Abstract
In Germany since 1980, more than 300 clinical studies have been carried out with standardized phytopharmaceuticals, including Crataegus, Silybum, Ginkgo, Hypericum, Sabal, Urtica, Kava-Kava, Allium sativum, Valeriana, Aesculus, Echinacea, and Viscum drugs. These studies assessed the efficacy of phytopharmaceuticals for the treatment of moderate or moderately severe diseases and prevention. Several comparative clinical trials showed that these phytopharmaceuticals had full therapeutic equivalence with chemotherapeutics and had the simultaneous advantage of being devoid of any adverse effects. The mechanism of action of herbal drugs and their extract preparations, which differ in many respects from that of synthetic drugs or mono substances, can be characterized as a polyvalent action and interpreted as additive or, in some cases, potentiating. Currently, a rationale for the observed reversal effects and optimal effects with very low doses after a long-term application has not been developed, but is under investigation by systematic research at the molecular level.