Research presented by P&G Beauty & Grooming scientists at the 68th Annual Meeting of the American Academy of Dermatology (Miami Beach, FL, March 5-9) examines skin care science from multiple perspectives, offering insights into how ingredient formulations, care regimens and gene expressions impact skin condition. Eleven studies are on display, discussing a wide range of topics, including lipid metabolism pathways in the stratum corneum, skin elasticity and male shaving regimens.
"This year, P&G Beauty & Grooming is presenting a diverse research portfolio covering topics such as male and female skin condition, whole body anti-aging treatments and skin care genomics," said Emma Kohring, Global Director, P&G Beauty & Grooming Science. "The 2010 American Academy of Dermatology (AAD) Annual Meeting is the ideal venue for P&G Beauty & Grooming scientists to share their research and discuss the findings with leaders in the world of dermatology."
The following research summaries are just a sample of the P&G Beauty & Grooming science that will be shared at the AAD Annual Meeting.
Hexamidine, a Protease Inhibitor, Promotes Stratum Corneum Lipid Biomarkers In Vitro (P104, PD 01)
Skin aging is a result of unrepaired damage as well as age-related physiological changes. The factors that accelerate skin aging are both intrinsic, such as free radicals, and extrinsic, such as UV exposure. In both intrinsically and extrinsically aged skin, there is a down-regulation of the gene expression involved in stratum corneum (the outer layer of the skin) lipid biosynthesis and metabolism, resulting in decreased levels of key lipids available for maintenance and repair.
P&G Beauty & Grooming scientists evaluated how hexamidine impacts the gene expression of stratum corneum (SC) lipid metabolism pathways in vitro. Using gene chip technology, scientists examined RNA from skin biopsies of young and older study subjects. In intrinsically and extrinsically aged skin, the epidermal cholesterol, fatty acid and sphingolipid synthetic pathway genes were down-regulated. Skin equivalents treated with hexamidine showed the opposite effect, with up-regulation of these pathways. Researchers concluded that the down-regulation of these pathways is consistent with previously reported global decreases in SC lipids in aging skin, and likely contributes to the decreased ability of aged skin to maintain and repair the skin barrier. By increasing the expression of genes involved in lipid biosynthetic pathways, hexamidine has the potential to increase the levels of these key lipids available for skin maintenance and repair. Thus, using hexamidine, P&G Beauty & Grooming scientists significantly increased expression of pathways essential for the production of lipids such as cholesterol, sphingolipids and fatty acids that have the potential to restore the stratum corneum and moisture content of aging skin.
Effect of Anti-Aging Products on Stratum Corneum Thickness and Barrier Integrity (P1009)
The outer layer of the skin, known as the stratum corneum (SC), helps keep the skin hydrated by absorbing moisture and preventing water evaporation. P&G Beauty & Grooming scientists used Confocal Raman Microspectrometry (CRM) and Transepidermal Water Loss (TEWL) measurements to assess the effect of three different anti-aging products on SC thickness. The products tested included a moisturizing cream containing niacinamide and hexamidine, a moisturizing serum containing niacinamide, Lys'lastine, peptides and caffeine and a lotion containing alpha lipoic acid. After four weeks of treatment, study results demonstrated that the SC thickened relative to baseline with each product. The niacinamide/hexamidine cream and niacinamide/Lys'lastine serum both produced statistically significant plumping of the SC relative to no treatment and treatment with the niacinamide/Lys'lastine serum thickened SC significantly more than alpha-lipoic acid lotion treatment. Additionally, all products significantly reduced TEWL after four weeks of treatment relative to no treatment, but the niacinamide containing products reduced TEWL significantly more than the alpha-lipoic acid lotion. Overall, products containing niacinamide and hexamidine or niacinamide and Lys'lastine plumped the SC and improved barrier function. Researchers believe the changes in SC thickness may be associated with the improvement in skin barrier function.
Petrolatum Depositing Body Wash Improves Skin Elasticity and Cohesion (P1637)
Daily activities can cause an increase in dryness and subsequent skin flaking, as well as a general loss of skin elasticity. In an effort to improve the health and viability of aging skin, P&G Beauty & Grooming scientists developed a petrolatum depositing body wash that is aesthetically pleasing to use and delivers benefits beyond typical moisturization. In developing the anti-aging wash, P&G Beauty & Grooming scientists combined fundamental body wash components with additional elements that remove dry skin cells and improve skin elasticity and cohesiveness. To assess the effect of the wash on dry skin, treatment was conducted over a three week period. Women with dry leg skin were separated into two groups: the first had their legs washed once daily with the randomly assigned body wash products. The other used a water alone treatment as a study control. Results of clinical testing indicated that the body wash delivered significant improvements in all standard moisturization measures and skin elasticity, supporting the conclusion that the petrolatum depositing body wash improves the overall condition of skin.
Male Facial Shaving Regimen Improves Overall Skin Condition (P1151)
As millions of men around the world shave their facial hair regularly, each individual's shaving technique, quality of razor and grooming products, and skin and facial hair characteristics shapes the quality of each shaving experience. To investigate the impact of an advanced shaving regimen on overall skin condition, researchers conducted a clinical study to compare an advanced 3-step shaving regimen to a typical male shaving regimen. The study found that the use of an advanced shaving regimen, which included cleansing the skin with a gentle cleanser, applying shave gel designed for sensitive skin, shaving with a 5-blade razor and hydrating the skin after shaving, can have a positive impact on skin condition and shave quality through improved hydration.