Ozone enema - A model of microscopic colitis in rats

Ozone is one of the most powerful oxidants available, with many application s in industry and medicine. Medically relevant features of ozone include ba cterial and virucidal properties, disinfection, sterilization, circulatory stimulation, and disruption of malignant cells. Ozone therapy is administer ed in various ways, including intravenously; intramuscularly, and intrarect ally. The latter modality is used for the treatment of colitis and hepatiti s. Our aim was to examine the effect of ozone water enema on normal and inf lamed rat colonic mucosa. Ozone water (20 mug/ml) was prepared via ozone ge nerator and administered intrarectally (0.5 ml) daily. Rats were killed one , three, and seven days after rectal ozone water administration, and their colons resected, rinsed, and weighed (grams per 10 cm). Damage was assessed macro- and microscopically and tissue processed for myeloperoxidase and ni tric oxide synthase activity. Rats receiving saline served as controls. In an additional experiment colitis was induced by intrarectal iodoacetamide. Ozone therapy caused no macroscopic damage. Ozone therapy induced microscop ic colitis, which lasted for at least a week and was accompanied by increas e in segmental weight, myeloperoxidase and nitric oxide activity, and prost aglandin E-2 generation. Ozone therapy had no protective effect on inflamed mucosa. In conclusion, ozone water therapy had a deleterious effect on nor mal colonic mucosa, suggesting intrarectal administration be reevaluated. O zone water enema may serve as a model of microscopic colitis.