MAIN GOALS FOR THERAPY OF JOINTS

1.    Shift net balance of chondrocyte metabolism from a catabolic to an anabolic process.

2.    Stimulate production of collagen and proteoglycans, while inhibiting degradation.

3.    Attempt to scavenge free radicals and promote non-COX-mediated anti-inflammatory effects.    

*DMOADs:   Disease modifying osteoarthritic drugs
*SYSADOAs:  Symptomatic slow-acting drugs for osteoarthritis        

*    These acronyms now largely replace “chondroprotection”

DEFINITIONS
 
GLUCOSAMINE:
-    An aminosaccharide used in the synthesis of glycosaminoglycans (GAGs)

GLYCOSAMINOGLYCANS (GAGs):
-    Forms side chains of proteins found in hyaline cartilage

CHONDROITIN:
-    GAGs found in hyaline cartilage (extracted from bovine trachea and lungs)

HYALINE CARTILAGE:
-    The smooth covering of joints that allows gliding action.
-    80% of cartilage is water; 10% is collagen; 10% is proteoglycan
-    Chief nourishment comes from synovial fluid, with 7 to 10% coming from blood vessels in subchondral bone

POLYSULFATED GLYCOSAMINOGLYCANS (PSGAGs):
-    Highly sulfated GAGs
-    Mostly comprised of chondroitin sulfate
-    Possible anabolic (building) effects
-    Decrease cartilage catabolic (breakdown) effects (i.e. degradative collagenase enzyme on articular cartilage invitro)
-    Protective effect on cartilage homeostasis in osteoarthritis
-    **  Precise mechanism unknown
-    i.e. Adequan:  stimulates HA synthesis by synovial membrane; has anti-inflammatory/ analgesic properties

COLLAGEN:
-    Supportive protein fibers that are imbedded in the matrix of material that makes up the cartilage layer

HYALURONANS:
-    Hyaluronic acid (HA)
-    Lubricates, nourishes, helps eliminate waste products from joint.
-    A non-sulfated GAG
-    Major constituent of synovial fluid lubricant of synovial membranes
-    Present in articular cartilage
-    Synthesized by chondrocytes and synoviocytes

PROTEOGLYCANS:
-    Molecules that provide shock absorption by attracting H2O from synovial fluid
-    Contain GAGs (chondroitin and kerato sulfate) which aggregate with hyaluronic acid

FLAVANOIDS:
-    Plant-derived chemicals responsible for colors/pigments of fruits and vegetables (early Vitamin P)
-    i.e. flavones, isoflavones, anthrocyans, flavonols
-    Flavanols: i.e. quercetin, retin, hesidenin
-    Potent antioxidants which decrease inflammation
-    Increase glutathione antioxidane
-    Possible use in human heart disease
-    Regulates immune responses and controls reactions of T and B lymphocytes, mast cells, and neutrophils
-    Inactivated by processing, high heat, farming