Curcumin, Oxidative Stress, and Breast Cancer

Breast cancer is the most frequent malignancy diagnosed in women in the western world. Oxidative stress is one of the important pathogenic factors of cancer development. Among the antioxidants, curcumin (1, 7-bis (4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione; diferuloylmethane) is a dietary natural yellow pigment derived from the rhizome of the herb Curcuma longa (Zingiberaceae). This chapter evaluates the oxidative effect of curcumin in an established in vitro experimental breast cancer model (Alpha model) as well as in isolated cells derived from breast specimens. Such a model was developed with the immortalized breast cell line, MCF-10F, which was exposed to low doses of high linear energy transfer (LET) α particles (150 keV/μm) of radiation, values comparable to α particles emitted by radon progeny, and cultured in presence of 17β-estradiol. It consisted of cell lines in different stages of transformation: (1) MCF-10F; (2) an estrogen-treated, named Estrogen; (3) a malignant one, named Alpha3; (4) a malignant and tumorigenic one, named Alpha5; and (5) a tumor cell line, named Tumor2, derived from a tumor after injection of previous one in nude mice. Free radical production is ubiquitous in all organisms and it is enhanced in many diseases. Curcumin interferes with multiple genes that promote carcinogenesis, therefore affecting genomic instability. Alteration of protein expressions involved in key signaling pathways render this model an important tool for monitoring effects of natural dietary compounds in breast carcinogenesis.