In vitro anti-bacterial and anti-inflammatory activities of lactic acid bacteria-biotransformed mulberry (Morus alba Linnaeus) fruit extract against Salmonella Typhimurium

Biotransformation is an effective system to provide various beneficial effects in food processing and pharmaceutical fields. The present study evaluated the anti-bacterial and anti-inflammatory activities of lactic acid bacteria (LAB)-biotransformed mulberry fruit extract (MFE) against Salmonella Typhimurium. Biotransformed MFE more effectively reduced S. Typhimurium growth compared to non-biotransformed MFE and significantly inhibited the biofilm formation of S. Typhimurium (P < 0.05) from an early time point. The viability of S. Typhimurium biofilm cells was decreased in the presence of biotransformed MFE, as further evidenced by scanning electron microscopy analysis. In addition, biotransformed MFE significantly inhibited the secretion of interleukin-8 by S. Typhimurium in human intestinal epithelial cells in a dose-dependent manner (P < 0.05), indicating that biotransformed MFE effectively attenuated the inflammatory response in vitro. Thus, these results suggest that LAB-biotransformed MFE efficiently exhibited anti-bacterial activity by reducing the growth and biofilm formation of S. Typhimurium as well as anti-inflammatory activity in the intestinal epithelial cells infected with the bacteria.