Chapter 2 - Polyphenols for skin cancer: Chemical properties, structure-related mechanisms of action and new delivery systems

Abstract

Polyphenols are widely spread in the plant kingdom as products of secondary metabolism. They are known for a series of biological properties that influence human health, and evidence exists that people can benefit from plant phenolics obtained either from diet or through skin application, because they can alleviate symptoms and inhibit the development of various skin disorders. The biosynthesis of polyphenols depends on abiotic and biotic factors. While phenolic stands for an aromatic ring bearing one (phenol), the term polyphenol is chemically defined as a substance bearing an aromatic ring with more than one hydroxy (OH) substituents. There is a vast number of distinct phenolic compounds in nature, but there are a limited number of metabolic pathways through which these compounds can be produced, presenting the same basic skeleton. Due to their low toxicity, polyphenols are receiving great attention as new bioactives for a series of diseases, including skin injuries. They also have prophylactic action in the progression of certain skin diseases such as cancer. This chapter revised the chemical properties of a series of phenolic compounds with biological properties against skin cancer, discussing the structure-related mechanisms of activity and revising the most recent literature about new strategies for the delivery of these bioactives for the treatment of skin cancer.