Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 51 9 2013 09 15 591 598 EN Hussein Rastegar Food and Drug Research Center, Ministry of Health and Medical Education, Tehran, Iran. Hamidreza Ahmadi Ashtiani Department of Biochemistry and Nutrition, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran. AND Department of Clinical Biochemistry, School of Medicine, Tarbiat Modares University and Institue of Medicinal Plants, Tehran, Iran. AND Department of Nutritional Hygiene, Faculty of Veterinary, Tehran University of Medical Sciences, Tehran, Iran. Soghra Anjarani Reference Research Center Lab, Ministry of Health and Medical Education, Tehran, Iran. Saeed Bokaee Faculty of Veterinary Medicine, Tehran University of Medical Sciences, Tehran, Iran. Arash Khaki Women's Reproductive Health Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. Leila Javadi Department of Nutrition Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. 2015 10 11 Breast cancer is the most commonly diagnosed invasive malignancy and first leading cause of cancer-related deaths in Iranian women. Based on silymarin's unique characteristics, its application in chemotherapy combined with doxorubicin can be effective to enhance the efficacy together with a reduced toxicity on normal tissues. The present study focus on evaluate the efficacy of silymarin in combination with doxorubicin, on viability and apoptosis of estrogen-dependent breast carcinoma cell line (MCF-7). After being cultured, MCF-7 cells were divided into 8 groups and treated as follows: 1st group received 75 μg silymarin, groups 2, 3, and 4 were treated with 10, 25, and 50 nM doxorubicin, respectively, and groups 5, 6, and 7 respectively received 10, 25, and 50 nM doxorubicin as well as 75 μg silymarin. Viability percentage and apoptosis of the cells were assessed with Trypan Blue staining after 16, 24, and 48 hours. Silymarin has a synergistic effect on the therapeutic potential of doxorubicin. Use of silymarin in combination with doxorubicin can be more effective on the therapeutic potential of doxorubicin and decreases its dose-limiting side effects. https://acta.tums.ac.ir/index.php/acta/article/view/4369 https://acta.tums.ac.ir/index.php/acta/article/download/4369/4348