INTRODUCTION:

Osteoarthritis (OA) is the commonest form of arthritis found worldwide that can affect the hands, hips, shoulders and knees. It is responsible for the largest burden of joint pain and is the single most important rheumatological cause of disability and handicap.1,2 In Osteoarthritis, the cartilage that protects the ends of the bones breaks down and causes pain and swelling. Drug and non-drug treatments are used to relieve pain and/or swelling. Osteoarthritis commonly affects the hands, feet, spine and large weight-bearing joints, such as the hips and knees. Most cases of osteoarthritis have no known cause and are referred to as primary osteoarthritis. When the cause of the osteoarthritis is known, the condition is referred to as secondary osteoarthritis. These are food supplements show promise for helping people with osteoarthritis, those are Glucosamine sulphate, Chondroitin sulphate, SAMe (s-adenosylmethionine), Vitamin C ( ascorbic acid), Beta Carotene3 and many more.
Glucosamine:
Glucosamine is almost synonymous with osteoarthritis as it has benefits for osteoarthritis. It can be found naturally in the body and is used by the body as one of the building blocks of cartilage.Glucosamine is an amino sugar produced from the shells of shellfish (chitin) and it is a key component of cartilage. Glucosamine (C6H13NO5) is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, cell walls in fungi and many higher organisms, glucosamine is one of the most abundant monosaccharides.3
Glucosamine is necessary for the construction of connective tissue and healthy cartilage. It is the critical building block of proteoglycans and other substances that form protective tissues. These proteoglycans are large protein molecules that act like a sponge to hold water giving connective tissues elasticity and cushioning effects. This also provides a buffering action to help protect against excessive wear and tear of the joints. Without glucosamine, our tendons, ligaments, skin, nails, bones, mucous membranes, and other body tissues can not form properly.

