Hamid Cheshomi - Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
Hamid Cheshomi - Cellular and Molecular Research Center, Faculty of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
Mohammad Hosseinzadeh Hesari - Paramedicine College, Sabzevar University of Medical Sciences, Sabzevar, Iran

Introduction & Aim: Natural phenolic compounds play key roles in cancer prevention and chemotherapy. several bioactivities of phenolic compounds are responsible for their anticancer properties (e.g., anticarcinogenic, antioxidant or antimutagenic and anti-inflammatory effects) and also contribute to their inducing apoptosis by arresting cell cycle, regulating carcinogen metabolism and ontogenesis expression, inhibiting DNA binding and cell adhesion, migration, proliferation or differentiation, and blocking signaling pathways. Gallic acid (3,4,5-trihydroxybenzoic acid), caffeic acid (3,4-dihydroxycinnamic acid) and thymol (5-methyl-2-isopropylphenol) are three famous natural phenolic compounds. Methods: In this study, to determine half maximal inhibitory concentration (IC50), we treated MCF-7 cells different concentrations of gallic acid (GA), caffeic acid (CA) and thymol by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Furthermore, subsequent to treatment with these compounds, morphological changes in MCF-7 breast cancer cells were examined. Results: Evaluation of cell survival by MTT assay revealed that the IC50 values of CA, GA and thymol on MCF-7 cells were 159μg/ml, 18μg/ml and 62μg/ml, respectively. However, we also found that these compounds have effects on induction of morphological changes in MCF-7 cells. Conclusion: Gallic acid, caffeic acid and thymol as the three important natural phenolic compounds can induce the cytotoxic effects in breast cancer cells. However, it seems like that these compounds can induce apoptosis process in MCF-7, and hence they can be considered as anticancer agents in the future.