Cytoprotective Polyphenols against Chronological Skin Aging and Cutaneous Photodamage

Background: Skin aging is a complex biological process influenced by a combination of intrinsic and extrinsic factors, leading to cumulative alterations of skin structure, function and appearance. Polyphenols, which are secondary plant metabolites, represent one of the largest classes of compounds used in dermatology and nutricosmetics to combat skin aging. The main objective is to provide an overview of the existing literature linking skin aging and the ability of polyphenols as regulatory elements able to maintain skin homeostasis. Methods: In this review, we discuss recent progress in understanding the molecular bases of skin aging, with specific emphasis on some well known and extensively studied polyphenols which have significant anti-aging influences and photoprotective effects. Results: Although no relevant clinical data exist and standard delivery systems have not been established, promising results have been obtained in many in vitro and animal models. A wide variety of polyphenols may minimize mechanisms underlying the functional manifestations of photoaging and chronological skin aging. Conclusion: Polyphenols exert their influence mostly through their antioxidant and anti-inflammatory effects, thereby abrogating collagen degradation and/or increasing procollagen synthesis.