ABSTRACT
Recent studies have shown that peroxisome proliferator- activated receptor- gamma [PPAR gamma] may participate in control of inflammation, especially in modulating the production of inflammatory mediators. Similarly, the cholesterol lowering drugs, statins, have been found to exhibit anti-inflammatory properties that are beyond their lipid lowering effects. The present study was conducted to investigate the effect of a PPAR gamma agonist [rosiglitazone] and a statin [pravastatin] on immunologically mediated chronic inflammation. Two models were chosen, namely, Freund's adjuvant arthritis [FA] and mixed- type hypersensitivity [MH] in rats. The effect of these drugs was assessed on the basis of biochemical markers in blood and / or inflammatory exudate. The investigated drugs were given orally daily during the course of inflammation development. The results of the present study demonstrated that, in either model, rosiglitazone and pravastatin reduced the elevated serum and exudate [local] leukotriene B[4] [LTB[4]] and interleukine-6 [IL-6] levels. The anti-inflammatory effect of these drugs was also accompanied by reduction or normalization of elevated systemic and or local levels of lipid peroxide [LP], superoxide dismutase [SOD], and reduced glutathione [GSH]. It could be concluded that long-term treatment with rosiglitazone or pravastatin confers a good anti-inflammatory activity against arthritis in rat, leading to improvement of the oxidative stress induced by the arthritic insult. The reparative effect of these drugs could be mediated via reduction of LTB[4] and IL-6