Application of standardized mistletoe extracts augment immune response anddown regulates metastatic organ colonization in murine models

The immunomodulatory and antimetastatic activity of standardized aqueous mi stletoe extracts from plants grown on fir trees (ME-A) and pine trees (ME-P ) were evaluated in BALB/c-mice. Regular subcutaneous (s.c.) and intraperit oneal (i.p.) applications (three times per week for 14 consecutive days; 5 and 50 mug per injection and mouse) upregulated thymus weight and periphera l blood leukocyte counts in tumor bearing mice. To check the influence of M E-A and ME-P treatment on growth of experimental metastases, RAW 117 H 10 l ymphosarcoma cells and L-1 sarcoma cells were intravenously inoculated into BALB/c-mice to establish liver and lung colonization. ME-A and ME-P were r egularly administered starting 24 h after tumor cell challenge. Organ colon ization was investigated on day 14 after tumor cell inoculation and demonst rated statistically significant (P < 0.05) reductions of experimental liver and lung metastases for ME-A and ME-P treated mice. (C) 2001 Elsevier Scie nce Ireland Ltd. All rights reserved.