| Corn silk is a well-known traditional Chinese medicine that has been widely usedfor treatment of some diseases. the " Southern Yunnan Materia Medica "," ChineseDictionary "and other classics of Chinese medicine have been documented, for thetreatment of nephritis, gallstones, diabetes, jaundice, measles, chylous urine,vaginal bleeding disorders. Modern nutrition analysis shows Corn containspolysaccharides, flavonoids, sterols, organic acids, vitamins, alkaloids, saponins,inositol, cryptoxanthin, and allantoin. The bioactive and medicinal value of CornSilk have been showed, such as anti-diabetic, adjusting blood pressure, immuneregulation, relieve fatigue, anti-tumor, anti-aging. On the clinical applicationshowed that Corn silk can be used for hypertension, diabetes and other diseases Inaddition, the "Chinese Dictionary " records the toxicity, the U.S. Food and DrugAdministration confirmed that corn silk to be safe.Previous research showed thatphenolic acids, favonoid, aglycons and related monosaccharides from corn silkpossessed anti-oxidative activities,and its polysaccharides could lead to weight lossand improve gastrointestinal movement. On the Other hand, the phenolic acids andfavonoids in corn silk have been well investigated, including extraction, structuralidentifcation, bioactivities and the relationship between antioxidant activity andcontents of various polyphenol classes.Therefore, on the basis of preliminary studies, polysaccharide compounds,flavonoids and sterols from Corn silk were extracted to optimize the best extractionprocess parameters. The anti-oxidation, anti-coagulation, anti-gout, α-glucosidaseand α-amylase inhibitory activity and hypotensive activity were screened invitro.The active substance was purified by chromatography and was fed a highblood sugar mice, by examining water intake, food intake, body weight, bloodglucose, and maximum tolerated dose of sugar and other indicators. Research clarityof purpose, to meet the needs of economic development in Jilin Province.First, the basic measurement method of a β-sitosterol, polysaccharide andflavonoids from corn silk, they were extracted and optimized by response surfacemethodology(RSM), based on a Box–Behnken design (BBD). By analysis ofvariance, regression model for each of the goodness of fit and significance tests,according to the multi-function extreme value theory to determine the optimal valueof each index under optimum conditions. The experimental data were ftted to asecond-order polynomial equation and also profled into the corresponding3-Dcontour plots. The β-sitosterol, polysaccharides compounds and flavonoids ofoptimal extraction conditions were as follows: extraction temperature48.8(℃),extraction time87.1(min), liquid-solid ratio42.1(ml/g) and ethanol concentrationwas84.3(%), in this condition, β-sitosterol yield of1.47%; extractiontemperature82.6(℃), extraction time77.3(min) and liquid-solid ratio of87.4(ml/g), under this condition, the yield was6.60%polysaccharides; ethanol concentration of74(%), extraction time3.96(h) and liquid-solid ratio of54.4(ml/g). Under these conditions, corn yield of flavonoids17.15mg/g.By the in vitro enzymatic screening platform, the functional activity of Corn silkwas screened. The sterols, flavonoids and crude polysaccharide compounds for theactivity of thrombin, angiotensin converting enzyme (ACE), α-glucosidase, α-amylase and xanthine oxidase inhibitory ability and free radical scavenging capacity,reducing power and metal ion chelating capabilities were investigated. The resultsshowed: Corn silk extracts had anticoagulant actives,and showed overall upwardtrend.The polysaccharide have higher anticoagulant activity in vitro; Corn silkcrude extracts on ACE inhibitory activity was not obvious, indicating that corn silkextracts can been used to regulates blood pressure not by inhibiting the activity ofangiotensin-converting enzyme ACE achieved; Corn silk polysaccharides, crudeflavonoids and crude sterols for α-glucosidase and α-amylase inhibitory abilitywere: crude polysaccharide> crude flavonoids> crude sterols; against xanthineoxidase inhibitory capacity as follows: crude flavonoids> polysaccharide> Thecrude sterols.Corn silk crud extracts have certain antioxidant activity, the radicalscavenging capacity were: Vc> polysaccharide> crude flavonoids> crude sterolextract. Restore the order of the size of the force: Vc> polysaccharide> crudeflavonoids> crude sterols. Metal ion chelating ability were: EDTA reference>polysaccharide> crude flavonoids> crude sterols.The highly active ingredients were separated, purified and enriched by usingcolumn chromatography. The single factor (sample volume, elution volume,elution and adsorption time) of purification by chromatography were screened toenrich polysaccharide. The optimal process parameters showed: the sample volumewas8ml, adsorption time was4h, the elution volume of100ml, polysaccharideretention rate was98.37%, protein removal rate was70.22%. In addition to thepurified polysaccharide compound from corn silk were measured sequentiallydetermined molecular weight and structure prediction by the infrared spectrum, andthe α-glucosidase and α-amylase inhibition rate.Meanwhile, the hypoglycemic activity in vitro of the polyamide purifiedfractions were screened by administering the high blood sugar mouse model. Theresults showed that the purified polysaccharide component from corn silk caneffectively reduce glucose levels in mice, and showed a significant hypoglycemiceffect in the fourth week, the effect is similar with metformin, while purifiedpolysaccharide component can significantly reduce the total blood cholesterol levelsin mice. In addition, high doses of purified polysaccharide can be used to improvingblood sugar and glucose tolerance, while also enabling improved resistance tofatigue and improve their depressive behavior.The aims of this project to study the screening of biological activity,hypoglycemic active ingredient purified and enriched, animal experiments bybiological enzyme technology, chromatographic techniques developed for theperspective of functional food research. If this research results can be application andindustrial transformation, not only the waste corn silk can be turned into a usefulresource, but also through the development of high value-added food products and has obvious economic benefits, has a very broad market prospects and significanteconomic and social benefits. |
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