Alterations of the Intestinal Barrier and Inflammatory Response, Caused by Chronic Ozone Exposure in a Rat Model.

Ozone pollution is a significant public health problem due to its association with chronic diseases. This study examines the effects of repeated exposure to low doses of ozone on intestinal barrier function in rats. Seventy-two male Wistar rats were divided into six groups. The control group was exposed to normal air, while the ozone groups received a dose of 0.25 ppm for four hours daily for periods of 7, 15, 30, 60, and 90 days, respectively. After treatment, the duodenum, jejunum, and colon were removed and analyzed by biochemical assays, Western blot, immunohistochemistry, and histological techniques. The results indicated an increase in oxidized lipids and structural alterations in the duodenum and jejunum after 7 days of ozone exposure. The result showed changes in haptoglobin, IL-1β, and IL-6. In addition, increased immunoreactivity varied according to intestinal structure and the duration of ozone exposure in the duodenum, jejunum, and colon. In conclusion: Ozone exposure causes an increase in proinflammatory cytokines that leads to a loss of regulation of the immune response in the duodenum, jejunum, and colon of rats, as well as structural changes that alter the intestinal barrier and perpetuate a state of chronic inflammation characteristic of inflammatory bowel diseases.