ABSTRACT
Lagerstroemia ovalifolia Teijsm. & Binn. has traditionally been used as an herbal medicine and possesses anti-inflammatory properties. However, the mechanisms underlying its anti-inflammatory effects remain poorly understood. For this purpose, we aimed to investigate the effects of methanolic extract of L. ovalifolia (LOME) on nitric oxide (NO) and prostaglandin E2 (PGE2) production, as well as the underlying molecular mechanisms responsible for these effects, in lipopolysaccharide (LPS)stimulated RAW264.7 macrophages. We examined the effects of LOME on the production of NO and PGE2 in LPS-stimulated RAW264.7 cells. To explore the anti-inflammatory mechanisms of LOME, we measured the mRNA or protein expression of the proinflammatory mediators induced by LOME in the LPS-stimulated RAW264.7 cells. LOME significantly inhibited the production of NO, PGE2, interleukin (IL)-6, IL-1ß, and tumor necrosis factor-α (TNF-α) in LPS-stimulated RAW264.7 cells. Moreover, LOME suppressed the mRNA and protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and inhibited the phosphorylation of the mitogen-activated protein kinases (MAPKs), with a reduction in the nuclear translocation of nuclear factor (NF)-κB in LPS-stimulated RAW264.7 cells. Taken together, these findings suggest that LOME may exert anti-inflammatory effects in vitro in LPS-stimulated RAW264.7 macrophages and thus, may have potential for use as an adjuvant treatment of inflammatory diseases.
Subject(s)
Inflammation/metabolism , Lagerstroemia/chemistry , Macrophages/metabolism , Macrophages/pathology , Methanol/chemistry , NF-kappa B/metabolism , Plant Extracts/pharmacology , Animals , Cell Death/drug effects , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Cell Survival/drug effects , Cyclooxygenase 2/metabolism , Cytokines/metabolism , Dinoprostone/metabolism , Enzyme Activation/drug effects , Inflammation/pathology , Inflammation Mediators/metabolism , Lipopolysaccharides , Macrophages/drug effects , Macrophages/enzymology , Mice , Mitogen-Activated Protein Kinases/metabolism , NF-KappaB Inhibitor alpha/metabolism , Nitric Oxide/biosynthesis , Nitric Oxide Synthase Type II/metabolism , Nitriles/pharmacology , Phosphorylation/drug effects , Protein Transport/drug effects , RAW 264.7 Cells , Sulfones/pharmacology , Transcription, Genetic/drug effectsABSTRACT
Rhododendron album Blume (RA) has traditionally been used as an herbal medicine and is considered to have anti-inflammatory properties. In the present study, we screened RA extracts with anti-inflammatory properties. The biological effects of an RA methanol extract (RAME) on inflammation were investigated in lipopolysaccharide (LPS)-stimulated mouse RAW264.7 cells. We investigated the effects of RAME on the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated RAW264.7 cells. To explore the anti-inflammatory mechanisms of RAME, we measured the mRNA and protein expression of pro-inflammatory mediators induced by RAME in the LPS-stimulated RAW264.7 cells by RT-PCR and western blot analysis, respectively. RAME significantly inhibited the production of NO, PGE2, interleukin (IL)-6, IL-1ß and tumor necrosis factor (TNF)-α in the LPS-stimulated RAW264.7 cells. It also suppressed the mRNA and protein expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and mitogen-activated protein kinases (MAPKs) with a concomitant decrease in the nuclear translocation of nuclear factor-κB (NF-κB) in the LPS-stimulated RAW264.7 cells. These results indicate that RAME inhibits LPS-induced inflammatory responses. These effects were considered to be strongly associated with the suppression of NF-κB activation. We therefore suggest that RAME may be prove to be an effective therapeutic agent for the treatment of inflammatory diseases.
