Inhibitory effects of extract from G. lanceolata on LPS-induced production of nitric oxide and IL-1β via down-regulation of MAPK in macrophages.

Grateloupia lanceolata is a red alga native to coastal areas of East Asia. In this study, extract from G. lanceolata (EGL) was investigated for suppressive effects on lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 macrophages. EGL was found to have anti-inflammatory properties with the inhibition of nitric oxide (NO), pro-inflammatory cytokine production, and MAPK signaling in LPS-induced RAW 264.7 macrophages. Moreover, treatment of RAW 264.7 macrophage with EGL inhibited LPS-induced IL-1β production in a dose-dependent manner. These inhibitory effects were found with the blockage of p38 mitogen-activated protein kinases (MAPK), extracellular signal regulated kinases 1 and 2 (ERK1/2), and also c-Jun N-terminal kinases 1 and 2 (JNK1/2). These results indicated that anti-inflammatory actions of EGL in RAW 264.7 macrophages involved in the inhibition of LPS-induced p38MAPK/ERK/JNK signaling pathways. In addition, our findings suggest that EGL holds great promise for use in the treatment of various inflammatory diseases.