OBJECTIVE: We sought to examine the role of the IL-33/ST2 axis in lung inflammation on acute ozone exposure in mice.
METHODS: ST2- and Il33-deficient, IL-33 citrine reporter, and C57BL/6 (wild-type) mice underwent a single ozone exposure (1 ppm for 1 hour) in all studies. Cell recruitment in lung tissue and the bronchoalveolar space, inflammatory parameters, epithelial barrier damage, and airway hyperresponsiveness (AHR) were determined.
RESULTS: We report that a single ozone exposure causes rapid disruption of the epithelial barrier within 1 hour, followed by a second phase of respiratory barrier injury with increased neutrophil recruitment, reactive oxygen species production, AHR, and IL-33 expression in epithelial and myeloid cells in wild-type mice. In the absence of IL-33 or IL-33 receptor/ST2, epithelial cell injury with protein leak and myeloid cell recruitment and inflammation are further increased, whereas the tight junction proteins E-cadherin and zonula occludens 1 and reactive oxygen species expression in neutrophils and AHR are diminished. ST2 neutralization recapitulated the enhanced ozone-induced neutrophilic inflammation. However, myeloid cell depletion using GR-1 antibody reduced ozone-induced lung inflammation, epithelial cell injury, and protein leak, whereas administration of recombinant mouse IL-33 reduced neutrophil recruitment in Il33-deficient mice.
CONCLUSION: Data demonstrate that ozone causes an immediate barrier injury that precedes myeloid cell-mediated inflammatory injury under the control of the IL-33/ST2 axis. Thus IL-33/ST2 signaling is critical for maintenance of intact epithelial barrier and inflammation.
AIMS AND OBJECTIVES: To compare the effectiveness of commercially available 0.2% chlorhexidine gluconate mouthrinse and dill seed oil mouthrinse on plaque levels and gingivitis.
MATERIAL AND METHODS: A randomized controlled, double blind parallel arm study was conducted over 90 days on 90 subjects. The subjects were randomly divided into 2 groups and baseline data was collected using Loe and Silness gingival index and Quigley Hein plaque index and oral prophylaxis was performed on all the subjects. The mouthrinses included in the present study were dill seed oil and Hexodent (0.2% chlorhexidine gluconate). Intervention regarding the mouthrinsing was given to the subjects and were followed up for 45 days and 90 days, after this post intervention changes were assessed using the respective indices.
RESULTS: It was observed that there is no significant difference in gingival & plaque scores among two mouthrinses from baseline to 45 days and 90 days. It was observed that there is statistical difference in gingival and plaque scores when compared with baseline to 45 days (p<0.001), baseline to 90 days (p<0.001) and 45 days to 90 days (p<0.001) when intergroup comparisons were done.
CONCLUSION: It was concluded that dill seed oil and Hexodent (0.2% chlorhexidine gluconate) mouthrinse have similar antiplaque and antigingival effectiveness.