Hypericum perforatum                Common name:  St. John’s wort

Family: Hypericaceae

Parts used: Flowering tops

Constituents:

• Volatile oils (pinene & cineole)
• Flavonoids & proanthocyanidins (hyperoside, hyperiforin, quercetin, rutin)
• Naphthodianthrones (hypericin, pseudohypericin, isohypericin, protohypericin)
• Carotenoids
• Phloroglucins (hyperforin)
• Tannins

Medicinal actions:

• Anti-depressant
• Anti-inflammatory
• Antimicrobial
• Astringent
• Nervine tonic
• Vulnerary

Medicinal uses:  

• Most useful in mild to moderate depression, seasonal affective disorder, anxiety and various somatoform disorders (neuralgia & myalgias).
• Is antiviral both internally and topically.
• Vulnerary actions make it a wonderful choice for topical wound healing (eg. burns).

Pharmacology: 

• Naphthodianthrones hypericin & pseudohypericin have received most of the attention in pharmacological studies based on their contributions to the antiviral properties of the plant as well as speculation (based on early in vitro data) that they may also contribute to the plant’s antidepressant actions. Recent research, however, indicates that other constituents such as hyperforin and flavonoid compounds, may also contribute to the antidepressant actions.
• Various proposed mechanisms exist for antidepressant effects, involving several neurotransmitters and hormones, specifically inhibition of monoamine oxidase (MAO) due to hypericin.
• Hyperforin can inhibit synaptosomal reuptake of serotonin, norepinephrine, and dopamine and has also been shown to have antimicrobial activity against gram-positive bacteria and numerous viruses.
• Hypericin is a powerful photosensitizer and has anti-tumor actions. Once taken up by tumor cells, hypericin reacts in the presence of oxygen and activates multiple apoptosis pathways that results in malignant cell death

Pharmacy:

• Infusion:  2-4 g / cup QD to TID
• Tincture (1:5, 40%), 1-4 ml TID
• Standardized extract:  500 to 1000 mg divided daily of extract standardized to 0.3% hypericin for mild-moderate depression.
• Note: May take 2-4 weeks to notice clinical results.

Toxicity:   

• Photosensitivity can occur in susceptible individuals. Fair-skinned individuals should take precautions when exposed to the sun, and It is advisable that the elderly use protective eyewear when exposed also.
• Reported side effects include gastrointestinal irritations, allergic skin reactions, tiredness and restlessness.

Contraindications:

• Speeds up the elimination of many drugs through phase liver detoxification and can interfere with MAOIs, SSRIs, narcotics & reserpine.

Interactions:

• Concomitant use with selective serotonin reuptake inhibitors (SSRIs) may result in serotonin syndrome.
• May reduce serum levels of indinavir, cyclosporine, theophylline, digoxin, warfarin, and oral birth control pills due to induction of the cytochrome P450 isoenzyme CYP3A4.
• Affects the hepatic metabolism of the cholesterol-lowering drugs simvastatin and pravastatin, omeprazole (a proton pump inhibitor), irinotecan, tacrolimus, verapamil, methadone, theophylline and oral contraceptives.