Aspirin eugenol ester ameliorates LPS-induced inflammatory responses in RAW264.7 cells and mice

Abstract

Introduction: Inflammation is a defensive response of the body and the pathological basis of many diseases. However, excessive inflammation and chronic inflammation impair the homeostasis of the organism. Arachidonic acid (AA) has a close relationship with inflammation and is the main mediator of the pro-inflammatory response. Based on the prodrug principle, the new pharmaceutical compound aspirin eugenol ester (AEE) was designed and synthesized. However, the effects of AEE on key enzymes, metabolites and inflammatory signaling pathways in the AA metabolic network have not been reported.Methods: In this study, the anti-inflammation effects of AEE were first investigated in mice and RAW264.7 cells in LPS induced inflammation model. Then, the changes of the key enzymes and AA metabolites were explored by RT-PCR and targeted metabolomics. Moreover, the regulatory effects on NF–kB and MAPKS signaling pathways were explored by Western Blotting.Results: Results indicated that AEE significantly reduced the number of leukocyte and increased the lymphocyte percentage. AEE decreased the expression levels of IL-1β, IL-6, IL-8 and TNF-α both in vivo and in vitro. In the liver of mice, AEE downregulated the levels of AA, prostaglandin D2 (PGD2) and upregulated 12- hydroxyeicosatetraenoic acid (12-HETE). However, the changes of PGE2, PGF2α, 6-keto-prostaglandin F1α (6-KETO-PGF1α), 9-hydroxy-octadecenoic acid (9- HODE), 13-HODE, 15-HETE, docosahexaenoic acid (DHA) and thromboxane B2 (TXB2) were not significant. Additionally, it was found that AEE decreased the relative mRNA expression levels of p65 and p38 and the ratio of p-p65/p65.Discussion: It was concluded that AEE might inhibit the LPS-induced inflammatory response through the regulation of AA metabolism. This study provides the theoretical foundation for the development of AEE as a medicinal anti-inflammatory drug.

Aspirin eugenol ester affects ileal barrier function, inflammatory response and microbiota in broilers under lipopolysaccharide-induced immune stress conditions

“…This would affect the integrity of the intestinal epithelial barrier, suggesting that the decrease in tight junction gene expression caused by LPS stimulation may involve the activation of the COX-2-related signaling pathway. Previous studies have confirmed that AEE can regulate the pathways associated with arachidonic acid metabolism and reduce the expression of COX-2 and other genes (20). Similarly, the data of this study showed that the addition of AEE significantly decreased the mRNA expression of COX-2 and mPGES-1 in the ileum of broilers under LPS-induced immune stress.…”

“…In this study, the expression of ileal inflammatory factor genes in the LPS + AEE group was significantly down-regulated compared with the LPS group, suggesting that AEE had a significant alleviating effect on ileal inflammation in broilers exposed to immune stress. Similar studies have confirmed that AEE shows good anti-inflammatory properties both in vivo and in vitro (20). It can inhibit the formation of LPS-induced inflammatory mediators, and significantly reduce the expression and secretion of inflammatory cytokines such as IL-1β, TNF-α, and IL-6, thus alleviating the inflammatory response (18).…”

“…Compared with the precursor drugs, AEE not only has low toxicity ( 15 ), long action time ( 16 ), and wide safety range ( 17 ), but also reduces the irritation of aspirin on the gastrointestinal tract ( 18 ) and enhances the stability of eugenol ( 19 ). Studies have shown that AEE has anti-inflammatory ( 20 ) and antioxidant ( 17 , 21 , 22 ) effects that are better than either aspirin or eugenol alone ( 23 ). In view of the fact that drugs entering the intestine always affect the intestinal microbiota ( 24 ), some researchers have conducted experiments with AEE and found that it can indeed alter the composition of the gut microbiota in mice and rats ( 25 , 26 ) and regulate the metabolomics of cecal contents and feces in rats ( 27 ).…”