| Exercise-fatigue is a common phenomenon in sports training and competition.In the process of exercise,the generation of exercise fatigue is a dynamic process,with the increase of the strength of exercise load,the body is prone to fatigue.It can impair the executive power and cognitive ability of athletes’ athletic skills.The treatment of fatigue has been one of the main focuses in the fields of medicine and physical education.The medical profession has been committed to finding a cure for the anti-fatigue.Cordycepin is the main function component of cordycepins militaris,a renowned traditional Chinese Medicine.Our previous studies have shown that cordycepin possesses an important regulating effect on central nervous system(CNS),including neuro-protective effect against ischemic insult on hippocampal neurons,and improvement effect on learning and memory.Additionally,we also found that cordycepin can prevent the repetitive stimulation-induced decrease in muscle contractile force.These results pose an insight that cordycepin may have an important effect on anti exercise-induced fatigue,and the mechanisms involving modulation on CNS function are strongly recommended.In this study,the effects of cordycepin on anti exercise-induced fatigue and its potential mechanism via modulating hippocampal function were be studied through exercise induced rat fatigue model in vivo by using behaviour test and biochemical technology.This study will provide an evidence for development of cordycepin as a novel potential ergogenic and prophylactic benefits for anti-fatigue and nourishment in sports health care market.Methods: Eighty male 6-week-old Kunming mice were adaptively fed for 2 days,and were given adaptive treadmill exercise at the speed of 10 m/min,10 min/1,once a day for 1 week.After 1 week,they were randomly divided into quiet group,Exercise fatigue control group,low-dose cordycepin administration group(5 mg/kg),medium-dose cordycepin administration group(10 mg/kg),and high-dose cordycepin administration group(25 mg/kg)with 16 mice in each group.cordycepin dosage group and sport fatigue control group according to body weight in mice,0.2 m L / 10 g to fill the stomach,every time 1 hour before exercise to lavage,sports fatigue in the control group was administrated with normal saline,once a day at a same time,continuous lavage for 21 days.After 15 days of intragastric administration,the mice were run at a speed of 18m/min,25 m/min and 30 m/min with a gradient of 0°.The mice were exhausted and the exhaustion time of the mice was recorded.According to the actual situation of the experiment,the total time between slides of the first three times of the mice sliding down the grid was recorded after the first 30 min,20 min and 10 min of each load stage.Change track speed every two days.After the last exercise,blood samples were collected,serum was separated,and fatigue related biochemical indexes were analyzed by serum.The supernatant was prepared from the homogenate of mouse hippocampal tissues.The content of neurotransmitters related to fatigue in mice was detected by enzyme-plate analyzer and spectrophotometry.Rat brain slices were prepared and observed by HE staining.Our results show that:1.Compared with the exercise fatigue control group,the exhaustion time of mice in the exercise groups treated with cordycepin at different concentrations was significantly prolonged(P < 0.001)and the total sliding interval time of the first three slides down the power grid 30 min,20min and 10 min before the stabilization of each load stage.2.Compared with mice in the rest group,six days of exhaustive exercise reduced the levels of liver glycogen(P < 0.001)and muscle glycogen(P < 0.01)in the exercise fatigue control group,and the activities of LDH(P < 0.01)and SOD(P <0.001)were decreased.In addition,the accumulation of lactic acid in blood(P <0.05),serum urea nitrogen(P < 0.001)and MDA(P < 0.001)in exercise fatigue control group was higher after exhaustive training.In addition,CK activity in blood of mice in exercise fatigue control group was increased(P < 0.01).3.Compared with the exercise fatigue control group,the levels of liver glycogen and muscle glycogen,SOD content in blood,BUN,MDA and lactic acid content in mice were increased in the exercise groups with different concentrations of cordycepin(P < 0.01),and LDH activity was increased(P < 0.001).In addition,compared with exercise fatigue control group,10mg/kg and 25mg/kg cordycepin exercise group could significantly reduce CK activity in blood of mice,and significantly increase glycogen levels in liver and muscle of mice.It was speculated that 10mg/kg cordycepin exercise group might be the best dose group.4.Compared with the quiet group,the content of ACh and Glu in the hippocampus of mice in the exercise fatigue control group was significantly decreased(P < 0.05).The content of 5-HT was significantly increased(P < 0.01);Compared with the exercise fatigue control group,the content of Glu was significantly increased(P < 0.001),the content of ACh in the hippocampus of the 5 mg/kg and 25 mg/kg cordycepin exercise group was significantly increased(P < 0.01),and the content of ACh in the hippocampus of the 10mg/kg cordycepin exercise group was significantly increased(P < 0.01);The content of GABA in hippocampus of mice treated with 25mg/kg cordycepin in exercise group was significantly increased(P < 0.01).5.Compared with the quiet group,the neuronal damage in hippocampal CA1 region was greater in the exercise fatigue control group,and the mean number of neuronal cells in the CA1 region was significantly reduced(P < 0.001).Compared with the exercise fatigue control group,the neuronal damage in the CA1 region in the cordycepin exercise group was less severe,but there was still cell swelling.The mean number of neurons in CA1 region was significantly increased.Studies have shown that cordycepin has a protective effect on hippocampal tissue damage.These results indicate that cordycepin can relieve fatigue by prolonging exhaustion time,increasing superoxide dismutase(SOD)and lactate dehydrogenase(LDH)levels,increasing blood glucose content,and decreasing blood malondialdehyde(MDA)and urea nitrogen content.In addition,cordycepin can improve the disorder of central neurotransmitters(ACh,GABA,Glu,5-HT). |
