NAC Fights Muscle Fatigue

SAO PAULO, BrailN-acetylcysteine (NAC) exerts antioxidant effects to protect against muscle injury, according to a new study (Scand J Med Sci Sports. ePub 2010 Jul 27). Researchers from the Institute of Biomedical Sciences at the University of Sao Paulo randomized male Wistar rats to determine the effect of NAC on fatiguing contractile activity-induced injury. The placebo group received an injection of phosphate buffer prior to contractile activity induced by electrical stimulation. The NAC group received 500 mg/kg of NAC, dissolved in the buffer, one hour prior to stimulation. Researchers examined several parameters including tetanic force, muscle fatigue, plasma activities of creatine kinase (CK), changes in muscle vascular permeability and muscle content of reactive oxygen species (ROS) and thiobarbituric acid-reactive substances (TBARS).

NAC treatment delayed muscle fatigue and preserved tetanic force in the animals. Further, it decreased plasma CK and lactate dehydrogenase (LDH) activities. NAC also decreased muscle-derived ROS and TBARS activity in the muscles. The researchers concluded NAC protected against muscle injury induced by fatiguing contractile activity.