Uncaria Rhynchophylla Inhibits The Production Of Nitric Oxide And Interleukin-1 Beta Through Blocking Nuclear Factor Kappa B, Akt, And Mitogen-Activated Protein Kinase Activation In Macrophages

The stems with hook of Uncaria rhynchophylla have been used in traditional medicine as an antipyretic, antihypertensive, and anticonvulsant in China and Korea. In this study, we investigated the mechanism responsible for anti-inflammatory effects of U. rhynchophylla in RAW 264.7 macrophages. The aqueous extract of U. rhynchophylla inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) and interleukin (IL)-1 beta secretion as well as inducible NO synthase (iNOS) expression, without affecting cell viability. Furthermore, U. rhynchophylla suppressed LPS-induced nuclear factor kappa B (NF-kappa B) activation, phosphorylation, and degradation of inhibitory protein I kappa B (I kappa B)-alpha, phosphorylation of Akt, extracellular signal-regulated kinase 1/2, p38 kinase, and c-Jun N-terminal kinase. These results suggest that U. rhynchophylla has the inhibitory effects on LPS-induced NO and IL-1 beta production in macrophages through blockade in the phosphorylation of Akt and mitogen-activated protein kinases, following I kappa B-alpha degradation and NF-kappa B activation.