Metabolic effects of avocado/soy unsaponifiables on articular chondrocytes.

Avocado/soy unsaponifiable (ASU) components are reported to have a chondroprotective effect by virtue of anti-inflammatory and proanabolic effects on articular chondrocytes. The identity of the active component(s) remains unknown. In general, sterols, the major component of unsaponifiable plant material have been demonstrated to be anti-inflammatory in vitro and in animal models.

Collagen Synthesis in tenocytes, ligament cells and chondrocytes exposed to a combination of Glucosamine HCl and chondroitin sulfate.

Clinical testing of the nutraceuticals glucosamine (glcN) and chondroitin sulfate (CS) has shown efficacy in providing relief from symptoms in osteoarthritic patients. In vitro and in vivo studies support existence of a synergistic relationship upregulating synthetic activity in chondrocytes. A combination of glcN and CS may also be useful as adjunct therapy in sports-related injuries if similar upregulation of collagen synthesis is elicited in accessory ligament and tendon joint tissue.

Smoking and osteoarthritis: differential effect of nicotine on human chondrocyte glycosaminoglycan and collagen synthesis.

Anecdotal suggestions and retrospective studies indicate an inverse relationship between the incidence of osteoarthritis and individuals who smoke. As a possible explanation, our studies confirm that nicotine upregulates glycosaminoglycan and collagen synthetic activity of articular chondrocytes at physiological levels seen in individuals who smoke.

Differential effects of nicotine and smoke condensate on bone cell metabolic activity.

Objective: Delayed or impaired healing of skeletal trauma in patients who smoke has been attributed to vascular responses of nicotine absorption and/or a direct effect of nicotine or other smoke components on bone cells. In vivo studies indicate variability in osteosynthetic response to nicotine versus smoke inhalation. We tested the hypothesis that components of cigarette smoke other than nicotine may be responsible for the adverse skeletal effects of smoking.

Glucosamine and chondroitin sulfate: biological response modifiers of chondrocytes under simulated conditions of joint stress.

Objective: To test the hypothesis that chondrocytes are more responsive to the chondroprotective agents, glucosamine (glcN) and chondroitin sulfate (CS), under in vitro conditions simulating in vivo joint stress.

Design: Synthetic and anticatabolic activities of bovine articular cartilage were assayed using 35-sulfate labeling and assaying the specific activity of glycosaminoglycans (GAGs) under the conditions of enzyme-induced matrix depletion, heat stress, mechanical compression and cytokine stress.

Results: The response of cartilage to simulated conditions of in vivo stress varies, depending on the type stress and age of the animal.