D-glucosamine and N-acetyl d-glucosamine: Their potential use as regenerative medicine

Abstract

Glucosamine (GlcN), an amino sugar, is a compound derived from substitution of a hydroxyl group of a glucose molecule with an amino group. GlcN and its acetylated derivative, N-acetylglucosamine (GlcNAc), have been widely used in food, cosmetics, and pharmaceutical industries and are currently produced by acid hydrolysis of chitin (a linear polymer of GlcNAc) extracted from crab and shrimp shells. In this review, distribution and production of GlcN and GlcNAc, their chemistry and determination in the complex samples will be treated first. This review will describe the procedure to identify a high-quality glucosamine product for Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) and to clarify confusing product information and nomenclature. GlcN is a precursor of the glycosaminoglycans and proteoglycans that make up articular cartilage. Glucosamine sulfate and glucosamine hydrochloride have used for the treatment of osteoarthritis for more than 30 years, with no major known side effects. The notion that augmenting the intake of the precursor molecule, glucosamine, may directly stimulate articular proteoglycan synthesis to modulate osteoarthritis has provided the rationale for its widespread use. Theoretically, exogenous glucosamine may augment glycosaminoglycan synthesis in cartilage. There is a simultaneous theoretical concern that it might also induce insulin resistance in insulin-sensitive tissues. While the efficacy of glucosamine was published in the definitive medical journals, there were views against it. This concern will be also discussed. While glucosamine was not effective without combination with chondroitin sulfate in the some trial, glucosamine alone was effective in the other trial. Some concerns about these trials will be discussed together with the mechanism of action of glucosamine and chondroitin for antiarthritic potential. Finally, the review will focus on the biomedical and other application of the glucosamine and chitosan oligosaccharide. Such biomedical applications include wound healing, bone regeneration, antibacterial effect, and oral hygiene. It also discusses the role of chitosan oligosaccharide as a drug carrier for molecular therapies, such as the drug and the gene delivery systems and the role in imaging for tumor and cancer detection.