Protective Effects And Selective Antioxidation Mechanism Of Hydrogen-Rich Water On Exercise-Induced Oxidative Stress Damage In Skeletal Muscle

Extensive researches confirmed that the acute intensive exercise, resulting inoxygen radicals increase, LPO accumulation, nitrite rise and antioxidant enzymesreduce, always caused LPO injury, protein and DNA damage, muscular fatigue, muscledamage, exercise impairment, excessive training and so on. So, large numbers ofadditional antioxidants were suggested to be supplemented to relieve oxidative damage,enhance competitive ability and extend sports life. In2007, an international study firstindicated that hydrogen-rich water, a fairly better antioxidant characterized by selectiveantioxidation, could significantly treat ischemia/reperfusion oxidative injuries.However,up to now, the study of hydrogen-rich water on exercise-induced oxidative stressdamage was still left a blank, especially, of which in vivo selective antioxidation andinherent mechanism remained unclear.Objective:This research was designed, with skeletal muscle, the organ of power supplyvulnerable to attack by ROS, to study the effects of hydrogen-rich water onexercise-induced oxidative stress damage, in such respects as ROS level, signaltransduction molecules, antioxidant defense system, exercise ability and so on,especially, to explore its in vivo selective antioxidation and probable mechanism by themethods of ROS determination.Methods:Eighty healthy SD male rats were equally and randomly divided into eight groups：sedentary control group（EC,C），exercise control group（EE,E）, intraperitoneal injectionof hydrogen-rich water before exercis（eEH,H）and combined intraperitoneal injection ofhydrogen-rich water before﹠after exercise（EM,M）.One week before experiment, each group, except EC and C, exercised for adaptation on a treadmill at low speed of10m·min^-1with0°slope for10min once a day.During formal experiment, intraperitonealinjection of hydrogen-rich water(10ml·kg^-1)were performed1min before exercise forgroup EH and H, while for group EM and M, intraperitoneal injection of hydrogen-richwater (10ml·kg^-1)were performed1min before exercise and immediately afterexercise,and the same amount of normal saline was intraperitoneally injected to groupEE and E1min before exercise. The three groups, EE, EH and EM participated inexhaustive exercise at the speed of28m·min^-1with0°slope. While, the other threegroups, E,H and M devoted to quantitative exercise（,the endurance time was defined bythe results of exhaustive exercise）,3hours after exercise,the gastrocnemius weredrawn from group E,H, M and C to determine the density of3-nitrotyrosine（3-NT）,8-hydroxy deoxyguanosine （8-OhdG） and protein kinase C （PKC） by Elisameasurement,and malonaldehyde（MDA）,superoxide dismutase（SOD）,glutathione（GSH）, total antioxidative capacity （T-AOC）,superoxide anion radical（O₂^-）,hydrogen peroxid（eH₂O₂）, peroxynitrite（ONOO^-）, hydroxyl radical（OH）,induciblenitric oxide synthase （iNOS）and nitric oxide （NO）by chemical colorimetry.Results:1.Hydrogen-rich water had marked anti-fatigue role by significantly extendingendurance time to exhaustion without a time-and dose-dependent manner.2.Exercise induced oxidative stress in skeletal muscle including increases of ROS,3-NT,MDA and8-OHdG,and weakened effects of SOD,GSH and T-AOC, and activationof PKC, iNOS,also, excessive generating of NO.3.Hydrogen-rich water had a strong protective effect on exercise-induced oxidativedamage, which was achieved by inhibiting O₂^-、H₂O₂、NO、ONOO^-and OH, especially,clearing away such powerful toxic substances as ONOO^-and OH in vivo, anddeveloping the effects of SOD, GSH and T-AOC, repressing the activation of PKC andiNOS, also, the excessive generating of NO, which relieved NO-induced toxicitydamage, as well as improved microcirculation of skeletal muscle cells. These resultssuggested that combined injection of hydrogen-rich water both before and after exercisehave syn-ergetic protective effect on exercise-induced oxidative stress damage. 4.The basis of its protective effects of hydrogen-rich water on exercise-inducedoxidative stress damage was its selective antioxidation;And, as a probable mechanismdue to the role that hydrogen-rich water inhibited the activation of signal transductionmolecules PKC and the excessive generating of NO resulting from a positive feedbackof its selectively cleared away such powerful toxic ROS as ONOO^-and OH, whichrelieved NO-induced toxicity, also, reduced oxidative stress medium, enhancedantioxidation capacity of skeletal muscle, inhibited a reduced ability to exercise byoxidative damage.Conclusions:1.Hydrogen-rich water had a function to anti-fatigue.2.Hydrogen-rich water had a strong protective effect on exercise-induced oxidativestress damage, which was achieved from multi-targets; and, the basis of which was itsselective antioxidation.3.In terms of intracellular signal transduction mechanism, the protective effect ofhydrogen-rich water on exercise-induced oxidative damage may be modulated byPKC-NO pathway.