St. John's Wort (Hypericum perforatum L.) Old and New

St. John's wort (Hypericum perforatum L) is a species that is widespread in Europe and belongs to the family of St. John's wort (Hypericaceae). There are around 450 species of Hypericum worldwide, with shrubs and trees occurring alongside herbaceous plants. In addition to H. perforatum, the species H. scabrum L and H. sampsonii Hance are used in Asia, the latter being a component of traditional Chinese medicine (TCM). H. perforatum has been monographed in European pharmacopoeias for many years and can be described as a typical flavonoid drug. In addition to numerous flavonoids, there are also many other substances that can be assigned to the naphthodianthrones such as hypericin, hyperforins, xanthones and essential oil substances. For this reason, medicinal plant breeding in recent decades has been based on the guidelines of the pharmacopoeia. In recent times, however, scientific evidence has increased that H. perforatum extracts can indeed be used to treat dementia, especially Alzheimer's disease. It seems that hyperforin and hypericin are not the only substances that determine the value. If H. perfora Cum were to prevail in the treatment of dementia and Alzheimer's disease, significant breeding efforts would be necessary to enrich the components that are effective in treating dementia. Finally, it must be mentioned that the Hypericum species listed above are used to treat a variety of other diseases, such as digestive problems and skin diseases.