Structure and anti-inflammatory capacity of peptidoglycan from Lactobacillus acidophilus in RAW-264.7 cells.

Probiotic bacteria, especially the Lactobacillus species, can potentially play a significant role in the antiviral and antimicrobial activity of a host's immune system. Lactobacillus acidophilus, an intestinal bacterium, is involved in the intestinal epithelial cell response when a pathogen adheres to a cell. In this study, the structure of peptidoglycan (PGN) isolated from L. acidophilus was determined with the help of HPLC, NMR, FT-IR and MALDI-TOF/TOF MS. The molecular mass of PGN is 875.260 Da. The anti-inflammatory capacity of PGN was evaluated in model RAW 264.7 cells. Epifluorescence microscopy images and western blot analysis provided compelling evidence of PGN's anti-inflammatory capacity on LPS-induced macrophages. A significant decrease in inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) levels when PGN was added up to 200 μg/ml. These data provide new insight into the cellular and molecular mechanisms by which probiotic bacteria can contribute to maintaining good health.