The Anti-Inflammatory Properties of Citrus wilsonii Tanaka Extract in LPS-Induced RAW 264.7 and Primary Mouse Bone Marrow-Derived Dendritic Cells.

Liping Cheng,Shu’Ang Peng,Dingbo Lin,Bo Zhong,Yujie Ren,Zhaocheng Ma

doi:10.3390/molecules22071213

Abstract

‘Zhique’ (Citrus wilsonii Tanaka) is a traditional Chinese medicine. Its fruits have been used to treat inflammation-related symptoms, such as cough and sputum, though the underlying mechanism remains poorly understood. The aim of this study was to investigate the anti-inflammatory properties of ‘Zhique’ pulp extract (ZQE) in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages and primary mouse bone marrow-derived dendritic cells (BMDCs). The flavonoid profiles of the ZQE were determined by high performance liquid chromatography. The anti-inflammatory activity was evaluated in LPS-induced inflammatory RAW 264.7 macrophages and BMDCs through enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and Western blot assays. Naringin was a predominant flavonoid occurring in ZQE, followed by eriocitrin, hesperidin, neohesperidin, rhoifolin, naringenin, and poncirin. ZQE exhibited a very low cytotoxicity in LPS-stimulated RAW 264.7 macrophages. Meanwhile, ZQE significantly inhibited the production of prostaglandins E2 and secretion of cyclooxygenase-2 protein in LPS-stimulated RAW 264.7 macrophages, and markedly suppressed the mRNA expression of inflammatory mediators, such as cyclooxygenase-2, tumor necrosis factor alpha, interleukin-1 beta (IL-1β), and IL-6 in LPS-induced RAW 264.7 macrophages and/or primary BMDCs. The ZQE inhibited the inflammatory responses in RAW 264.7 macrophages and BMDCs triggered by LPS. The results suggested that ‘Zhique’ has a high potential as a novel therapeutic agent to treat chronic inflammatory diseases.

Highlights

IntroductionCitrus wilsonii Tanaka (Xiangyuan in Chinese), belongs to the citrus genus in plant taxonomy [1]
Citrus wilsonii Tanaka (Xiangyuan in Chinese), belongs to the citrus genus in plant taxonomy [1].It is called ‘Zhique’ in the region of the Southern Qinling Mountains in China [2]
ZQE was a very complex mixture containing 399 compounds detected by LC-electrospray ionization (ESI)-MS/MS analysis, and the result is presented in detail in Figure S1 and Table S1

Summary

Introduction

Citrus wilsonii Tanaka (Xiangyuan in Chinese), belongs to the citrus genus in plant taxonomy [1]. It is called ‘Zhique’ in the region of the Southern Qinling Mountains in China [2]. It is recorded that the dried fruit of Citrus wilsonii Tanaka fruit is one of the Fructus Citri, which is a traditional Chinese medicine in the Chinese Pharmacopoeia [3]. The dried ‘Zhique’ fruits have been used to treat stagnated qi in the liver and stomach, chest and rib pain, epigastric abdominal distention and fullness, vomiting and belching, and coughing and phlegm. Fructus Aurantii has a similar function compared to Fructus Citri in curing chest tightness, “qi” stagnation, abdominal fullness pain, indigestion, phlegmy throat, and organ sagging [3]. Inflammation is a common cause of some of these diseases mentioned above, such as coughing and phlegmy throat [5,6]

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