Chondroitin Sulfate and Hyaluronic Acid

7 Chondroitin Sulfate, Heparin and Hyaluronic Acid pH/ Ion-Responsive Networks 

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The dimethylamino sugar mycaminose is a constituent of riiacrolide antibiotics synthesized in Actinomycetes (D 4). 2-Methylamino-L-glucose and 2,6-diamino-D-glucose are building blocks of amino and guanidino cyclitol antibiotics (D 1.3). Also the polysaccharides heparin, chondroitin sulfate, and hyaluronic acid (Table 22) formed in animals contain amino sugars. 

Polysaccharides containing carboxyl groups, such as chondroitin sulfate and hyaluronic acid, are derivatized with cysteine methyl ester by substituting carboxyl groups of polysaccharides and subsequently cross-linked by mild oxidation to form hydrogels. IPNs and semi-lPNs can also be degraded from backbone. 

Denuziere, A., Ferrier, D. and Domard, A. (2000) Interactions between chitosan and glycosaminoglycans (chondroitin sulfate and hyaluronic acid) physicochemical and biological studies, Ann. Pharmaceut. Francoises 58,47-53. 

In various types of arthritis, proteoglycans may act as autoantigens, thus contributing to the pathologic feamres of these conditions. The amount of chondroitin sulfate in cartilage diminishes with age, whereas the amounts of keratan sulfate and hyaluronic acid increase. These changes may contribute to the development of osteoarthritis. Changes in the amounts of cer-... 

Fig. 2 Structures of the major and minor disaccharide sequences of heparin and heparan sulfate as well as the major disaccharide units of chondroitin sulfate, dermatan sulfate, keratan sulfate, and hyaluronic acid, where Ac is acetyl.

Six major classes of glycosaminoglycans There are six major classes of glycosaminoglycans. These include chondroitin 4- and 6-sulfates, keratan sulfate, dermatan sulfate, heparin, heparan sulfate, and hyaluronic acid. 

Figure 3 Proposed interactions between mechanical strain, proteoglycans (PGs), and transforming growth factor (TGF)-P in the extracellular environment of the airway wall. Excessive mechanical strain stimulates fibroblasts to increase PG secretion and deposition. The altered viscoelastic properties of the matrix subsequently modulate transmission of the mechanical signal to the airway structural cell and, thereby, protect the cell from mechanical strain-induced injury. In addition, increases in decorin may result in enhanced binding of TGF-P and thereby influence the effects of this cytokine on the fibroblast. Finally, changes in small PGs, such as decorin and lumican, may affect formation of collagen fibrils. CS, chondroitin sulfate HA, hyaluronic acid.

The hyaluronidases under consideration here have three important characteristics (1) whether they act upon choiidroitin sulfates, as well as chondroitin itself and hyaluronic acid (2) whether traiisglycosylation is a strong feature of their activity and (3) whether they catalyze the hydrolysis of an endohexosamiiiidc linjkage, or act by an intramolecular ohmination of w ater (hyaluronate lyase E.C.4.3.99.1) to produce oligosaccharides with nonreduciiig terminal unsaturated uronic acid residues of the type LIX. 

The dermis contains several types of cells, including fibroblasts, fat cells, macrophages, histiocytes, mast cells, and cells associated with the blood vessels and nerves of the skin. The predominant cell is the fibroblast, which is associated with biosynthesis of the fibrous proteins and ground substances such as hyaluronic acid, chondroitin sulfates, and mucopolysaccharides. 

Chondroitin Sulfate and Glucosamine in OA therapy have efficacy comparable to placebo as showed by a National Institute of Health study. Intraarticular hyaluronic acid for pain relief is inferior compared to intraarticular corticosteroids. Temporary crepitus reduction or eradication may last several years in radiological stages I and II Knee OA with intraarticular hyaluronic acid. 

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