Equine joint supplements may contain a wide variety of ingredients, including nutraceuticals and herbs. It’s not known precisely how these ingredients work, but some information that is available is outlined below.
Supplies building blocks for glycosaminoglycan synthesis, stimulates hyaluronic acid production, and inhibits inflammatory mediators including nitric oxide, nuclear factor kappa B, and prostaglandin E2, and degradative enzymes such as collagenase and aggrecanase. Glucosamine protects against cartilage degradation in damaged or osteoarthritis samples in vitro. Neither glucosamine nor chondroitin have been found to inhibit COX enzymes.
Its mode of action is believed to be a replacement of the proteoglycans in articular cartilage, which are lost in damage and/or inflammation, an anti-inflammatory effect and inhibition of enzymes involved in cartilage breakdown, as for glucosamine. Chondroitin also protects against cartilage degradation in damaged or osteoarthritis samples in vitro.
The biologically active ingredients are boswellic acids, and research studies have found that in particular, a compound called 3-O-acetyl-11-ketobetaboswellic acid (AKBA) seems to be active in inhibiting the action of 5-lipoxygenase, an enzyme involved in inflammation. The extra benefit of using boswellia as a joint-supporting supplement is that it doesn’t have the cartilage-degradative and stomach-irritating properties of commonly-used anti-inflammatory drugs.
A biologically available source of sulphur, MSM’s therapeutic properties are believed to come from its antioxidant activity. It also has anti-inflammatory effects and blocks inflammatory mediators in human cartilage cells.
A group of pigments giving turmeric its yellow colour, curcuminoids, are believed to be the active component. Curcuminoids are powerful antioxidants and anti-inflammatories. They inhibit the inflammatory mediator nuclear factor kappa B and block the interleukin-1-induced degradation of cartilage in in vitro models.
The active components – primarily phenolic compounds including gingerols – act on inflammatory mediators, inhibiting both prostaglandin and leukotriene synthesis, and inhibiting COX enzymes, thus having an anti-inflammatory effect.
These active ingredients are fed to a great number of horses. Joint-supporting products are the biggest selling supplements, and many owners report good results. Recent research is encouraging. Researchers at Texas A&M University have found that supplementary glucosamine (15 g for a 500 kg horse) tended to ‘increase new cartilage production’ and ‘decrease the breakdown of existing cartilage’ in damaged joints of young horses. Researchers at the Animal Health Trust in Newmarket, UK recently presented a study showing that adult horses with slight lameness (1/10 to 4/10 lame) fed a joint supplement (containing a variety of ingredients including glucosamine and MSM) had a lower lameness grade than those on a placebo or before supplementation.