| People's diet has changed a lot due to the improvement of living standards.The incidence rate of hyperlipidemia has been greatly increasing which caused by excessive high fat,protein,sugar and salt diet intake.Hyperlipidemia is an important factor leading to atherosclerosis,diabetes,kidney disease,hypothyroidism and other diseases.Due to the complication of its pathogenesis and course,it's hard for drugs with single target to produce a marked effect on such kind of metabolic diseases.However,natural products are gradually concerned by various fields based on their rich targets.Among them,many polyphenols have been identified as having preventive and therapeutic effects on metabolic diseases.There are kinds of polyphenols in Aronia Melanocarpa Elliot and the fruits of this plant have been used as raw material for many products that have entered the market.What is overlooked under the situation of broad market prospect is that pomaces are largely abandoned.However,there must be a good development prospect which has special significance for the development of the industry to realize the reuse of pomace.In this research,Aronia Melanocarpa Elliot pomace is used as raw material.To achieve the purpose of pomace reuse,the polyphenols of the fruit were extracted and enriched,and their therapeutic effects on hyperlipidemia were studied.To obtain a high yield of polyphenols from the pomace,the optimal extraction method was studied through response surface methodology.The purification process was studied by single factor experiment to achieve the high-efficiency enrichment of polyphenols.And the effect of reducing plasma lipid of Aronia Melanocarpa Elliot polyphenols was validated by hyperlipidemia mice model.The main research conclusions are as follows:(1)Determination the best process conditions of ultrasonic assisted extraction of polyphenols in Aronia Melanocarpa Elliot pomace.Ultrasonic power,ultrasonic time,liquid-material ratio and solvent concentration were selected as the factors to be optimized while the extraction amount of polyphenols in Aronia Melanocarpa Elliot pomace was taken as the response value based on the single factor experiments.And the optimization of process parameters of ultrasonic assisted extraction was achieved through Design-Expert,a response surface design software.The optimized extraction conditions are shown as below: 550 W for ultrasonic power,83 minutes for ultrasonic time,20:1 m L/g of the liquid-to-material ratio and 52% of the ethanol concentration,through which the polyphenol extraction amount from the Aronia Melanocarpa Elliot pomace was 61.72 ± 0.16 mg/g.(2)Choose the best macroporous resin material and explore the best purification conditions.Static adsorption and desorption experiments were adopted to choose the best one from four common types of microporous resin materials,then the experiments of purification methodology was carried out.And this method was also applied to determine the best mass concentration of sample solution,equilibrium time of adsorption,equilibrium time of desorption,p H value of sample solution and concentration of eluent.Dynamic adsorption and desorption experiments were taken to determine the flow rate of the sample solution and eluent respectively during the adsorption and the desorption time.The results showed that the DM-130 macroporous resin reflected better adsorption and desorption capabilities.The optimized purification conditions was that 4.56 mg/m L for the liquid mass concentration of the sample solution,4 hours for equilibrium time of adsorption,2 hours for equilibrium time of desorption,the best p H=4 of the sample,80% of the eluent ethanol concentration,2 BV/h of the flow rate at adsorption 2 BV/h of the flow rate at desorption.The purity of polyphenols can be increased from 12.52% to 71.36% under the modified conditions.(3)To evaluate the treatment effect on hyperlipidemia of the polyphenols in Aronia Melanocarpa Elliot through animal experiments.60 male KM mice were divided into the normal group,the high-fat model group,the positive administration group,the low-dose administration group,the medium-dose administration group and the high-dose administration group,and 10 of them for each group.The mice in normal group were fed with normal diet while the rest of the mice in other 5 groups were fed with high-fat diet.The positive administration group was given atorvastatin.It was found that the plasma total cholesterol(TC),triglyceride(TG)and low-density lipoprotein(LDL-C)of high-fat group increased significantly while high-density lipoprotein(HDL-C)decreased by comparing the serological indexes of mice.Compared with the normal group,the mice in the high-fat group had significantly increased body weight growth rate,food utilization rate,and liver index.This indicated the successful establishment of the disease model that the mice in the high-fat group had already suffered from hyperlipidemia.The plasma TC,TG,and LDL-C were reduced to different degrees in the low-dose,medium-dose,and high-dose administration group while the HDL-C was significantly increased.The aspartate aminotransferase(AST)and alanine aminotransferase(ALT)in liver tissues were reduced,and the body weight and liver index of mice were significantly reduced,indicating that Aronia Melanocarpa Elliot polyphenol has lowering plasma lipid effect on mice with hyperlipidemia. |
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