A Polysaccharide from Tomato (Lycopersicon esculentum) Peels Affects NF-kB Activation in LPS-Stimulated J774 Macrophages.

We investigated the effect of PS (1) on nitrite and reactive oxygen species (ROS) production in J774 macrophages stimulated with bacterial lipopolysaccharide (LPS) for 24 h. PS (1) inhibited in a concentration-dependent manner nitrite and ROS production as well as inducible nitric oxide synthase (iNOS) protein expression induced by LPS. Incubation of cells with PS (1) determined a significant decrease of nuclear factor-?B (NF-?B)/DNA binding activity which was correlated with a marked reduction of iNOS mRNA levels. These results show that PS (1) inhibits NF-?B activation and iNOS gene expression by preventing the reactive species production and suggest a role for this compound in controlling oxidative stress and/or inflammation.