Mohiuddin AK. Skin Aging & Modern Age Anti-Aging Strategies. Int J Clin Dermatol Res. 2019;7(4):209-240. 209 OPEN ACCESS https://scidoc.org/IJCDR.php International Journal of Clinical Dermatology & Research (IJCDR) ISSN 2332-2977 Skin Aging & Modern Age Anti-Aging Strategies Research Article Mohiuddin AK * Assistant Professor, Department of Pharmacy, World University of Bangladesh, Green Road, Dhanmondi, Dhaka, Bangladesh. *Corresponding Author: Abdul Kader Mohiuddin, Assistant Professor, Department of Pharmacy, World University of Bangladesh, 151/8, Green Road, Dhanmondi, Dhaka-1205, Bangladesh. Tel: +8801716477485 E-mail: trymohi@gmail.com Received: May 18, 2019 Accepted: June 25, 2019 Published: July 29, 2019 Citation: Mohiuddin AK. Skin Aging & Modern Age Anti-Aging Strategies. Int J Clin Dermatol Res. 2019;7(4):209-240. doi: http://dx.doi.org/10.19070/2332-2977-1900052 Copyright: Mohiuddin AK © 2019. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited. Abstract As the most voluminous organ of the body that is exposed to the outer environment, the skin suffers from both intrinsic and extrinsic aging factors. Skin aging is characterized by features such as wrinkling, loss of elasticity, laxity, and rough-textured appearance. This aging process is accompanied with phenotypic changes in cutaneous cells as well as structural and functional changes in extracellular matrix components such as collagens and elastin. With intrinsic aging, structural changes occur in the skin as a natural consequence of the biological changes over time and produce a certain number of histological, physiological, and biochemical modifcations. Intrinsic aging is determined genetically (infuence of gender and ethnic group), variable in function of skin site, and also infuenced by hormonal changes. Visually it is characterized by fne wrinkles. By comparison, “photoaging” is the term used to describe the changes occurring in the skin, resulting from repetitive exposure to sunlight. The histological, physiological, and biochemical changes in the different layers of the skin are much more drastic. From a mechanical point of view, human skin appears as a layered composite containing the stiff thin cover layer presented by the stratum corneum, below which are the more compliant layers of viable epidermis and dermis and further below the much more compliant adjacent layer of subcutaneous white adipose tissue. Upon exposure to a strain, such a multi-layer system demonstrates structural instabilities in its stiffer layers, which in its simplest form is the wrinkling. These instabilities appear hierarchically when the mechanical strain in the skin exceeds some critical values. Their appearance is mainly dependent on the mismatch in mechanical properties between adjacent skin layers or between the skin and subcutaneous white adipose tis- sue, on the adhesive strength and thickness ratios between the layers, on their bending and tensile stiffness as well as on the value of the stress existing in single layers. Gradual reduction of elastic fbers in aging signifcantly reduces the skin’s ability to bend, prompting an up to 4-fold reduction of its stability against wrinkling, thereby explaining the role of these fbers in skin aging. Anti-aging medicine is practiced by physicians, scientists, and researchers dedicated to the belief that the process of physical aging in humans can be slowed, stopped, or even reversed through existing medical and scientifc interventions. This specialty of medicine is based on the very early detection and prevention of age-related diseases. Physicians practicing anti-aging medicine seek to enhance the quality of life as well as its length, limiting the period of illness and disability toward the end of one’s life. Anti-aging medicine encompasses lifestyle changes (diet and exercise); hormone replacement therapies, as needed, determined by a physician through blood testing (DHEA, melatonin, thyroid, human growth hormone, estrogen, testosterone); antioxidants and vitamin supplements; and testing protocols that can measure not only hormone levels and blood chemistry but every metabolic factor right down to the cellular level. Keywords: Skin Care; Anti-Aging; Photoaging; Wrinkles; Antioxidants; Keratinocytes; Retinoids. Abbreviations: Luteinizing Hormone (LH); Follicle Stimulating Hormone (FSH); Adrenocorticotropic Hormone (ACTH); Growth Hormone (GH); Transforming Growth Factor Beta (TGF-β); Matrix Metalloproteinases (MMPs); Activator Pro- tein-1 (AP-1); Glycosaminoglycan (GAG); Reactive Oxygen Species (ROS); 4-hydroxy-2-Nonenal (HNE); Particulate Matter (PM2.5); Transepidermal Water Loss (TEWL); Glycation end Products (AGEs); National Health and Nutrition Examina- tion Surveys (NHANES); Dutch Healthy Diet Index (DHDI); Principal Component Analysis (PCA); Carboxymethyl Lysine (CML); Dermal White Adipose Tissue (dWAT); Peroxisome Proliferator-Activated Receptor γ (PPARγ); Hypothalamic-Pitu- itary-Adrenal (HPA); Glucocorticoid Receptors (GRs); Nuclear Receptor Subfamily 3 Group C Member 1 (NR3C1); Pulsed Electromagnetic Fields (PEMFs); Multipolar Magnetic Pulse (MP)2; Sun Protection Factor (SPF); Epidermal Growth Factor (EGF); Cytoplasmic Transduction Peptide (CTP); Ferric-Reducing Activity of Plasma (FRAP); Sodium-Dependent Vitamin C Transporters (SVCTs); Matrix Metalloproteinase-1 (MMP-1); Epithelial/Epidermal Growth Factor (EGF); Insulin-Like Growth Factor (IGF-1); Nuclear Factor Erythroid 2-Related Factor (Nrf2); Collagen Type I α 1 (Col1A1); Basic Fibroblast Growth Factor (bFGF).