J. Cosmet. Sci., 69, 47–56 ( January/February 2018) 47 Simulation of the Elastin and Fibrillin in Non-Irradiated or UVA Radiated Fibroblasts, and Direct Inhibition of Elastase or Matrix Metalloptoteinases Activity by Nicotinamide or Its Derivatives NEENA PHILIPS, JOVINNA CHALENSOUK-KHAOSAAT, and SALVADOR GONZALEZ, Department of Biology, Fairleigh Dickinson University, Teaneck, NJ (N.P., J.C-K.) and Department of Dermatology, Medicine and Medical Specialties, Alcala University, Madrid, Spain (S.G.). Accepted for publication November 28, 2017. Synopsis Skin aging/photoaging is associated with altered the structure of collagen and elastin fi bers, and in- creased activity of matrix metalloproteinases (MMP) and elastase. Nicotinamide and its derivatives, 2,6-dihydroxynicotinamide, 2,4,5,6-tetrahydroxynicotinamide, and 3-hydroxypicolinamide (collectively niacin derivatives) stimulate fi brillar collagen and heat shock proteins in dermal fi broblasts. The goal of this research was to extend the understanding of the anti–skin aging mechanism of these niacin derivatives through the stimulation of elastin (at the protein and promoter levels), fi brillin (1 and 2) in nonirradiated or ultraviolet (UVA) radiated dermal fi broblasts, and through the direct inhibition of MMP (1, 3, and 9) and elastase activities. UVA radiation stimulated elastin and inhibited fi brillin-1 and fi brillin-2 in dermal fi broblasts. The niacin derivatives signifi cantly stimulated the expression of elastin (transcriptionally), fi brillin-1 and fi brillin-2 in nonirradiated and UVA radiated fi broblasts, and directly inhibited MMP or elastase activity. Overall, the niacin derivatives, more so nicotinamide and 2,6-dihydroxynicotinamide, have anti–skin aging potential through the stimulation of elastin and fi brillin, and the direct inhibition of the extracellular matrix proteolytic enzymes. INTRODUCTION The structural integrity of the extracellular matrix (ECM), composed predominantly of collagen and elastin fi bers, is essential to skin structure and function (1–8). The structure of the ECM deteriorates with intrinsic aging, and exposure to environmental factors such as ultraviolet (UV) radiation (1–27). UVA radiation can penetrate the dermis and damage ECM through the generation of oxidative stress and infl ammation, and direct damage of biomolecules (9–14). The dermal fi broblasts are the primary synthesizers of the ECM proteins (1–4,8). Address all correspondence to Neena Philips at nphilips@fdu.edu and neenaphilips@optonline.net.

JOURNAL OF COSMETIC SCIENCE 48 Polyphenols with their antioxidative and anti-infl ammatory properties have been identi- fi ed to benefi cially regulate the ECM, and thereby, prevent skin aging or cancer (1–8,27). The structure of the phenolic components includes at least one aromatic ring with one or more hydroxyl groups (5). The activity of the phenolic compounds is dependent on the number and location of these hydroxyl groups, in addition to their structure (5,28–34). The structure of nicotinamide or its derivatives, such as 3-hydroxypicolimanide, has pho- tophysical and UV radiation absorptive properties (28–34). Skin aging or photoaging reduces cellular antioxidant defense, ECM structure, and NAD content (1–8,35). Nico- tinamide serves as a precursor for several cellular coenzymes that are essential to metabolism and counteracts inhibition of ATP/glycolysis, oxidative DNA damage, oxidative stress, and infl ammation (35–41). Nicotinamide improves skin appearance, independently or in combination with retinoids, by reducing hyperpigmentation and wrinkles (42–46). We recently reported an anti–skin aging mechanism of nicotinamide through the stimula- tion of fi brillar collagen and heat shock proteins in dermal fi broblasts (27). The goal of this research was to determine the anti–skin aging mechanism of nicotinamide and three of its derivatives, 2,6-dihydroxynicotinamide, 2,4,5,6-tetrahydroxynicotinamide, and 3-hydroxypicolinamide (collectively niacin derivatives), through the benefi cial regula- tion of elastin and fi brillin (1 and 2) in nonirradiated or UVA-radiated dermal fi broblasts, and direct inhibition of on matrix metalloproteinases (MMP) (1, 3, and 9) and elastase activities. The hypothesis of this research was that the niacin derivatives would stimulate expression of elastin and fi brillin, and directly inhibit ECM proteolytic activity. METHODS CELL CULTURE AND DOSING Human neonatal dermal fi broblasts from two donors (Cascade Biologics, part of Ther- mofi scher Scientifi c, Waltham, MA) were cultured in complete Dulbecco’s Modifi ed Eagle’s Medium (DMEM) supplemented with 10% heat inactivated fetal bovine serum, 1% penicillin/streptomycin (P/S), and 1% L -glutamine (Sigma, St. Louis, MO). The cells were rinsed with Hank’s Balanced Salt solution (Sigma) and nonirradiated (control) or radi- ated with 2.5 J/cm2 (minimal toxicity) of UVA radiation using a four-tube UVA lamp with irradiance of 1E-03 W/cm2 for a sum of wavelengths from 320 to 400 nm (2,4,27). The nonirradiated or UVA-radiated cells were then not exposed (control or UVA-radiated con- trol) or exposed to 0.01% (0.05 mM), 0.1% (0.5 mM), or 1% (5 mM) of each of the niacin derivatives in experimental media (DMEM containing 1% serum replacement and 1% P/S) for 24 h (2,4,27). Four independent experiments, in replicates of 3–4, were performed with dermal fi broblasts at passages 4–12. The cells were examined for cell viability by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H- tetrazolium, inner salt) assay (Promega, Madison, WI). The cell viability was not altered at these concentrations of UVA radiation or niacin derivatives. ELASTIN, AND FIBRILLIN (-1, -2) PROTEIN LEVELS The elastin and fi brillin proteins levels in the media of nonirradiated or UVA radiated fi broblasts ± niacin derivatives were determined by using enzyme linked immunosorbant assay (ELISA) (Kirkguaard and Perry Laboratories Inc., Milford, MA Elastin Products Co.)