| Malus domeri(Bois)Chev. belongs to Crataegus cuneata Sieb. et Zucc., which comes from breeding and grafting. Malus domeri(Bois)Chev. cultivation in Guangxi has a history of more than 80 years and the main producing areas is in the northeast of Guangxi, especially in Hezhou and Guilin area. The bigger fruit is one of the main characters of Malus domeri(Bois)Chev. In Guangxi. The surface is smooth and bright and it tastes sweet and sour. Malus domeri(Bois)Chev. is rich in flavonoids. Flavonoid is natural and non-toxic, which has a variety of biological activity. In this study, we choose Malus domeri(Bois)Chev. from south、north and east area of Guangxi as the research object. First, study on the extraction process of flavonoids by response surface method. Second, study on the flavonoid extract for scavenging free radicals and bile salts binding in vitro experiment. Third, using the mice as experimental animal. Analyzes on hyperlipidemia model in mice related physiological and biochemical indexes by feeding Malus domeri(Bois)Chev. extract. The evaluation of Malus domeri(Bois)Chev. flavonoids antioxidant and hypolipidemic effect are based on the above study. It can provide a reference for the rational use of funtional food. The main results are as follows:1、The fresh fruit of Malus domeri(Bois)Chev. was used as material. Four factors of ethanol concentration, solid/liquid ratio, time and temperature were chosen in the response surface analysis. The quadratic regression model with the response values of flavonoids was established by Box-behnken design. The optimized extraction conditions were as follows:ethanol concentration of 50%, temperature of 70℃, time of 3.5h and solid/liquid ratio of 1:18. The flavonoids of 22.68mg/g was achieved under the optimized conditions.2、Phytochemistry qualitative appraisal indicated that Malus domeri(Bois) Chev. extract contains flavonoids, polysaccharides, alkaloids and polyphenols. The flavonoids of Zhaoping、Danlong、Xinli and Pingle are as follow: 22.68mg/g、25.02mg/g、23.89mg/g、21.25mg/g. Different areas in Malus domeri(Bois)Chev. sorting function of active matte content as follows: Danlong>Xinli> Zhaoping> Pingle. Compared with the Crataegus cuneata Sieb. et Zucc, the contents of polyphenols and flavonoids is higher, but the content of polysaccharide was lower.3、Malus domeri(Bois)Chev. flavonoids have antioxidant capacity and it has good scavenging effect on OH and DPPH-free radicals. The scavenging rate on the -OH and the DPPH-of extracts in Zhaoping, Danlong, Xinli and Pingle was 59.26%,63.93%,61.18%,53.11% and 81.38%、86.25%.83.75%. 79.75%. With the increase of flavonoids content in the extract, free radical scavenging ability increased gradually. But when the flavonoids content reaches a certain value, the scavenging rate changed little. So its flavonoids content of extract has an effect on the free radical scavenging, but has no significant dose effect relationship.4、Malus domeri(Bois)Chev. flavonoids have the binding ability of bile salts in vitro. Compared with the cholestyramine group, the Malus domeri(Bois)Chev. flavonoids extract from Danlong、Xinli and Zhaoping combine STC, SGC and SC is better than that extracts of Pingle area.5、The Malus domeri(Bois)Chev. extract from Danlong has the best combination of bile salts. Compared with cholestyramine, its combination with the STC, SGC and SC values were 38.4%,46.5%,42.8%, and cholate binding capacity is related to the reaction time and the extraction of flavonoids. At the beginning of the reaction, the extract combines three cholic acid salt is faster and the reaction time of 40min has been basically reached equilibrium. When the initial concentration of flavonoids in the extract was low, its ability of combining bile salts is higher, and changes with the initial concentration of flavonoids. When the content of flavonoids reached 0.20mg, it finally reaches a maximum value and no change.6、SD mice were used as experimental animals. The mice hyperlipidemia model was established and analyzed the effect on hyperlipidemia mice’s physiological and biochemical indexes by feeding Malus domeri(Bois)Chev. flavonoids. Malus domeri(Bois)Chev. flavonoids hypolipidemic function: compared the experimental mice of high fat group with blank control group, the levels of total cholesterol (TC), triglyceride (TG) content increased significantly, difference is very significant (P<0.001), which indicates the success of modeling. Xuezhikang can significantly reduce serum TC, TG (P< 0.01), and increase HDLC and decrease LDLC. So Xuezhikang has good lipid-lowering effect, can be used as a positive control drug experiment. After feeding, Chinese hawthorn flavonoids low, middle and high dose group were able to make the content of serum and liver decrease in TC, TG, and the high dose group (300mg/kgbw/d) was significantly (P<0.05)low. But the flavonoids of Malus domeri(Bois)Chev. has no significant effect on HDLC content and LDLC content in serum (P>0.05). It has a decreasing effect on the body weight and organ index in hyperlipidemic mice, but the effect is not significant.7、Effect of Malus domeri(Bois)Chev. flavonoids on the total antioxidant capacity and antioxidant enzymes:compared with the normal group, the serum levels of SOD and T-AOC in experimental mice hyperlipidemia model group were significantly reduced, indicating that the total antioxidant capacity decreased in high fat group. Malus domeri(Bois)Chev. flavonoids groups can improve the serum SOD and T-AOC, and it showed a certain dose effect relationship. The high dose group (300mg/kgbw/d)has an significant influence (P<0.05). For the liver tissue SOD, middle dose and high dose group was very significant (P< 0.01), but the T-AOC value seldom changed in the liver tissue. The difference between groups effect was not significant (P>0.05). |
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