| With humans′ s living standard improving, the incidences of diabetes and hyperlipidemia are higher than before, both of them have become a serious threat to human health. Some chemical or biological synthesis hypoglycemic cholesterol-lowering drugs are developed and use to clinical markets, these drugs have a certain therapeutic effect, but easy to produce drug dependency or side effects, the complications of the treatment effect is limited with high prices. Natural products containing a variety of active ingredients to treat disease have more function and target(mechanism), and might have better curative effect. In the meantime, natural products are more safety and no side effects, the price of them is cheaper also.Thus looking for hypoglycemic and hypolipidemic effect of natural food resources, with no side effects of functional foods become a focus of global research.In my paper, according to the demands of functional food industry, the aim is to use natural food resources and food medicine and plant resources by scientific formula to develop a safe and effective in hypoglycemic and hypolipidemic products and evaluate their activity. The main results are as follows: 1、The hpyerglycemic and hypolipidemic research of plant extract:On the basis of the literature, the inhibitory effects of α-glycosidase, α- amylase, pancreatic lipase, cholesterol esterase and cholesterol micelle solubility were the evaluation index and then screened 9 functional factors. Tea polyphenols, gingko flavonoids, gynostemma saponins, peony seed oil and momordica charantia extracts were the final formula of the active ingredients.the hpyerglycemic effect of peony seed oil: continuous low-dose STZ(40 mg/kg bw)intraperitoneal injection was exhibited to establish diabetes model. The result revealed that compared with the diabetic mice without treatment, the inhibition of α- amylase and α-glycosidase by peony seed oil leaded to the delay of the absorption of carbohydrates in small intestine, and the blood glucose level was decreased. On the other side, peony seed oil significantly promoted the insulin release, the liver glycogen synthesis and lowed the glycosylated hemoglobin levels(p<0.05). Secondly, the hypolipidemic effects of peony seed oil(20%, w/w)was also studied, compared to lard oil(20%, w/w)and safflower oil(20%, w/w) group. Peony seed oil significantly increased Eiscosapentaenoic(EPA) and docosahexenoic acid(DHA) level in serum and liver, and decreased the ratio of n-6/n-3. Peony seed oil significantly decreased the rats weight and lipid. QRT-PCR revealed that the expression of SREBP1 C, FAS and ACC mRNA were significantly decreased, and peroxisome proliferators-activated α(PPARα) m RNA, Acyl Coenzyme A Oxidase(AOX) mRNA, decoupling the protein 2(UCP-2) mRNA were significantly increased(p<0.05). Then, it can be concluded that the hypolipidemic effects of peony seed oil was via inhibition of lipogenesis and up-regulation of fatty acid β-oxidation.The hpyerglycemic effect of gingko flavonoids: STZ(120 mg/kg bw)was used to establish diabetes model by intraperitoneal injection. Compared with the diabetic mice without treatment, gingko flavonoids significantly redued blood glucose level(p<0.05). On the other side, gingko flavonoids significantly promoted the insulin release, the liver glycogen synthesis and lowed the glycosylated hemoglobin levels(p<0.05). secondly, the hyperlipidemic rats were established by high fat diet(20%,w/w). The result revealed that compared with the high fat diet without treatment, gingko flavonoids significantly reduced the level of body weight, TG, TC and LDL-C, increased HDL-C. Meanwhile, the fat and cholesterol in faeces were also significantly increased(p<0.05). QRT-PCR revealed that gingko flavonoids significantly up-regulated the expression of AMPK and CPT-1, the expression of ACC、FAS、SREBP-1C and HMG-CoA reductase were significantly decreased(p<0.05). Orthogonal t value analyzed that the main components in formula were peony seed oil, gingko flavonoids and tea polyphenols. The animal study in vivo demonstrated that the hpyerglycemic and hypolipidemic effects can be exhibited by peony seed oil and gingko flavonoids. They can be used as plant extracts source to low lipid and blood glucose level. 2、The hpyerglycemic and hypolipidemic formula design in vitroInhibitory rate of α- amylase and cholesterol esterase were used as evaluation index to determin the main components of the formula by the method of orthogonal t value analysis and weighted synthesis. The main compositions were tea polyphenols, gingko flavonoids and peony seed oil, the adjuvant were gynostemma saponins and momordica charantia extracts. D value optimization method was exhibited to determine the formula ratio of tea polyphenols: ginkgo biloba extract: gynostemma saponins: peony seed oil: balsam pear extract = 6:8:5:8:8(w/w/w). With the purpose of developing a safe and healthy functional food, according to abundance distribution of functional factors in the plant extracts, tea water extract, ginkgo extract, gynostemma water extract, peony seed oil and balsam pear water extract were determined as the final determined raw material formula. 3、The hpyerglycemic and hypolipidemic effects of functional food formula were exhibited in vivo by the animal experiment analysisFirstly, STZ(120 mg/kg bw)was used to establish diabetes model via intraperitoneal injection. Compared with the diabetic mice without treatment, formula(0.1 g/day/kg bw)significantly redued blood glucose level(p<0.05). The result revealed that the inhibition of α- amylase and α- glycosidase by formula leaded to the delay of the absorption of carbohydrates in small intestine, and the blood glucose level was decreased. On the other side, formula significantly promoted the insulin release, the liver glycogen synthesis and lowed the glycosylated hemoglobin levels(p<0.05). Meanwhile, the formula improved diabetes mice liver tissue oxidative stress injury. The levels of superoxide dismutase(SOD)、glutathione peroxidase(GSH-PX)and glutathione(GSH)were significantly increased(p<0.05), and malondialdehyde(MDA) was significantly decreased. Secondly, hyperlipidemic model was established to evaluate the hypolipidemic effect of formula. The result revealed that compared to hyperlipidemic rats without treatment, formula(0.1 g/day/kg bw)significantly reduced the lipid level(p<0.05). Fluorescence quantitive real-time PCR(QRT-PCR) revealed that the expression of cholesterol esterase mRNA, FAS m RNA and HMG-Co A reductase mRNA were significantly decreased(p<0.05). Meanwhile, the fat and cholesterol in faeces were also increased. Small intestine environment was simulated to detect the inhibitory effect of pancreatic lipase and cholesterol micelle solubility in vitro, in vivo study speculated that the increased fat and cholesterol in faeces due to the suppressed pancreatic lipase activity, triglyceride cannot be fully hydrolysis, and finally be discharged. The reduced cholesterol micelle solubility in the small intestine resulted in the prevention of absorption of cholesterol in small intestine, and finally be discharged. 4、The interaction of functional factors with α- amylase, pancreatic lipase, cholesterol esterase and cholesterol micelle interactionThe mainly technologies were circular dichroism and fluorescence spectrum and were used to evaluate the change of enzyme conformation. The results found that functional factors changed the secondary structure of α- amylase, pancreatic lipase, cholesterol esterase, and fluorescence spectrum study found that trp was exposed to polar environment, fluorescence quenching phenomena occurred. Hence, the interaction of functional factors and protein resulted in the decrease of enzyme activity. TEM showed that gingko flavonoids, gynostemma saponins and momordica charantia extracts interacted with cholesterol micelle and formed complexes resulting in the decreased cholesterol micelle solubility. |
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