The anti-inflammatory potential of Cortex Phellodendron in vivo and in vitro: Down-regulation of NO and iNOS through suppression of NF-κB and MAPK activation You Yeon Choi a , Mi Hye Kim a , Jae Min Han a , Jongki Hong b , Tae-Hee Lee c , Sung-Hoon Kim d , Woong Mo Yang a, ⁎ a College of Korean Medicine and Institute of Korean Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea b College of Pharmacy, Kyung Hee University, Seoul 130-701, Republic of Korea c Formulae Pharmacology Department, School of Oriental Medicine, Gachon University, Seong-Nam, Kyunggi-Do, Republic of Korea d Cancer Preventive Material Development Research Center, College of Korean Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea abstract article info Article history: Received 6 November 2013 Received in revised form 19 December 2013 Accepted 15 January 2014 Available online 4 February 2014 Keywords: Phellodendron amurense Lipopolysaccharide (LPS) Cytokine Inflammation Cortex Phellodendri amurensis (CPA), derived from the dried bark of Phellodendron amurense Rupr., is a tradition- al medicine widely used to treat various inflammation-related diseases. The aim of this study was to investigate the anti-inflammatory activity and molecular mechanism of CPA in vivo and in vitro. Mice were pretreated with CPA (200 mg/kg, p.o.) for three consecutive days; 2 h after the last CPA treatment, mice were intraperitoneally injected with lipopolysaccharide (LPS) to induce endotoxemia (35 mg/kg). After treatment, we assessed survival rate, protein levels and cytokine expression. In addition, we confirmed the mo- lecular mechanism of anti-inflammatory effects of CPA in LPS-stimulated macrophage RAW 264.7 cells. The results showed that CPA significantly increased mice survival rates and down-regulated LPS-induced inter- leukin (IL)-6, IL-1β and macrophage chemo-attractant protein (MCP)-1 in serum. In addition, CPA inhibited in- ducible nitric oxide synthase (iNOS), activation of nuclear factor (NF)-κB by degradation and phosphorylation of IκBα, and attenuated phosphorylation of mitogen-activated protein kinases (MAPKs; ERK 1/2, p38 and JNK) from mice challenged with LPS. Moreover, in RAW 264.7 cells, CPA dose-dependently down-regulated LPS- stimulated NO, iNOS expression, as well as inflammatory cytokines and protein expression, consistent with the results in vivo. The anti-inflammatory properties of CPA in vitro and in vivo suggest its utility for attenuating inflammation- related diseases. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Inflammation is a highly regulated defense process that removes in- flammatory stimuli and initiates healing [1]. However, an excessive in- flammatory response, characterized by the release of cytokines and growth factors and transmigration of inflammatory cells from the blood to affected tissues, may cause sepsis and chronic inflammation [2]. Acute exposure to lipopolysaccharides (LPS) provokes the innate immune system, initiating a cascade of inflammatory cell influx and in- crease of pro-inflammatory mediators and cytokines, such as interleu- kin (IL)-6, IL-1β, and macrophage chemo-attractant protein (MCP)-1, as well as adhesion enzymes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) [3,4]. In addition, several other signal transduction pathways also contribute to inflammation. Nuclear factor (NF)-κB-dependent gene expression plays an important role in inflammatory responses and increases the expression of genes encoding cytokines and receptors involved in pro-inflammatory enzyme path- ways, such as iNOS and COX-2 [5]. The mitogen-activated protein ki- nases (MAPKs) family, including extracellular signal-regulated kinase (ERK) 1/2, p38 and c-Jun NH2-terminal kinase (JNK), plays a significant role in transducing signals triggered by cytokines, growth factors, and environmental stress involved in various cellular functions [6,7]. Although several drugs are currently available for the treatment of acute and chronic inflammations, they also produce various side effects. Thus, high biological effects and fewer side effects in herbal medicine for the treatment of inflammation research have attracted great interest [8]. Cortex Phellodendri amurensis (CPA), the dried trunk bark of Phellodendron amurense Rupr., contains a number of alkaloids (e.g., ber- berine, palmitine, phellodendrine) known as anti-inflammatory agents [9,10]. In particular, berberine, an isoquinoline alkaloid from Phellodendron amurense Rupr., has multiple pharmacological actions International Immunopharmacology 19 (2014) 214–220 ⁎ Corresponding author at: College of Korean Medicine and Institute of Korean Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701, Republic of Korea. Tel./fax: +82 2 961 2209. E-mail address: wmyang@khu.ac.kr (W.M. Yang). 1567-5769/$ – see front matter © 2014 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.intimp.2014.01.020 Contents lists available at ScienceDirect International Immunopharmacology journal homepage: www.elsevier.com/locate/intimp