Viscotoxins Small proteins that exhibit cell-killing activity and possible immune system stimulating activity. A large group of nitrogen-containing chemicals produced by plants. Limited experimental evidence indicates that mistletoe alkaloids may also have anticancer activity. In view of mistletoe's ability to stimulate the immune system, it has been classified as a type of biological response modifier. Biological response modifiers constitute a complex group of biologic substances that have been used individually, or in combination with other agents, to treat cancer or to lessen the adverse effects of anticancer drugs.
Higher doses have a sedative effect.
For example, Iscador is an aqueous extract of Viscum album L. that is available in both fermented and unfermented forms. In addition, Iscador products can be subdivided according to the species of host tree. IscadorM is obtained from apple trees, IscadorP comes from pine trees, IscadorQ comes from oak trees, and IscadorU comes from elm trees. Helixor is an unfermented aqueous extract of Viscum album L., with HelixorA from spruce trees, HelixorM from apple trees, and HelixorP from pine trees. Helixor is reported to be standardized by its biologic effect on human leukemia cells grown in the laboratory.