Anti-inflammatory effect of recombinant human superoxide dismutase in rats and mice and its mechanism.

OBJECTIVE

To investigate the anti-inflammatory effects and mechanism of recombinant human superoxide dismutase (rhSOD).

METHODS

Inflammation models such as croton oil-induced ear swelling and carrageenan-induced hind paw edema in mice and rats were prepared. The nitric oxide synthase (NOS ) activity was measured by NADPH-diaphoras stain assay, N-acetyl-beta-D-glucosaminidase (beta-NAG) activity by spectrophotography, malondialdehyde (MDA) content by thiobarbituric acid (TBA) fluorescence technique, and interleukin-1beta (IL -1beta), tumor necrosis factor alpha (TNF alpha), and IL-8 content by radioimmunoassay (RIA).

RESULTS

rhSOD 20-80 mg/kg ip, 40-80 mg/kg im, and 80 mg/kg ip significantly inhibited carrageenan-induced paw edema in rats, croton oil-induced ear swelling in mice, and carrageenan-induced hind paw edema in mice, respectively. In the rat arthritis induced by carrageenan, rhSOD 40 mg/kg reduced MDA content in inflamed paws, inhibited NOS activity, and lowered the content of IL-1beta and TNFalpha in exudate significantly. The inhibitory effect of rhSOD 40 mg/kg ip on IL-1beta production was more evident than that of dexamethasone 2 mg/kg ip. Also rhSOD obviously inhibited neutrophil infiltration; However, rhSOD had no effect on beta-NAG activity in exudate.

CONCLUSIONS

rhSOD has anti-inflammatory effect on experimental inflammation in rats and mice, and its mechanisms are relevant to oxygen free radical scavenging, anti-lipid peroxidation, inhibition of neutrophil infiltration, and formation of inflammatory cytokines.