Nitric oxide involvement in the anti-tumor effect of mistletoe (Viscum album L.) extracts Iscador on human macrophages.
Lectins from different types of mistletoe (Viscum album, VA) have cytotoxic and immunomodulatory properties that may be relevant in the inhibition of tumor growth. The mechanism of this anti-tumoral activity remains unknown, although recent investigations point out the induction of anti-tumoral cytotoxic T cell activation. In this study therapeutically available mistletoe extracts (Iscador) prepared from Quercus (VA-Q), apple (Malus, VA-M) or pine (Pinus, VA-P) were used to investigate their capacity to induce tumor regression through the modulation of another T helper-1 (Th-1)-mediated anti-tumoral activity: the activation of macrophages. Macrophages are essential targets for both pro- or anti-inflammatory drugs and constitute an essential member of the anti-tumoral immune response. Freshly isolated human monocyte-derived macrophages are activated and various VA extracts are directly incorporated to cultures to assay their properties on the inflammatory and/or tumor cytotoxic responses. The data indicate that immunomodulatory activities of VA extracts differ according to their origin. VA-M and VA-P were able to increase anti-tumoral activity of activated human macrophages, with a possible role for nitric oxide in this effect.
Mossalayi
M Djavad
MD
Laboratoires d'Immunologie et Parasitologie, UFR Pharmacie, Université Victor Segalen Bordeaux II, Bordeaux, France.
Alkharrat
Abir
A
Malvy
Denis
D
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D006801:Humans; D007155:Immunologic Factors; D007249:Inflammation / Q000503:physiopathology; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects*; D009569:Nitric Oxide / Q000502:physiology*; D010936:Plant Extracts / Q000494:pharmacology*; D010940:Plant Proteins / Q000494:pharmacology*; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects; D018417:Th1 Cells / Q000187:drug effects
D000972:Antineoplastic Agents, Phytogenic; D016207:Cytokines; D007155:Immunologic Factors; D010936:Plant Extracts; D010940:Plant Proteins; D009569:Nitric Oxide; C077177:viscum album peptide