Anti-inflammatory effects of linezolid on carrageenan-induced paw edema in rats

The immunomodulatory activity of linezolid has recently been reported using in vitro experimental models. However, the anti-inflammatory activity of linezolid has not yet been demonstrated using in vivo experimental models. Therefore, the aim of the present study was to demonstrate the anti-inflammatory activity of linezolid and other anti-MRSA agents using the carrageenan-induced rat paw edema model. The pretreatment with 50 mg/kg linezolid significantly suppressed edema rates, compared with control (5% glucose), with edema rates at 0.5 and 3 h after the administration of carrageenan being 17.3 ± 3.5 and 30.8 ± 3.0%, respectively. On the other hand, edema rates were not suppressed by the pretreatments with 50 mg/kg vancomycin, teicoplanin, arbekacin, and daptomycin. Furthermore, we demonstrated that linezolid exhibited anti-inflammatory activity in a concentration-dependent manner. These effects were observed at linezolid concentrations that are achievable in human serum with conventional dosing. In conclusion, the results of the present study suggest that the anti-inflammatory activities of linezolid, in addition to its antimicrobial effects, have a protective effect against destructive inflammatory responses in areas of inflammation.