Abstract The effect of honeybee venom on the tumor growth and metastasis formation in mice was studied. Bee venom was injected into mice either subcutaneously (s.c.) or intravenously (i.v.) at different doses. The tumor was a transplantable mammary carcinoma (MCA) weakly immunogenic to the syngeneic CBA mouse. The tumor was generated by injecting lOS MCA cells i.v. When the tumor cells were injected s.c, into the footpad immediately after bee venom, the growth of the tumor was suppressed regardless of the dose of the venom. The survival of the mice treated with 0.30 mg of bee venom was prolonged as compared to the controls. The number of lung metastases in the mice treated i.v. with 0.15 or 0.075 mg of bee venom was significantly lower (P < 0.001) than that in nontreated mice. However, both doses of bee venom given s.c. did not reduce the number oflung metastases, indicating that the antitumor effect of the venom could be highly dependent on the route of injection. Key words: murine mammary carcinoma, antitumor and antimetastatic activity, honeybee venom. Kljucne rijeci: karcinom mlijecne zlijezde misa, protutumorsko i protumetastatsko djelovanje, pCelinji otrov
