Pseudomonas aeruginosa is a common biofilm-forming bacterial pathogen implicated in lung, skin, and systemic
infections. Biofilms are majorly associated with chronic lung
infection, which is the most severe complication in
cystic fibrosis patients characterized by drug-resistant biofilms in the bronchial mucus with zones, where
reactive oxygen species concentration is increased mainly due to neutrophil activity. Aim of this work is to verify the anti-Pseudomonas property of
propolis or bud poplar resins extracts. The antimicrobial activity of
propolis and bud poplar resins extracts was determined by MIC and biofilm quantification. Moreover, we tested the
antioxidant activity by DPPH and neutrophil oxidative burst assays. In the end, both
propolis and bud poplar resins extracts were able to inhibit P. aeruginosa biofilm formation and to influence both swimming and swarming motility. Moreover, the extracts could inhibit proinflammatory
cytokine production by human PBMC and showed both direct and indirect
antioxidant activity. This work is the first to demonstrate that
propolis and bud poplar resins extracts can influence biofilm formation of P. aeruginosa contrasting the
inflammation and the oxidation state typical of
chronic infection suggesting that
propolis or bud poplar resins can be used along with
antibiotic as adjuvant in the
therapy against P. aeruginosa
infections related to biofilm.