Effects of andrographolide on infection of human bronchial epithelial cells caused by clinical strains of pseudomonas aeruginosa

Abstract:

Objective：To infect human bronchial epithelial cell （BEAS-2B） model by pseudomonas aeruginosa（PA） and to observe andrographolide’s effects on the bacterial infection ability and the host cell inflammatory response. Methods：PA01 and clinical strains of PA，Cq1（exoU-） and Cq40（exoU+） were respectively used to infect BEAS-2B. In vitro lysogeny broth culture was conducted and the effect of andrographolide（300 μmol/L） on the bacterial growth was observed. PA invasive capability on BEAS-2B was tested by colony counting method. With double antibody sandwich enzyme-linked immunosorbent assay（ELISA），lactate dehydrogenase（LDH） releasing and inflammatory cytokines，interleukin-6（IL-6） and IL-8 expression were measured. Pretreated by different concentrations of andrographolide（3.0 μmol/L and 4.5 μmol/L），effects of andrographolide on BEAS-2B infection caused by different strains of PA were detected. Results：Similar to PA01，high concentration（300 μmol/L） andrographolide exerted no impact on either exoU or exoU-PA growth. 3.0 μmol/L and 4.5 μmol/L andrographolide significantly reduced the intracellular colony number of PA，LDH releasing and generation of IL-6 and IL-8. Conclusions：Andrographolide can attenuate invasive effects of clinical strains of PA on hu－man bronchial epithelial cell and reduce the related cell damage and inhibit inflammatory response.