| In order to conduct profound exploration and utilization of bitter gourd, a fruit both edible and officinal, this research implemented a series of studies on flavonoids and polysaccharides in it, including analysis on the extraction process of flavonoids and polysaccharides in bitter gourd and the bioactivity of other gourds in its series, which consists of following aspects:1. Optimization for ultrasonic-assisted extraction technology of bitter gourd flavonoids. The effect of ethanol concentration, ultrasonic power, extracting time and ratio of material to liquid on efficiency of flavonoids from Bitter Gourd were studied. The optimum extraction conditions of flavonoids by using orthogonal experiment and statistics analysis method were obtained as ethanol concentration80%, ultrasonic power70w, extraction time30min and ratio of material to liquidl:35. Under this condition, the yield of flavonoids was4.02mg/g.2. Optimization for extraction technology of bitter gourd polysaccharides. By using water extraction method, the extraction process of polysaccharide from Bitter Gourd was studied. The optimum extraction conditions were established through single-factor test, orthogoganal test and statistics analysis method as follows: extraction temperature was90℃, extraction time was4h, ratio of materials to liquid wasl:40and the optimal conditions of ethanol deposition were concentration times of4, the concentration of ethanol of80%and the deposition time of6h.3. In order to select the better antioxidant raw material, using Vc as the positive contrast, the antioxidant activities of extracts from Bitter Gourd were essayed by three different methods:the Fenton method, the Pyrogallol autoxidation method and the DPPH-method. The results were as follows:The flavonoid and polysaccharide of bitter gourd both had rather impressive scavenging activity to three kinds of free radicals including superoxide anion free radical (O2-), hydroxyl free radical (-OH) and1,1-diphenyl-2-picrylhyrazyl free radical(DPPH-), and water extract showed rather highier activity in scavenging the free radicals, whose activity was equal to or even surpassing the positive contrast Vc. Three different solvent extracts of flavonoids all demonstrated high scavenging activity, among which water extract was the most powerful in scavenging the three free radicals, while the impressive scavenging activity of ethyl acetate extract and n-butanol extract was relatively poor.4. MTT assay was used to analyze the inhibitory effect of different solvent extracts to A549human lung adenocarcinoma cell. Three different solvent extracts of Bitter Gourd flavonoid all showed a certain inhibitory effect on the proliferation of A549human lung adenocarcinoma cell. The inhibitory effect was evident at high concentration of0.2mg/mL, while the effect was not significant at low concentration, when the concentration was0.002mg/mL, there was almost no inhibitory effect. The results also showed that water extract show the most powerful inhibitory effect, when cultivating48h, the rate of inhibiting A549was up to48.92%, and showed a dose-dependent inhibitory effect on the proliferation of A549cell.5. The antimicrobial activities of some common microorganisms were determined by three different methods of filter paper disc-agar diffusion method, beating holes method and MIC method. Results showed that flavonoid extract could effectively inhibit the growth of a series of microorganism, especially Staphylococcus aurens and Bacillus subtilis and polysaccharide extract had stronger antimicrobial effects for Shigeus and Pseudomonas aerugino-sa, but not for the others.6. This study used the high fat diet mouse model to evaluate the pharmacological activity of the flavonoid and polysaccharide of Bitter Gourd lipid-lowering.Both flavoniod extracts and polysaccharide extracts decreased significantly triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol(LDL-C), increased markedly high density lipoprotein cholesterol(HDL-C) in serum in hypercholesterolaemic mice, there was always a significant difference (P <0.05) compared with model group, which showed hypocholesterolaemia effect. Besides, the flavonoid extracts also decreased significantly triglyceride(TG) and total cholesterol(TC) in liver of mice while polysaccharide extracts without obvious effect, with the model group, significant differences,(P<0.05, P<0.01). Both flavonoid extracts and polysaccharide extracts decreased significantly atherosclerosis index (All, AI2), with the model group, significant differences (P<0.05) and prevented atherosclerosis effect. |
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