Inhibition of Nitric Oxide and Tumor Necrosis Factor-.ALPHA. (TNF-.ALPHA.) Production by Propenone Compound through Blockade of Nuclear Factor (NF)-.KAPPA.B Activation in Cultured Murine Macrophages

Abstract

Lipopolysaccharide (LPS), which is a component of the cell walls of gram-negative bacteria, is one of the most potent macrophage activators. LPS induces the production of pro-inflammatory cytokines and small mediators, such as nitric oxide (NO) and PGE 2 in macrophages. Macrophage activation is known to play an important role in the inflammatory process.1) Increasing evidence also suggests that NO, a bioactive free radical, is involved in various pathophysiological processes including inflammation and septic shock. 2,3) Therefore, NO production might reflect the inflammation process and provide a measure for assessing the effects of drugs on this process. NO production is regulated by NO synthases (NOSs) and three NOS isoforms have been identified and cloned. The neural (nNOS) and the endothelial (eNOS) isoforms are constitutively expressed in selected tissues, and their enzymatic activity is regulated by changes in the intracellular free Ca 2ϩ concentration. A third member of the NOS family is type II NOS (inducible NOS, iNOS), which is produced in large quantities in response to inflammatory stimuli such as LPS and interferon-g (IFN-g). 4,5) Proinflammmatory cytokines (tumor necrosis factor-a (TNF-a), IL-1b and IL-6) have been suggested to induce tissue damage, and are considered to be an important initiator of the inflammatory responses. The expression of these cytokines depends on the activation of the transcriptional factor, nuclear factor (NF)-kB. NF-kB is a critical intracellular mediator of the inflammatory cascade because these proinflammatory molecules are regulated at the transcription level. [6][7][8][9][10] In a study of anti-inflammatory activities of chemically synthetic propenone compound, 1-furan-2-yl-3-pyridin-2-ylpropenone (FPP-3) ( Fig. 1) was found to inhibit LPS-stimulated NO and TNF-a production in RAW264.7 macrophages in a preliminary in vitro test. The aim of the present study was to evaluate the mechanism by which FPP-3 inhibits NO and TNF-a production in macrophages. The results clearly demonstrated that treatment with FPP-3 decreases LPS-stimulated iNOS protein expression and TNF-a production through the inhibition of NF-kB activation. MATERIALS AND METHODSMaterials 2-Acetylfuran and 2-pyridinecarboxaldehyde were purchased from Aldrich Chemical Co. (St. Louis, MO, U.S.A.) and were reagent grade. Thin-layer chromatography (TLC) and column chromatography were performed with Kieselgel 60 F 254 (Merck) and silica gel Kieselgel 60 (230-240 mesh, Merck), respectively. Compounds were visualized on TLC plates with UV light and r-anisaldehyde solution. Nuclear magnetic resonance (NMR) spectra were taken on a Bruker AMX 250 MHz, and tetramethylsilane was used as an internal standard. Chemical shifts (d) were recorded in ppm, and coupling constants (J) in Hz. RPMI 1640 and phosphatebuffer saline were obtained from GIBCO-BRL (Grand Island, NY, U.S.A.). Fetal bovine serum was purchased from Hyclone Laboratories (Logan, UT, U.S.A.). Rabbit polyclonal iNOS antibody, and anti-rabbit IgG peroxidase-co...

Anti-Inflammatory Effect of Buckwheat Sprouts in Lipopolysaccharide-Activated Human Colon Cancer Cells and Mice

“…Recent studies of natural products with anti-inflammatory activity have been reported, and many of them had been done using macrophage-like cell lines, RAW264.7 cells 8,10,16,[26][27][28] and THP-1 cells. 11,13) However, we chose human colon carcinoma cells for screening because we were focusing on anti-inflammatory compounds in dietary products which might be effective through the mucosal immune response.…”

“…15) Although the mechanisms of the anti-inflammatory effects of those materials are different, a wellknown mechanism has been described as inhibition of NF-B activation and NO production caused by antioxidant active compounds. 8,10,16) Buckwheat (Fagopyrum esculentum) is a health food in that it is rich in flavonoids such as rutin. 17) Rutin is an effective radical scavenger, 18) and Mukoda et al 19) have reported that buckwheat hull extract showed strong antioxidant activities in vitro and in vivo.…”

Bach1 Deficiency Ameliorates Hepatic Injury in a Mouse Model

“…2). LPS is known to induce NO production in macrophages (Lee et al 2004). It was suggested previously that NO may participate in the development of liver injury (Morikawa et al 1999).…”

Hepatotoxic Effects of 1-Furan-2-yl-3-pyridin-2-yl-propenone, a New Anti-Inflammatory Agent, in Mice

“…FPP-3 (purity, ＞99%) used in this study was chemically synthesized in our group Lee et al, 2004). Bovine serum albumin, p-nitrophenol, thiobarbituric acid (TBA), 5,5′-dithiobis-2-nitrobenzoic acid, NADPH, glucose 6-phosphate, glucose 6-phosphate dehydrogenase, ethoxyresorufin, methoxyresorufin, pentoxyresorufin, benzyloxyresorufin, erythromycin, D,L-glyceraldehyde and corn oil were purchased from Sigma Chemical Co. (St. Louis, MO, USA).…”