The Importance of Glucosamine and chondroitin sulfate

Glucosamine and chondroitin sulfate are natural substances found in and around the cells of cartilage. Researchers believe these substances may help in the repair and maintenance of cartilage. In addition, researchers believe that glucosamine inhibits inflammation and stimulates cartilage cell growth, while chondroitin sulfate provides cartilage with strength and resilience.

Chondroitin Sulfates are one of six glycosaminoglycans (GAGs), formerly knows as mucopolysaccharides. They are composed of an amino sugar, galactosamine (the immediate precursor of which is glucosamine), and a sugar acid (glucuronic). CS are long chains of repeating disaccharides that are sulfated. Two other GAGs are also sulfated, keratan and dermatan. Sulfated GAGs have negative charges which cause them to repel each other and attract water, which in turn fills space in three dimensions and enables cartilage to absorb shock. The chains of CS are much longer than the other sulfated GAGs. This is one of the reasons some people feel that CS is the most important GAG. The second way CS can be defined is as a dietary supplement in a new category called chondroprotective nutraceuticals.

A systematic analysis of clinical trials on glucosamine and chondroitin sulfate for treating osteoarthritis (OA) has shown that these compounds may have some efficacy against the symptoms of this most common form of arthritis, in spite of problems with trial methodologies and possible biases. The study, by Timothy E. McAlindon, D.M., and colleagues at the Boston University School of Medicine, published in the March 15, 2000, issue of the Journal of the American Medical Association (JAMA), recommends that additional, rigorous, independent studies be done of these compounds to determine their true efficacy and usefulness.

"About 21 million adults in the United States have OA," says Stephen I. Katz, M.D., Ph.D., director of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), which funded this study and has helped launch a major clinical trial on the compounds in OA, along with the National Center for Complementary and Alternative Medicine (NCCAM), both parts of the federal government's National Institutes of Health (NIH). "Effective treatments are key to improving the quality of life of Americans affected by this common disorder."

OA, also called degenerative joint disease, is caused by the breakdown of cartilage, which cushions the ends of bones within the joint. It is characterized by pain, joint damage, and limited motion. It generally occurs later in life, and most commonly affects the hands and large weight-bearing joints, such as the knees and hips.

The Boston researchers point out that glucosamine and chondroitin sulfate have received significant media attention and have been used in Europe for OA for over 10 years. The researchers say that physicians in the United States and the United Kingdom have been skeptical about these products, probably because of well-founded concerns about the quality of scientific trials conducted to test them. Glucosamine and chondroitin sulfate, which are sold in the United States as dietary supplements, are natural substances found in and around the cells of cartilage. Researchers believe these substances may help in the repair and maintenance of cartilage.

In a double-blind, placebo-controlled trial of 119 patients with osteoarthritis of the fingers, the group which received oral CS at 400 mg three times a day had no progression of osteoarthritis in their fingers, unlike the placebo group, who had evidence of continuing degeneration.

In a short trial, 24 patients with osteoarthritis were given CS in a single dose of 800 mg daily for 10 days. Joint aspiration revealed an increase in hyaluronic concentration and joint viscosity, and a decrease in phospholipase A2, a marker of inflammation. Researchers also stated that the CS group displayed a decrease in collagenolytic activity. This paper demonstrated that oral administration of chondroitin sulfate reaches target tissues (synovial fluid and cartilage) at levels that can be objectively measured in less than two weeks.

The effects of chondroitin sulfate-C on type II (CII) collagen - induced arthritis in mice were evaluated. DBA/1J mice were immunized with bovine CII emulsified in Freund's complete adjuvant, followed by a booster injection 21 days later. Chondroitin sulfate-C at doses of 100, 300 and 1000 mg/kg was administered orally once daily beginning 14 days before initial immunization. An arthritis index and hind paw edema were examined from day 0 to day 49, when the mice were killed by ether anesthesia for histopathological examination. The delayed-type hypersensitivity (DTH) reaction, serum anti-CII antibody titer, and histopathologic characteristics of both synovitis and destruction of articular cartilage were analyzed. Both the arthritis index and the serum anti-CII antibody titer were reduced by treatment with chondroitin sulfate-C in a dose-dependent manner. Chondroitin sulfate-C (1000 mg/kg) significantly inhibited hind paw edema, synovitis and destruction of the articular cartilage, but not DTH reaction.



The signs and symptoms of osteoarthritis are common complaints seen in patients suffering with chronic temporomandibular disorders (TMD), specifically, internal derangements with a diagnosis of osteoarthritis. With or without the complaints of pain and swelling, joint noises are bothersome and annoying to both the patient and at times, to those seated close to the patient during mealtime. In fact, many patients are driven to seek care by family members because of his or her TMJ noises. For years in veterinarian medicine, glucosamine and chondroitin sulfates have been used to treat symptoms of osteoarthritis. Recently, the use of these two supplements has been recommended for human beings as well. Reports of decreased joint noises, pain and swelling after the administration of therapeutic doses of these supplements have sparked an interest in their possible use in the treatment of osteoarthritis.

This is an impressive set of studies which show that standing alone CS can help patients suffering from osteoarthritis. Based on these studies, oral ingestion of chondroitin sulfate is safe, well tolerated, and is equally effective when taken all at once or in divided doses. It appears that chondroitin sulfate helps patients in three ways: the first being metabolic by increasing joint viscosity; the second is in an antidegradative fashion by reducing collagenolytic activity; and the third is by reducing inflammation, which was demonstrated in the Ronca paper by showing decreased levels of phospholipase A2 in inflamed joints. In turn, this leads to less pain, greater mobility and an apparent retardation of joint space erosion.

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