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Oral N-acetylglucosamine supplementation improves skin conditions of female volunteers: Clinical evaluation by a microscopic three-dimensional skin surface analyzer

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Abstract

Within the skin tissues, acidic mucopolysaccharides such as hyaluronic acid are present in the corium layer and play a large part in water retention and skin resilience. Hyaluronic acid is a polymer composed of dimers containing N-acetylglucosamine and glucuronic acid. Although applications of the use of hyaluronic acid in cosmeceutical food have been reported, the beauty efficacy of orally-ingested hyaluronic acid cannot be predicted adequately because little is known about its digestion and absorption in humans. The purpose of this study was to investigate the effect of long-term oral N-acetylglucosamine supplementation on skin conditions in females who have a common tendency of xeroderma and rough skin. The subjects (average age: 25.5 ± 10.7) were assigned randomly and double-blind to either a N-acetylglucosamine group (n=11) or a placebo group (n=11), and ingested a daily 1000-mg dose of N-acetylglucosamine or lactose, respectively, for 60 days. Dermatological examination by doctors suggested that N-acetylglucosamine supplementation favorably affects skin conditions; that is, improvements were observed in the desiccation of facial and whole body skin. After N-acetylglucosamine supplementation for 60 days, the moisture content of the region below the left eye was increased significantly; conversely, a significant decrease in the oil and fat content was observed. In addition, clinical evaluation by a microscopic three-dimensional skin surface analyzer confirmed that oral N-acetylglucosamine supplementation is useful for mitigating the roughness of the skin and the epidermolysis of the corneum. These results indicate that oral N-acetylglucosamine supplementation may be of benefit in enhancing skin hydration. By contrast, no significant improvement was observed in the skin condition of the placebo group, as appraised by either dermatological examination or digital analysis. The beautification effect produced by ingestion of N-acetylglucosamine indicates that this compound may be a potential ingredient for cosmeceutical foodstuffs.

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... In addition to the observation that NAG-containing formulations reduce the appearance of spots, 14,15 such formulations have also been reported to increase skin hydration, reduce the appearance of wrinkles, increase exfoliation, and improve the appearance of acne. [16][17][18] Although all these effects are relatively small, there seems to be a wide range of actions on skin. Regarding increased skin hydration, the likely mechanism is that NAG is a precursor to the water-binding hyaluronic acid (HA). ...
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N-acetyl glucosamine (NAG) has been shown to be effective in reducing the appearance of hyperpigmented spots. From published in vitro mechanistic testing, glucosamine inhibits enzymatic glycosylation, a required processing step in converting inactive human pro-tyrosinase to the active tyrosinase, a key enzyme in the production of melanin. There is also published literature discussing the anti-inflammatory and antioxidant properties of glucosamine compounds. To identify additional mechanisms by which NAG might affect melanin production, an in vitro genomics experiment was conducted in SkinEthic skin equivalent cultures, which were topically dosed with NAG vs. a vehicle control. Relative to vehicle, NAG reduced melanin production, and the expression of several pigmentation-relevant genes were affected (down-regulated or up-regulated) by NAG treatment. Thus, there are several mechanisms that may be operative in the observed pigmentation effects.
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Citation: Ashkani-Esfahani S, Emami Y, Esmaeilzadeh E, Bagheri F, Namazi MR (2012) Glucosamine Enhances Tissue Regeneration in the Process of Wound Healing in Rats as Animal Model: A Stereological Study. J Cytol Histol 3:150. Abstract Introduction: Glucosamine (GA), a water soluble hexosamine made from chitin or chitosan, was showed to have stimulatory effect on matrix formation, enhancing inflammatory response, modulating hyaluronic acid synthesis which promotes extracellular matrix remodeling leading to better wound healing. GA was also shown to have antioxidant and immunomodulatory effect which play roles in wound healing process. In this study we aimed to determine the effect of topical administration of GA on wound healing process in rats as animal model. Material and methods: 36 Wistar rats were divided into 3 groups; the control group which received no treatment; the Glucosamine group that received GA gel with 2% GA concentration, and the Base group that was treated with the vehicle. A 1 cm full-thickness wound was created on the posterior of each rat's neck. Treatments took place every 24 hours for 15 days. The wound closure rate, volume density of collagen bundles and vessels, fibroblast population, length density and mean diameter of the vessels were estimated by using unbiased stereological and histomorphometrical methods. Results: GA enhanced the wound closure rate consequently as well as fibroblast proliferation, collagen synthesis and proliferation of hair follicles in contrast with the base and the control group. Although not statistically significant, GA also improved the revascularization process in the wound site. Conclusion: Results of this study indicate that GA has the potential for being used for treatment of skin wounds; however, still further evaluations on its mechanisms of action and clinical advantages and disadvantages should be performed.
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The effect of N-acetylglucosamine (NAG) on in vitro synthesis of glycosaminoglycans by human peritoneal mesothelial cells and fibroblasts was studied. In contrast to isosmotic concentrations of glucose, NAG increases the synthesis of hyaluronan by mesothelial cells and fibroblasts in a dose-dependent manner. This effect of NAG can be demonstrated in the presence of increased glucose levels in a medium, or in a medium mixed with effluent dialysate obtained from continuous ambulatory peritoneal dialysis (CAPD) patients. Glucose inhibits synthesis of sulphated glycosaminoglycans by peritoneal mesothelial cells and fibroblasts, whereas NAG stimulates their production. Our results demonstrate that NAG is an effective stimulator of the in vitro glycosaminoglycans synthesis by human peritoneal mesothelial cells and fibroblasts.