Antioxidant Evaluation And Mechanism Study Of Polyphenol Extracts From Rosa Roxburghi

In daily life,the body will inevitably exposed to unfavorable external environment,such as ultraviolet light,smoke dust,smog,the bad life style and personal behaviour,all can lead to a certain degree of redox state of imbalance.Now,in order to balance the intracellular redox system of state again,taking antioxidant is one of the most effective.Natural antioxidants come from a wide range of sources,low toxicity and strong antioxidant capacity,Rose roxburghii tratt.is extremely rich in antioxidants,its antioxidant properties can be further studied.In this paper,Rose roxburghii tratt.was used as the main raw material to extract,purify and separate polyphenols from Rose roxburghii tratt.To research the polyphenol content,component structure,antioxidant activity and its mechanism of action.The main results are as follows:(1)Purification process of Rose roxburghii tratt.polyphenols extractRose roxburghii tratt.polyphenol extract(RRTP-E)was used as raw material.To explore the purification process of Rose roxburghii tratt.polyphenols by investigating the adsorption time,desorption concentration,sample loading volume,p H,eluent dosage and other factors.The results showed that compared with other types of macroporous resin,AB-8 is more suitable for the adsorption of Rose roxburghii tratt.polyphenols,the adsorption process was in accordance with Freundlich thermodynamic model(R~2>0.9900)and Langmuir model(R~2>0.9500),which was more conducive to the adsorption of Rose roxburghii tratt.polyphenols by macroporous resin at 298 K.The optimal purification parameters were as follows:adsorption time 600 min,desorption solvent 80%ethanol solution,sample volume 10m L,eluent volume 50 m L.Under these parameters,the average polyphenol content of Rose roxburghii tratt.increased from 30.45%to 56.92%.The antioxidant activities of Rose roxburghii tratt.polyphenols before and after purification were compared.The data showed that the antioxidant capacity of Rose roxburghii tratt.polyphenols were significantly improved after purification by AB-8 macroporous resin.The results showed that the process was feasible and stable,and could be used as the purification condition of Rose roxburghii tratt.polyphenols.(2)Separation and structural characterization of Rose roxburghii tratt.polyphenolsFurther Purification of Rose roxburghii tratt.polyphenols by solvent extraction(RRTP-P),Fr1 and Fr2 were obtained.The FT-IR and UV test shows that both Fr1and Fr2 contain the characteristic functional groups of polyphenols.Found by in vitro antioxidant activity,the antioxidant capacity of Fr1 was stronger than Fr2.Fr1 was separated by HSCCC to obtain four componentsⅠ,Ⅱ,ⅢandⅣ.The four components all contain the characteristic functional groups of multiple polyphenol compounds.The FT-IR and HPLC test shows that four components may include chlorogenic acid,quercetin and ellagic acid.Meanwhile,total antioxidant capacity and ABTS~+·and·OH scavenging were determined,the order of antioxidant activity was:Ⅰ<Ⅲ<Ⅱ<Ⅳ.(3)In vivo antioxidant mechanism of Rose roxburghii tratt.polyphenolsThe effects of componentsⅠ,Fr1 and Fr2 on antioxidant stress in D-gal induced aging mode mice were studied to explore the possible mechanism.Experimental mice were randomly divided into control group,model group and multiple treatment groups according to body weight,the model were modeled and treated for 45 days.Observe the general behavior characteristics of each group of mice,compared with other groups,mice in MC group had reduced diet,more sparse hair and slower movement.ACH-E,MDA,CAT,GSH-PX and SOD in brain tissue and serum were determined.The results showed that MDA content in MC group was significantly increased(P<0.05),ACH-E content was significantly decreased(P<0.05),CAT,GSH-PX and SOD activity levels were significantly decreased(P<0.05),proving that the modeling is successful.Compared with the MC group,the aging symptoms of mice in other groups were alleviated to varying degrees.The experiment showed that each component of Rose roxburghii tratt.polyphenols had certain intervention effect on the aging symptoms caused by D-gal.The protein expression levels of Nrf2,GPX1,GCLC,SOD3,GSTP1 and ACAT1 were detected by western blot.The results show that:compared with the normal group,the expression levels of Nrf2 and its downstream GCLC,SOD3,GSTP1 and other proteins in the model group decreased,indicating that the continuous intake of D-gal could inhibit the Nrf2 signaling pathway.The intervention of Rose roxburghii tratt.polyphenols could significantly up-regulate the expression of Nrf2,GPX1,GCLC,SOD3,GSTP1 and ACAT1,suggesting that Rose roxburghii tratt.polyphenols may improve the ability of body to resist oxidative stress by regulating Nrf2 signaling pathway.