Molecular Immunology 52 (2012) 125–132 Contents lists available at SciVerse ScienceDirect Molecular Immunology jo u rn al hom epa ge: www.elsevier.com/locate/molimm Inhibition of the transcription factor c-Jun by the MAPK family, and not the NF-B pathway, suggests that peanut extract has anti-inflammatory properties Úrsula Catalán a , Sara Fernández-Castillejo a , Neus Anglès b , Jose Ramón Morelló b , Martí Yebras c , Rosa Solà a,∗ a Unitat de Recerca en Lípids i Arteriosclerosi, CIBERDEM, Hospital Universitari Sant Joan, IISPV, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Reus, Tarragona, Spain b La Morella Nuts S.A., 43206 Castellvell del Camp, Tarragona, Spain c Serveis Científics i Tècnics, Universitat Rovira i Virgili, Spain a r t i c l e i n f o Article history: Received 22 December 2011 Received in revised form 8 May 2012 Accepted 9 May 2012 Available online 4 June 2012 Keywords: Lipopolysaccharide THP-1 NF-B Tumor necrosis factor- Tumor necrosis factor- converting enzyme a b s t r a c t Background: Tumor necrosis factor- (TNF-) is involved in inflammatory responses in atherosclerosis. We propose an in vitro cellular assay to evaluate the anti-inflammatory mechanisms of potential modifiers such as food extracts. In the current model we assessed an anti-inflammatory effect of polyphenol-rich peanut extract in lipopolysaccharide (LPS)-induced THP-1 monocytes. Methods: THP-1 monocytes were incubated with peanut extract (5, 25, 50 and 100 g/mL) consisting of 39% flavonols, 37% flavanols and 24% phenolic acid (or BAY 11-7082 (5 M) as experiment control) for 1 h and then stimulated with LPS (500 ng/mL) for 4 h. Cytotoxicity was measured as lactate dehydrogenase (LDH) activity release. NF-B and MAPK family were determined by TransAm kit while TNF- mRNA levels and its mRNA stability by RT-PCR. Intra- and extracellular TNF- protein was measured by ELISA, and TNF- converting enzyme (TACE) activity by a fluorimetric assay. Results: Peanut extract inhibited the maximal LPS-induced extracellular TNF- protein secretion by 18%, 29% and 47% at 25, 50 and 100 g/mL, respectively (P < 0.05). LPS stimulation revealed that 85% of TNF-  was released extracellularly while 15% remained intracellular. Peanut extract did not modify NF-B but, instead, reduced c-Jun transcription factor activity (P < 0.05), decreased TNF- mRNA (albeit non- significantly) and had no effect on mRNA stability and TACE activity. Conclusion: Polyphenol-rich peanut extract reduces extracellular TNF- protein by inhibiting c-Jun transcription factor from MAPK family, suggesting an anti-inflammatory effect. The proposed THP-1 monocyte model could be used to assess food extract impact (site and size effects) on the inflammation pathway. © 2012 Elsevier Ltd. All rights reserved. 1. Introduction Atherosclerosis is a complex inflammatory process involved in cardiovascular disease (CVD), the principal cause of morbid- ity and mortality in industrialized countries (Gerszten et al., 2011). Inflammation is characterized by the presence of mono- cytes/macrophages and T lymphocytes in the atheroma plaque (Ross, 1999). Monocytes promote atherosclerosis via production of various key mediators such as tumor necrosis factor- (TNF-). TNF- is commonly found in atherosclerotic lesions contributing to ∗ Corresponding author at: Unitat de Recerca en Lípids i Arteriosclerosi, Hospital Universitari Sant Joan, IISPV, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, Sant Llorenc ¸ , 21, 43201 Reus, Tarragona, Spain. Tel.: +34 977 75 93 69; fax: +34 977 75 93 22; mobile: +34 609 906 991. E-mail address: rosa.sola@urv.cat (R. Solà). the inflammatory process (Katsume et al., 2011). Concentrations of TNF- are increased in patients with increased risk of atheroscle- rosis (Devaraj et al., 2002). The mechanisms underlying the first part of the pro- inflammatory lipopolysaccharide (LPS)-induced TNF- signaling pathway have been well described (Gee et al., 2002). The exposure of cells to LPS, which is a major component of the outer membrane of Gram-negative bacteria, triggers the binding of LPS to the LPS bearing protein (LBP) and is transferred to the CD14 at the cell surface. LPS then interacts with the signaling toll-like receptor 4 (TLR4) and the accessory protein MD-2. LPS stimulates the acti- vation of various mitogen-activated protein kinase (MAPK) family pathways, including the extracellular signal-regulated kinase (ERK) 1 and 2, c-Jun N-terminal kinase (JNK), and p38 pathways. These pathways directly or indirectly phosphorylate and activate vari- ous transcription factors including Elk-1, c-Jun, c-Fos, ATF-1, ATF-2, SRF, and CREB. In addition, LPS activates the IKK pathway which 0161-5890/$ – see front matter © 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.molimm.2012.05.007