Clinical Evaluation of a Multi-Modal Facial Serum That Addresses Hyaluronic Acid Levels in Skin
September 2017 | Volume 16 | Issue 9 | Original Article | 884 | Copyright © September 2017
Susana Raab MS,a Margarita Yatskayer MS,a Stephen Lynch PhD,a Megan Manco MS MPS,b and Christian Oresajo PhDa
aL’Oréal Research and Innovation, Clark, NJ bSkinceuticals, New York, NY
BACKGROUND: Hyaluronic acid (HA), the major glycosaminoglycan present in the human skin, is a key contributor to water retention and mechanical support in skin. The level, size, and functionality of cutaneous HA are known to diminish with age. Topical treatments designed to increase the HA content of skin have been met with limited success. The purpose of this study was to evaluate the tolerance and efficacy of a multi-modal facial serum containing HA, Proxylane (C-Xyloside), purple rice extract, and dipotassium glycyrrhizate in addressing HA levels in skin.
METHODS: A 12-week, single center, clinical study was conducted on 59 women with mild to moderate photodamage. Clinical grading to assess the efficacy and tolerability was conducted on the face at baseline and at weeks 4, 8, and 12. Bioinstrumentation measurements were taken, including corneometer, tewameter, ultrasound, and standardized digital imaging. A randomized subset of 20 subjects from the study population had 3 mm punch biopsies collected for quantitative RT-PCR analysis from 2 sites on the face at baseline and week 12. Additionally, a 4-week, single center, clinical study was conducted on the photodamaged forearms of 12 subjects. At both baseline and week 4, a 4 mm punch biopsy was obtained from the subjects’ randomized forearms. Biopsy samples were subjected to immunohistochemical staining and analysis of HA content.
RESULTS: Statistically-significant improvements in all facial skin attributes (weeks 4, 8, and 12), stratum corneum hydration (week 12), and transepidermal water loss (week 12) were observed. Tolerability was excellent, with no increases in irritation parameters noted. A significant increase of HA content in skin after 4 weeks of treatment was observed. By PCR analysis, there was a significant increase in hyaluronan synthase 2, as well as a significant increase in collagen type 1a1 after 12 weeks of application.
CONCLUSION: The findings suggest that this novel topical facial serum is capable of stimulating HA and skin extracellular matrix components, as well as improving skin hydration and skin quality in women with mild to moderate photodamage.
J Drugs Dermatol. 2017;16(9):884-890.
The earliest work on skin was devoted predominantly to the discreet cellular compartments of skin: the epidermis, dermis, and underlying subcutis. There has been an emerging appreciation for the materials that lie between cells -- the extracellular matrix components -- which have major instructive roles for cellular activities.3 The major component of skin extracellular matrix (ECM) is the glycosaminoglycan (GAG), hyaluronic acid (HA). Matrix hyaluronan has been implicated in several skin epidermal functions. Since collagen constitutes the main structural element of the ECM — providing tensile strength, regulating cell adhesion, supporting chemotaxis and migration, and directing tissue development18 — HA serves a critical role in filling space around collagen brils, maintaining the extracellular space, and preserving tissue hydration.1 The HA content of the epidermis and the dermis helps regulate the cutaneous moisture levels and barrier function of human skin.1 Hyaluronic acid also plays an important role in skin aging. A decrease in HA levels, reduction in HA size, and loss of HA functionality all directly impact the biomechanical properties of aging skin, resulting in loss of elasticity, rmness, and overall plumpness and volume. In young skin, large amounts of HA are found at the periphery and intersections of collagen and elastin fibers.2 On the other hand, upon chronic exposure to ultraviolet (UV) radiation, GAGs appear to be deposited on elastotic material and diffusely associated with UV-damaged collagen fibers.1 Photoaged skin is characterized by reduced HA and increased levels of chondroitin sulfate proteoglycans.6 Matrix metalloproteinases (MMPs), the main collagen degrading enzymes, are also over-expressed in photoaged skin.7 Due to the importance of HA in maintaining skin plumpness and hydration, and its decrease in intrinsically and photoaged skin, a goal in skincare has been to restore lost HA. While a multitude of anti-aging strategies have been developed based on the concept of replenishing the HA content in skin, there is limited evidence to demonstrate a meaningful influence on endogenous HA levels in human skin. In this study we evaluated, in vivo, a unique