ABSTRACT
Orostachys japonicus shows various biological activities. However, the molecular mechanisms remain unknown in LPS-stimulated macrophages. Here, we investigated the anti-oxidizing effect of the dichloromethane (DCM) and hexane fractions from O. japonicus (OJD and OJH) against oxidative stress in RAW 264.7 cells stimulated by LPS. OJD and OJH significantly increased the expression of heme oxygenase-1 (HO-1) in a dose- and time-dependent manner. Additionally, it was found that the expression of HO-1 was stimulated by Nrf2 activated via degradation of Keap1. ERK and p38 inhibitors repressed HO-1 induced by OJD and OJH in LPS-stimulated cells, respectively. In conclusion, these results suggest that OJD and OJH may block oxidative damage stimulated by LPS, via increasing the expression of HO-1 and Nrf2, and MAPK signaling pathway.
Subject(s)
Antioxidants/chemistry , Crassulaceae/chemistry , Mitogen-Activated Protein Kinase Kinases/metabolism , NF-E2-Related Factor 2/metabolism , Plant Extracts/chemistry , Adaptor Proteins, Signal Transducing/metabolism , Animals , Antioxidants/isolation & purification , Antioxidants/pharmacology , Cell Line , Cell Survival/drug effects , Crassulaceae/metabolism , Cytoskeletal Proteins/metabolism , Heme Oxygenase-1/metabolism , Hexanes/chemistry , Kelch-Like ECH-Associated Protein 1 , Lipopolysaccharides/toxicity , Methylene Chloride/chemistry , Mice , Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors , Plant Extracts/pharmacology , Signal Transduction/drug effects , Up-Regulation/drug effects , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
In this study, powder of Orostachys japonicus A. Berger (O. japonicus) was extracted with 95% ethyl alcohol and fractionated using a series of organic solvents, including n-hexane (hexane), dichloromethane (DCM), ethylacetate (EtOAc), n-butanol (BuOH), and water (H(2)O). We investigated the anti-inflammatory effects of these O. japonicus extracts on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Their effects on the expression of inflammatory mediators and transcription factors were analyzed by Western blotting. DCM fraction significantly inhibited formation of reactive oxygen species (ROS) as well as nitric oxide (NO) in LPS-stimulated RAW 264.7 cells. Phosphorylation of the pro-inflammatory transcription factor complex nuclear factor-kappa B (NF-κB) p65 and expression of inducible nitric oxide synthase (iNOS), one of its downstream proteins, were also suppressed by DCM fraction. These effects were regulated by upsteam proteins in the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase/Akt (PI3K/Akt) signaling pathways. Taken together, our data suggest that O. japonicus could be used as a potential source for anti-inflammatory agents.