Glucosamine works to stimulate joint function and repair. Everyone produces a certain amount of glucosamine within their bodies. Normally we generate sufficient amounts of glucosamine in our bodies to form the various compounds needed to generate connective tissue and healthy cartilage. But gradually the rate at which our bodies use glucosamine begins to gradually change with our increased athletic activity, injuries, burns, arthritis and other inflammatory disorders, age and other chronic degeneration.3 In such situations our bodies may not be able to keep up with the demand for glucosamine, leading to a decrease in the amount of proteoglycans produced. This can lead to a decrease in the amount of protective lubricating substances like the synovial fluids, which cushion our joints, and protects them from damage. In a nutshell, more glucosamine is needed but less is produced.
As the age advances, body loses the capacity to make enough glucosamine. Having ample glucosamine in the body is essential to producing the nutrients needed to stimulate the production of synovial fluid, the fluid which lubricates cartilage and keeps the joints healthy. Without enough glucosamine, the cartilage in weight-bearing joints, such as the hips, knees, and hands deteriorates. The cartilage then hardens and forms bone spurs, deformed joints, and limited joint movement. This is how the debilitating disease of osteoarthritis develops.4
Therefore, in short, glucosamine is a major building block of proteoglycans needed to make glycosaminoglycans, proteins that bind water in the cartilage matrix which also acts as a source of nutrients for the synthesis of proteoglycans and glycosaminoglycans. It is also a stimulant to chondrocytes and playing key factor in determining how many proteoglycans are produced by the chondrocytes needed to spur chondrocytes to produce more collagen and proteoglycans acts as a regulator of cartilage metabolism which helps to keep cartilage from breaking down. 5
Glucosamine is the supplement most commonly used by patients with osteoarthritis. It is an endogenous amino sugar that is required for synthesis of glycoproteins and glycosaminoglycans, which are found in synovial fluid, ligaments, and other joint structures. Exogenous glucosamine is derived from marine exoskeletons or produced synthetically. Exogenous glucosamine may have anti-inflammatory effects and is thought to stimulate metabolism of chondrocytes.
Glucosamine is available in multiple forms. The most common are glucosamine hydrochloride and glucosamine sulfate. Some products contain a blend of these, and many combine one of the forms with a variety of other ingredients. Glucosamine has been safely used in long-term clinical trials Overall, the evidence supports the use of glucosamine sulfate for modestly reducing osteoarthritis symptoms and possibly slowing disease progression.
Chondroitin
Chondroitin, an endogenous glycosaminoglycan, is a building block for the formation of the joint matrix structure. Chondroitin sulfate is a sulfated glycosaminoglycan (GAG) composed of a chain of alternating sugars (N-acetylgalactosamine and glucuronic acid). It is usually found attached to proteins as part of a proteoglycan.6 Chondroitin sulfate is an important structural component of cartilage and provides much of its resistance to compression. Along with glucosamine, chondroitin sulfate has become a widely used dietary supplement for treatment of osteoarthritis. Chondroitin is a molecule that occurs naturally in the body. It is a major component of cartilage,the tough, connective tissue that cushions the joints. Chondroitin helps to keep cartilage healthy by absorbing fluid (particularly water) into the connective tissue. It may also block enzymes that break down cartilage, and it provides the building blocks for the body to produce new cartilage.
Chondroitin sulphate Chondroitin is the most abundant glycosaminoglycan in cartilage and is responsible for the resiliency of cartilage and it has various effects in relieving symptoms of osteoarthritis and those are its anti-inflammatory activity, the stimulation of the synthesis of proteoglycans and hyaluronic acid, and the decrease in catabolic activity of chondrocytes inhibiting the synthesis of proteolytic enzymes, nitric oxide, and other substances that contribute to damage cartilage matrix and cause death of articular chondrocytes. chondroitin sulfate reduced the IL-1β-induced nuclear factor-kB (Nf-kB) translocation in chondrocytes. In addition, chondroitin sulfate has recently shown a positive effect on osteoarthritic structural changes occurred in the subchondral bone.7 A number of scientific studies suggest that chondroitin may be an effective treatment for osteoarthritis
Therefore, chondroitin sulphate is effective as it reduces osteoarthritis pain, improves functional status of people with hip or knee osteoarthritis, reduces joint swelling and stiffness and ultimately provides relief from osteoarthritis symptoms for up to 3 months after treatment is stopped
S-Adenosyl methionine
S-Adenosyl methionine (SAM, SAMe, SAM-e) is a dietary supplement that has been clinically shown to support and promote joint health, mobility and joint comfort.It is a compound produced by our bodies from methionine. Methionine is an amino acid found in protein-rich foods and a common co-substrate involved in methyl group transfers. SAM-e is critical in the manufacture of joint cartilage and in the maintenance of neural cell membrane function.8
Administration of SAMe exerts analgesic and antiphlogistic activities and stimulates the synthesis of proteoglycans by articular chondrocytes with minimal or absent side effects on the gastrointestinal tract and other organs and improving pain and stiffness related to osteoarthritis
Vitamin C
Vitamin C( ascorbic acid) may help reduce the progression of osteoarthritis. Vitamin C is involved in the formation of both collagen and proteoglycans (two major components of cartilage, which cushions the joints). Vitamin C is also a powerful antioxidant that helps to counteract the effects of free radicals in the body, which can damage cartilage. Ascorbic acid(vitamin c) is a sugar acid with antioxidant properties. Its appearance is white to light-yellow crystals or powder, and it is water-soluble. One form of ascorbic acid is commonly known as vitamin C. In human plasma, ascorbate is the only antioxidant that can completely protect lipids from detectable peroxidative damage induced by aqueous peroxyl radicals. Ascorbate appears to trap virtually all peroxyl radicals in the aqueous phase before they diffuse into the plasma lipids. Ascorbate is a highly effective antioxidant, as it not only completely protects lipids from detectable peroxidative damage, but also spares alpha-tocopherol, urate, and bilirubin.Ascorbic acid stimulates collagen synthesis and modestly stimulates synthesis of aggrecan (a proteoglycan present in articular cartilage), Sulfated proteoglycan biosynthesis is significantly increased in the presence of ascorbic acid thus it may offer some protective effect against the super oxide and free radicals and limiting and delaying the osteoarthritis progression

Beta-carotene
Beta-carotene belongs to a family of natural chemicals known as carotenoids. Widely found in plants, carotenoids along with another group of chemicals, bioflavonoids, give color to fruits, vegetables, and other plants.
Beta-carotene is another antioxidant that also seems to help reduce the risk of osteoarthritis progression. Beta-carotene is a particularly important carotenoid from a nutritional standpoint, because the body easily transforms it to vitamin A. While vitamin A supplements themselves can be toxic when taken to excess, it is believed (although not proven) that the body will make only as much vitamin A out of beta-carotene as it needs. Assuming this is true, this built-in safety feature makes beta-carotene the best way to get your vitamin A. A high dietary intake of beta-carotene is associated with a significantly slower progression of osteoarthritis, according to a study in which researchers followed 640 individuals over a period of 8 to 10 years .10
Conclusion:
In conclusion,there are nutrients and foods that may help to halt the progression osteoarthritis before it becomes severe as well as helping to reduce the pain and inflammation associated with it.



n.b.: This article was an exercise of e learning by final year medical student Saleh from Melaka Manipal Medical College


REFERENCES

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