Cancer is the main causes of morbidity throughout the world [1][2] . Among the different cancers, breast cancer is the second most important cause of cancer death. Though significant progress has been made in breast cancer treatment, only a few patients benefit from breast cancer by adjuvant chemotherapy and most patients with metastatic cancer are resistant to chemotherapy [3] . In addition, chemotherapy causes acute and chronic toxicities that include sterility, congestive heart failure, osteoporosis and neuropathy [4] . Recently, many new avenues of cancer treatment have opened up but the costs of treatment have sky-rocketed too. Hence, screening of indigenously available plant and animal resources for anticarcinogenic potential is an important branch of anticancer research. Chili peppers are the regularly consumed naturally occurring spices worldwide [5][6] . Capsaicin, (8-methyl-N-vanillyl-6nonenamide, fig. 1a) is the main constituent of chili peppers with therapeutic activity [7] . The chemical formula of capsaicin is C 18 H 27 NO 3 and the molecular weight is 305.4 g/mol [8] . Capsaicin is a hydrophobic, colourless, pungent and volatile crystalline powder. It has a benzene ring and a polar amide group with a long hydrophobic carbon tail. Due to its water insolubility, alcohols and organic solvents are used to dissolve capsaicin.Capsaicin induces apoptosis in several cancer cell lines including liver cancer, prostate cancer, colon cancer, pancreatic cancer, and breast cancer without affecting normal cells [9] . In human breast cancer, epidermal growth factor-2 (HER-2) and human epidermal growth factor receptor are over expressed [10,11] . Capsaicin inhibited breast cancer cell growth in vitro by reducing the protein expression of human epidermal growth factor receptor and epidermal growth factor-2 [12] .