Study on anti-inflammatory and immunomodulatory effects of fluoxetine in rat models of inflammation

Abstract

The aim of the present study was to evaluate the anti-inflammatory effect of fluoxetine in carrageenan- and lipoplysaccharide-induced models of inflammation by investigating the changes in serum levels of pro-inflammatory cytokine TNF-α and anti-inflammatory cytokines IL-10 and TGF-β after single and repeated administration of the drug. To study the effect of a single and repeated dose fluoxetine on carrageenan-induced paw edema male Wistar rats were divided into five groups (n = 8): control group; positive control group; and three experimental groups treated with 5, 10, and 20 mg/kg bodyweight (bw) fluoxetine, respectively. To study the effect of a single and repeated dose of fluoxetine on serum cytokine levels, the animals were divided in four groups (n = 8): two control groups treated with saline and two experimental groups treated with fluoxetine 20 mg/kg bw. Carrageenan and LPS were injected immediately after fluoxetine or saline injection. Serum cytokine concentrations were tested by enzyme immunoassay. In single administration only the highest dose used inhibited carrageenan-induced inflammation. Edema inhibition was seen with 10 and 20 mg/kg bw fluoxetine after repeated administration. At 24 h a statistically significant effect on inhibition of carrageenan edema was found only in rats treated with 20 mg/kg bw fluoxetine In carrageenan-induced inflammation, fluoxetine significantly increased Il-10 and decreased TNF-α after repeated administration. Surprisingly, in single-dose treated animals an increase in TNF-α values upon fluoxetine administration was observed in this model of inflammation. In LPS-induced inflammation, fluoxetine significantly decreased TNF-α after single and repeated treatment. Fluoxetine has anti-inflammatory and immunomodulatory effect in the carrageenan-induced model of exudative inflammation. In LPS-induced inflammation it showed an immunomodulatory effect manifested with a decrease in pro-inflammatory cytokine TNF-α.