| Macamides are the active ingredients of maca(Lepidium meyenii Walp.).And they may be the effective ingredients of maca for anti-fatigue effect.Due to the minor amount of macamides in complex composition of maca tuber,systematic extraction and separation process for macamides is lacking.And the researches on the anti-fatigue effect of macamides were mainly focused on the activity verification level.In the present study,we prepared cure macamides extract(CME)and purified macamides extract(PME)of maca by enzymatic assisted extraction and macroporous resin separation,respectively.And then the anti-fatigue effect and mechanism of them was examined and providing a scientific basis for further study on the anti-fatigue mechanism of Maca.The specific research results are as follows:(1)Taking the content of macamides as an index,the enzymatic assisted extraction of total macamides was optimized by response surface methodology.The optimal conditions were as follows: Maca powder was pretreated for 2 h by p H=4.5citric acid solution in a proportion of 1:4(w/v)at 50 °C.And then the pretreated maca powder was extracted for 2.8 h by 95% ethanol,twice under refluxin a proportion of 1:15(w/v)at 70 °C.Under this process,the total maleimide content was 2.12 mg/g in the maca powder.(2)By comparing the adsorption and desorption ability of four kinds of macroporous resins,the X-5 macroporous resin is the most suitable for coarse separation of the crude extracts.The optimal conditions were as follows: 100 m L crude extracts solution,with the concentration of 0.212 mg / m L,was instilled into the column chromatography over X-5 macroporous resin(20 g),at a rate of 2 m L/min.And let it standing for 3.5 h at room temperature till the sample was absolutely adhered to the resin.After that the resin was washed with distilled water until there was no color in the eluate.And then,the resin was eluted by 140 m L 90% ethanol successively at 2 m L/min.Subsequently,the eluate was collected and concentrated to dryness under vacuum.The contents of total macamides were 17.09 mg/g of the extract.(3)Both CME and PME have significant effect of relieving physical fatigue,and the effect of PME after X-5 macroporous resin separation is better than that of CME.Compared with the normal control group(NG),the swimming time of CME and PME groups was prolonged by 49.5-77.6% and 95.6-137.5%,respectively.Compared with the positive control group(PG),the PME groups significantly prolonged the swimming by 44.8-75.9%.There had no statistical significance difference between low dose group of CME(CME-L)and the PG.Moreover,high dose group of PME(PME-H)significantly prolonged the swimming by 58.8% than the CME-L.Compared with PG,the liver glycogen and muscle glycogen of PME-H were significantly increased by 18.8% and 25.2%;and the level of BLA was significantly decreased by 7.26%.However,the effects of CME and PME on reducing BUN levels were poor.The levels of LDH,CK and NEFA in the CME and PME groups significantly decreased by 8.10-20.04%,15.29-42.68%,and 12.95-23.2% than that of NC group,respectively.And the degree of skeletal muscle and myocardial damage in CME and PME groups was slightly lower than those in CG and PG groups.The mechanism of these two macamides extracts anti-fatigue might lie in regulating of energy metabolism,accelerating of the oxidation of fatty acids,and alleviating the damageof skeletal muscle and myocardium cell membrane in exercise. |
PDF Full Text Request