Anti-inflammatory Effects And Underlying Mechanisms Of Royal Jelly Fatty Acids

Royal jelly(RJ)is a well known traditional health food.The composition of royal jelly is complex,including water,protein,carbohydrates,and lipids.RJ not only has a very high nutritional value,but also has a wide range of biological activities such as anti-oxidative,bacteriostatic,anti-inflammatory,neurotrophic,immune regulatory activities,etc.Fatty acids are important functional components of royal jelly,however,our knowledge about the anti-inflammation activity of royal jelly acids are quite limited.Based on our previous researches on the quality control of royal jelly fatty acids,in this study,we extracted the royal jelly lipids and investigated its fatty acids composition.The anti-inflammatory effects of three characteristic fatty acids:Trans-10-Hydroxy-2-decenoic acid(10-HDA),10-Hydroxy-decanoic acid(10-HDAA)and Sebacic acid(SEA)against the cell wall components of gram-negative bacteria {Lipopolysaccharide,LPS)and gram-positive bacteria(Lipoteichoic acid,LTA)in vivo and in vitro were also studied.Lastly,the protective effects of on 10-HDA on LTA-induced mice acute lung injury were investigated.The main results are as listed follows:1.Composition analysis of royal jelly lipids extract(RJL)Determination of 10-HDA,10-HDAA and SEA content in lyophilized royal jelly powder using GC were conducted.The royal jelly lipids(RJL)were extracted and its fatty acids composition were analyzed by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry.The results showed that 10-HDA,10-HDAA and SEA were the major fatty acids identified in RJL,so were a few long-chain fatty acids such as hexadecanoic acid and octadecanoic acid.2.Effects of RJ and RJL on LPS induced inflammation in comparisonThe effects of RJ and RJL on LPS-stimulated inflammation were investigated by griess assay and qRT-PCR analysis.The results showed that RJL had significant inhibitory effects on the release of nitric oxide,interleukin-10 and interleukin-6.Several key inflammatory genes have also been modulated.The results suggested that the activites of RJL may contribute to the RJ anti-inflammatory benefits.3.Anti-inflammatory effects of 10-HDA,10-HDAA and SEA on LPS induced macrophages and its underlying mechanisms10-HDA,10-HDAA and SEA are the three major fatty acids in royal jelly.We evaluated and compared the in vitro anti-inflammatory effect of these RJ fatty acids in LPS-stimulated RAW 264.7 macrophages.The results showed that 10-HDA,10-HDAA and SEA had potent,dose-dependent inhibitory effects on the release of the major inflammatory mediators and nitric oxide.Several key inflammatory genes have also been modulated by them,with 10-HDA 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-?B signaling pathways.Taken together,these findings provided novel references for using RJ against inflammatory diseases.4.Effects and mechanisms of 10-HDA,10-HDAA and SEA on LTA-stimulated macrophages and effect of 10-HDA on LTA-induced mice acute lung injuryThe in vitro anti-inflammatory effect of 10-HDA,10-HDAA and SEA in LTA induced RAW 264.7 macrophages were evaluated.Additionally,we also investigated the effect of 10-HDA on the MAPK pathway in LTA-induced macrophages and the production of inflammatory mediators,pulmonary damage in LTA-stimulated mice.The results showed that 10-HDA,10-HDAA and SEA had potent,dose-dependent inhibitory effects on the release of IL-6,10-HDA could also down-regulate the expression of several key inflammatory genes,including IL-1?,IL-10,IL-6 and COX-2.Furthermore,10-HDA could regulate ERK,p38 and JNK pathway significantly.It was found that the administration of 10-HDA(100 mg/kg)can provide protective effects by attenuating lung histopathological changes and modulating the secretion of LTA-stimulated inflammatory cytokines in mice,such as IL-10,MCP-1 and TNF-a..