Oregonin inhibits lipopolysaccharide‐induced iNOS gene transcription and upregulates HO‐1 expression in macrophages and microglia

Oregonin isolated from Alnus formosana is a diarylheptanoid derivative, which appears to have antioxidative and anti‐inflammatory activities. In this study, our data demonstrated inhibitory actions of oregonin on the LPS‐induced iNOS protein in RAW264.7 macrophages and BV‐2 microglial cells. We also suggested that HO‐1 induction by oregonin might contribute to this action. Oregonin is able to dose‐dependently reduce NO production, iNOS protein and iNOS promoter activity stimulated by LPS in RAW264.7 and BV‐2 cells. Oregonin also showed inhibition of LPS‐mediated NF‐κB promoter activity and DNA‐binding ability, as well as p65 nuclear translocation and phosphorylation. However, oregonin had no effect on IKK activity. AP‐1 promoter activity and p38 MAPK activation but not PKC, ERK and JNK activation induced by LPS were attenuated by oregonin. Accompanying with iNOS protein reduction, moreover, we found that oregonin was able to induce HO‐1 protein level. Results using a CO donor, [Ru(CO)3Cl2]2 further showed the ability of CO in reduction of iNOS protein level induced by LPS through the blockade of NF‐κB and AP‐1. Taken together, these results provide new evidences into the anti‐inflammatory actions of oregonin, which include the inhibition of iNOS gene transcription via suppressing transcriptional activity of NF‐κB and AP‐1, as well as the upregulation of anti‐inflammatory molecule HO‐1. The HO‐1‐derived CO may also be involved in the suppressive effect on iNOS gene regulation.

[1]  M. Maines.  Heme oxygenase: function, multiplicity, regulatory mechanisms, and clinical applications , 1988, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[2]  J. Alam,et al.  Protective Effect of Heme Oxygenase-1 Gene Transfer against Oxyhemoglobin-Induced Endothelial Dysfunction , 2001, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[3]  Wan-Wan Lin,et al.  Proteasome inhibitors up-regulate haem oxygenase-1 gene expression: requirement of p38 MAPK (mitogen-activated protein kinase) activation but not of NF-kappaB (nuclear factor kappaB) inhibition. , 2004, The Biochemical journal.

[4]  S. Ryter,et al.  Heme oxygenase-1 and carbon monoxide in pulmonary medicine , 2003, Respiratory research.

[5]  A. Choi,et al.  Suppression of Inflammatory Cytokine Production by Carbon Monoxide Involves the JNK Pathway and AP-1* , 2003, Journal of Biological Chemistry.

[6]  A. Choi,et al.  Carbon Monoxide Inhibition of Apoptosis during Ischemia-Reperfusion Lung Injury Is Dependent on the p38 Mitogen-activated Protein Kinase Pathway and Involves Caspase 3* , 2003, The Journal of Biological Chemistry.

[7]  Tzong-Shyuan Lee,et al.  Induction of Heme Oxygenase-1 Expression in Murine Macrophages Is Essential for the Anti-inflammatory Effect of Low Dose 15-Deoxy-Δ12,14-prostaglandin J2* , 2003, Journal of Biological Chemistry.

[8]  Soo-Min Cho,et al.  Melanogenesis inhibitory activities of diarylheptanoids fromalnus hirsuta turcz in B16 mouse melanoma cell , 2002, Archives of pharmacal research.

[9]  M. Maines,et al.  The heme oxygenase system: a regulator of second messenger gases. , 1997, Annual review of pharmacology and toxicology.

[10]  Wan-Wan Lin,et al.  PKC‐ and ERK‐dependent activation of IκB kinase by lipopolysaccharide in macrophages: enhancement by P2Y receptor‐mediated CaMK activation , 2001, British journal of pharmacology.

[11]  P. Datta,et al.  Heme oxygenase-1 induction attenuates inducible nitric oxide synthase expression and proteinuria in glomerulonephritis. , 1999, Journal of the American Society of Nephrology : JASN.

[12]  H. Schröder,et al.  Heme oxygenase-1 is a cGMP-inducible endothelial protein and mediates the cytoprotective action of nitric oxide. , 2000, Arteriosclerosis, thrombosis, and vascular biology.

[13]  S. Joo,et al.  Augmentation of macrophage antitumor activities and nitric oxide production by oregonin , 2002, Archives of pharmacal research.

