ANIMAL TOXICOLOGY

Mutagenic potential

"St. John's Wort (Hypericum perforatum) contains hypericin and hypericin-like substances as well as flavonoids, of which particularly Quercetin has generated a wide-spread controversial discussion with respect to mutagenic action." Using standardized aqueous ethanolic hypericum extracts the genotoxicity was studied using in-vivo and in-vitro test systems with mamalian cells. h" Both the in-vitro tests as well as the in-vivo tests--fur spot test of the mouse and the chromosome aberration test with the bone marrow cells of the chinese hamster—were negative, giving completely no indication of a mutagenic potential of Hypericum extract. These investigations lend support to the view that results from bacterial short-term tests are of very limited transferability to human." ⁷⁶

"Sheep given different dosages and frequencies of Hypericum perforatum had decreased hemoglobin, red blood cell count, packed cell volumes, total protein ,glucose, cholesterol, triglycerides, and serum alkaline phosphotase activities. Blood urea nitrogen, sodium, potassium, bilrubin (total and direct), and the activities of aspartate aminotransferase, alanine aminotransferase, lactatedehydrogenase and gamma glutamyltransferase increased. Hemato- biochemical assays were useful diagnostic a.d. to determine the severity of this plant''s toxic effects." ⁷⁷

Photosensitivity Disease (see also adverse effects)

"A report about a case of St. John's Wort poisoning in German Blackface sheep is given. After the ingestion of St. John''s Wort (Hypericum perforatum) all slightly pigmented parts of the skin, that were rarely covered with hair, were photosensitized. In summer many sheep suffered from inflammatory skin alterations at the ears, the bridge of the nose and at the surroundings of the eyes." ⁷⁸

• St. John's Wort is contraindicated in cases of genetic predisposition or history of photosensitivity.
• Due to it's photosensitizing effects it is not advised if undertaking ultraviolet or solarium treatments.
• It is contraindicated if currently taking an antidepressant unless otherwise specified by a physician.
• St. John's Wort, as with any herbal or prescription drug, may interact with other medications you are be taking. If taking other medications, please consult your physician.
• No not use if pregnant (no clinical data available - there is some information available suggesting it may have emmenagogue and abortifacient effects) ⁸²
• It has been suggested that foods or substances that interact with MAO or serotonin uptake inhibitors should be avoided. ⁸²
• Hypericin may trigger severe skin reactions in AIDs patients ⁸⁶

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