Methyl Sulphonyl Methane, more commonly known as MSM, is a naturally occurring sulphur compound. It was assessed in conjunction with Vitamin C to see if it could alleviate exercise-induced oxidative stress in horses.
Twenty-four jumping horses involved in competition during winter in the south of Spain were used.
Horses were given one of the following three treatment diets: The control diet had no supplementation. Another had MSM at 8mg per kilogram of body weight, and the third diet comprised MSM at the 8mg rate as well as Vitamin C at 5mg per kg.
Blood samples were collected before exercise and afterwards. Nitric oxide, carbon monoxide, lipid hydroperoxides and the antioxidant enzymes, glutathione peroxidase, glutathione transferase and glutathione reductase, plasma levels were determined.
The researcher found that competition induced a significant increase in lipid peroxidation, nitric oxide and carbon monoxide. The exercise also reduced glutathione as well as antioxidant enzyme activities.
However, MSM administration significantly eased all these exercise-related changes, and this effect was improved by Vitamin C, reaching values in some of the parameters similar to those found before competition.
"These results suggest that jumping exercise could induce harmful effects on horses, probably due to an increase in oxidative damage and proinflammatory molecules," the researchers said.
"In addition, we have demonstrated that MSM could exert some protective effect on oxidative and inflammatory exercise-induced injury."
Vitamin C is a powerful natural antioxidant in mammals. It is present in high concentrations in leukocytes and there is evidence that it is involved quenching cellular reactive oxygen species.
However, results from previous studies examining supplementation with Vitamin C exercise-stimulated oxidative damage have been inconclusive.
On the other hand, MSM is known to play a role in the synthesis of glutathione and is one of the most important intracellular antioxidants.
MSM has been shown to provide protection against many diseases in humans, such as hyperacidity, parasites, constipation, musculoskeletal pain, arthritis and allergies.
"However, to our knowledge little is known about the mechanism by which MSM may exert its protective effect against exercise-induced oxidative stress in horses."
The 24 horses in the study were aged 8 to 13 and comprised 2 stallions, 13 geldings and 9 mares. They were assigned randomly to each of the diets for the research.
The researchers said their findings suggest the need to investigate the mechanisms behind the protective effect of MSM, in order to develop strategies capable of increasing the performance in sport horses.