Exploitation of Nontraditional Crop, Yacon, in Breast Cancer Prevention Using Preclinical Rat Model

摘要

Yacon has recently been introduced into farmer's markets and natural food stores in the US, but its preventive activity for breast cancer has rarely been evaluated. Objective are to determine the effect of dietary yacon on 1- methyl-1-nitrosourea (MNU) induced mammary carcinogenesis in rat; to evaluate the circulating factors and their association with the carcinogenesis; and to determine cellular signaling pathways HDAC and downstream targets - AMPK/Akt- mTOR and ghrelin-IGF1 axis. Mammary carcinogenesis was initiated by injection of female rats with 50 mg MNU/kg body weight (i.p.) at 21 days of age. One week later, the rats were fed diets containing yacon powder at 0%, 15%, 30% or 60% (30 rats/group) for 8 weeks, respectively. Results showed that dietary yacon reduced the promotion and progression of MNU-induced mammary carcinogenesis in rat, which is associated with downregulation of IGF-1/HDAC/Akt/mTOR signaling pathway and anti-inflammation, i.e. reduction of plasma IL-6, TNFalpha, and C- reactive protein. Future work will focus on the effect of yacon on obesity and anti-inflammation that are factors indused breast cancer. The study will provide crucial biological information to complement the knowledge of natural functional foods that is relevant to a number of foods rich in non-digestible, fermentable oligosaccharides.