Studies On Antibacterial,Antioxidant And Inhibition Of α-Glucosidase Of Alcohol Extracts From Allium Tenuissimum Flowers

Allium tenuissimum belongs to Allium plants in liliaceae,its inflorescence is edible and having a unique fragrance,which is especially loved by people in the north.Until now,there are more researches on Allium plants,but less on Allium tenuissimum.It is necessary and significant to systematically study the antibacterial,antioxidant,and inhibitory ofα-glucosidase effects for ethanol extracts from Allium tenuissimum flowers.And it is helpful to the development and utilization of Allium tenuissimum.In this paper,the ethanol extracts of Allium tenuissimum flowers were prepared.Firstly,the active ingredients were determined by high-performance liquid chromatography and the antibacterial effects were studied;Secondly,the antioxidation and inhibition of nitrosation in vitro experiments were carried out by means of spectrophotometric method.Finally,the author made a primary study on the inhibition of α-glucosidase for ethanol extracts from Allium tenuissimum flowers.The main research contents and conclusions are as follows:(1)The chemical constituents and antibacterial effects of alcohol extracts from Allium tenuissimum flowers.The active ingredient of Allium tenuissimum flowers was extracted by different concentrations of ethanol and the content of astragalin was determined by high performance liquid chromatography.The antibacterial effect,minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of extracts against Staphylococcus aureus,Bacillus subtilis and Escherichia coli were carried out by Oxford Cup bacteriostatic test and tube double dilution method.The determination was performed on Agela Venusil XBP-C18 with mobile phase consisted of acetonitrile-water(gradient elution)at the flow rate of 0.8 m L/min under the detection wavelength of 260 nm.The results showed that astragalin was the main chemical component of ethanol extracts from Allium tenuissimum flowers,and its content was the highest for 60% alcohol extracts.The ethanol extracts of Allium tenuissimum flowers had a certain inhibitory effect on Staphylococcus aureus,Bacillus subtilis and Escherichia coli.The antibacterial effects were gradually enhanced with the increase of the concentration of alcohol extracts especially for 60% alcohol extract has the best bacteriostatic effect,and the inhibition effect is the strongest against Staphylococcus aureus among the studiedthree bacterias.(2)Analysis of the Antioxidant activity of ethanol extracts from Allium tenuissimum flowersThe antioxidative activity of ethanol extracts from Allium tenuissimum flowers was analyzed by employing three different in vitro assays including DPPH· scavenge activity,ABTS· removal and total reducing power activity.In addition,nitri te scavenging capacity and inhibitory effect on nitrosamine formation of Allium tenuissimum flowers ethanol extracts were studied under the condition of simulate gastric juice(p H 3.0 with temperature 37 ℃)in vitro by the method of spectrophotography.The results indicated that ethanol extracts from Allium tenuissimum flowers showed scavenging capacities against free radicals and nitrite.And the scavenging capacity of 60% alcohol extracts against DPPH radicals,ABTS radicals,total reducing power activity and nitrite was higher than that of other extracts.In the meantime,the ethanol extracts from Allium tenuissimum flowers exhibited dose-dependent antioxidant activity and nitrite scavenging capacity and inhibition of nitrosamine formation.At 10 mg/m L the 60% alcohol extracts,the scavenging capacities against nitrite and nitrosamine were71.56% and95.22%,respectively.(3)Inhibition of α-glucosidase for ethanol extracts from Allium tenuissimum flowersIn this experiment,the inhibition effect of α-glucosidase for ethanol extracts from Allium tenuissimum flowers was researched by spectrophotometry.The type of inhibition was explored by Lineweaver-Burk double reciprocal mapping method.The results indicated that the alcoholextracts of Allium tenuissimum flowers had certain inhibitory effect onα-glucosidase,and the inhibition effect of 60% alcohol extracts is the best among other extracts.The maximum inhibition rate was 83% in the range of 50~70 mg/mL.