Artemisinin-transferrin conjugate retards growth of breast tumors in the rat.

BACKGROUND Artemisinin is a compound isolated from the wormwood Artemisia annua L. It reacts with iron and forms cytotoxic free radicals. It is selectively more toxic to cancer than normal cells because cancer cells contain significantly more intracellular free iron. Previously, we found that covalently tagging artemisinin to transferrin enhanced the selectivity and toxicity of artemisinin toward cancer cells in vitro. In the present research, artemisinin-transferrin conjugate was tested in a rat breast cancer model. MATERIALS AND METHODS Breast tumors were induced in rats by subcutaneous implantation of rat MTLn3 breast cancer cells. Once tumors were formed, daily intravenous injections of artemisinin-transferrin conjugate were administered. RESULTS The conjugate significantly retarded the growth rate of breast tumors in the rat. No significant side effect was observed in the rats during treatment. CONCLUSION Artemisinin-transferrin conjugate could be developed into a potent therapeutic agent for cancer in humans.