Chapter 16 – Dietary Proanthocyanidin Modulation of Pancreatic β Cells: Molecular Aspects

Proanthocyanidins have been defined as hypoglycemic agents, and in this chapter we analyze this effect by reviewing the various animal models used for these studies and the molecular interactions described, and focusing on their modulation of pancreatic β cell. Proanthocyanidin treatments in fructose and high-fat diet-induced insulin resistant models improve glycemia and insulin sensitivity. More controversial results were found in genetically obese or cafeteria diet–induced insulin-resistant models. Human studies, although limited, further support the hypoglycemic effect of proanthocyanidins. These effects could be explained by a peripheral action on insulin-sensitive tissues, stimulating glucose uptake, limiting lipogenesis, and improving their oxidative/inflammatory state. At the insulin-producing tissue, the pancreas, proanthocyanidins modulate insulin secretion and production and β-cell mass, although the available results are divergent. The proanthocyanidins' impact on β cells could be also due to their interaction with the incretin system, which has been shown to be a target for proanthocyanidins.