Study On Separation, Purification And Antidiabtic Mechanisms Of Flavonoids From Natural Portulaca Oleracea L.

According to statistics, the global quantity of people with diabetes melltitus (DM) maintains the sustained growth.There will be nearly 550 million people with DM around the world in 2030. Clinical drugs have a lot of distinct drawbacks in the treatment of DM. The increasing interest has been attracted for the development and utilization of antidiatic plants because they have less side effects, efficacy and stability.Portulaca oleracea L. flavonoids (POF), which is one of the main ingredient of Portulaca oleracea L, has been reported to possess a variety of bioactivities such as antioxidant, antiinflammatory and antidiatics. Many papers investigating POF are mainly focused on extraction or detection, nevertheless, few experiments for about the mechanisms of lipid regulation、lowering blood glucose and improving insulin resistance of POF. The extraction and purification of POF were investigated in my experiments, then antidiabetic pathogenesis of POF were investigated from the level of the animal、cellular and molecular biology.Ultrasonic extraction and response surface analysis was applied to optimize the extraction technology POF. The optimal extraction conditions of the POF were obtained:The ethanol concentration is 39%, ratio of water to material is 24:1 (v/m), extraction temperature is 55℃,the time is 15 min. And the yield of flavonoids is 16.25 mg/g.Quercetin is separated from the POF, and it is verified by HPLC and TLC.The antioxidant activity of POF was evaluated by colorimetric method. The results showed that POF exerted scavenging activity of ·OH, DPPH and O2-, so the POF exerts the stronger oxidation resistance.Research of molecular mechanism about improving insulin resistance (IR) in HIT-T15 cells by POF and Quercetin:Compared with the IR model group,0.5 mg/mL POF and quercetin incubate HIT-T1524 h, respectively. They can significantly suppress the cytotoxicity induced by the medium of high glucose and high-fat, meanwhile, the glucose absorption had significantly been improved. Their mechanisms may be related to improve the expression of IR、IRS-2、PKB/Akt、 GLUT-2.Research of molecular mechanism about regulating lipid metabolism of type Ⅱ diabetes by POF:A combination of high-fat diet and STZ intraperitoneal injection was used to build type Ⅱ diabetes model which was treated by different concentrations of POF. Compared with the type Ⅱ diabetes model group, POF can significantly reduce glucose, regulate blood lipid content and enhance activity of oxidation resistance in the model rats. Their mechanisms may be related to improve the expression of IR、IRS-1、PKB/Akt.The extraction, hypoglycemia, antioxidant, antidiatic molecular mechanisms of POF were discussed in this paper. It provided scientific evidence for development of POF as a functional food or a drug precursor compounds of natural antidiatic herb.