Implication of solvent polarities on browntop millet (Urochloa ramosa) phenolic antioxidants and their ability to protect oxidative DNA damage and inhibit α-amylase and α-glucosidase enzymes.

Phenolics of browntop millet extracted in solvents with varying polarities [water, methanol, acetone (80%),
ethanol (70%)] were comparatively assessed for their phenolic profiles, antioxidant activities, DNA damage
protection and enzyme inhibitory properties. Results indicated that acetone (80%) and ethanol (70%) were most
effective in extracting millet phenolics than other solvents. Gallic, caffeic and ferulic acids were the major
phenolic acids, myricetin and kaempferol were the most abundant flavonoids detected in all the extracts of
browntop millet. Phenolics extracted in 80% acetone and 70% ethanol offered noticeable contributions toward
several antioxidant mechanisms and prevented the oxidative DNA damage than water and methanol extracts. All
the millet extracts exhibited potent inhibition towards α-glucosidase than α-amylase activities. These results
suggest that the solvents and their polarities impacted the extraction and bioactivities of millet phenolics and
provided useful information for the effective utilization of browntop millet as a functional food ingredient to
manage hyperglycemia.