For example, we know of at least one animal study [11] and one human study [10] that has focused on the role of MSM to attenuate exercise-induced oxidative stress. Marañon and colleagues studied competitive jumping horses receiving

either a standard control diet, a MSM diet (8 mg/kg MSM), or a combined MSM + vitamin C diet (8 mg/kg MSM + 5 mg/kg vitamin C) for a period leading up to competition [11]. Blood was collected before and within 15 minutes following competition and analyzed for a variety of oxidative Ku-0059436 in vivo stress markers. The competitive exercise resulted in noted increases in lipid peroxidation, nitric oxide metabolites, and carbon monoxide, with decreases in reduced glutathione and antioxidant enzyme activity. Supplementation with MSM significantly attenuated the observed

changes due to competition, with a more pronounced effect noted with MSM + vitamin C treatment. Moreover, in a recently published human study [10], MSM supplementation at 50 mg/kg was provided to untrained healthy men for 10 days prior to performing a 14 km run. Blood was collected before and at times through 48 hours of exercise recovery and analyzed for lipid, protein, and glutathione oxidation. As expected, acute exercise resulted in an increase in oxidative stress; however, this increase was blunted significantly with MSM supplementation as compared to placebo. Collectively, the results Fedratinib mouse of Marañon et al. [11] and Nakhostin-Roohi et al. [10] provide initial evidence that prophylactic intake of MSM prior to exercise may alleviate the oxidative stress that is often observed following strenuous bouts of exercise, in particular in those who are not accustomed to the stress of exercise [20]. Although ROS have been linked to potential problems in muscle integrity and the generation of muscle force [21], the above

studies did not include any measure of physical performance in the design. This is certainly a limitation and such measures should be considered in future studies investigating the impact of MSM on isometheptene exercise recovery. Aside from measures of antioxidant status (TEAC and glutathione), we included the measure of homocysteine in the current design. Homocysteine is a non-protein amino acid, with elevated levels in circulation thought to be associated with an increased risk of cardiovascular disease; although recent evidence questions this association [22]. A study by Kim et al. reported a statistically significant lowering of homocysteine (8.0 to 7.2 μmol·L-1) in a sample of knee osteoarthritis patients following intake of MSM at a dosage of 6 grams per day for 12 weeks [4]. Data from the present investigation somewhat corroborate the work of Kim and colleagues, as we noted a lowering of homocysteine during the post-exercise period after subjects were supplemented with MSM for four weeks (Figure 3).