Study On The Composition And Polysaccharide Activity Of The Stem In Okra's

Objective The effective components were screened from the stem of okra,and the content of the components,such as polysaccharides,flavonoids and proteins,was determined.Then we optimized the extraction and purification process and analyzed the monosaccharide composition of Polysaccharides from stem of okra.Finally,he antioxidant activity in vitro and the hypoglycemic and hepatoprotective activities in vivo were investigated of polysaccharides from stem in okra.Methods The effective components in okra stem were determined by chemical qualitative analysis.The contents of polysaccharides,flavonoids,protein,water-soluble vitamins and calcium in okra stem were determined by phenol sulfuric acid method,HPLC,Kay and EDTA titration.The polysaccharides from okra stem were obtained by ultrasonic assisted extraction.The best extraction process of okra stems was determined by orthogonal experiment design.The effects of four factors on the extraction rate of Polysaccharides from okra stem were discussed,including the ratio of material to liquid,ultrasonic power,ultrasonic temperature and ultrasonic time.The crude polysaccharide were purified by ethanol ammonium sulfate aqueous two-phase systemin and the monosaccharide composition were analysed by pre column derivatization HPLC chromatography from the stem of okra.Vitamin C as the control,using1,1-two-2-three phenyl 4-dinitrophenylhydrazine free radical?DPPH?and hydroxyl radical?-OH?method were used to study the antioxidant the activity of the purified polysaccharide from Okra stems.The weight of the mice,the value of fasting blood glucose,the content of malondialdehyde?MDA?and glutathione peroxidase?GSH-P_X?in the serum were measured in the mouse induced by four pyrimidine to study the hypoglycemic activity of the polysaccharide from the stem of okra.To study the effect of Polysaccharides on acute liver injury from the stem of okra by measuring the changes of weight and the values of alanine aminotransferase?ALT?,aspartate aminotransferase?AST?and alkaline phosphatase?ALP?in serum.In addition,the content of globulin?GLB?,albumin?ALB?,total protein?TP?,glutathione peroxidase?GSH-P_X?and malondialdehyde?MDA?in liver tissue.Results There were polysaccharide,protein,quercetin,luteolin,VC,VB₂,VB₃,calcium and other ingredients of okra stems,which contains polysaccharides 45.52 mg·100g^-1?protein35.13 mg·g^-1?and calcium 120.28 mg·100g^-1,quercetin 57.2 mg·100g^-1,luteolin of 61.8 mg100g^-1,VC 26.99 mg·100g^-1,VB₂ 9.59 mg·100g^-1,and VB₃ 13.03 mg·100g^-1.The optimum extraction conditions of polysaccharides of okra stem:liquid ratio at 1:25,140 min of ultrasonic time,ultrasonic temperature 90?,ultrasonic power 450 W,the average extraction rate of Polysaccharide from okra stems was 23.59%;The best ethanol ammonium sulfate aqueous two-phase system was 28%ammonium sulfate?w/w?,18%ethanol?w/w?and pH 6.8,and the yield of polysaccharides reached 83.75%,the decolorization rate was 63.28%,and the deproteinization rate reached 57.92%.The polysaccharide consists of glucuronic acid,xylose,fucose,galacononic acid and five monosaccharides of Arabia sugar.The results of in vitro antioxidant activity showed that the IC₅₀ scavenging rate of okra polysaccharides and vitamin C on·OH and DPPH radicals was 2.25 mg·mL^-1 and 0.67 mg·mL^-1,11.16 mg·mL^-1 and 0.005mg·mL^-1,In vivo hypoglycemic activity results showed that:the negative control group and okra polysaccharide low dose group compared with normal group,significant weight loss?p<0.01?,blood glucose increased significantly?p<0.01?,high MDA content?p<0.05?,the activity of GSH-P_X was significantly lower?p<0.01?;okra stem polysaccharide high dose group and normal group compared there was no significant difference in body weight,blood glucose,MDA content and the activity of GSH-P_X?p>0.05?.Study on the protective effect on acute liver injury of okra stem polysaccharide induced by CCl₄:Compared with the normal group,the liver index increased significantly,the values of TP,ALB,ALT,AST,ALP,GLB activity had significant difference?p<0.01?,the content of malondialdehyde?MDA?in liver tissue decreased,glutathione peroxidase?GSH-P_X?activity increased?p<0.01?.The activities of TP and ALB in okra stem polysaccharides group were significantly higher than those in the negative group,and the activities of ALT,AST,ALP and GLB in serum were significantly lower than those in negative group.The content of MDA in liver tissue was decreased and the activity of GSH-P_X was obviously increased.Conclusions There were polysaccharide,protein,quercetin,luteolin,VC,VB₂,VB₃,calcium and so on,and rich in incontent.The ultrasonic water extraction and alcohol precipitation method can effectively extract the polysaccharide from the stem of the okra.It is easy to operate and save time and labor.The extraction process of ethanol-ammonium sulfate aqueous two-phase can effectively purify polysaccharide and remove the protein at the same time and remove the pigment.The purified monosaccharide composition of okra polysaccharides includes five kinds of monosaccharide,including glucuronic acid,xylose,fucose,galactohydric acid and arabia sugar.It has strong antioxidant activity,has a good protective effect on acute liver injury induced by CCl₄,and has a strong hypoglycemic effect.Therefore,the stem of the okra is a new resource that can be used for development.