Purification And Biological Activities Of Intracellular Polysaccharides From Cordyceps Gunnii

Objective: Cordyceps gunnii(Cordyceps gunnii(Berk.)Berk)also known as Cordyceps hawkesii,is a parasitic bat moth larvae in the larger Cordyceps,it is a kind of compound fungus,with sexual and asexual types of life forms.Cordyceps gunnii has a variety of pharmacological activity,such as antifatigue,antitumor,prevent arrhythmia,enhance the immunologic functions,improve intelligence,antioxidant,antidepressant and hypoglycemic.This study aimed to isolate and purify polysaccharides from Cordyceps gunnii and investigate their antifatigue and immunomodulatory activity.Methods: Firstly,the artificial neural network(ANN)and genetic algorithm(GA)were used for optimizing ultrasonic assisted extractitve conditions of Cordyceps gunnii polysaccharides.Based on the single-factor test,the non-linear relationship among the three independent factors was analyzed by ANN-GA method.Secondly,this experiment extract polysaccharide using hot water extraction method,followed by concentration,sevag method for removing protein,ethanol precipitation method to obtain the intracellular polysaccharides.The crude polysaccharide was isolated and purified by ion exchange chromatography and gelchromatography,respectively.Then the anti-fatigue activity of the purified polysaccharides was explored,CG1 and CG2 in vivo,with Kunming mice.The saline control group,shenqigranule group,CG1 high / medium / low dose group,CG2 high / medium / low dose group,orally once a day by gavage for 30 consecutive days.After the last administration,the content of urea nitrogen,the swimming time and the hepatic glycogen in liver were tested.Lastly,we studied the immunomodulatory activity of CG1 and CG2 by the immunosuppressive model of BALB /c mice established by cyclophosphamide(CTX).Thymosin ?1(T?1)was used as a positive control drug.The cytotoxic activity of NK cells and T lymphocyte transformation activity in mice were detected.And the levels of immune-related cytokines in mice plasma were determined by ELISA.Results: The optimum extraction conditions obtained by ANN-GA were as follows: extraction power 323 W,the extraction time 456 s,the solid/solvent ratio 1:83.The maximal extraction rate was 1.88% and the relative error was 1%.CG1 and CG2 are two main peak elution respectively.But CG1 and CG2 are not a single polysaccharide and also contain other kinds of polysaccharide,but with a main polysaccharide.The results showed that,high doses of CG1 and CG2 could significantly increase the time of weight forced swimming,the content of hepatic glycogen and decrease the level of urea nitrogen.CG1 also could significantly enhance the cytotoxic activity of NK cells and T lymphocyte proliferation and regulate body weight,viscera index and the levels of immune-related cytokines(interleukin-2,interleukin-6,interleukin-10,interleukin-12,interferon-alpha,interferon-?,tumor necrosis factor-alpha and nuclear factors-?B),while no similar results were viewed in CG2 groups.Conclusion: An optimum extraction condition of Cordyceps gunnii polysaccharides was gained.Two polysaccharides CG1 and CG2 were separated and purified.CG1 and CG2 could relieve the fatigue of mice,while,CG1 but not CG2 improve the immunity activity of mice.