Abstract
Background: Lycium barbarum berries have been utilized in Asia for many years. However, the mechanisms of its lung-defensive properties are indeterminate. Methods: We investigate whether L. barbarum polysaccharide could weaken Pseudomonas aeruginosa infection-induced lung injury. Mice primary air-liquid interface epithelial cultures were pretreated with L. barbarum polysaccharide (LBP) and subsequently treated with pyocyanin (PCN). Lung injury, including apoptosis, inflammation, and oxidative stress, was estimated by western blot, ELISA and Q-PCR. Flow cytometry was used to test cell apoptosis. Moreover, Balb/c mice were used to evaluate the tissue injury. We used hematoxylin-eosin staining and immunofluorescence to detect the expression of related proteins and tissue damage in mouse lungs and spleen. Results: The flow cytometric analysis shows the potential of Lycium barbarum polysaccharide (LBP) to reduce time-dependent cell death by PCN. Mechanistically, LBP reduces PCN-induced expression of proapoptotic proteins, caspase3, and induces the activation of Bcl-2 in mice bronchial epithelial cells. Similarly, LBP reduces PCN-induced intracellular reactive oxygen species (ROS) production. Moreover, LBP inhibits the production of inflammatory cytokines, IL-1β, TNF, IL-6, and IL-8. Conclusion: Our study confirms the ability of LBP to retard PCN-induced injury in mice lung and spleen. Inhibition of PCN-induced lung injury by LBP is capable of protecting mice cells from injury.