Study Of Purification And Hepatoprotective Effect In Mice Of Triterpenic Acids In Jujube

Jujube is a kind of characteristic fruit in China with high nutritive value,and it is rich in bioactive components such as triterpenic acids and so on.In this study,the distribution of triterpenic acids and phenolic compounds was investigated by HPLC.Then,the enzyme-assisted extraction,acidolysis and chloroform extraction and the purification with macroporous resins of jujube triterpenic acids in Cultivar"Muzao"was studied,and the antioxidant activity in vitro was evaluated.Finally,the protective effects of betulinic acid and jujube total triterpenic acids on liver injury in mice were investigated.The results are as follows:(1)The composition and content of triterpenic acids in different parts of jujube were significant different.Jujube peels was rich in triterpenic acids.The total content of betulinic acid,oleanolic acid and ursolic acid could reach a high level of 12522.10?g/g,and the content of betulinic acid,oleanolic acid was higher in jujube peel,which could reach high levels of 6414.68?g/g and 5327.57?g/g respectively.The content of triterpenic acids in seed and pulp was lower than peel,and betulinic acid was the most abundant triterpenic acid in seed of most cultivars,which could reach a level of 248.02?g/g,while ursolic acid was the most abundant triterpenic acid in pulp.In addition,The composition and distribution of phenolic compound in different kinds of jujube had significant difference.Of the three parts of jujube,peel was the richest in phenolic compound,followed by seed,and the third was pulp.Rutin and caffeic acid were the most abundant triterpenic acid in peel and seed of most cultivars,which were more than 70%of total.And the contents of chlorogenic acid,caffeic acid and catechin were higher than others in pulp.Cultivars and regions could also influence the distribution and contents of triterpenic acids and phenolic compound of jujube.(2)The extraction,purification and antioxidant activity in vitro of triterpenic acids was studied.The optimal extraction conditions were as follows:amount of enzyme of 1.5mg/g;enzymolysis temperature of 60?;enzymolysis pH of 4.5;enzymolysis time of 45 min.The crude extraction was acidulated after extraction,and then ultrasonic treatment was done with chloroform,the treatment condition were as follows:solid-liquid ratio of 1:15(w:v,g/mL),ultrasonic temperature of 40?,ultrasonic time of 30 min,extraction times of 2.In addition,D101 macroporous resin exhibited good capabilities of adsorption and desorption of triterpenic acids from jujube,and the kinetics was fitted the pseudo-second-order rate equation and its equilibrium adsorption data for triterpenic acids was accordance with Freundlich adsorption isothermal equation.Furthermore,the adsorption capacity was increased with higher temperature.The optimal purification condition was as follows:7 BV of sample solution(pH 7.0)and then 5 BV of ethanol solution(95%,pH 11.0)as eluent.The crude and purified extracts both had the antioxidant activity,the abilities of triterpenic acids from jujube to scavenge ABTS~+�and�OH were increased,while the abilitities to scavenge DPPH�and reducing power were decreased after purification.(3)Betulinic acid and jujube total triterpenic acids could effectively protect liver in mice from injury induced by alcohol.Compared with model group,the weight development of the group treated with betulinic acid or jujube total triterpenic acids was improved,and the liver index and degree of liver pathological injury was reduced,and also the ALT and AST activities were decreased significantly,indicating the improvement of liver function.In addition,the TC,TG,LDL-C levels in serum were decreased while HDL-C levels was increased,suggesting that betulinic acid and jujube total triterpenic acids could improve the fatty metabolism in mice.The increase of SOD,GSH-Px activities and decrease of MDA levels in liver tissue suggested that betulinic acid and jujube total triterpenic acids could improve the antioxidant capacity of liver and inhibit the formation of peroxidation product of cell membrane lipid in mice.