Abstract
Flavonoids are a category of natural compounds characterized by diverse phenolic structures, present in a wide range of sources including fruits, vegetables, grains, bark, roots, stems, flowers, tea, and wine. Flavonoids are directly related to human dietary ingredients and health; structure and function relationships need to be evaluated. This large group of phenolic plant constituents can be divided into several classes: flavanols, flavanones, flavanols, isoflavones, flavones, chalcones, and anthocyanins. Flavonoids interacts with great number of cellular targets such as anti-cancer, anti-oxidant, anti-viral, anti-inflammatory, cardiovascular properties. Flavonoids are regarded as essential elements in numerous applications across nutraceutical, pharmaceutical, medicinal, and cosmetic fields. Besides their large potential of applicability in the industry, flavonoids still face some issues and challenges being necessary to develop strategies to improve their bioavailability and stability. Thus, to overcome these challenges, several cutaneous delivery systems have been extensively studied. Incorporating flavonoids with good encapsulation capacity and low toxicity into lipid or polymer-based nanoparticles seems to be a particularly successful method for cutaneous administration. This review focuses on different classes of flavonoids in the skin, challenges, future aspects and highlighting their potential application as therapeutic and preventive agents.