St. John’s wort (Hypericum perforatum L.): Challenges and strategies for production of chemically-consistent plants

Plants are by far the most important source of natural therapeutics, and the role of plants in enhancing the longevity and the quality of life is increasingly accepted throughout the world. A series of problems with medicinal plant products, such as contamination with biological and environmental pollutants, quantitative and qualitative variations of bioactive compounds, adulteration with misidentified species, and the concern of unsustainable harvest, has prompted the introduction of regulations to ensure the quality and safety of medicinal plant products in Canada. In the future, Natural Health Products in Canada will be manufactured to a new standard of quality and these changes in the industry have necessitated new approaches to the breeding, production, and processing of medicinal plant tissues. The continuing growth in the medicinal plant marketplace has also brought about the challenge of maintaining a balance between consumer demand and the need to protect medicinal biodiversity. St. John’s wort (Hypericum perforatum L.) is one of the most popular medicinal plants with a history of use spanning more than two millennia and modern studies demonstrating efficacy. However, inconsistencies in the results of various clinical trials and difficulties in identifying a specific medicinal molecule with defined pharmaceutical function prompted our efforts to improve St. John’s wort products. Development of elite varieties with predictable phytochemical profiles, mass clonal propagation in vitro, large-scale production in sterile environments and controlled environment production systems, have been combined to produce a new standard in the production of St. John’s wort. Key words: St. John's wort, chemical consistency, hyperforin, melatonin, controlled environment systems