Study On Quality Standards Of Mulberry Leaf Polyphenols And Correlated Antioxidant And Lipid Regulation Activities

1 Background and purposeMulberry cultivation history in C hina is nearly 5000 years, mulberry leaf, one of the largest part of the above-ground biomass, is traditional C hinese medicine in China. Since ancient times mulberry leaves as teas and dietary supplements are edible, its extract ion in a cell and animal model was proved with antioxidant and anti-diabetic activity, and these effects closely relationship with phenolic compounds in mulberry leaves. About the quality of mulberry leaves in the national pharmacopoeia standard rutin at only one monomer, that was not enough to fully reflects the characteristics of mulberry leaf chemical components, it is necessary to further supplement and perfect of the phenol monomer type, and lipid metabolic regulation effect on mulberry leaves were mostly based on animal research results, the level of molecular mechanism of its in-depth research is rarely reported. According to the above problem, this paper study on the spectrum of mulberry leaf phenolics, establish mulberry leaf polyphenol quality standards, in order to study the main cell line 3T3-L1 preadipocyte lipid metabolism as object, study of mulberry leaf polyphenol role on the improvement of the lipid metabolic disorders, in order to investigate mulberry leaf polyphenol in the regulatory mechanism of lipid metabolic disorder.Because of mulberry varieties, maturity, and harvest time will cause great influence to mulberry leaf polyphenol content, at the same time, extraction solvent, material liquid ratio, extraction temperature and other factors in mulberry leaves of polyphenols rate effect is also important to mention, so this topic is in mulberry leaves polyphenol extraction process optimization, on the basis of further study on different maturity, varieties, harvest time on mulberry leaf antioxidant activity and the influence of the phenolic content of monomer composition, determine the optimal maturity of mulberry leaf polyphenol, varieties and harvest time, establish a mulberry leaves of polyphenols and its monomer as the core of mulberry leaf quality standard, screening of phenolics best mulberry varieties.With mulberry leaf polyphenol extracts as the research object, examine the 3T3- L1 preadipocyte proliferation and differentiation and the effect of tracking the change of cell lipid accumulation, proven mulberry leaf polyphenol to related lipid phenotype and gene expression.Research results can provide auxiliary mulberry leaves fall hematic fat cholesterol- lowering functional food and provide theoretical basis for pharmaceutical research. 2 MethodsThis research chooses "da 10" mulberry leaf as raw material, through the single factor experiment on the basis of mulberry leaves was optimized by using response surface polyphenols extraction process, select the best process conditions; the optimal met hod is used to "nongsang 12" different maturity and 8 species in seven different collection of mulberry leaf as raw material, the extraction of mulberry leaf polyphenol, using high performance liquid chromatography(HPLC) external standard statutory quantitative detection of mulberry leaf phenol monomer composition and content of mulberry leaf polyphenol spectrum was the dynamic change law of the detection of antio xidant capacity index(ORAC) of absorptive capacity of oxygen free radicals, DPPH capability of clear and total phenol content detection; With 3T3- L1 preadipocyte as research tools, CCK 8 method to detect cell proliferation, the lipid accumulation oil red staining method and enzymatic detection cells that concentration of free fatty acids and cell supernatant fluid of triglyceride and total cholesterol concentration, real-time fluorescent quantitative PCR method to detect former process of 3T3-L1 preadipocyte differentiation and lipid metabolism related genes expression of PPARγ, C/EBPα, Adiponectin, FAS. 3 ResultsThe best extraction conditions as follows: ethanol concentration 70%, quality of material liquid concentration of 0.03 g/mL, ultrasonic time for 60 min. Maturity of mulberry leaves the sum total of phenol monomer, antioxidant activity were negative correlation rule, the influence of the mulberry leaf contains the main free phenol chlorogenic acid, benzoic acid, rutin and st John’s wort glycosides and maturity is negatively correlated. The total phenol monomer content o f "a 2", "zibai 4" and "kangqing 10" in eight varieties is higher, and antioxidant activity is higher in seven different harvest months, harvested in October each type combined phenol monomer content and antioxidant activity of the highest, followed by march. Comprehensive cultivation and actual applications, the October 10 "kangqing 10" is the best option. Mulberry leaf polyphenol under certain concentration can reduce the 3T3-L1 preadipocyte lipid accumulation, reduce the apparent index overflow, free fatty acids in the cell of triglyceride and cholesterol concentration, reduce the cell differentiation associated genes expression of PPARγ, FAS, C/EBPα, and Adiponectin. 4 ConclusionsThis study discussed the effect of maturity, varietie s and harvest month of mulberry leaf on phenol monomer composition, content, composition and antioxidant activity, elucidate differences in our represe ntative mulberry leaf phenols mass spectrometry, and make clear the dynamic changes rules of mulberry leaf phenolic substances collected in different months. The paper which prove that mulberry leaf polyphenols can reduce expression of differentiation phenotype related gene in 3T3-L1 preadipocyte can provide a good and important theoretical basis for developing functional food which can change dyslipidemiabe by use of mulberry leaves.