title: Nitric oxide involvement in the anti-tumor effect of mistletoe (Viscum album L.) extracts Iscador on human macrophages.
abstract: 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.
authors.affiliation: Laboratoires d'Immunologie et Parasitologie, UFR Pharmacie, Université Victor Segalen Bordeaux II, Bordeaux, France.
authors.forename: M Djavad
authors.initials: MD
authors.lastname: Mossalayi
authors.forename: Abir
authors.initials: A
authors.lastname: Alkharrat
authors.forename: Denis
authors.initials: D
authors.lastname: Malvy
mesh_terms: 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
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D016207:Cytokines; D007155:Immunologic Factors; D010936:Plant Extracts; D010940:Plant Proteins; D009569:Nitric Oxide; C077177:viscum album peptide