Aim: This study investigated the efficacy of selenium (Se) in reducing Escherichia coli O157:H7 verotoxin production and toxin gene expression. Additionally, the effect of Se on globotriaosylceramide (Gb3) receptor in human lymphoma cells was determined.
Materials & methods: The effect of Se on verotoxin synthesis was determined by standard ELISA, whereas its effect on Gb3 receptor was determined by flow cytometry and real-time quantitative PCR.
Results & conclusions: Se reduced extracellular and intracellular verotoxin concentration by 40-60% and 80-90%, respectively (p < 0.05), and downregulated verotoxin genes (p < 0.05). Se reduced Gb3 receptor synthesis in lymphoma cells, and real-time quantitative PCR data revealed a significant downregulation of LacCer synthase gene (GalT2) involved in Gb3 synthesis. Further studies are warranted to validate these results in an appropriate animal model.
Keywords: E. coli O157:H7; Gb3 receptor; selenium; verotoxin.