Extract of Oenothera biennis L. stem inhibits LPS-induced inflammation by regulating MAPK and NF-κB signaling pathways

Oenothera biennis L. is a perennial herb distributed across America, Asia, and Europe. The pharmacological effect of Oenothera biennis L. stem is poorly understood. We demonstrated that lipopolysaccharide (LPS)-induced the high production of inflammatory mediators nitric oxide (NO) and prostaglandin E-2 (PGE(2)), and the pro-inflammatory cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-1 beta in peritoneal macrophages (PMs) were significantly inhibited by the crude extract The inflammation related signaling extra cellular signal-regulated ERK, P38 of MAPK and NF-kappaB (NF-kappa B) activated by LPS dramatically inhibited. In conclusion, our results suggested that the stems of Oenothera biennis L.possess a high anti-inflammatory property, thus, can be used in the industrial production of medicinal products as the raw material in the future.