Background: The aim of this study was to investigate the effect of methanolic extract of Achillea millefolium L. (MEA) on the antiproliferative activity of bleomycin on human prostate cancer and normal skin cells.

Materials and Methods: Human prostate cancer cell (DU-145) and human non-malignant fibroblast cell (HFFF2) were treated with MEA at various concentrations ( 20, 100, 500, 1000 and 2000 µg/ml), bleomycin alone and with their combinations. Further their MEA and bleomycin effects on cell viability were evaluated. Free radical scavenging property was determined for this herbal extract.

Results: The combination of Achillea millefolium with bleomycin increased significantly inhibition of cell growth in cancer cell. MEA enhanced significantly cytotoxicity induced by bleomycin with 60% and 49% in survival rate at doses 1000 and 2000 µg/ml, respectively, while it was 85% in bleomycin-treated cells. MEA did not exhibit any cytotoxicity on HFFF2 cells.

Conclusion: Study suggests that Achillea millefolium enhanced the cell toxicity induced by bleomycin in the prostate cancer cell without any significant toxicity on normal cell.