Evaluation of the effects of ozone therapy in the treatment of intra-abdominal infection in rats

INTRODUCTION: The antibacterial effect of ozone (O(3)) has been described in the extant literature, but the role of O(3) therapy in the treatment of certain types of infection remains controversial. OBJECTIVES: To evaluate the effect of intraperitoneal (i.p.) O(3) application in a cecal ligation/puncture rat model on interleukins (IL-6, IL-10) and cytokine-induced neutrophil chemoattractant (CINC)-1 serum levels, acute lung injury and survival rates. METHODS: Four animal groups were used for the study: a) the SHAM group underwent laparotomy; b) the cecal ligation/puncture group underwent cecal ligation/puncture procedures; and c) the CLP+O(2) and CLP+O(3) groups underwent CLP+ corresponding gas mixture infusions (i.p.) throughout the observation period. IL-6, CINC-1 and IL-10 concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Acute lung injury was evaluated with the Evans blue dye lung leakage method and by lung histology. P<0.05 was considered significant. RESULTS: CINC-1 was at the lowest level in the SHAM group and was lower for the CLP+O(3) group vs. the CLP+O(2) group and the cecal ligation/puncture group. IL-10 was lower for the SHAM group vs. the other three groups, which were similar compared to each other. IL-6 was lower for the SHAM group vs. all other groups, was lower for the CLP+O(3) or CLP+O(2) group vs. the cecal ligation/puncture group, and was similar for the CLP+O(3) group vs. the CLP+O(2) group. The lung histology score was lower for the SHAM group vs. the other groups. The Evans blue dye result was lower for the CLP+O(3) group vs. the CLP+O(2) group and the cecal ligation/puncture group but similar to that of the SHAM group. The survival rate for the CLP+O(3) group was lower than for the SHAM group and similar to that for the other 2 groups (CLP and CLP+O(2)). CONCLUSION: Ozone therapy modulated the inflammatory response and acute lung injury in the cecal ligation/puncture infection model in rats, although there was no improvement on survival rates.