The skin aging exposome

Skin aging and oxidative stress: Equol's anti-aging effects via biochemical and molecular mechanisms.

Sunlight damages human skin, resulting in a wrinkled appearance. Since natural sunlight is polychromatic, its ultimate effects on the human skin are the result of not only the action of each wavelength separately, but also interactions among the many wavelengths, including UV, visible light, and infrared (IR). In direct sunlight, the temperature of human skin rises to about 40°C following the conversion of absorbed IR into heat. So far, our knowledge of the effects of IR radiation or heat on skin aging is limited. Recent work demonstrates that IR and heat exposure each induces cutaneous angiogenesis and inflammatory cellular infiltration, disrupts the dermal extracellular matrix by inducing matrix metalloproteinases, and alters dermal structural proteins, thereby adding to premature skin aging. This review provides a summary of current research on the effects of IR radiation and heat on aging in human skin in vivo.

https://www.jidsponline.org/article/S1087-0024(15)30504-9/pdf

Effects of Infrared Radiation and Heat on Human Skin Aging in vivo

Angiogenesis, the process of generating new blood vessels, is affected by various physiological and pathological conditions of skin. The skin aging process can be divided into intrinsic aging and photoaging. With aging, cutaneous blood vessels undergo pronounced alterations. A reduction of the cutaneous microvasculature has been observed in the skin of elderly individuals. Human skin is exposed daily to solar ultraviolet (UV) radiation, infrared rays and heat, and these stimuli are known to induce skin angiogenesis. Interestingly, although acute UV irradiation stimulates skin angiogenesis, cutaneous blood vessels are decreased in chronically photodamaged skin. The reason for the differential effects of acute and chronic UV exposure on skin angiogenesis remains to be elucidated. This review discusses the vascularization changes in intrinsically aged and photoaged human skin, the effects of UV irradiation, infrared rays and heat on skin angiogenesis, and the effects of topical retinoic acid treatment on UV-induced angiogenesis and cutaneous vascularity in aged and photoaged human skin. An understanding of the molecular mechanisms of aging- and photoaging-dependent changes of skin angiogenesis may provide us with new insights to prevent and treat the skin aging process.

Angiogenesis in skin aging and photoaging.

The exposure to ultraviolet radiations (UVR) is the key source of skin sunburn; it may produce harmful entities, reactive oxygen species (ROS), leading to aging. The skin can be treated and protected from the injurious effects of ROS by using various pharmaceutical formulations, such as cream. Cream can be loaded with antioxidants to quench ROS leading to photo-protective effects. Moreover, modern medicines depend on ethnobotanicals for protection or treatment of human diseases. This review article summarizes various in vivo antioxidant studies on herbal creams loaded with phyto-extracts. These formulations may serve as cosmeceuticals to protect skin against injurious effects of UVR. The botanicals studied for dermatologic use in cream form include Acacia nilotica, Benincasa hispida, Calendula officinalis, Camellia sinensis, Camellia sinensis, Nelumbo nucifera, Capparis decidua, Castanea sativa, Coffea arabica, Crocus sativus, Emblica officinalis Gaertn, Foeniculum vulgare, Hippophae rhamnoides, Lithospermum erythrorhizon, Malus domestica, Matricaria chamomilla L., Moringa oleifera, Morus alba, Ocimum basilicum, Oryza sativa, Polygonum minus, Punica granatum, Silybum marianum, Tagetes erecta Linn., Terminalia chebula, Trigonella foenum-graecum, and Vitis vinifera. The observed anti-aging effects of cream formulations could be an outcome of a coordinating action of multiple constituents. Of numerous botanicals, the phenolic acids and flavonoids appear effective against UVR-induced damage; however the evidence-based studies for their anti-aging effects are still needed.

/pdf/anti-aging-potential-of-phytoextract-loaded-pharmaceutical-1xcf8ga6fx.pdf

Jin Young Seo

Papers

Thermal aging: A new concept of skin aging