What Chondroitin Sulfate is?

Chondroitin sulfate is the main component of the extracellular network of cartilage, and it plays an important role in maintaining the structural integrity of the tissue.

Capable of binding and releasing water molecules due to their negative side charges, Chondroitin- proteins complexes can modify the characteristics of cartilaginous tissues varying loads, conferring cartilage its typical hardness, elasticity, surface smoothness and capacity to absorb and dampen mechanical stress and strain.

Chondroitin Sulfate, a glycosaminoglycans (GAGS), actively participates in the physiology of cartilaginous tissue, and it is the basic element of the amorphous extracellular substances of connective tissues. The main constituents of cartilaginous tissue are Chondroitin Sulfate A (Chondroitin -4-Sulfate) and Chondroitin Sulfate C (Chondroitin-6-Sulfate) and, to a lesser degree, keratin Sulphate and hyaluronic acid. They are glycoside polymers formed by repetition of dissacharides units composed of a hexoxamine (present as a sulfuric acid ester and hexuronic acid).

The number of negative charges present in the molecules is fundamental to their biological activities, due to the carboxylic groups and dissociated sulfates.

Chondroitin Sulfate is present in the human body in complexes with proteins building proteoglycans (PGs), which are present in the cartilaginous matrix in the form of gel, in contact with the collagen networks which form the structural support for cartilaginous tissue. The chondrocytes are responsible for the synthesis and, presumably, for the maintenance of the network as well.

In inflammatory and non-inflammatory joint diseases there is a reduction in the concentration of PGs due to both depolymerization of their GAG precursors, which experience a net loss, and the synthesis of altered and smaller PGs with reduced aggregation capacity and which are hydrodynamically less active than normal. Their bonds are weaker, leading to permeability to enzymatic molecules, which can attack PGs and collagen fibres more easily, since they lack the protection offered by the Chondroitin complex.