In Vitro Anti-Inflammatory Effects of Three Fatty Acids from Royal Jelly

Mediators of Inflammation, Oct 2016

Trans-10-hydroxy-2-decenoic acid (10-H2DA), 10-hydroxydecanoic acid (10-HDAA), and sebacic acid (SEA) are the three major fatty acids in royal jelly (RJ). Previous studies have revealed several pharmacological activities of 10-H2DA and 10-HDAA, although the anti-inflammatory effects and underlying mechanisms by which SEA acts are poorly understood. In the present study, we evaluated and compared the in vitro anti-inflammatory effects of these RJ fatty acids in lipopolysaccharide-stimulated RAW 264.7 macrophages. The results showed that 10-H2DA, 10-HDAA, and SEA had potent, dose-dependent inhibitory effects on the release of the major inflammatory-mediators, nitric oxide, and interleukin-10, and only SEA decreased TNF-α production. Several key inflammatory genes have also been modulated by these RJ fatty acids, with 10-H2DA showing distinct modulating effects as compared to the other two FAs. Furthermore, we found that these three FAs regulated several proteins involved in MAPK and NF-κB signaling pathways. Taken together, these findings provide additional references for using RJ against inflammatory diseases.

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In Vitro Anti-Inflammatory Effects of Three Fatty Acids from Royal Jelly

In Vitro Anti-Inflammatory Effects of Three Fatty Acids from Royal Jelly Yi-Fan Chen,1 Kai Wang,2 Yan-Zheng Zhang,1 Yu-Fei Zheng,1 and Fu-Liang Hu1 1College of Animal Sciences, Zhejiang University, Hangzhou 310058, China 2Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China Received 8 August 2016; Accepted 18 September 2016 Academic Editor: Jie Yin Copyright © 2016 Yi-Fan Chen et al. This 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. Abstract Trans-10-hydroxy-2-decenoic acid (10-H2DA), 10-hydroxydecanoic acid (10-HDAA), and sebacic acid (SEA) are the three major fatty acids in royal jelly (RJ). Previous studies have revealed several pharmacological activities of 10-H2DA and 10-HDAA, although the anti-inflammatory effects and underlying mechanisms by which SEA acts are poorly understood. In the present study, we evaluated and compared the in vitro anti-inflammatory effects of these RJ fatty acids in lipopolysaccharide-stimulated RAW 264.7 macrophages. The results showed that 10-H2DA, 10-HDAA, and SEA had potent, dose-dependent inhibitory effects on the release of the major inflammatory-mediators, nitric oxide, and interleukin-10, and only SEA decreased TNF-α production. Several key inflammatory genes have also been modulated by these RJ fatty acids, with 10-H2DA showing distinct modulating effects as compared to the other two FAs. Furthermore, we found that these three FAs regulated several proteins involved in MAPK and NF-κB signaling pathways. Taken together, these findings provide additional references for using RJ against inflammatory diseases. 1. Introduction Royal jelly (RJ) is a viscous secretion from the mandibular and hypopharyngeal glands of worker bees (Apis mellifera) and is known as an essential food for the queens [1]. RJ is also an important functional substance that has been widely used in commercial products, dietary supplements, and cosmetics [2]. RJ has been shown to possess versatile bioactive properties such as antibacterial [3], immunomodulatory [4], antiviral [5], wound-healing [6], growth promoting [7], antioxidant [8], nephroprotective [9], and anti-inflammatory [10] activities. Fresh RJ consists of water (50–60%), lipids (3–8%), proteins (18%), carbohydrates (7–18%), and other trace elements [11]. The lipid composition of RJ comprises 80–85% fatty acids, together with proteins that contribute to its biological activities [12]. Fatty acids (FAs) can be classified as long-chain (more than 12 C), medium-chain (6–12 C), and short-chain (less than 6 C) fatty acids, of which medium-chain fatty acids (MCFAs) exist mostly in the free form [13]. The major MCFAs found in RJ are trans-10-hydroxy-2-decenoic acid (10-H2DA), 10-hydroxydecanoic acid (10-HDAA), and sebacic acid (SEA) (Figure 1) [14]. Trans-10-hydroxy-2-decenoic acid (10-H2DA), an unsaturated hydroxyl fatty acid, is predominant and is one of the most extensively studied MCFAs in RJ, constituting more than 50% of the free FAs. A saturated hydroxyl fatty acid, 10-HDAA, comprises 60–80% of the total FAs, together with 10-H2DA. SEA (1, 10-decanedioic acid), a dicarboxylic fatty acid, accounts for 3.3% of the FA family found in the RJ [15, 16]. Chemical characteristics of FAs in RJ have been determined by gas chromatography-mass spectrometry (GC-MS), high performance liquid chromatography (HPLC), and ultraperformance liquid chromatography (UPLC) methods from lyophilized royal jelly [17–19]. Previous studies have investigated the ability of SEA to inhibit histone deacetylase [20] and modulate the estrogen receptor [21]. Both 10-H2DA and 10-HDAA have been shown to possess diverse pharmacological activities such as immunomodulatory [22], estrogenic [21, 23], and anti-inflammatory effects [24] in vitro. In vivo models demonstrated that 10-H2DA effectively protected against the depression and anxiety in mice when intraperitoneally administered [25]. However, the pharmacological activities of SEA have remained elusive. Owing to similarities in the chemical structures of the three abovementioned MCFAs, we hypothesized that SEA may also exhibit similar pharmacological activities. Figure 1: Chemical structures of 10-H2DA, 10-HDAA, and SEA. Inflammation is an important host response of tissues to injury or infection, which may be triggered by chemical toxins, mechanical injuries, and many other reactions. Cell cytokines, like interleukin-6 (IL-6), IL-10, and tumor necrosis factor-α (TNF-α), play important roles in mediating inflammation [26]. Mitogen-activated protein kinases (MAPKs) comprise protein kinases that participate in the regulation of key cellular processes like inflammatory responses. Extracellular signal-regulated kinases (ERKs), p38, and c-Jun N-terminal kinase (JNK) are the major classes of MAPKs that play impor (...truncated)


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Yi-Fan Chen, Kai Wang, Yan-Zheng Zhang, Yu-Fei Zheng, Fu-Liang Hu. In Vitro Anti-Inflammatory Effects of Three Fatty Acids from Royal Jelly, Mediators of Inflammation, 2016, 2016, DOI: 10.1155/2016/3583684