Textual Research And Polysaccharides Structure Features And Anti-diabetic Activities Of Maidong

Objective: To perform textual researches on name,origin and distribution of Maidong,to clarify the medicinal varieties and history records in ancient literatures and provide evidence for clinical use.To study and compare primary structures,hypoglycemic activities and mechanism of polysaccharides from three species of Maidong and to provide experimental basis for clinical application.Methods: Ancient herbal works were performed for textual research,and the resource investigation and modern data were analyzed.Under the same experimental conditions,the polysaccharides of Liriope spicata var.prolifera,Ophiopogon japonicus,Liriope muscari were extracted,separated and purified from different sources.Total polysaccharide content was determined by anthrone sulfuric acid method.Gas chromatography was used to determinate the monosaccharide composition.Average molecular weights of polysaccharides were measured by high performance gel permeation chromatography(HPGPC).Periodate oxidation-smith degradation combined with GC-MS method was carried out to check the substituent positions and methylation was used to test the linkage models of sugar residues.FT-IR,NMR were used to determinate the basic structures of three polysaccharides.Glucose metabolism,RT-PCR and western blot experiments in insulin resistant model Hep G2 cells and 3T3-L1 cells were used to test hypoglycemic activity and mechanism of polysaccharides.Results: According to the ancient herbal records and modern researches,Maidong had lots of alias,while only Maimendong and Maidong were used as the medicine common names.According to the records of main origin,original plant morphological and medicinal characteristics of Maimendong,it was preliminarily concluded that Maidong recorded in the ancient herbal records was mainly produced in Jiande of Zhejiang province,Quanzhou of Fujian province,Mianyang of Sichuan province,Xiangyang of Hubei province and the surrounding areas.They are from the roots of Liliaceae Ophiopogon and Liriope plants,which ancient and modern medicine basically the same.Extraction rate of LSP,LMP and OJP were 53.2�0.78%,54.7�0.76% and 55.2�1.86%,respectively,which were higher than the other extraction methods reported.Anthrone sulfuric acid method revaeled that the polysaccharides content of LSP,LMP and OJP were 92.7�3.5%,90.1�4.7% and 91.1�5.1%,respectively.The average molecular weight of the purified LSP,LMP and OJP were estimated to be 4742,4138 and 4925 Da with polydispersity index of 1.14,1.20 and 1.12,respectively.Gas chromatography result revealed that LSP,OJP and LMP were all composed of ?-fructose and ?-glucose,with fructose being the major monosaccharide.Judging from the peak area,AUC ratio between fructose and glucose were 28:1(LSP),24:1(LMP)and 29:1(OJP),respectively.The backbones of polysaccharides were formed by Fruf-(2?,?2)-Fruf-(6?,?6)-Glcp-(1? and ?1,2)-Fruf-(6? with a molar ratio of 4.99:18.16:1.0:5.28(LSP),6.84: 15.75: 1.0: 5.80(OJP),8.26: 12.29: 1.0: 3.87(LMP).On the C-1 of partial ?1,2)-Fru-(6? residues,branches formed by ?-Fructose were existed.Periodate oxidation-smith degradation experiments determinated the substituent position of polysaccharides,no formic acid was produced and GC-MS analysis showed that the acetylation production was triglyceride,which suggested that 3,4 hydroxyl of furan fructose has not been replaced.NMR and FT-IR were used to further infer the structure of polysaccharides.Three kinds of polysaccharides could increase the sugar consumption of Hep G2 and 3T3-L1 in insulin resistance model,which were significantly different from those of model groups,and the difference of hypoglycemic activity of different polysaccharides was not significant.The expression of Ins R,PI3 K,AKT,PPAR? m RNA and protein in polysaccharide group was significantly higher than that in model group,and the expression of PTP1 B was significantly lower than that of model group,which indicated that all three polysaccharides could promote glucose uptake by improving insulin resistance.Conclusion: The origins and distributions of Maidong from Sichuan,Zhejiang,Hu bei and Fujian Province in modern are the same with ancient herbal records,are all used as traditional Chinese medicine Maidong.The linkage connections of the three polysaccharides were the same,but there were some differences in the proportion of sugar residues.In vitro,all of them had hypoglycemic activities,and there was no significant difference among them.The results of this paper provide the basis for the evaluation of the quality of Maidong and the treatment of diabetes without difference.