Mistletoe extracts Iscador ArzneimForschDrugRes

This issue of Arzneimittel-Forschung/Drug Research contains peer-reviewed articles, the results of which have been presented at the “International Conference on the Mode of Action of Iscador − Facing the Challenge”, June 21 − 22, 2005, Dornach, Switzerland. The modern scientific propositions, which still seem to be valid today, go back to Galileo, Bacon, Descartes and others [1]. The validity of knowledge depended on its implementation in both material and technique. The continuous successes in medicine have obviously proved that this interpretation is valid. Moreover, the new paradigm of molecular medicine in the 21st century appears to reinforce the mechanistic view of genetic and molecular pathogenesis of diseases. Complementary to molecular medicine, is another type of medicine that emphasises an understanding of the human being in health and disease as the sum of all somatic, emotional, and social attributes [2]. In the past, these two different approaches have been vigorously competing with one another, with the treatment strategies being molded by the predominant theoretical framework. Despite decades of basic and clinical research on promising new therapies, solid tumors, especially in adults, remain a major cause of morbidity and mortality. The modest clinical successes hide the extent to which advances have been made in understanding the biology of cancer. There is a tremendous gap between the exciting outcome of solid experimental cancer research and clinical benefits for patients. Treatment results in clinical oncology have stagnated and predictions of a therapeutic breakthrough have only materialized for a few tumor entities. The three aims of treatment of patients with cancer (i) clinical cure, (ii) improvement of quality of life, and (iii) prolongation of survival are still proving to be elusive. Whilst it is difficult to predict which element of research will have a positive clinical impact in the 21st century, it would be reasonable to expect further success if, and only if, current state-of-the-art treatment is combined with new approaches without any ideological censorship. Effective protocols of chemotherapy and/or radiation should not be excluded from being questioned only because certain closed shops in the scientific community might have emotional or conceptual reservations. From an ethical point of view, any form of reasonable therapy − old and/or new ones − should be rigorously explored, provided a well-founded theory is put forward. The series of peer-reviewed articles presented in this special edition of Arzneimittel-Forschung/Drug Research represents the most updated collection of translational mistletoe research. This body of work should be seen as an experimental database for critical review and further discussion within the scientific community on the clinical value, risk-benefit and social and economic benefit of mistletoe therapy in cancer patients. The selection of the invited papers followed a wellfounded scientific criticism expressed by a respected oncologist, M. Hallek, Department of Internal Medicine I of the University of Cologne, Germany, in an Editorial in Onkologie [3] which accompanied an article published in the same journal [4]: “Finally, no effort was undertaken to study the actions of Iscador on cell proliferation, apoptosis or other functional parameters” [3]. This collection of papers is the scientific door-opener in the above mentioned sense, or to put it in Hallek’s own words: “... more systematic functional analyses are warranted in the future to learn more about the potential stimulation of malignant cell proliferation by V. album extracts” [3]. The scene is set in a presentation by K. Urech, G. Schaller, C. Jäggy, Verein für Krebsforschung, Hiscia, Arlesheim, Switzerland, on the most investigated pharmacologically active mistletoe compounds, viscotoxins and mistletoe lectins in European mistletoe Viscum album L. and in the pharmaceutical mistletoe preparations Iscador. Urech et al. critically discuss the two crucial factors of plant extracts, (i) the origin of the plant and (ii) the production process for medical use. Despite well differentiated chemical and biochemical analyses they conclude that, Iscador can not be reduced to one or a few active components. This conclusion indicates that there are major pitfalls with a reductionist approach that aims to pin down safety and efficacy on single molecular substances. The paper by G. Kelter and H.-H.Fiebig, Onkotest GmbH, Freiburg, Germany, clearly shows that tumor growth in 26 well established cells could not be stimulated by the mistletoe extract Iscador M special, P and Qu when incubated with different concentrations. Therefore, the debate on possible in vitro tumor growth stimulation with Iscador preparations can finally be closed and the publication by Gabius et al. [5] should be considered obsolete.