Effects of mistletoe extract on markers of platelet activation and aggregation

Abstract

BACKGROUND: Viscum album preparations are extensively used as complementary therapy in cancer and are shown to exert antitumor activities which involve the cytotoxic properties, induction of apoptosis, inhibition of angiogenesis and several other immunomodulatory mechanisms. AIM: The aim of this study was to investigate the eft fects of mistletoe extract on platelet as well as monocyte functions, as an important factors in immunomodulation of cancers metas tatic potencial and angiogenesis in tumors. METHODS: The effect of different concentrations of mistletoe extract on agonist-induced platelet activation markers and their aggregation with leukocytes was examined in the blood of healthy subjects ( n = 6 ) using flow cytometry. Effects on LPS -induced activation markers was det ermined in the blood of healthy subj ects as well as on THP- 1 cell line using an ELISA essays and flow cytometry. RESULTS: Mistletoe extract significantly inhibited agonist induced P selectin expression and platelet-monocytes aggregation. Additionally, mistletoe extract exerts anti-tumor effect through the stimulation of TNF-a production in LPS induced monocytes activation. CONCLUSION: Obtained data demonstrate that mistletoe extract was effective in modulating platelet and monocyte functions, as a part of pleiotropic anticancer effect.

UVOD: Preparati biljke Viscum album se intenzivno koriste kao komplementarna terapija u lecenju kancera. Mehanizmi antitumorskog delovanja, potvrđeni in vitro, ukljucuju citotoksicno delovanje, indukciju apoptoze, inhibiciju angiogeneze, imunomodulatorno delovanje. CILJ: Cilj ovog istraživanja je ispitivanje uticaja ekstrakta bele imele na funkciju trombocita i monocita kao važnih faktora u imunomodulaciji kancerskog procesa, metastatskom potencijalu i tumorskoj angiogenezi. METODE: Uticaj razlicitih koncentracija ekstrakta bele imele na markere agonistom indukovane aktivacije trombocita i njihove agregacije sa leukocitima ispitivan je u krvi zdravih ispitanika (n=6) primenom protocne citometrije. Uticaj na markere LPS indukovane aktivacije određivan je u krvi ispitanika i kulturi THP-1 celija korišceenjem ELISA eseja i protocne citometrije. REZULTATI: Ekstrakt imele znacajno inhibira ekspresiju P-selektina i trombocitno-monocitnu agregaciju. Pokazana stimulacija produkcije TNF-a u LPS-om aktiviranim monocitima dodatno doprinosi antitumorskom potencijalu. ZAKLJUČAK: Dobijeni rezultati potvrđuju potenci jal ekstrakta imele da modulira trombocitnu i monocitnu funkciju, kao deo pleotropnog antitumorskog delovanja.