Study On Optimization Of Extraction Technology Of Polysaccharide And Antioxidant Activity Of Polysaccharide From Dendrobium Officinale

Dendrobium officinale,a kind of high medicinal value orchid plant,has the name of "life-saving grass" reputation.It mainly distributed in Guangxi province,Zhejiang province,Anhui province,and other places.The study on breeding,planting,activity of extraction becomes more importan recent years in Dendrobium officinalein.In this paper,the extraction technique of polysaccharide from Dendrobium officinale was optimized.The difference of ability of removing DPPH radicals and hydroxyl radicals of polysaccharides between from ultrasonic assisted extraction method and traditional water extraction method was evaluated.The bacteriostatic function of polysaccharides and water extraction of Dendrobium officinale was verified by antibacterial test;The effect of polysaccharides from Dendrobium officinale on the anti-aging were studied by feeding Drosophila melanogaster and measuring the activity of antioxidant enzymes and the ability of anti-gravity crawling.Using response surface method,low-power ultrasonic-assisted extracts extraction method is optimized in Dendrobium officinale,the results showed that the optimum extraction conditions were as follows: the extraction temperature was 40 ?,the ratio of material vs liquid was 50:1,the ultrasonic treatment time was 30 min,and the extraction number of times was two times.The extraction rate of Dendrobium officinale polysaccharide was(25.28% ± 0.26%)and the theoretical error was 1.02% under optimum extraction conditions.Comparing with the traditional hot water extraction,the polysaccharides extraction rate using optimum extraction technique was increased by 18%.Using of low-power ultrasonic-assisted extraction polysaccharide from Dendrobium officinale,the activity of antioxidant was effectively protected.The ability of scavenging DPPH free radical was better than that of traditional hot water extraction.The antioxidant activities of polysaccharides from different producing areas were evaluated.The results showed that,the ability of polysaccharide scavenging hydroxyl radicals from Jiangsu province was better than that from Yunnan and Anhui province;The ability of polysaccharide scavenging DPPH free radicals from Anhui province was better than that from Yunnan and Jiangsu province;The ability of scavenging superoxide anion from Anhui,Yunnan and Jiangsu province was basically same,those provide some references for selecting Dendrobium officinale.Experiments indicate that the method of removing the protein by Sevage method was better than that of acid precipitation due to high purity and antioxidant activity of polysaccharides of Dendrobium officinale.Study on the bacteriostatic function of polysaccharides and water extraction from Dendrobium officinale showed that the water extraction of Dendrobium officinale had a certain effect on the pathogen of Fu's disease,and had no effect on B-type bacteria,Escherichia coli and Staphylococcus aureus,the polysaccharides from Dendrobium officinale were not inhibited on the above strains.The activities of SOD,CAT and the contents of MDA,the life span,the ability of reverse gravity crawling and the average body weight were studied by measuring the effect of different doses of polysaccharides from Dendrobium officinale in Drosophila melanogaster.It was found that that the activity of SOD,CAT and the content of MDA,the life span and the ability of reverse gravity crawling of treatment group of feeding polysaccharides were better than those of control group.The activities of SOD,CAT and the contents of MDA that in the middle doses of polysaccharides was better than those in the high dose group and low dose group.Compared with the control group,the activity of SOD,the CAT activity,the average maximum life,the half lethal time,the longest life in mid-dose group of male Drosophila melanogaster were was increased by 25.77%,28.88%,21.52%,29.29%,,22.97%,respectively,and the content of MDA were decrease by 46.51% in middle doses of polysaccharides of meal Drosophila melanogaster.The CAT activity,the average maximum life,the half lethal time,the longest life in mid-dose group of male Drosophila melanogaster were was increased by 6.70%,59.62%,15.42%,35.06%,16.577%,respectively,and the content of MDA were decrease by 18.34% in middle doses of polysaccharides of female Drosophila melanogaster.The Drosophila melanogaster was fed polysaccharides of Dendrobium officinale may improve the antioxidant properties of the body by increasing the activity of SOD and CAT,prolong the life span of Drosophila melanogaster and improve the reverse gravity crawling ability and average body weight.