Photoaging of the skin

Abstract

Photoaging of the skin46 Solar radiation at the surface of the earth includes ultraviolet radiation (UV : 290-400nm), visible light (400-760nm) and infrared radiation (760nm-1mm) (Fig 1).Extrinsic skin aging is superimposed on intrinsic skin aging process and is due primarily to UVR (solar ultraviolet radiation) and partly by other factors, such as infrared light, smoking and air pollutants. UVR has been divided into ultraviolet B (UVB: 290-320nm) which principally generates pyrimidine dimer type DNA damage through direct absorption and ultraviolet A (UVA: 320-400nm), which indirectly produces base oxidation via UVinduced ROS.Recently , UVA radiation at high dose is reported to produce cyclobutane pyrimidine dimmers.Intrinsic aging of the skin, on the other hand, is characterized by the decline of biological function, a decrease in adaptation to stress, and structural damage due to reactive oxygen species (ROS) from cellular metabolism.Recent advances in understanding mechanisms of aging and photoaging have enhanced our ability to develop strategies to prevent, slow, and rejuvenate the altered structure and function of photoaged skin.In this review, we discuss the mechanisms of photoaging of the skin with relevance to acute and chronic skin reactions to solar UVB, UVA and infrared radiation, and summarize briefly the clinical approaches for prevention and the treatment of photoaging with topical and systemic use of anti-aging materials. Finally, a range of therapeutic modalities available to reverse or retard the visible signs of photoaged skin will be discussed briefly. There are three lights with different waveband, infrared light (IR) having waveband between 760nm and 1mm, visible light (VL) from 400nm to 760nm, and ultraviolet light (UV) from 290nm to 400nm. IR, VL and UV occupy 42 %, 52 % and 6 % of the solar light on the earth, respectively. UV light is divided into two types according to waveband, UVA having waveband between 320nm and 400nm and UVB from 290nm to 320nm. Sunburn, acute skin reaction is caused predominantly by UVB which occupies only 5~6 % of total UV light. UVA radiation, however, penetrates deeply into the dermis, around 20 % of the surface of the skin.

Active Constituents of Pomegranates (Punica granatum) as Potential Candidates in the Management of Health through Modulation of Biological Activities

“…63 Evidences based on research demonstrated that pomegranate shows photo-protection activity [ Table 2]. Previous finding revealed that pomegranate seed oil was shown to stimulate keratinocyte proliferation in monolayer culture.…”

Effectiveness of Topical Mangosteen Pericarp Extract Against Angiogenesis in Mice Exposed to Ultra Violet B

“…Acute UV exposure stimulates angiogenesis through vascular endothelial growth factor (VEGF) upregulation via the MEK-ERK pathway activation and down regulation of thrombospond in-1 (TSP-1) through activation of the P13K-Akt pathway in the human epidermis. However, in chronic exposure, decreased blood vessels have been found on skin damaged by UV (Ichihashi et al, 2009 UVB radiation induces VEGF-A in the basal layer of the epidermis, whereas the expression of TSP-1 is downregulated in the epidermis. Thus, the down regulation of TSP-1 and the upregulation of VEGF-A appear to contribute to a molecular level trigger of the induction of angiogenesisin the skin due to UVB radiation (Sawane and Kajiya, 2012).…”

“…With intrinsic skin aging, there were no significant differences in vascular density, although a decrease in blood vessel size was found between young skin and old skin. In one study on papillary dermis skin photo aging, donors' aged skin showed significant differences in the size of blood vessels and the number of blood vessels when compared to young skin (Ichihashi et al, 2009). Acute UV exposure stimulates angiogenesis through vascular endothelial growth factor (VEGF) upregulation via the MEK-ERK pathway activation and down regulation of thrombospond in-1 (TSP-1) through activation of the P13K-Akt pathway in the human epidermis.…”

In-vitro Evaluation of Antioxidant Activity and Anti-collagenase Activity of Thalassia hempricii as a Potent Ingredients for Anti-Wrinkle Cosmetics

“…The pharmacological actions of phenolic antioxidants against free radical scavenging is very important to inhibit wrinkle, because skin which repeatedly exposed to ultraviolet light every day, can occurred wrinkles. 19 The presence of some phytoconstituents, such as phenols, flavonoids and tannins in seagrasses may be the cause of antioxidant activity in preventing occurred wrinkles or inhibit collagenase activity. 20 The selection of solvent types is essential for efficiency of the extraction process, because the compound of solvent with different polarity provides different antioxidant potential.…”