Sweet Potato Peels and Cancer Prevention.

A bioassay-guided fractionation of an alcoholic extract from the peels of Ipomoea batatas Lam has been carried out. Sulforhodamine B and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays were used to evaluate the anticancer and antioxidant potential, respectively, while silica gel column chromatography (CC) was used to isolate compounds that were characterized using 1D- and 2D-NMR (Nuclear Magnetic Resonance) and mass spectrometry. The alcoholic extract was fractionated into n-hexane, ethyl acetate, n-butanol, and water. The n-hexane fraction which showed the most promising anticancer activity was further fractionated via silica gel CC into IB-F002A, IB-F002B, and IB-F002C. Of these, IB-F002C was the most active with IC50 values 24.75, 47.91, 52.37, 34.17, 46.07, and 25.89 μg/ml against breast, colon-1, colon-2, ovary, lung, and head/neck cancer cell lines, respectively. The bioassay-guided isolation from IB-F002C afforded a glucocerebroside, which showed 10.51%, 12.19%, 16.14%, and 34.05% inhibition of head and neck, breast-1, colon-1, and ovarian cancer cell lines, respectively. Octadecyl coumarate, 7-hydroxycoumarin, and 6-methoxy-7-hydroxycoumarin that showed different antioxidant potentials were also identified in this study. Sweet potato peel, which is usually discarded as waste, contains constituents that can serve as dietary components to prevent the development of different types of cancer.