Research Article Torilin Inhibits Inflammation by Limiting TAK1-Mediated MAP Kinase and NF-B Activation Mehari Endale, 1 Tae-Hwan Kim, 2 Yi-Seong Kwak, 3 Na-Mi Kim, 3 Seung-Hyung Kim, 4 Jae Youl Cho, 5 Bong-Sik Yun, 6 and Man-Hee Rhee 2 1 Division of Neonatology and Pulmonary Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, OH, USA 2 College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Republic of Korea 3 Research and Development Headquarters, Korea Ginseng Corporation, Daejon 305-805, Republic of Korea 4 Institute of Traditional Medicine & Bioscience, Daejeon University, Daejeon 300-716, Republic of Korea 5 Department of Genetic Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea 6 College of Environmental & Bioresource Sciences, Chonbuk National University, Iksan 570-752, Republic of Korea Correspondence should be addressed to Bong-Sik Yun; bsyun@jbnu.ac.kr and Man-Hee Rhee; rheemh@knu.ac.kr Received 9 October 2016; Accepted 27 December 2016; Published 20 February 2017 Academic Editor: Tˆ ania Silvia Fr¨ ode Copyright © 2017 Mehari Endale et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Torilin, a sesquiterpene isolated from the fruits of Torilis japonica, has shown antimicrobial, anticancer, and anti-inflammatory properties. However, data on the mechanism of torilin action against inflammation is limited. is study aimed at determining the anti-inflammatory property of torilin in LPS-induced inflammation using in vitro model of inflammation. We examined torilin’s effect on expression levels of inflammatory mediators and cytokines in LPS-stimulated RAW 264.7 macrophages. e involvement of NF-kB and AP-1, MAP kinases, and adaptor proteins were assessed. Torilin strongly inhibited LPS-induced NO release, iNOS, PGE 2 , COX-2, NF-, IL-1, IL-6, and GM-CSF gene and protein expressions. In addition, MAPKs were also suppressed by torilin pretreatment. Involvement of ERK1/2, P38 MAPK , and JNK1/2 was further confirmed by PD98059, SB203580, and SP600125 mediated suppression of iNOS and COX-2 proteins. Furthermore, torilin attenuated NF-kB and AP-1 translocation, DNA binding, and reporter gene transcription. Interestingly, torilin inhibited TAK1 kinase activation with the subsequent suppression of MAPK- mediated JNK, p38, ERK1/2, and AP-1 (ATF-2 and c-jun) activation and IKK-mediated I-B degradation, p65/p50 activation, and translocation. Together, the results revealed the suppression of NF-B and AP-1 regulated inflammatory mediator and cytokine expressions, suggesting the test compound’s potential as a candidate anti-inflammatory agent. 1. Introduction e study of such inflammatory responses including inflam- matory mediators and cytokines activation is best charac- terized using suitable macrophage cell-lines including RAW 264.7 cells as models. In macrophages, LPS activates Toll- like receptor-4 (TLR4) and the activated receptor recruits the adaptor proteins (e.g., MyD88 or TRAM) and initi- ates MyD88 dependent or independent signaling pathways. MyD88 recruits and associates with two IL-1R-associated kinases (IRAK4 and IRAK1) leading to TNF receptor asso- ciated factor-6 (TRAF6) activation [1]. e activated TRAF6 is then ubiquitinated and recruited to the TGF-activated kinase 1 (TAK1)-TGF-activated kinase-1 binding protein 1 and 2 (TAB1/2) complex via binding to TAB2 [2]. is promotes the activation of TAK1, which in turn activates the canonical NF-B [2] and the MAP kinases signaling pathways [3]. TAK1-TAB1/2 complex is thus a common route for the IB kinase (IKK) and for MAPKs pathways (ERK1/2, JNK, and p38) [4]. ese signaling pathways in turn activate a variety of transcription factors including NF-kB (p50/p65) and AP- 1 (c-Fos/c-Jun) that coordinate the induction of many genes encoding inflammatory mediators [5]. ese mediators such as iNOS, COX-2, and cytokines (TNF-, IL-1, IL-6, and GM-CSF) are the common inflammatory mediators tran- scriptionally regulated by the above indicated transcription factors [6]. erefore, targeting these transcription factors, adaptor proteins, protein kinases, inflammation mediators, or Hindawi Mediators of Inflammation Volume 2017, Article ID 7250968, 13 pages https://doi.org/10.1155/2017/7250968