Polyphenols from whole millet grain (Setaria italica) alleviate glucose and lipid homeostasis in diet‐induced obese mice by increasing endogenous GLP‐1

Abstract BACKGROUND Foxtail millet ( Setaria italica ) is a whole millet grain that has been considered for improving the disorder of glucose and lipid metabolism. The purpose of the work is to explore the extraction and enrichment of polyphenols from foxtail millets which can regulate the disorder of glucose and lipid metabolism by increasing endogenous GLP‐1 (glucagon‐like peptide‐1). RESULTS The optimum ultrasound‐assisted extraction (UAE) of foxtail millet polyphenols (FMPs) was as follows: 70 °C and 400 W and 70% ethanol concentration, further purification using macroporous resin. In vitro , the FMP eluent of 60% ethanol (FMP‐60) has the best effect in promoting GLP‐1 secretion from L cells among the different active components of FMP. Millet polyphenols (MPs) were obtained from finishing foxtail millet with the bran removed by the same extraction and purification method. Compared with MP‐60, FMP‐60 mainly included eight active phenolic constituents and contained more ferulic acid, p ‐coumaric acid, 2‐hydroxycinnamic acid, and coniferaldehyde. After gavage treatment of diet‐induced obese (DIO) mice with FMP‐60, FMP‐60 promoted endogenous GLP‐1 secretion in mice and ameliorated disorders of glucolipid metabolism in DIO mice. CONCLUSION FMP‐60 could improve glucose homeostasis and ameliorates metabolic disease by promoting the endogenous GLP‐1 level and preventing weight gain in DIO mice. © 2023 Society of Chemical Industry.