apathy, depression, insomnia and feelings of worthlessness. Recent work suggests the herb also exerts an inhibiting effect on serotonin re-uptake, that is to say, the loss of serotonin from the synapses of the brain, resulting in a very gradual rise in brain serotonin levels.
- Anti-microbial. Hypericin and pseudohypericin, two of the principal compounds, are known to show powerful anti-viral activity against herpes simplex 1 and 2, influenza types A and B, mononucleosis, vesicular stomatitis virus and the Epstein-Barr virus. These two compounds appear to also possess anti-retroviral properties as recently demonstrated against two animal retroviruses, Friend leukemia virus and radiation leukemia virus, both in vitro and in vivo. The herb also has a broad-spectrum anti-bacterial activity against both gram-positive and gram-negative bacteria, such as Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Staphyloccocus aureus, and Streptococcus mutans. The mechanism of action is thought to be the production of oxygen free-radicals that can damage the envelope of viruses. In fact, non-enveloped viruses such as polio and adenovirus are unaffected by hypericin.
- Sedative and relaxant. Given the effects of the herb on anxiety and insomnia, it is not surprising to find that St John’s wort is also an effective sedative and relaxant, especially capable of easing states of nervous tension and improving sleep patterns. It is remarkable that the herb’s activity with depressed patients, provided relief from both insomnia but also oversleeping, an adaptogen par excellence.
- Wound healing. The flavonoids and probably other compounds of the herb, have also wound healing and anti-inflammatory activity, used in case of burns, deep cuts, while internally the herb has been used against ulcers and gastritis.
Caution. Hypericin is a photosensitive compound, and when on the herb care should be taken to avoid overexposure to sunlight, tanning lights or ultra-violet sources. Avoid the herb’s use with MAO inhibitors and selective serotonin re-uptake inhibitor drugs (SSRIs) or consult with experienced health care professional.