Enhanced antitumor activity of irinotecan combined with propolis and its polyphenolic compounds on Ehrlich ascites tumor in mice

The effects of the anticancer drug irinotecan combined with ethanolic extract of propolis (EEP), a water-soluble derivate of propolis (WSDP), quercetin and naringin on the growth of Ehrlich ascites tumor (EAT) and the life span of tumor-bearing Swiss albino mice were studied. Test components were given to mice intraperitoneally (i.p.) at doses of 100 mg kg−1 for three consecutive days before the i.p. injection of EAT cells (1 × 106). Irinotecan was administered i.p. at dose of 50 mg kg−1 on days 1, 13, and 19 after tumor cell inoculation. The results clearly demonstrate the synergistic action of irinotecan and EEP on survival time. These results suggest that clinical trials using a propolis preparation EEP combined with irinotecan may be beneficial in maximizing antitumor activity and minimizing post-chemotherapeutic reactions to the cytostatic drug.