Berberine Inhibits Staphylococcus Aureus α-hemolysin And The Oxidative Damage Induced By α-hemolysin

It is well known that Staphylococcus aureus is a very serious foodborne pathogen.Not only will it lead to food poisoning,but it will also induce a variety of deadly infectious diseases.As a result,It poses a serious threat to people safety.According to research,caused by Staphylococcus aureus pathogenicity is the main reason which can secrete a variety of virulence proteins such as α-hemolysin、SEA and SEB.The α-hemolysin is the most important virulence factor.Berberine,as a natural compound that is extracted from Podocarpus in strong activity of isoquinoline alkaloids.According to previous reports,the diffusion of berberine can control certain pathogens.But there is no literature reported the effect of berberine secretion of α-hemolysin、SEA and SEB against Staphylococcus aureus.Based on consulting domestic and foreign literature,the effects of berberine on Bacteriostasis mechanism of Staphylococcus aureus and oxidative damage induced by α-hemolysin were studied in the following three aspects.(1)Study on the inhibitory effect of berberine on Staphylococcus aureus and Staphylococcus aureus of berberine on cell membrane.The MIC values of berberine against Staphylococcus aureus are determined,we concluded that the MIC values of berberine against Staphylococcus aureus strains were 128 μg/mL.Through the determination of different time of Staphylococcus aureus growth in different concentrations of berberine,reflecting berberine on Staphylococcus aureus.The disk diffusion method was used to investigate the inhibitory effect of berberine hydrochloride on Staphylococcus aureus,showed that in 128 g had the strongest inhibitory effect in a dose-dependent manner.In addition,the absorption of berberine concentration was 0μg /mL,16μg /mL,32μg /mL,64μg /mL of Staphylococcus aureus bacteria suspension UV determination and permeability experiment showed that berberine intima,Staphylococcus aureus β-galactosidase has inhibitory effect on 64μg /mL when the highest degree of cell membrane damage.SEM observation of berberine in different time to act on the bacteria,cells deform.With the prolongation of time was 3h,cell surface is uneven or swelling,so nutrients and genetic material leakage.(2)Study of berberine on three kinds of virulence factors of Staphylococcus aureus secretion(α-hemolysin and SEA and SEB)mechanism research.First,The hemolysis test showed that compared to the control group,when the concentration was 8μg /mL,16μg /mL,32μg /mL,64μg /mL berberine,the hemolysis ratio are reduced to 81.1%,68.01%,36.61%,8.34%.Then,Western blotting was observed in subinhibitory concentration under the action of berberine can effectively inhibit α-hemolysin,SEA and SEB secretion in a dose-dependent manner.Finally,ELISA determination of different concentrations of berberine in liver cells in L02 cell factor TNF-α、IL-6、IL-1β emissions decreased gradually.(3)Study on berberine has an inhibitory effect on α-hemolysin induced oxidative damage to L02.First of all,MTT measured in the control group,α-hemolysin group,low dose of berberine + α-hemolysin group,middle dose of berberine + α-hemolysin group,high dose of berberine + α-hemolysin group cell proliferation activity.Then,MDA and SOD,GSH-Px activity was determined.Research shows that oxidative damage of berberine can inhibit α-hemolysin induced liver cells caused by L02,and the inhibition was dose dependent.Finally,flow cytometry was used to detect ROS and change of mitochondrial membrane potential further to determine the inhibitory effect of berberineAccording to the experimental data,berberine,as a natural antibacterial agent,clearly demonstrates the inhibition mechanism of berberine on Staphylococcus aureus and the oxidative damage induced by α-hemolysin.Therefore,this study provides a basis for berberine as a natural compound with potential research and development in the field of food and pharmaceutical industry.