几种功能性物质抑制产肠毒性大肠杆菌的效果及作用机制研究OA北大核心CSTPCD

IPEC-1 cells were treated with different concentrations of puerarin(PR),ethyl pyruvate(EP),tyrosol(TS)or zinc oxide(ZnO),and then cell viability was detected by CCK-8 method.The lactate dehydrogenase(LDH)kit was used to detect the effect of functional substances on the cytotoxic effects of ETEC K88.Real-time PCR was used to detect the effects of different functional substances on the rel-ative expression levels of genes related to IPEC-1 cells infected with ETEC K88.Results ∶PR,EP and ZnO could promote the proliferation of IPEC-1 cells,and the optimal concentrations were 5 μM,1 mM and 1 μM,respectively.TS had no obvious effect on the proliferation of IPEC-1 cells.After being infected with ETEC K88,the LDH activity of IPEC-1 cells significantly increased(P＜0.05).Compared with the K88 infected group,the addition of 5 μM PR,1 mM EP and 1 μM ZnO significantly reduced LDH activity(P＜0.05).Infection with ETEC K88 caused significant increases in the relative expression of inter-leukin-6(IL-6),interleukin-8(IL-8),tumor necrosis factor-α(TNF-α),chemokine ligand 2(CXCL2),heat shock protein 70(HSP70)and nuclear factor E2-related factor(Nrf2)genes(P＜0.05).The relative expression of cyclin protein D(cyclin D)and villin protein(villin)genes was significantly decreased(P＜0.05).PR significantly increased the relative expression of IL-8 and villin genes in IPEC-1 cells(P＜0.05).EP significantly down-regulated the relative expression of TNF-α and CXCL2 genes in cells(P＜0.05).ZnO significantly increased the relative expression of villin and cyclin D genes(P＜0.05).In addition,PR,EP and ZnO significantly reduced the relative expression of 16S rRNA gene in E.coli genes(P＜0.05).In conclusion,PR,EP and ZnO can inhibit the proliferation of ETEC K88 and have antibacterial effects,EP can reduce the expression of inflammatory genes caused by K88,PR can increase the expression of intestinal villi genes,and ZnO can increase the expression of cell cycle genes.