For the first time the authors have extracted an endophytic fungus from the stems of St. John’s Wort herb (Hypericum perforatum) which produces hypericin. The fungus produces emodin, also. The authors believe emodin is a precursor to hypericin, as is protohypericin. St. John’s Wort, which is of limited supply, is the only known source of hypericin. Harvesting for hypericin requires destroying the perennial St. John’s Wort plants.
St. John’s Wort was used against depression by the ancient Greeks. It is classified pharmaceutically as a monoamine oxidase (MAO) inhibitor. Other effects include general healing, antiviral, anti-inflammatory, antimicrobial and antioxidant activity. St. John’s Wort works against sinusitis and seasonal affective disorder (SAD.) St. John’s Wort is native to Europe, Asia, North Africa, North America and Australia.
The wild St. John’s Wort plants studied were collected in India. Stem fragments were collected and incubated for fungus. DNA was isolated from the fungus grown and the fungal DNA was determined. Further studies are being done to identify the fungus.
St. John’s Wort is not the only herb found in association with an endophytic fungus that produces the active chemical. Another herbal chemical, Taxol (an anticancer drug,) has been reported to be produced by an endophytic fungus. The mechanism of the development of this relationship between plant and fungus is not clear at this time. There is a question of whether horizontal transfer of genes can occur from a plant to a fungus.
CONCLUSION: A fungus extracted from St. John’s Wort produces hypericin and emodin, precursors of hypericin. Perhaps the fungus could be used on a large scale as a cost-effective way of producing hypericin. St John’s Wort is of limited supply and the plants must be destroyed to obtain the hypericin at this time.
NOTE: Endophytic fungi are parasitic plants living in the bodies of other plants. MAO inhibitors are medications used for depression (anti-depressants.)
PMID: 18220354.
Summary #292.
