Neural Protective Effects of Millet and Millet Polyphenols on High-Fat Diet-Induced Oxidative Stress in the Brain.

A high fat diet (HFD) is considered to be a risk factor for the development of dementia because it increases oxidative stress in the brain; thus, diets rich in antioxidants, such as polyphenols, may protect against oxidative damage. In this study, we explored the antioxidant activity and neural protective function of millet on high fat diet-induced oxidative stress in rat brains. Our results suggested that the intake of millet could alleviate oxidative stress in the hippocampus and downregulate the expression of the Alzheimer's disease (AD)-related genes amyloid precursor protein (App), tau, and γ-secretase. Furthermore, we extracted millet polyphenols and verified whether they play important roles during this process. The results showed that millet polyphenols significantly prevented H2O2-induced cell death of SH-SY5Y cells and decreased oxidative stress levels in cells. In addition, the expression levels of pro-inflammatory factors and AD-related genes were also downregulated by treatment with millet polyphenols. The above results indicated that millet and millet polyphenols could exert neural protective effects under high fat diet-induced oxidative stress by upregulating the expression of antioxidant enzymes and downregulating the expression of AD-related genes.