Plant phenolics with promising therapeutic applications against skin disorders: A mechanistic review

Abstract

Skin aging is a complex biological process influenced by a combination of intrinsic and extrinsic factors, leading to cumulative alterations in the structure, function, and appearance of skin. Strong or chronic exposure to a variety of stresses (e.g., ultraviolet radiation, xenobiotic agents, free radicals, and others) may contribute to premature skin aging, immune suppression, and tumorigenesis/carcinogenesis. Plant phenolics represent one of the largest classes of compounds used in dermatology and nutricosmetics to combat skin aging. They are produced via the polyketide and shikimate pathway. These increase skin cell longevity via the MPK-1/ERK or SIR-2.1/DAF-16, insulin/IGF-1 signaling (IGF) pathways, particularly through enhanced capacity to scavenge free radicals and fend off oxidative stress provided by the use of DAF-16 transcription factor; a sole ortholog of the FOXO family of transcription factors. Dietary polyphenols may exert their role in prevention of the skin aging effects through several possible mechanisms, such as ROS scavenging, reduction in melanin synthesis, UV impairment, removal of carcinogenic agents, modulation of cancer cell signaling antioxidant enzymatic activities, and induction of apoptosis as well as cell cycle arrest. Therefore, a search for prevention strategies to circumvent such unfavorable outcomes is being constantly pursued. The current article is designed to provide an overview of the existing literature related to skin aging and the ability of polyphenols to maintain skin homeostasis. In this review, we discuss recent progress in understanding the molecular basis of skin aging, with specific emphasis on some well-known and extensively studied polyphenols that have significant anti-aging influences and photoprotective effects.

Keywords

• Polyphenols
• Skin aging
• ROS scavenging
• Apoptosis
• Cancer cell signaling
• Photoprotective effects