The present study focused on probiotic characterization and safety evaluation of Enterococcus isolates from different artisanal dairy products. All the isolates exhibited inhibitory activity against several food spoilage bacteria and food-borne pathogens, including Shigella flexneri, Staphylococcus aureus, Listeria monocytogenes, Yersinia enterocolitica, Klebsiella pneumoniae, Escherichia coli, and Bacillus subtilis. The PCR results indicated the presence of at least one enterocin structural gene in all the tested strains. The Enterococcus isolates were further evaluated regarding their safety properties and functional features. The isolates were susceptible to vancomycin, gentamycin, and chloramphenicol. The results of PCR amplification revealed that all the tested isolates harbored none of the tested virulence genes except E. faecalis (ES9), which showed the presence of esp gene. The Enterococcus isolates showed cholesterol lowering properties. The selected isolates showed a high tolerance to low pH, and toward bile salts. They also demonstrated hydrophobicity activity, auto-aggregation, and adhesion ability to the human intestinal Caco-2 cell line. These properties may contribute the bacteria colonizing the gut. This study revealed that the Enterococcus isolates, especially E. durans ES11, ES20 and ES32, might be excellent candidates for production of functional foods to promote health benefits.

Doxorubicin Changes Bax /Bcl-xL Ratio, Caspase-8 and 9 in Breast Cancer Cells

The goal of this study was to establish paclitaxel resistant MCF-7 cells, as in vitro model, to identify the molecular mechanisms leading to acquired chemoresistance in breast cancer cells. Resistant cells were developed by stepwise increasing exposure to paclitaxel. Gene expression levels of Bax and Bcl-2 along with protein levels of caspase-8 and caspase-9 were evaluated in two resistant cell lines (MCF -7/Pac64 and MCF -7/Pac5 nM). Morphological modifications in paclitaxel resistance cells were examined by light microscopy and fluorescence activated cell sorting (FACS). As an important indicator of resistance to chemotheraputic agents, the Bcl-2/Bax ratio showed a significant increase in both MCF-7/Pac5nM and MCF-7/Pac 64nM cells (p<0.001), while caspase-9 levels were decreased (p<0.001) and caspase-8 was increased (p<0.001). FACS analysis demonstrated that MCF -7/Pac64 cells were smaller than MCF-7 cells with no difference in their granularity. Our results support the idea that paclitaxel induces apoptosis in a mitochondrial-dependent manner. Identifying breast cancer patients with a higher Bcl-2/Bax ratio and caspase 9 level and then inhibiting the activity of these proteins may improve the efficacy of chemotheraputic agents.