Effect of superoxide dismutase from bovine erythrocytes on different activity parameters in adjuvant-induced arthritis.

BACKGROUND The purpose of this work was to evaluate the effect of superoxide dismutase (SOD) on primary swelling, lipoperoxidation, body thymus, and spleen weight in the adjuvant-induced arthritis (AIA) model in rats. METHODS Orally and intraperitoneally administered SOD (100 U/kg) from bovine erythrocytes, as well as naproxen (40 mg/kg) and dexamethasone (25 mg/kg), were evaluated against placebo. RESULTS Primary edema was not decreased by SOD; in contrast, naproxen and dexamethasone showed good anti-inflammatory activity. Lipoperoxidation increased 1.8, 2.5, and 2.8 times with intraperitoneal SOD, naproxen, and dexamethasone administration, respectively, while oral SOD decreased lipoperoxidation levels to approximately one-half of that found in the control group. Body weight increased with SOD but decreased with dexamethasone. Naproxen did not change the animal weight. Thymus weight remained unchanged with SOD and naproxen, while it decreased with dexamethasone. Spleen weight remained the same with SOD, but increased with naproxen and decreased with dexamethasone. No side effects were observed in the SOD group, whereas 20% of the rats in the naproxen group died of gastrointestinal hemorrhage, and 50% of the rats in the dexamethasone group, of pulmonary infection. CONCLUSIONS In conclusion, SOD showed no anti-inflammatory activity but decreased lipoperoxidation when administered orally. No deleterious effects in primary and secondary immunologic organs were observed with this agent.