RAW 264.7 macrophages were treated with LPS and/or DMPO for different time points, cell damage, production of inflammatory mediators, inducible nitric oxide synthase (iNOS) expression, NF-魏B p65 activation, phosphorylation of MAPKs and Akt, and intracellular reactive oxygen species (ROS) were determined.
After cells were treated with LPS and/or DMPO for 24 h, DMPO reduced the LPS-induced inflammatory response as indicated by downregulated iNOS expression and production of inflammatory mediators. Accordingly, DMPO protected cells from LPS-induced cytotoxicity. In order to understand the mechanistic basis of these DMPO effects, the NF-魏B p65 activation and the phosphorylation of MAPKs and Akt were examined. We found, by assaying cells treated with LPS and/or DMPO for 15-60 min, that DMPO inhibited the phosphorylation of MAPKs, Akt, and I魏B伪, and reduced the NF-魏B p65 translocation. Furthermore, we demonstrated that DMPO inhibited LPS-induced ROS production.
DMPO showed the anti-inflammatory activity and attenuated LPS-induced cell damage, most likely by reducing ROS production and thus preventing the subsequent inflammatory activation and damage.