Co-administration of sodium selenite and sodium arsenite exacerbates hepatic, renal, pulmonary and splenic inflammation in rats

Abstract

This study examined the effect of co-administration of sodium selenite (SS) and sodium arsenite (SA) on inflammation in rats. Thirty (30) male Wistar rats were separated into 6 groups of five animals each. Group I (control) was given distilled water, groups II, III, IV and V were exposed to 20 and 40 ppm SA in drinking water, but in addition to that, groups IV and V only were co-exposed with 0.25 mg/kg bwt SS, while group VI was exposed to 0.25 mg/kg bwt SS only orally. Following 5 weeks of exposure, levels of pro-inflammatory cytokines (TNF- α, IL-1 βand IL-6) were increased in SA-exposed groups. Synergistic and antagonistic effects were observed in co-exposed groups depending on dose and the spe- cific tissue being considered. Synergism was observed in tissues co-exposed to higher dose (40 ppm) of SA + 0.25 mg/kgbwt SS except in the liver, where these markers were de- creased compared with control. Level of IL-10 (anti-inflammatory marker) decreased in all the tissues investigated except in the lungs of animals co-exposed with 40 ppm SA. There was alteration in tissue architecture, revealing steatosis and hemorrhagic lesions as the common features in co-exposed groups. Results obtained indicate that the dose of SS used in this study may be toxic and not therapeutic against SA-induced tissue inflammation in rats.