Chondroitin sulfate is a chemical found in human and animal cartilage. It is usually taken orally with glucosamine or other ingredients to treat osteoarthritis. Chondroitin sulfate is one of the building blocks of cartilage. In osteoarthritis, the cartilage in the joints breaks down. Taking chondroitin sulfate might slow this breakdown. It is usually made from animal sources, such as shark and cow cartilage. It can also be made in a lab.

Figure 1. Chondroitin Sulfate

Chondroitin sulfate is used to treat osteoarthritis and cataracts. It is usually taken with other ingredients, including manganese ascorbate, hyaluronic acid, collagen peptides, or glucosamine. Chondroitin sulfate is also used for many other conditions, but there is not enough scientific evidence to support these uses.

Uses

Cataracts.

The FDA has approved an injection containing chondroitin sulfate and sodium hyaluronate for eye protection during cataract surgery. It is not clear whether taking chondroitin sulfate in a different form helps.

Osteoarthritis.

Taking chondroitin sulfate by mouth appears to relieve osteoarthritis pain and improve function. High-quality, pharmaceutical-grade products show the greatest benefit. Chondrosulf (IBSA Institut Biochimique SA), Chondrosan (Bioiberica, S.A.), and Structum (Laboratoires Pierre Fabre) are examples of these products.

Mechanism of Action

Chondroitin sulfate is a major component of the complex extracellular matrix. It has been proposed that the supply of chondroitin sulfate provides new building blocks for the synthesis of new matrix components.

The anti-inflammatory effects of chondroitin sulfate are thought to be caused by the inhibition of the synthesis of inflammatory intermediates, such as inhibition of nitric oxide synthase, COX-2, microsomal prostaglandin synthase 1, and prostaglandin E2. Toll-like receptor 4 is also reported to have inhibitory activity, followed by inhibition of the inflammatory cytokines NFkB and MyD88. This activity suggests that the MAP kinase pathway is modulated. On the other hand, some reports suggest that the PKC/PI3K/Akt pathway is induced in neuroblastoma.

The anabolic effects of chondroitin sulfate are thought to occur by inhibiting metalloproteinases such as MMP-1, -3, and -13, and ADAMTS-4 and -5).

Side Effects

When taken orally: Chondroitin sulfate is POSSIBLY SAFE for up to 6 years. It can cause mild stomach pain and nausea. Other possible side effects include bloating, diarrhea, and constipation.

When put into the eye: Chondroitin sulfate is POSSIBLY SAFE when used with other ingredients in eye drops.