Anti-inflammatory effects in LPS-induced macrophages and antibiofilm activity of the mannose-rich exopolysaccharide produced by B3-15.

The mannose-rich exopolysaccharide EPS B3-15, produced by the thermophilic B3-15, was previously reported to possess promising potentialities as antiviral and immunomodulatory agent, and in preventing the adhesion of and . In this study, EPS B3-15 was evaluated for its anti-inflammatory activity in LPS-induced macrophages and the ability to contrast the adhesion of and as pathogenic bacteria of the respiratory tract. Without affecting the macrophages viability, the EPS at low concentration (300 μg/mL) significantly downregulated the gene expression of iNOS and the consequent NO generation, and it also decreased the production of pro-inflammatory cytokines. Moreover, the EPS reduced the adhesion of (47 %) more efficiently than (38 %), due to its ability to modify the abiotic surfaces properties and alter the charges of bacterial-cell surface of Gram-positive more than Gram-negative. As able to reduce the inflammatory responses in macrophage cells and simultaneously prevent biofilm-related to the respiratory tract infections, EPS B3-15 could have potential use as nasal spray with anti-inflammatory action and surface-coating agent for medical devices.