engleski

The negative influence of bacterium Lactobacillus plantarum on the growth of human HEp-2 laryngeal cancer cells

The human digestive tract includes the changing ecosystem composed of various species of microorganisms. In healthy individuals there is homeostasis between probiotic and pathogenic bacteria. The aim of our study was to determine the competitive interaction between the selected strain of Lactobacillus plantarum isolated in Croatia and pathogenic bacterium Salmonella enterica serovar Typhimurium during binding to HEp-2 laryngeal cancer cells. Competitive potential of the investigated bacteria for binding to HEp-2 epithelial cells was measured over a period of 30 and 60 minutes, with two concentrations of bacteria. The impact of the bacterial cell on HEp-2 laryngeal cancer cells was determined by the measuring of amount of metabolic products and by detection of intracellular proteins, using the methods HPLC and MALDI-TOF / TOF, consequently. After exposure HEp-2 epithelial cells, at a first 30 minutes to S. enterica, and then 30 minutes to L. plantarum cells, it was found better binding of L. plantarum regardless of the initial bacteria concentration used. Comparing other combinations of bacteria that were used in the experiments, it was obtained that the treatment of HEp-2 epithelial cells with L. plantarum led to low levels of lactic acid which implies a reduction in ATP levels, and also the inhibition of growth of these cells. Differential analysis of intracellular proteins in HEp-2 cells demonstrated reduced levels of protein thioredoxin, participants in the oxidative stress, and Hgstp1-1, required for detoxification, after treatment with L. plantarum. Previous studies have shown the great potential of L. plantarum in the protection of intestinal epithelium against enteropathogenic Escherichia coli, and our research points to the possibility of influencing our selected autochthonous strain to prevent the growth of HEp-2 laryngeal cancer cells.

Lactobacillus plantarum ; Salmonella enterica serovar Typhimurium ; HEp-2 cells

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