Hypericum perforatum

Hypericum perforatum (St. John's Wort) is not consumed as a food for macronutrient value; it is used as a medicinal herb. Its significance lies entirely in its bioactive phytochemical profile. Key compounds include: • Hypericin (a naphthodianthrone): ~0.05–0.3% of dried herb weight; primary marker compound, photosensitizing agent, implicated in antidepressant and antiviral activity. • Pseudohypericin: typically present at 2–4× the concentration of hypericin (~0.1–0.6% dry weight); similar naphthodianthrone with comparable bioactivity. • Hyperforin (a phloroglucinol derivative): ~2–5% of dried herb in high-quality specimens; considered the principal antidepressant constituent via inhibition of serotonin, dopamine, norepinephrine, GABA, and glutamate reuptake. Highly lipophilic and unstable (degrades with light/oxygen exposure, reducing bioavailability). • Adhyperforin: ~0.2–1.5% dry weight; structural analog of hyperforin with similar but less potent activity. • Flavonoids: including rutin (~1.6%), hyperoside (hyperin, ~0.5–1.0%), isoquercitrin (~0.3%), quercitrin (~0.3%), quercetin (~0.1–0.3%), and amentoflavone (a biflavonoid, trace amounts); contribute antioxidant and potential MAO-inhibiting activity. Total flavonoid content approximately 2–4% dry weight. • Procyanidins (condensed tannins): ~5–12% dry weight; oligomeric proanthocyanidins that may modulate bioavailability of other constituents. • Phenolic acids: including chlorogenic acid (~0.5–1.0%) and caffeic acid (trace). • Essential oil (trace, ~0.1–0.3%): contains α-pinene, β-pinene, myrcene, limonene, and caryophyllene. • Xanthones: ~0.01–0.1% including 1,3,6,7-tetrahydroxyxanthone. • Vitamins and minerals: Not a significant source; negligible amounts of vitamins C and A precursors; trace minerals (calcium, magnesium, iron, zinc) present but not at nutritionally relevant levels given typical dosing (300–900 mg extract/day). • Bioavailability notes: Hypericin has poor aqueous solubility and oral bioavailability estimated at ~14–21%; peak plasma levels reached in 4–6 hours with a long half-life (~24–48 hours). Hyperforin is lipophilic with moderate oral absorption but is highly unstable — standardized extracts often use CO₂ extraction or stabilization with salts (e.g., dicyclohexylammonium hyperforinate) to preserve content. Hyperforin is a potent inducer of CYP3A4, CYP2C9, CYP1A2, and P-glycoprotein via PXR activation, significantly affecting the metabolism and bioavailability of co-administered pharmaceuticals. Procyanidins may reduce absorption of hypericin and hyperforin if taken in crude herb form versus standardized extracts. Standardized extracts are typically normalized to 0.3% hypericin and/or 3–5% hyperforin.