2 - Polyphenols: Absorption, bioavailability, and metabolomics

Abstract

Polyphenols, which occur in many vegetable and herbal medicines, are considered as the most active constituents to ameliorate metabolic syndrome in vitro and in vivo. To date, a great number of research works and reviews have addressed the bioefficient effect of phenolic compounds, however, the considerable diversity of their structures and in vivo bioavailability make them effect on different signaling pathways. First, polyphenols will be hydrolyzed by enzymes in intestinal before absorption. The large portion of polyphenolic compounds consist of several hydroxyl groups, which are enzymatic catalyzed by methylation, glucuronidation, or sulfatation. However, only 5%–10% of total polyphenolic compounds may be absorbed in the small intestine. The rest of polyphenols may be accumulated in the large intestinal and excreted in the faeces. During the process of absorption, polyphenols are often conjugated in the small intestine and later in the liver. The current chapter describes the absorption, bioavailability, and metabolomics of polyphenols.