Epigenetic and disease targets by polyphenols.

An epigenetic change is defined as an alteration in gene expression that does not involve a change in the DNA sequence. Epigenetic modifications, including DNA methylation, histone modification (acetylation, methylation and phosphorylation) and miRNA, are critical for regulating developmental events. However, aberrant epigenetic mechanisms may lead to pathological consequences such as cardiovascular disease (CAD), neurodegenerative disease, obesity, metabolic disorder, bone and skeletal diseases and various cancers. Given that epigenetic modifications are heritable and reversible, in contrast to genetic changes, they have been identified as promising targets for disease prevention strategies. Over the past few decades, polyphenols, which are widely present in foods such as fruits and vegetables, have been shown to exhibit a broad spectrum of biological activities for human health. Polyphenols reverse adverse epigenetic regulation by altering DNA methylation and histone modification, and they modulate microRNA expression or directly interact with enzymes that result in the reactivation of silenced tumor suppressor genes or the inactivation of oncogenes. Therefore, dietary polyphenol- targeted epigenetics becomes an attractive approach for disease prevention and intervention. In this review, we summarize the current knowledge and underlying mechanisms of the most common dietary polyphenols and their influence on major epigenetic mechanisms associated with disease intervention.