"While a great deal is known about glucosamine's safety profile and anti-inflammatory and anti-oxidant properties, there have been few well-controlled studies on how these properties could be used to improve skin health," says Alexa Kimball, M.D., assistant professor of dermatology, Harvard Medical School, who supervised one of the studies presented at the AAD. " It is really gratifying to see this level of research and validation on a topical cosmetic application. These findings could impact the way dermatologists treat UV related skin damage."
Data from three studies presented at the meeting focused on a formulation including N-acetyl glucosamine, a more stable version of glucosamine. N-acetyl glucosamine is a substance that inhibits glycosylation of pro-tyrosinase – a key process in melanin overproduction in UV damaged skin cells. The in vivo and in vitro studies highlight improvements in hyperpigmentation, skin tone and barrier function. Data from the SIAscope, a non-invasive skin imaging system developed by Cambridge UK-based company Astron Clinica, enabled scientists to view the effects of the N-acetyl glucosamine complex on pigment producing cells – giving scientists the ability for the first time ever to see the distribution of melanin across an entire human face.
NAG/Niacinamide Reduces Appearance of Hyperpigmentation in Vivo
Two double-blind placebo-controlled clinical studies examined the effects of N-acetyl glucosamine alone and a complex containing N-acetyl glucosamine plus niacinamide, a vitamin B derivative, which has previously been shown to be effective in reducing facial hyperpigmentation. , , The first study involved 50 Japanese women (ages 25-55) who were randomized to use either a topical placebo formulation or an N-acetyl glucosamine formulation. The second study involved 35 Caucasian women (ages 35-65) who were randomized to use either a topical formulation containing niacinamide or N-acetyl glucosamine plus niacinamide complex. Researchers concluded that N-acetyl glucosamine was more effective in reducing hyperpigmentation over the placebo and a complex of N-acetyl glucosamine and niacinamide were more effective in reducing hyperpigmentation than niacinamide alone.
Another study, supervised by Harvard dermatologist Dr. Kimball, 200 subjects (ages 40-60) with facial hyperpigmenation used an SPF-15 moisturizing sunscreen lotion product and a moisturizing cream. One hundred of these subjects used an SPF-15 moisturizing sunscreen lotion product and a moisturizing cream with an N-acetyl glucosamine and niacinamide complex and 100 subjects received the lotion and cream without the active complex. Results showed that a topical N-acetyl glucosamine plus niacinamide complex is clinically effective in reducing the appearance of facial hyperpigmented spots. Additionally, the combination was significantly effective on top of any effect provided by the SPF-15 sunscreen included in the daytime test products.
These 200 subjects underwent additional testing using the SIAscope, a technology that models and measures the interaction of light within the skin to produce full-face visual maps of melanin distribution. These maps revealed that treatment with an N-acetyl glucosamine and niacinamide complex resulted in a reduction in both hyper-melanized spot size and heterogeneity of melanin distribution. "This unique SIAscope technology allows us to non-invasively measure and understand biological components that comprise skin tone. It is an amazing clinical tool to help us evaluate new treatments and their ability to improve the skin," said Dr. Paul Matts, a principal scientist from P&G Beauty, a division of Procter & Gamble, and co-author of the study with Dr. Kimball.
NAG Increases Hyaluronic Acid, Water Content, Biomarkers of Healthy Skin
In this study, the effects of N-acetyl glucosamine and niacinamide were tested in in vitro human skin cultures, as well as a clinical facial trial of 35 to 60 year old women with moderate-severe fine lines and wrinkles. The in vitro work found that the N-acetyl glucosamine plus niacinamide complex stimulated the production of hyaluronic acid, a key component in skin's hydration, as well as increased collagen (procollagen-1) expression. In human subjects, this improved hydration of the skin reduced the appearance of facial fine lines and wrinkles, particularly in the eye area of the face. Researchers hypothesize that the improved skin tone and moisturization may come from the role that glucosamine plays in hyaluronic acid synthesis, as well as improvements in collagen structure.
Additional Information Images, abstracts and final AAD presentations of the studies mentioned above are available upon request.
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