Study Of Immunomodulatory Activity And Structure-activity Relationship Of Polysaccharide From Lonicera Japonica Thunb

Objective: To study the fractionation and purification,basic structure analysis and immunomodulatory activity of Lonicera japonica Thunb polysaccharide(LJP,Lonicera japonica Thunb polysaccharide)from two producing places;To clarify the similarities and differences in structure and immunomodulatory activity of Lonicera japonica Thunb polysaccharide from different producing places,and to preliminarily explore the structureactivity relationship of immunomodulatory activity of Lonicera japonica Thunb polysaccharide.Methods: Firstly,Lonicera japonica Thunb polysaccharide in Pingyi,Shandong Province(PYLJP)and Lonicera japonica Thunb polysaccharide in Fengqiu,Henan Province(FQLJP)were obtained by boiling distilled water extraction and alcohol precipitation.Secondly,Shandong Pingyi neutral polysaccharide(PYLJP-N),Shandong Pingyi acid polysaccharide(PYLJP-A),Henan Fengqiu neutral polysaccharide(FQLJP-N)and Henan Fengqiu acid polysaccharide(FQLJP-A)were obtained through fractionation and purification of LJP from two producing places by DEAE cellulose column.Further,fractionation and purification were performed for FQLJP-A and PYLJP-A by DEAE Sepharose Fast Flow anion-exchange column with different concentrations of Na Cl solution.Four components were obtained,namely FQLJP-A-1~FQLJP-A-4 and PYLJP-A-1~PYLJP-A-4.The molecular weight and monosaccharide composition of PYLJP and FQLJP and their sub components were analyzed by HPGPC,HPLC and FT-IR.Finally,the immunosuppressive mouse model induced by CTX was used to analyze the effects of FQLJP-A,PYLJP-A,FQLJP-N and PYLJP-N on thymus index,spleen lymphocyte proliferation,serum cytokine and immunoglobulin content and peritoneal macrophage phagocytosis activity of immunosuppressive mice.Furthermore,the similarities and differences of the immunomodulatory effects of the four polysaccharides were compared.Results: PYLJP and FQLJP were obtained by hot water extraction and alcohol precipitation(the yields were about 5.95% and 5.34% respectively).PYLJP-N,PYLJP-A,FQLJP-N and FQLJP-A were obtained by fractionation and purification by DEAE cellulose(the yields were about 31.28%,53.71%,29.05% and 40.28% respectively).After further purification of FQLJP-A and PYLJP-A,FQLJP-A-1,FQLJP-A-2,FQLJP-A-3,FQLJP-A-4,PYLJP-A-1,PYLJP-A-2,PYLJP-A-3 and PYLJP-A-4 were obtained respectively(the yields were about 19.0%,46.2%,6.3%,2.7% and 37.0%,14.0%,5.0% and 4.8%).The results of monosaccharide composition showed that the monosaccharide composition of PQLJP-N and FQLJP-N was similar,but the molar ratio of monosaccharide composition was different.There were great differences in monosaccharide composition and molar ratio between PYLJP-A and FQLJP-A,as well as their sub-components.PYLJP-A-1 and PYLJPA-4 were mainly composed of Gal,Glc and Gal A,and their molar ratios were 4.93:1.06:0.95 and 4.35:2.13:1.52 respectively.PYLJP-A-2 and PYLJP-A-3 were mainly composed of Gal,Glc and Man,and their molar ratios were 4.58:3.61:0.41 and 4.08:4.26:0.42 respectively.FQLJP-A-1 ~ FQLJP-A-4 were mainly composed of Gal,Glc and Gal A,and their molar ratios were 4.29:1.19:0.84,2.89:2.81:1.22,1.87:2.31:4.75 and 0.76:0.54:8.18 respectively.FQLJP-A-1 and FQLJP-A-2 also contained a small amount of Man and Rha.The results of molecular weight analysis showed that the average molecular weights of PQLJP-N and FQLJP-N were similar,while PYLJP-A,FQLJP-A and their sub-components were quite different from each other.Infrared spectra showed that PQLJP-N and FQLJP-N had similar structures,while PYLJP-A and FQLJP-A had obvious differences in the degree of methylation of carboxyl groups.Finally,immunomodulatory experiments showed that FQLJP-A,PYLJP-A,FQLJP-N and PYLJP-N could alleviate the immunosuppression induced by CTX in mice,and the immunomodulatory activities of FQLJP-A and PYLJP-A were stronger than FQLJP-N and PYLJP-N.Conclusion: Lonicera japonica Thunb polysaccharide from two producing places was fractionated and purified into one neutral polysaccharide component and five acidic polysaccharide components.There were obvious differences in the basic structure of these polysaccharide components,especially between acidic polysaccharides.The above polysaccharide components showed certain immunomodulatory activity,among which acid polysaccharides showed relatively high immunomodulatory activity,which may be related to their basic structure(molecular weight,monosaccharide composition,etc.).This study provides a certain experimental basis for the further development of new immunomodulators or adjuvants.