Extraction,Purification And Antioxidant Activity Of Total Flavonoids From Penthorum Chinense Pursh

Penthorum chinense Pursh?P.chinense?belongs to the family Saxifragaceae.It has been historically used as Miao folk food and medicine for the treatments of jaundice,cholecystitis,edema,traumatic injury,and infectious hepatitis.Modern pharmacological studies have revealed that P.chinense possesses anticancer activity,hypoglycemic effects,hepatoprotective activity,antibacterial activity,antinflammatory,anti-aging activity,and so on,which mainly attributed to its abundant flavonoids.Flavonoids possessing variety of biological properties,such as weight management,neuroprotection,anticancer etc.In addition,flavonoids exhibit strong antioxidant capacities through scavenging oxygen free radicals,promote anti-oxidase or inhibit oxidative enzymes.Therefore,flavonoids have attracted increasing attention recently.In the study,we optimized the extraction and purification conditions of total flavonoids from P.chinense.Furthermore,the in vitro and in vivo antioxidant activities of total flavonoids from P.chinense were investigated.The results of this study can promote further development and utilization of total flavonoids from P.chinense.The main results were as follows:1.Flavonoids were extracted from P.chinense by ethanol extraction.Based on the results of single factor experiments,response surface methodology was used to optimize the extraction conditions of flavonoids from P.chinense.The optimal extraction conditions were:ratio of liquid to material 22 mL/g,ethanol concentration 68%,extraction temperature 82°C,extraction time 2.2 h,respectively.Under the optimized conditions,the experimental flavonoids yield was 10.72%,the relative error between the theoretical prediction and experimental value was 0.32%.It indicated that the optimized extraction condition was reliable and practical.2.The total flavonoids from P.chinense were purified by macroporous resin.The DM130 macroporous resin was selected as the most suitable one from seven different macroporous resins.Moreover,its optimum parameters were as follows:the total flavonoids concentration of sample solution of 1.0 mg/mL,pH of 5,loading flow rate of1.0 mL/min,the loaded amount of 110 mL,the eluent of 70%ethanol,pH of 8,elution amount of 40 mL,elution rate of 1.0 mL/min.Under this conditions,the recovery rate of total flavonoids was 82.07%,the purity of total flavonoids was increased from 20.04%to43.93%,increased 23.89%.It suggested that DM130 resin revealed a good ability to purification total flavonoids from P.chinense.3.The unpurified and purified total flavonoids from P.chinense all exhibit strong in vitro antioxidant activity.Compared with unpurified total flavonoids,DPPH radical,ABTS radical and hydroxyl radical IC₅₀ value of purified total flavonoids decreased by0.117 mg/mL,0.203 mg/mL,0.394 mg/mL,the maximum scavenging rate increased by3.83%,5.17%,17.39%,respectively.Meanwhile,the maximum reducing power and chelating activity of ferrous ion of purified total flavonoids increased by 0.121 and16.34%.The purified total flavonoids from P.chinense exhibit significantly stronger in vitro antioxidant activities than unpurified.4.The in vivo antioxidant activities of total flavonoids from P.chinense were evaluated in the mode of Caenorhabditis elegans?C.elegans?.The C.elegans in control group were all died after 14 h thermal stress and the survival rates of wild-type worms treated with unpurified and purified total flavonoids from P.chinense were approximately 9.33%and 17.33%.Compared with blank control group,the C.elegans pretreated with with unpurified and purified total flavonoids,the SOD activities were significantly increased by 27.16%and 47.09%,the CAT activities were significantly increased by 25.37%and 77.80%,the MDA level decreased by 35.28%and 59.90%.The purified total flavonoids from P.chinense exhibit significantly stronger in vivo antioxidant activities than unpurified.