Study On The Protective Effect Of Anthocyanin From Purple Sweet Potato On Oxidative Injury In Overtrained Rats’ Skeletal Muscle

Objective:In this study,the overtrained male SD rats were supplemented to the anthocyaninfrom purple sweet potato in a long term.The microstructure of skeletal muscle、changeof the rats’MDA、SOD、SOD/MDA、CAT、Na+-K+-ATP enzyme in the skeletal muscleand CK、LDH in the plasma were tested in different station in order to explore theprotection of the anthocyanin from purple sweet potato on rats’ skeletal muscle and tolay a theoretical basis for its application in competitive sports.Methods:The experimental method was used in this study.There were84healthy male SDrats that were randonmly divided into four groups according to their weights: controlgroup(C, n=12)、normal swimmng group(C, n=24)、overtraining group(C, n=24) andovertraining anthocyanin group(C, n=24).Rats in control group were killed in peacefulappearance. The sporting rats were killed in different condition.Some of them werekilled immediately after the last training and the others were in peacefulappearance.The normal swimming training model and the overtraining model wereestablished by swimming training of incremental exercise load.The normal swimmnggroup、 overtraining group and overtraining anthocyanin group used the modelrespectively.The rats of the overtraining anthocyanin group were taken anthocyaninfrom purple sweet potato with the dose of490mg/kg every morning. And the remainingrats were orallyed the measured saline for six weaks.The overtraining model wereverified by the change of the rats’ general situation、body weight、training situation、athletic ability and the testosterone、cortisol、testosterone/cortisol in the serum.Themicrostructure of skeletal muscle was observed and the malondialdehyde (MDA)、superoxide dismutase(SOD)、catalase(CAT)、Na+-K+-Atpase and creatine kinase(CK)、lactate dehydrogenase(LDH) in the plasma were enterminationed.All datas wereanalysed by the statistical software of SPSS17.0.Results:1. Compared with the rats in Group C and Group NS,The rats in Group OT generallyturned to have a deterioration in general condition、weight loss and exercisecapacity after incremental load swimming training for six weeks.The testosterone andtestosterone/cortisol in the serum were significantly decliced(P<0.05or P<0.01). Thecortisol were significantly improved(P<0.01).2. Through the hematoxylin-eosin staining,the skeletal muscles’ fiber bundles turned toexpanded space significantly. There were interstitial edema and more infiltration ofinflammatory cells.3.Compared with the rats in Group C and Group NS, CK and LDH in the plasma of therats in Group OT were both significantly improved(P<0.01).4. Compared with the rats in Group C and Group NS, MDA of rats’ skeletal muscles inGroup OT was significantly improved(P<0.01)； SOD、CAT、Na+-K+-Atpase of rats’skeletal muscles in Group OT were significantly decliced(P<0.01).5. Compared with the rats in Group OT, CK and LDH of rats in Group TA weresignificantly declined (P<0.05or P<0.01).6. Compared with rats in Group OT, MDA of the rats in Group TA were significantlydeclined(P<0.01)；SOD、CAT、SOD/MDA、CAT、Na+-K+-Atpase were significantlyimproved(P<0.05or P<0.01).7. Compared with rats in Group TA in the mmediate state, rats’ CK、MDA weresignificantly declined (P<0.05or P<0.01) and SOD/MDA、 Na+-K+-ATP weresignificantly improved (P<0.05or P<0.01)24hours after exercise.Conclusions:1. The overtraining model established in this experiment by incre mental loadswimming training for six weeks is successful.2. The tissue morphology of rats’ skeletal muscle is injured after overtraining.Anthocyanins from purple sweet potato has protective effects on morphology of skeletalmuscle.3.The radical generation in the rats’ skeletal muscle is increased.The scavenging abilityis reduced.Free radical damage occurs,resulting in membrane’s damage and reductionin the function of the skeletal muscle.The tissue antioxidant enzyme in skeletal muscleis significantly decreased and the lipid peroxidation is enhanced.The anthocyanin frompurple sweet potato plays an important role in enhancing the antioxidant and plasmaenzyme’s activity.It canreduce the damage caused by the free radical in skeletal muscleduring overtraining and helps to increase the body’s resistance to fatigue and athleticability.And it is an ideal natural radical scavenger.