Advances in Breast Cancer Research, 2014, 3, 100-105 Published Online July 2014 in SciRes. http://www.scirp.org/journal/abcr http://dx.doi.org/10.4236/abcr.2014.33015 How to cite this paper: Hajighasemlou, S., et al. (2014) Study of the Effect of Silymarin on Viability of Breast Cancer Cell Lines. Advances in Breast Cancer Research, 3, 100-105.http://dx.doi.org/10.4236/abcr.2014.33015 Study of the Effect of Silymarin on Viability of Breast Cancer Cell Lines Saieh Hajighasemlou 1,2 , Mohammadmorad Farajollahi 2,3* , Mahmoud Alebouyeh 1 , Hossein Rastegar 1 , Mojgan Taghizadeh Manzari 1 , Milad Mirmoghtadaei 4 , Behjat Moayedi 5 , Maryam Ahmadzadeh 6 , Mansure Kazemi 7 , Farzad Parvizpour 8 , Safoora Gharibzadeh 9 1 Iran Foods and Drug Organization, Tehran, Iran 2 Department of Biotechnology, Iran University of Medical Sciences, Tehran, Iran 3 Alborz Food and Drug Laboratory, Fardis, Iran 4 School of Medicine, Tehran University of Medical Sciences, International Campus (TUMS-IC), Tehran, Iran 5 Isfahan University of Medical Sciences, Isfahan, Iran 6 Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran 7 Department of Tissue Engineering, School of Medical Advanced of Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran 8 Department of Applied Cell Sciences, School of Medical Advanced of Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran 9 Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Email: * mahdiy@yahoo.com Received 1 May 2014; revised 1 June 2014; accepted 28 June 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Background: Breast cancer is the most prevalence cancer and results in 14% of cancer-related deaths among women worldwide. The aim of this study is to investigate the anticancer effects of Silymarin on two breast cancer cell lines (BT-474, SK-BR-3). Methods and Material: Two breast cancer cell lines—SK-BR-3 and BT-474—were incubated for 24 hours in standard conditions be- fore adding 100, 200, 400, 800, 1600 µM Silymarin to each well. Alamar blue was then added to the wells after 24, 48 and 72 hours of incubation and cell viability was determined using fluorescence reader to detect the optical density. Results were analyzed using generalized estimating equations (GEE) method in STATA 12.0. Results: we demonstrated the Silybum marianum inhibition of two-cell lines SK-BR-3 and BT-474 growth at different concentrations after 24, 48 and 72 hours. Silymarin increased cell death in both cell lines. Conclusion: Silymarin can be combined with other anti-neoplastic agents to obtain better results. * Corresponding author.