Role of PGE-2 and Other Inflammatory Mediators in Skin Aging and Their Inhibition by Topical Natural Anti-Inflammatories

Abstract

Human skin aging is due to two types of aging processes, “intrinsic” (chronological) aging and “extrinsic” (external factor mediated) aging. While inflammatory events, triggered mainly by sun exposure, but also by pollutants, smoking and stress, are the principle cause of rapid extrinsic aging, inflammation also plays a key role in intrinsic aging. Inflammatory events in the skin lead to a reduction in collagen gene activity but an increase in activity of the genes for matrix metalloproteinases. Inflammation also alters proliferation rates of cells in all skin layers, causes thinning of the epidermis, a flattening of the dermo-epidermal junction, an increase in irregular pigment production, and, finally, an increased incidence of skin cancer. While a large number of inflammatory mediators, including IL-1, TNF-alpha and PGE-2, are responsible for many of these damaging effects, this review will focus primarily on the role of PGE-2 in aging. Levels of this hormone-like mediator increase quickly when skin is exposed to ultraviolet radiation (UVR), causing changes in genes needed for normal skin structure and function. Further, PGE-2 levels in the skin gradually increase with age, regardless of whether or not the skin is protected from UVR, and this smoldering inflammation causes continuous damage to the dermal matrix. Finally, and perhaps most importantly, PGE-2 is strongly linked to skin cancer. This review will focus on: (1) the role of inflammation, and particularly the role of PGE-2, in accelerating skin aging, and (2) current research on natural compounds that inhibit PGE-2 production and how these can be developed into topical products to retard or even reverse the aging process, and to prevent skin cancer.

Ethosomes for Coenzyme Q10 Cutaneous Administration: From Design to 3D Skin Tissue Evaluation

“…In order to design a nanotechnological formulation suitable for the delivery of the lipophilic CoQ10 (log P 19.4, [ 43 ]), its solubility has been investigated in different solvents, namely water, ethanol, methanol, dimethyl sulfoxide, and acetonitrile. The drug was insoluble in almost all the solvents, while a slight solubility has been observed in ethanol, namely 0.3 ± 0.2 mg/mL.…”

Exploring the Applications of the Photoprotective Properties of Anthocyanins in Biological Systems

“…Moreover, UVR stimulates the production and secretion of certain proinflammatory mediators in fibroblasts and particularly in keratinocytes, including prostaglandin E2 (PGE2), tumor necrosis factor (TNF-α), and interleukin-1 (IL-1). These mediators consequently trigger molecular pathways that result in decreased synthesis of collagen and increased MMPs activity and they can further amplify the inflammatory response by binding to their specific receptors on neighboring skin cells or on the cells where they were originally produced, intensifying the skin damages [ 58 , 68 , 69 , 70 ].…”

Collagen Hydrolysates for Skin Protection: Oral Administration and Topical Formulation

“…Aging of the skin has been widely studied in order to understand its molecular mechanisms [2] as well as factors that affect this condition. It is well-known that skin aging is the result of the combination of both intrinsic and extrinsic effects [3]. Intrinsic aging involves inherent factors related to age [4], in a neuroendocrine aspect [5], while extrinsic aging is the result of external factors such as ultraviolet A (UVA) and ultraviolet B (UVB) radiation exposure [6][7][8][9], environmental pollution [10,11], and production of ROS [12].…”