Extraction Of Flavonoids From Red Raspberry Seeds And Its Antioxidant,Anti-fatigue And Hpoglycemic Activities

Red raspberry seeds were selected as raw materials in this study.Microwave combined with surfactant-assisted was used to extract flavonoids from red raspberry seeds on the basis of organic solvent extraction.The crude extract obtained is subjected to AB-8 macroporous resin purification to obtain purified red raspberry seeds flavonoids.In vitro and in vivo anti-oxidation,anti-fatigue and hypoglycemic activities of flavonoids were studied to provide a basis for the development and utilization of red raspberry seeds.The main research contents are as follows:(1)Microwave combined with surfactant-assisted was used to process red raspberry seeds powder,and the cell wall was destroyed by its solubilization and biological effects to shorten the extraction time,so that the red raspberry seeds flavonoids were quickly dissolved and the flavonoids yield was improved.On the basis of single-factor experimental result,the optimal extraction process of red raspberry seeds flavonoids was optimized by response surface design.The optimum technological parameters of flavonoids extraction were as follows:81%ethanol,553W microwave power,solid-liquid ratio 1:25g/mL,4%SDS.Under these conditions,the yield of red raspberry seeds flavonoids was up to45.17±1.09mg/g by maintaining microwave power for 5min.(2)The present study was designed to evaluate the antioxidant activity of the flavonoids purified in vivo and in vitro.The results showed that in vitro antioxidant research,the ABTS~+free radical scavenging ability,nitrite scavenging ability,total antioxidant capacity and anti-liposome peroxidation ability of the purified flavonoids were better than V_C;In the anti-oxidation study in vivo,RFL,RFM,RFH and V_E groups compared with the normal control group can significantly improve the activity of SOD,GSH-PX and CAT in mice serum,liver and kidney tissues.RFL,RFM and vitamin E groups relative to normal control group can obviously reduce serum MDA content and improve the activity of CAT in mice liver tissue.It shows that red raspberry seeds flavonoids can remove free radicals in the body and protect membrane lipid peroxidation.(3)The present study was designed to evaluate the anti-fatigue activity of the flavonoids purified in vivo.The mice were used as the test subjects to evaluated it by measuring the exhaustive swimming time,BUN,BLA,LG and MG contents of the mice,and compared them with octacosanol.The results showed that the flavonoids purified and octacosanol group significantly increased the swimming time,decreased the serum BUN and BLA content,and increased the LG and MG content in the mice compared with the normal control group.It shows that red raspberry seeds flavonoid has anti-fatigue effect.(4)The present study was designed to evaluate the hypoglycemic effect of the flavonoids purified in vivo.Mice were used as experimental subjects and metformin hydrochloride as positive control.The hypoglycemic activity of purified flavonoids were evaluated by measuring the changes of body weight,food intake,water intake,OGTT,serum GSP,TG,HDL-C,LDL-C and T-CHO content.The experimental resulted showed that the flavonoids purified and metformin hydrochloride group significantly control the food intake and water intake,increase the body weight of mice,and can effectively adjust the OTGG,GSP,TG,TC,T-CHO,LDL-C and HDL-C content in serum.It shows that red raspberry seeds flavonoids have the functions of lowering blood sugar and lowering blood lipids,and have developed into a health care product with hypoglycemic effect.