Bioavailability and hypolipidemic effects of peanut skin polyphenols

Peanut skin is a rich source of polyphenols, such as proanthocyanidins. Peanut skin proanthocyanidins mainly consist of a subgroup called procyanidins. Peanut-based procyanidins contain oligomers of both type A and type B procyanidins. Recent studies have shown that peanut skin extracts exert protection against hepatic steatosis induced on rats fed with a high-fat diet. Studies have shown that proanthocyanidins protect against cardiovascular diseases (CVDs). The mechanism of CVD protection and hypolipidemic effect of peanut skin procyanidins has been gradually revealed in recent years. Due to the high molecular weight of procyanidins, they are not readily absorbed through the gut barrier. It is hypothesized that procyanidins exert their effect by inhibiting the absorption of dietary lipid and chylomicron secretion by enterocytes. In this review, we aim to highlight the hypolipidemic effects of peanut skin polyphenols and discuss the various molecular mechanisms, with which the polyphenols may exert the lipid-lowering function observed by weighing the absorption characteristics as well as gene expression mechanism responsible for lipid homeostasis.