Polyphenolic compounds from propolis modulate immune responses and increase host resistance to tumour cells

Propolis contains a variety of polyphenolic compounds. We investigated the effect of a water-soluble derivative of propolis (WSDP) and polyphenolic compounds, components of propolis, on growth of Ehrlich ascites tumour ( EAT) in mice. Tumour in peritoneal cavity was produced by 2 x 10(6) EAT cells. WSDP and polyphenolic compounds ( caffeic acid-CA, caffeic acid phenethyl ester-CAPE and quercetin-QU) were given to mice perorally (po). It was found that the volume of ascitic fluid induced by EAT cells and total number of cells present in the peritoneal cavity was markedly reduced in EAT-bearing mice treated with test components and the survival time of treated mice was prolonged. Inhibition of EAT growth was due to their effect on the immune system of mice. When innate and acquired immune responses were evaluated, a dose-related increase of cytotoxic T-cell, NK and B cells activity was observed in test components-treated mice. Furthermore, exposure of animals to test components increased functional activity of macrophages to produce factors regulating the function of B-, T-, and NK-cells respectively. In conclusion, these findings imply that the antitumour activity of WSDP and polyphenolic compounds of propolis enhanced host resistance in the EAT tumour model, increasing the activities of macrophages, cytotoxic T cells, B cells and NK cells.