Phytoferritin and its implications for human health and nutrition

Background: Plant and animal ferritins stem from a common ancestor, but plant ferritins exhibit various features that are different from those of animal ferritins. Phytoferritin is observed in plastids (e.g., chloroplasts in leaves, amyloplasts in tubers and seeds), whereas animal ferritin is largely found in the cytoplasm. The main difference in structure between plant and animal ferritins is the two specific domains (TP and EP) at the N-terminal sequence of phytoferritin, which endow phytoferritin with specific iron chemistry. As a member of the nonheme iron group of dietary iron sources, phytoferritin consists of 24 subunits that assemble into a spherical shell storing up to similar to 2000 Fe3+ in the form of an iron oxyhydroxide-phosphate mineral. This feature is distinct from small molecule nonheme iron existing in cereals, which has poor bioavailability. Scope of review: This review focuses on the relationship between structure and function of phytoferritin and the recent progress in the use of phytoferritin as iron supplement. Major conclusions: Phytoferritin, especially from legume seeds, represents a novel alternative dietary iron source. General significance: An understanding of the chemistry and biology of phytoferritin, its interaction with iron, and its stability against gastric digestion is beneficial to design diets that will be used for treatment of global iron deficiency. (C) 2010 Elsevier B.V. All rights reserved.