Study On Purification Process Of Polysaccharides From Dendrobium Huoshanense And Its Anti-Inflammatory Activity

Dendrobium huoshanense is a traditional Chinese herbal medicine and native in Anhui province.It has been used as medicine and food for a long history standing.A lot of researches have shown that Dendrobium huoshanense has regulatory function on chronic inflammatory diseases such as hyperglycemia,hypertension,hyperlipidemia,adiposity and hepatic adipose infiltration,which can effectively improve the health status.Semi-bionic extraction and anion exchange resin deproteinization methods have advantages of low production cost,easy enlargement,green and safe operation process,and are suitable for the purification of the major bioactive components of Dendrobium huoshanense – Dendrobium huoshanense polysaccharides(DHP).In this paper,the polysaccharides purification process was established and optimized.The polysaccharides prepared by this purification process were subjected to chemical composition analysis and anti-inflammatory activity evaluation.The main contents and results are as follows:(1)Optimization of semi bionic extraction for bioactive components from Dendrobium huoshanense extraction.Using simulated gastric fluid extract,the optimal conditions were solid-liquid ratio of 1:30,extraction temperature of 80?,extraction time of 1.5 h.Using simulated intestinal fluid extract,the optimal conditions were solid-liquid ratio of 1:30,extraction temperature of 80?,extraction time of 2.5 h.Under the optimized conditions,the yield of polysaccharides were 60.9±1.2 mg/g.Compared with the traditional water extraction,polysaccharides yield increased by 16.55%.(2)Optimization of deproteinization process of Dendrobium huoshanense polysaccharides by using anion exchange resin.The deproteinization process was optimized by single factor experiment and orthogonal experiment.The optimal conditions were p H 8.5,temperature of 35?,buffer concentration of 0.02 mol/L,polysaccharides concentration of 0.8 mg/m L,volume flow rate of 2 BV/h,diameter to height ratio of 1:9,the maximum sample volume of 40 m L.(3)Chemical composition analysis of Dendrobium huoshanense polysaccharide.The molecular weights of Dendrobium huoshanense polysaccharides were determined by HPGPC.Ubbelohde viscometer was used to determine the viscosity of polysaccharides.PMP pre-column derivatization was used to determine the monosaccharide composition of polysaccharides.Compared with DHP-1,the viscosity of DHP-2 is smaller.The Mw of DHP-2 is significantly larger than the Mw of DHP-1,and the molecular weight distribution of DHP-2 is wider.Their monosaccharide composition are similar and the molar ratio of the individual monosaccharides are different.(4)Evaluation of anti-inflammatory activity of purified polysaccharides from Dendrobium huoshanense.MTT assays were used to determine the effect of refined polysaccharides from Dendrobium huoshanense on the growth of RAW264.7 cells.The anti-inflammatory activity of purified polysaccharides from Dendrobium huoshanense was investigated by the release of NO and IL-1? and the expression of i NOS and IL-1? m RNA in RAW264.7 cells.The results showed that Dendrobium huoshanense polysaccharides could inhibit the secretion of NO and IL-1? and reduce the expression of i NOS and IL-1? m RNA.In contrast,DHP-2 has better anti-inflammatory activity than DHP-1.