[14]  Wan-Wan Lin,et al.  HMG-CoA reductase inhibitors upregulate heme oxygenase-1 expression in murine RAW264.7 macrophages via ERK, p38 MAPK and protein kinase G pathways. , 2006, Cellular signalling.

[15]  Wan-Wan Lin,et al.  HMG-CoA Reductase Inhibitors Inhibit Inducible Nitric Oxide Synthase Gene Expression in Macrophages , 2003, Journal of Biomedical Science.

[16]  A. Choi,et al.  Carbon monoxide has anti-inflammatory effects involving the mitogen-activated protein kinase pathway , 2000, Nature Medicine.

[17]  C. Nathan,et al.  Regulation of biosynthesis of nitric oxide. , 1994, The Journal of biological chemistry.

[18]  David Baltimore,et al.  NF-κB: Ten Years After , 1996, Cell.

[19]  A. Choi,et al.  Mitogen-activated protein kinases regulate HO-1 gene transcription after ischemia-reperfusion lung injury. , 2002, American journal of physiology. Lung cellular and molecular physiology.

[20]  D. Pinsky,et al.  Paradoxical rescue from ischemic lung injury by inhaled carbon monoxide driven by derepression of fibrinolysis , 2001, Nature Medicine.

[21]  E. Zandi,et al.  Lipopolysaccharide Induces Rac1-dependent Reactive Oxygen Species Formation and Coordinates Tumor Necrosis Factor-α Secretion through IKK Regulation of NF-κB* , 2001, The Journal of Biological Chemistry.

[22]  A. Yachie,et al.  [Heme oxygenase 1 deficiency]. , 2001, Ryoikibetsu shokogun shirizu.

[23]  A. Choi,et al.  Heme oxygenase-1: the "emerging molecule" has arrived. , 2002, American journal of respiratory cell and molecular biology.

[24]  James L. Park,et al.  Heme oxygenase-1 protects against vascular constriction and proliferation , 2001, Nature Medicine.

[25]  Y. Niida,et al.  Oxidative stress causes enhanced endothelial cell injury in human heme oxygenase-1 deficiency. , 1999, The Journal of clinical investigation.

[26]  Jerry L. Adams,et al.  A protein kinase involved in the regulation of inflammatory cytokine biosynthesis , 1994, Nature.

[27]  G. Ramadori,et al.  Gene regulation of heme oxygenase-1 as a therapeutic target. , 2000, Biochemical pharmacology.

[28]  G. Haegeman,et al.  p38 and Extracellular Signal-regulated Kinase Mitogen-activated Protein Kinase Pathways Are Required for Nuclear Factor-κB p65 Transactivation Mediated by Tumor Necrosis Factor* , 1998, The Journal of Biological Chemistry.

[29]  S. Tonegawa,et al.  Reduced stress defense in heme oxygenase 1-deficient cells. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[30]  F. Bach,et al.  Heme oxygenase-1: unleashing the protective properties of heme. , 2003, Trends in immunology.

[31]  D. Baltimore,et al.  I kappa B: a specific inhibitor of the NF-kappa B transcription factor. , 1988, Science.

[32]  Wan-Wan Lin,et al.  Lymphotoxin β Receptor Induces Interleukin 8 Gene Expression via NF-κB and AP-1 Activation , 2002 .

[33]  Wan-Wan Lin,et al.  Inhibition of Interleukin-1β-induced NF-κB Activation by Calcium/Calmodulin-dependent Protein Kinase Kinase Occurs through Akt Activation Associated with Interleukin-1 Receptor-associated Kinase Phosphorylation and Uncoupling of MyD88* , 2002, The Journal of Biological Chemistry.

[34]  L. Ignarro,et al.  Regulation of inducible nitric oxide synthase expression in advanced glycation end product-stimulated raw 264.7 cells: the role of heme oxygenase-1 and endogenous nitric oxide. , 2004, Diabetes.

[35]  Joel Moss,et al.  Cytokine-mediated Transcriptional Induction of the Human Inducible Nitric Oxide Synthase Gene Requires Both Activator Protein 1 and Nuclear Factor κB-binding Sites* , 1998, The Journal of Biological Chemistry.

