Immunomodulation with Viscum album and Echinacea purpurea extracts.

Extracts of Viscum album (Plenosol) and Echinacea purpurea (Echinacin) are used clinically for their non-specific action on cell-mediated immunity. In vitro we could prove that these two extracts have a stimulating effect on the production of lymphokines by lymphocytes and in the transformation test. A toxic effect on cells was produced only with very high, clinically irrelevant concentrations. Clinical application of these extracts can produce a stimulation of cell-mediated immunity (one therapeutic administration followed by a free interval of one week) or can have a depressive action (daily administrations of higher doses). These observations were confirmed by lymphokine production and assay, 3H-thymidine incorporation and a skin test with recall antigens (Multitest Merieux).