Stauntonia hexaphylla leaf extract (YRA-1909) suppresses inflammation by modulating Akt/NF-κB signaling in lipopolysaccharide-activated peritoneal macrophages and rodent models of inflammation

BACKGROUND: Inflammation is emerging as a key contributor to many vascular diseases and furthermore plays a major role in autoimmune diseases, arthritis, allergic reactions, and cancer. Lipopolysaccharide (LPS), which is a component constituting the outer membrane of Gram-negative bacteria, is commonly used for an inflammatory stimuli to mimic inflammatory diseases. Nuclear factor-kappa B (NF-κB) is a transcription factor and regulates gene expression particularly related to the inflammatory process. Stauntonia hexaphylla (Lardizabalaceae) is widely used as a traditional herbal medicine for rheumatism and osteoporosis and as an analgesic, sedative, and diuretic in Korea, Japan, and China. OBJECTIVE: The purpose of this study was to investigate the anti-inflammatory activity of YRA-1909, the leaf aqueous extract of Stauntonia hexaphylla using LPS-activated rat peritoneal macrophages and rodent inflammation models. RESULTS: YRA-1909 inhibited the LPS-induced nitric oxide (NO) and proinflammatory cytokine production in rat peritoneal macrophages without causing cytotoxicity and reduced inducible NO synthase and prostaglandin E(2) levels without affecting the cyclooxygenase-2 expression. YRA-1909 also prevented the LPS-stimulated Akt and NF-κB phosphorylation and reduced the carrageenan-induced hind paw edema, xylene-induced ear edema, acetic acid-induced vascular permeation, and cotton pellet-induced granuloma formation in a dose-dependent manner in mice and rats. CONCLUSIONS: S. hexaphylla leaf extract YRA-1909 had anti-inflammatory activity in vitro and in vivo that involves modulation of Akt/NF-κB signaling. Thus, YRA-1909 is safe and effective for the treatment of inflammation.