[36]  Y. Surh,et al.  Molecular mechanisms of chemopreventive effects of selected dietary and medicinal phenolic substances. , 1999, Mutation research.

[37]  Wan-Wan Lin,et al.  HMG-CoA reductase inhibitors inhibit inducible nitric oxide synthase gene expression in macrophages. , 2003, Journal of biomedical science.

[38]  Y. Cha,et al.  Biphasic induction of heme oxygenase-1 expression in macrophages stimulated with lipopolysaccharide. , 2004, Biochemical pharmacology.

[39]  A. Choi,et al.  Regulation of IL-1beta -induced GM-CSF production in human airway smooth muscle cells by carbon monoxide. , 2003, American journal of physiology. Lung cellular and molecular physiology.

[40]  M. Karin.  The Regulation of AP-1 Activity by Mitogen-activated Protein Kinases (*) , 1995, The Journal of Biological Chemistry.

[41]  S. Ohta,et al.  Triterpenoids, diarylheptanoids and their glycosides in the flowers of Alnus species , 1990 .

[42]  Hui-Yi Lin,et al.  Anti‐inflammatory effect of heme oxygenase 1: Glycosylation and nitric oxide inhibition in macrophages , 2005, Journal of cellular physiology.

[43]  Byung-Min Choi,et al.  3-Hydroxyanthranilic acid, one of metabolites of tryptophan via indoleamine 2,3-dioxygenase pathway, suppresses inducible nitric oxide synthase expression by enhancing heme oxygenase-1 expression. , 2004, Biochemical and biophysical research communications.

[44]  P. Colville-Nash,et al.  Inhibition of inducible nitric oxide synthase by peroxisome proliferator-activated receptor agonists: correlation with induction of heme oxygenase 1. , 1998, Journal of immunology.

[45]  E. Moilanen,et al.  Inhibition of extracellular signal-regulated kinase suppresses endotoxin-induced nitric oxide synthesis in mouse macrophages and in human colon epithelial cells. , 2000, The Journal of pharmacology and experimental therapeutics.

[46]  L. Chau,et al.  Heme Oxygenase-1 Attenuates Interleukin-1β-Induced Nitric Oxide Synthase Expression in Vascular Smooth Muscle Cells , 2004, Journal of Biomedical Science.

[47]  D. K. Maity,et al.  Role of phenolic O-H and methylene hydrogen on the free radical reactions and antioxidant activity of curcumin. , 2003, Free radical biology & medicine.

[48]  Ronald V. Maier,et al.  Mitogen-activated protein kinases. , 2002, Critical care medicine.

[49]  V. Cattell,et al.  Heme oxygenase is induced in nephrotoxic nephritis and hemin, a stimulator of heme oxygenase synthesis, ameliorates disease. , 1998, Kidney international.

[50]  Seaver,et al.  Nitric oxide as a secretory product of mammalian cells , 2004 .

[51]  Hui-Yi Lin,et al.  Inhibition of lipopolysaccharide-induced nitric oxide production by flavonoids in RAW264.7 macrophages involves heme oxygenase-1. , 2003, Biochemical pharmacology.

[52]  S. Shyue,et al.  Adenovirus-Mediated Heme Oxygenase-1 Gene Transfer Inhibits the Development of Print , 2001 .

[53]  P. Sarathchandra,et al.  Carbon Monoxide-Releasing Molecules: Characterization of Biochemical and Vascular Activities , 2002, Circulation research.

[54]  Y. C. Kim,et al.  Diarylheptanoids with in vitro inducible nitric oxide synthesis inhibitory activity from Alnus hirsuta. , 2000, Planta medica.

[55]  C. Jefferies,et al.  Rac1 Regulates Interleukin 1-induced Nuclear Factor κB Activation in an Inhibitory Protein κBα-independent Manner by Enhancing the Ability of the p65 Subunit to Transactivate Gene Expression* , 2000, The Journal of Biological Chemistry.

[56]  W. Lesslauer,et al.  Blockade of p38 Mitogen-activated Protein Kinase Pathway Inhibits Inducible Nitric-oxide Synthase Expression in Mouse Astrocytes* , 1997, The Journal of Biological Chemistry.

[57]  K. Youssef,et al.  Synthesis of Curcumin Analogues as Potential Antioxidant, Cancer Chemopreventive Agents , 2004, Archiv der Pharmazie.