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The use of plants such as Nerium oleander containing cardiac glycosides for medicinal purposes has been reported in ancient texts for more than 1500 years. Nerium oleander plant has been used traditionally as folk remedies for a wide variety of maladies and conditions, including dermatitis, eczema, psoriasis, herpes, sores, abscesses, warts, corns, skin cancer, ringworm, scabies, epilepsy, abortifacients, asthma, malaria dysmenorrheal, emetics, diuretics and heart tonics. Despite their potential to cause side effects, application of plants containing cardiac glycosides for treatment of malignant disease may extend back to Arab physicians in the 8th century. The potential use of cardenolide-like compounds for the treatment of cancer, initially investigated forty years ago, however, was abandoned because of the toxicity of these compounds.It was only recently, that Scandinavian oncologists such as J. Haux have suggested that the apoptosis (cell death) produced by cardiac glycosides such as digitalis in human tumor cells occurred at concentrations that could be without toxicity in humans and, therefore, this |
agent and plant extracts containing related cardiac glycosides (e.g. oleandrin from Nerium oleander) might be useful for treatment of cancer. Within the past ten years there has been a substantial increase in the number of studies reported in peer-reviewed science journals that deal with the effects of cardiac glycosides on the growth of human malignant tumor cells. Our understanding of the spectrum of the pharmacologic activities of cardiac glycosides has increased significantly since the discovery of their effectiveness for treatment of congestive heart failure. It is now recognized that certain cardiac glycosides are involved in complex cell signal transduction mechanisms that may have important consequences in their application to the prevention and/or treatment of malignant diseases. Thus, it is reasonable to bring this history of the use of plant extracts containing cardiac glycosides to the point of clinical tests in patients with cancer.
Clinical Testing
To date, however, there are only two Nerium oleander plant extracts containing cardiac glycosides (oleandrin) that have been developed for treatment of cancer and completed testing for safety in a Phase 1 clinical trial in the United States. These trials continue to provide data for determination of product safety levels.
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