Photoaging

Abstract

The incident of photoaging mainly depends upon the intensity of UV-R and the amount of melanin present in the skin. UV-R is known to cause photoaging, photoallergy, and immune suppression to human skin, noted more than a century ago. From last 10 years, several laboratory studies show that UV rays impaired the collagen synthesis, blocked collagen expression, and reduced the elasticity of skin and solar scar formation which is ultimately visible by clinical pattern such atrophy and wrinkle formation. Which further leads to UV-R induced premature aging of the skin. UV radiation alters the ECM by raising the level of matrix metalloproteinases (MMP), decreasing the structural elastin and collagen, directly or indirectly damaging the DNA, and enhancing the cell surface receptors which are present at the surface of keratinocytes and fibroblasts of skin. AP-1 and NF-kB are key signaling molecules which involve in UV-R promoted skin aging. The photoprotective approaches to prevent or treat photocarcinogenesis and photoaging involve natural supplements absorption by orally and topically. Skin accommodates a complex system of endogenous enzymatic and nonenzymatic photoprotective antioxidants. However, their role in the UV-R-induced oxidative damage has not been fully elucidated. Recently, the researchers have elucidated that skin antioxidative defense system is increased in presence of vitamins and nutritive agents and combination of various kinds of antioxidants also produce synergistic results.