Glucosamine: A Simple Ingredient for Health and Skin Care Benefits
In the world of science, it's no longer just a question of inventing new and wondrous ingredients. Rather, scientists are finding new applications and more potent forms of tried and tested remedies. Used clinically in Europe since the 1960s, glucosamine gained popularity in the U.S. in the mid-1990s as a treatment for joint and arthritis pain. However, recent research indicates that glucosamine may have a variety of other applications, including several dermatologic/cosmetic applications.
Glucosamine is a 6-carbon amino sugar occurring throughout nature, primarily as derivatives such as N-acetyl glucosamine. Polymers of N-acetyl glucosamine, or chitin, are found in a variety of organisms, from fungi to insects to marine invertebrates (for example crabs and shrimp), where it is a principle component of the exoskeleton (shell).
Chitin in its de-acetylated form has found utility in several chemical applications, such as water treatments, photographic emulsions and dye enhancers for synthetic fibers and fabrics. However, glucosamine, whether as a derivative such as chitin or as another polymer, is also widely used in biological applications.
Biological Role and Applications of Glucosamine
Glucosamine is a fundamental building block for important biopolymers such as hyaluronic acid. Such polymers serve critical functions in joints and skin. In joints, the biopolymers provide cushioning between adjoining bones in the hip, knee and ankle, as well as elasticity in the joint. Over time or with physical injury, there is potential damage to and loss of these polymers, which contributes to the pain and stiffness of joints many associate with age or arthritis.
Clinical studies have shown the benefits of reduced joint pain and stiffness and increased joint flexibility. This has contributed to the introduction of over-the-counter glucosamine supplements that many consumers use to reduce the pain they may feel from these conditions, or in order to maintain flexibility prior to any potential loss. Such oral supplements have also been widely used in veterinary medicine for aging household pets and for larger animals such as horses to extend their riding and jumping careers.
Hyaluronic acid also serves as a water-binding polymer in the skin. By binding and retaining some moisture in a wound, repair such as reepithelialization can proceed more quickly. This water-binding effect is also important for cosmetic uses of glucosamine. It can increase the skin's content of hyaluronic acid to increase moisturization, leading to enhanced skin barrier properties and reduced dryness.
Glucosamine has also been reported to have potential to inhibit skin melanin production. In in vitro melanocyte cell culture evaluation, glucosamine has been shown to inhibit glycosylation, the addition of polysaccharide units to proteins. Glycosylation is a required step in the conversion of certain inactive pro-enzymes to their active forms. Active tyrosinase, a key enzyme in the pathway for melanin production, is glycosylated. Thus, glucosamine inhibits the production of melanin in melanocytes.
Challenge for Use of Glucosamine in Cosmetic Products
Glucosamine has the potential to deliver important skin care benefits, such as barrier enhancement, moisturization and tone evenness. A challenge with this ingredient in emulsion formulation is its potential to easily oxidize, which results in yellow-brown products. Scientists are working to deal with this problem by defining a pH where oxidation is minimized, including antioxidants A substance that reduces oxidative damage. This damage due to ROS most commonly is related to free radicals. An antioxidant usually works by giving up one of its own electrons to quench the free radical. It also helps stop the ongoing chain reaction or further propagation of free radicals which can lead to additional damage. (not including oxygen) when creating product formulas and using oxygen impermeable packaging. Additionally, using stable - yet still skin-active - derivatives of glucosamine may offer a satisfactory solution.