Chondroitin: benefits, dosage, contraindications

Vision

Chondroitin has viscoelastic properties that make it useful for ophthalmic applications. Chondroitin sulfate is used as a viscoelastic substance to protect and lubricate cells and tissues during eye surgery, as well as to preserve corneas prior to transplantation. In corneal organ culture in vitro, chondroitin sulfate inhibited the adhesion of Candida albicans.

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Bone density

Chondroitin exerts anti-arthritic effects by stimulating the synthesis of proteoglycans (it is a glycoprotein, a combination of a protein and a glycosaminoglycan) and by reducing the catabolic activity of chondrocytes (the cells that make up cartilage). Indeed, it inhibits the synthesis of proteolytic enzymes and has anti-inflammatory activity and effects on osteoblasts in the subchondral bone, with a decrease in bone resorption. Moreover, chondroitin appears to protect cartilage against degradation by inhibiting enzymes in the synovial fluid, such as elastase and hyaluronidase, which damage articular cartilage. It improves the nutrition of chondrocytes by increasing the production of hyaluronic acid in joint cells and therefore the fluid content of the extracellular matrix, which not only acts as a shock absorber but also supplies nutrients to the cartilage.

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Anti-inflammatory

Chondroitin exerts an anti-inflammatory action with an inhibitory effect on complement. In an in vitro study of bovine cartilage, chondroitin alone, and in combination with glucosamine, regulates gene expression and the synthesis of nitric oxide and prostaglandin E2, which may explain its anti-inflammatory properties. It has been suggested that the multiple anti-inflammatory effects of chondroitin in chondrocytes and synoviocytes are mainly due to a common mechanism, through inhibition of NF-κB nuclear translocation (a protein involved in the immune response and the cellular stress response). Furthermore, it has also been shown that chondroitin sulfate inhibits the production of prostaglandin E2 and matrix metalloproteinases (a family of enzymes of the peptidase class that have a metal ion in their active site) in osteoblasts, which suggests that the action of chondroitin in osteoarthritis is not only due to effects on cartilage but may also be due to effects on subchondral bone.

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Anticancer

In vitro evidence suggests that exogenous chondroitin sulfate regulates the adhesion, motility, and migration of fibrosarcoma cells (a malignant tumor that originates in fibrous connective tissues). There is also evidence that chondroitin may be useful in cancer surveillance. Indeed, the concentration of chondroitin sulfate is increased in the prostatic tissue of men with prostate cancer. There is evidence that measurements of endogenous chondroitin sulfate in the peritumoral stromal tissue of the prostate may be a useful biomarker for disease progression in prostate cancer.

Antiviral

Preliminary research suggests that the chemically oversulfated form of chondroitin is active against HIV, herpes simplex virus, human cytomegalovirus, and dengue virus.

Neurological

In vitro and in vivo evidence suggests that the antioxidant and anti-inflammatory effects of chondroitin contribute to its neuroprotective properties.