hondroitin retains moisture by drawing water molecules to the spaces among the hairs like a magnet (Fig. 4). Furthermore, since oxygen and nutrients carried by blood are dissolved in the water, chondroitin plays a role of distributing these components in the tissues by drawing the water.

That is, chondroitin supplies nutrients to the joint cartilage where no blood vessel exists, and plays a role of inhibiting the enzymes which decompose the joint cartilage and a role of accelerating the formation of a new joint cartilage. Thus, by the actions of chondroitin, the elasticity and plasticity, which are the functions of the joint cartilage can be maintained.