Study On Antioxidant And Hypoglycemic Effects Of Zijuan Black Tea Extract

In the research,it was systematically studied that the antioxidant capacity and hypoglycemic effect of tea polysaccharide?tea polyphenols?anthocyanins?thearubigins?theabrownin extract in Zijuan black tea.Separation and extraction of the main components from Zijuan black tea,The antioxidant activity of each extract in Zijuan black tea were fully compared in vitro by separately determined the clearance rate to DPPH·?O₂^-·?·OH and total antioxidative capacity separately.At the same time,it was studied that the ability to inhibit activity of?-glucosidase in vitro and hypoglycemic effect of diabetic mice,the hypoglycemic effect of each extract in Zijuan black tea was determined.Main achievements were summarized below:(1)Extraction and determination of main components of Zijuan black tea.Separation and extraction of tea polysaccharide?tea polyphenols?anthocyanins?thearubigins?theabrownin from Zijuan black tea content were determined by water and organic solvent extraction,organic solvent extraction and column chromatography of DEAE cellulose.The content of tea polysaccharide in tea polysaccharide extract was 53.34%;the content of tea polyphenols in tea polyphenols extract was 62.27%;the content of anthocyanin in anthocyanin extract was12.68%;the content of thearubigins in thearubigins extract was 36.78%;the content of theabrownin in theabrownin extract was 46.52%;the main content of water extract:the tea polysaccharide was 8.21%,the tea polyphenols was 39.76%,the anthocyanins was 3.06%;the theaflavins was 1.03%;the thearubigins was 4.23%;the theabrownin was 9.18%.(2)Antioxidant capacity of Zijuan black tea extract.The each extract in Zijuan black tea had the strongest scavenging ability to DPPH·,and the clearance rate was more than50%.Through the IC₅₀ calculation,tea polyphenol extract had the strongest scavenging activity and higher than ascorbic acid.Clearance rates of tea polyphenols and anthocyanins extract in Zijuan black tea to O₂^-were more than 50%,tea polyphenol extract had the strongest scavenging activity but lower than ascorbic acid.Clearance rates of anthocyanins?thearubigins and tea polyphenols extract in Zijuan black tea to·OH were more than 50%,anthocyanins and thearubigins extract had the strongest scavenging activity but lower than ascorbic acid.The total antioxidant activity of tea Zijuan black tea extract was tea polyphenol extract>theabrownin extract>anthocyanins extract>water extract>tea polysaccharide extract>thearubigins extract.(3)The ability to inhibit activity of Zijuan black tea extract to?-glucosidase.With the increase of mass concentration,the ability to inhibit the activity of Zijuan black tea extract to?-glucosidase was enhanced.In addition to the thearubigins extract,the inhibition rate of other extract was more than 50%.The inhibitory ability of tea polyphenols and tea polysaccharide extracts was higher than that of positive control acarbose by IC₅₀ calculation.Among them,the inhibitory ability of tea polyphenols was the strongest,which was 4.37 times that of acarbose.(4)Effects of Zijuan black tea extract on alloxan-induced diabetic mice.The extract of Zijuan black tea has certain control and improvement effect on the blood glucose level of diabetic mice.After 15 days of intragastric administration,the fasting blood glucose concentration in mice administered with high or low dose of extracts of tea polysaccharide?tea polyphenols and the high dose of theabrownin extract,which were lower than that in modeling.and high dose of tea polyphenols and tea polysaccharide extract hypoglycemic effect is better than positive drugs.The level of glucose tolerance in mice administered with high or low dose of extracts of tea polysaccharide?tea polyphenols and the high dose of anthocyanin?theaflavin and water extracts,which was significantly enhanced and compared with the diabetic group were significantly different.Compared with the positive drug group,the high dose of tea polysaccharide extract and tea polyphenol extract had significant difference and significant difference,the effect of postprandial hyperglycemia was better than that of positive drug.After diabetic mice were administered with extracts of Zijuan black tea,diabetic mice could increase the average weight and reduce the average amount ingestion and water intake,mice respond more sensitive,more lively.