Antiproliferative potential and DNA scission inhibitory activity of phenolics from whole millet grains

Phenolic extracts from seven millet varieties (kodo, finger (Ravi), finger (local) proso, foxtail, little and pearl) were evaluated for their total phenolic content (TPC), total flavonoid content (TFC), ferrous ion chelating activity and singlet oxygen scavenging capacity. Furthermore, the potency of millet phenolic extracts in the inhibition of peroxyl and hydroxyl radical induced supercoiled DNA scission, as well as xanthine oxidase and their antiprolifeative activities against HT-29 cells were studied. In addition, lipid peroxidation inhibition of extracts was examined in a liposome system. The TPC and TFC ranged from 146 to 1156 μmol ferulic acid equivalents and 25 to 1203 μmol catechin equivalents per gram crude extract, respectively. All varieties employed in this study exhibited a notable inhibition of lipid peroxidation in liposomes, singlet oxygen quenching and DNA scission inhibition to varying degrees. At the end of day 4 millet extracts inhibited cell proliferation in the range of 28–100%. Thus, the present study demonstrates that millet phenolics may be effective in the prevention of cancer initiation and progression in vitro. Millet grains may therefore serve as a nutraceutical and functional food ingredient in health promotion and disease risk reduction.

► Phenolics in millet grains are effective natural antioxidants.
► Phenolic extracts inhibited cell proliferation and DNA scission.
► Millet phenolics may regulate initiation and progression of carcinogenesis.