Gleditsia sinensis thorns inhibit the production of NO through NF-kappaB suppression in LPS-stimulated macrophages

The thorns of Gleditsia sinensis LAM. (Leguminosae) have been used in traditional medicine for the treatment of inflammatory diseases including swelling, suppuration, carbuncle and skin diseases in China and Korea. In this study, we investigated the mechanism responsible for anti-inflammatory effects of Gleditsia sinensis thorns in RAW 264.7 macrophages. The aqueous extract of Gleditsia sinensis thorns (AEGS) inhibited LPS-induced NO secretion as well as inducible nitric oxide synthase (iNOS) expression, without affecting cell viability. Furthermore, AEGS suppressed LPS-induced NF-kappaB activation, phosphorylation and degradation of IkappaB-alpha, phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). These results suggest that AEGS has the inhibitory effects on LPS-induced NO production and iNOS expression in macrophages through blockade in the phosphorylation of MAPKs, following IkappaB-alpha degradation and NF-kappaB activation.