Structural chemistry to therapeutic functionality: A comprehensive review on proanthocyanidins

Proanthocyanidins (PA) are polyphenolics composed of oligo- or polymers of monomeric flavon-3-ols having health and industrial implications. Vegetables, fruits, stems, bark, leaves, and seeds contain varieties of PA. They are treated as offensive and defensive biomolecules due to their effects on human health. This state-of-art review comprehensively addressed the existing concerns associated with PA including pharmacokinetics, structure-activity relationship, their physiological benefits, formulation, and drug delivery. Also how the variance in their biological groups impart different bioactive potentials like anti-microbial, anti-cancer, anti-inflammatory, antioxidant activities are also discussed. Online academic databases (Web of Science, ScienceDirect, PubMed, GoogleScholar, and CNKI) were searched using search terms "Proanthocyanidins", "Pharmacology" and "formulations'' combinations to include published studies of PA from 1957 to 2022. Current understanding of nutraceutical effects alleviating conditions like ageing, diabetes, alopecia, cardioprotection, obesity, cancer, and novel delivery approaches to deliver them in the human body reported to date are also discussed.