Paraquat (PQ) is an effective and commercially important herbicide that is widely used worldwide. However, PQ is highly toxic and can cause various complications and acute organ damage. Aspirin eugenol ester (AEE) is a potential new compound with anti-inflammatory and antioxidant stress pharmacological activity. The present study was to reveal the therapeutic effects and the protective effect of AEE against PQ-induced acute lung injury (ALI) with the help of PQ-induced oxidative damage in A549 cells and PQ-induced lung injury in rats. AEE might have no significant therapeutic effect on PQ-induced lung injury in rats. However, AEE had a significant protective effect on PQ-induced lung injury in rats. AEE pretreatment significantly reduced the stimulatory effect of PQ on malondialdehyde (MDA), the inhibitory effect of PQ on catalase (CAT) activity, superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, the ratio of GSH/GSSH, the activity of caspase-3 and the overexpression of p38 mitogen-activated protein kinase (MAPK) phosphorylation in vivo. In vitro, A549 cells were treated with 250 μM PQ for 24 h. Incubation of A549 cells with PQ led to apoptosis, and increased the level of superoxide anions, reactive oxygen species (ROS), malondialdehyde and the activity of caspase-3 and up-regulation of phosphorylated p38-MAPK, reduced mitochondrial membrane potential (ΔΨm) and the activity of SOD. However, after 24 h on AEE pretreatment of A549 cells, the above-mentioned adverse reactions caused by PQ were significantly alleviated. In addition, AEE pretreatment reduced p38-MAPK phosphorylation in PQ-treated A549 cells. SB203580, the specific p38-MAPK inhibitor, and p38-MAPK shRNA attenuated the activation of the p38-MAPK signaling pathway. N-acetylcysteine (NAC) reduced the level of phosphorylated p38-MAPK and the production of intracellular ROS and inhibited apoptosis. The results showed that AEE may inhibit PQ-induced cell damage through ROS/p38-MAPK-mediated mitochondrial apoptosis pathway.

Hyperlipidemia, with an increasing of prevalence, has become one of the common metabolic diseases in companion animal clinic. Aspirin eugenol ester (AEE) is a novel compound that exhibits efficacious anti-hyperlipidemia activities. However, its mechanisms are still not completely known. The objective of present study was to investigate the intervention effects of AEE on cecal contents metabonomics profile and microbiota in hyperlipidemia rats. Three groups of rats were fed with a control diet, or high fat diet (HFD) containing or not AEE. The results showed the beneficial effects of AEE in HFD-fed rats such as the reducing of aspartate aminotransferase (AST) and total cholesterol (TCH). Distinct changes in metabonomics profile of cecal contents were observed among control, model and AEE groups. HFD-induced alterations of eight metabolites in cecal contents mainly related with purine metabolism, linoleic acid metabolism, glycerophospholipid metabolism, sphingolipid metabolism and pyrimidine metabolism were reversed by AEE treatment. Principal coordinate analysis (PCoA) and cluster analysis of microbiota showed altered patterns with distinct differences in AEE group versus model group, indicating that AEE treatment improved the negative effects caused by HFD on cecal microbiota. In addition, the correction analysis revealed the possible link between the identified metabolites and cecal microbiota. This study showed regulation effects of AEE on cecal contents metabonomics profile and microbiota, which could provide information to reveal the possible underlying mechanism of AEE on hyperlipidemia treatment.

Atherosclerosis is a chronic immune inflammatory disease. Aspirin eugenol ester (AEE) is a novel safe and non-toxic compound with many pharmacological effects such as anti-inflammatory, anti-hyperlipidemic and anti-thrombotic action. In order to investigate the effect of AEE on the inhibition of aortic lipid plaque formation and macrophage-derived foam cell formation induced by oxidized low density lipoprotein (ox-LDL), in vivo atherosclerosis model by feeding ApoE^-/- mice with a high-fat diet and foam cells formation in vitro model by ox-LDL-induced RAW264.7 macrophages were established. It was found that AEE decreased the levels of TC and LDL-C in serum, and the plaque formation area and lipid accumulation in the aortic intima of ApoE^-/- mice. In vitro studies showed that AEE could prevent the uptake of ox-LDL and reduce the contents of TC and FC in cells. AEE enhanced the cholesterol efflux by increasing the expression of ABCA1, ABCG1 and PPARγ, which effectively alleviated excess cholesterol accumulated in the cells. Meanwhile, AEE also reduced the secretion and expression of inflammatory factors in the cells. In addition, AEE could reverse the action of PPARγ inhibitor T0070907 and/or ox-LDL. Therefore, AEE may become an effective candidate drug for the prevention of atherosclerosis.

Based on the pro-drug principle, aspirin and eugenol were esterified to synthesize aspirin eugenol ester (AEE). The anti-hyperlipidemia effect of aspirin eugenol ester has been confirmed in hyperlipidemic rat induced by high fat diet (HFD). However, its effect on liver and feces metabonomic profiles remains unknown. Suspension of AEE was prepared in 5% carboxymethyl cellulose sodium (CMC-Na). Thirty rats were divided into control, model and AEE groups. The control and model rats were fed with normal diet or HFD for 13 weeks, respectively. Rats in AEE-treated group were fed with HFD for 8 weeks to induce hyperlipidemia, and then given AEE once daily by oral gavage for 5 weeks at the dosage of 54 mg/kg body weight. After drug intervention, lipid profile analysis and oil red O staining were carried out to confirm the lipid accumulation in liver tissue. UPLC-Q-TOF/MS-based liver and feces metabonomics coupled with pathway analysis were conducted to evaluate the changes of metabolic profile and endogenous metabolites. In liver tissue, oral administration of AEE significantly reduced lipid droplets and the levels of triglyceride (TG) and low-density lipoprotein (LDL). Using principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA), distinct changes in metabolite patterns in feces and liver were observed. Liver and feces samples in control, model and AEE groups were scattered in PLS-DA score plots. 28 metabolites in liver and 22 in feces were identified as potential biomarkers related to hyperlipidemia. As possible drug targets, the perturbations of those biomarkers can be regulated by administration of AEE. Anti-hyperlipidemia effect of AEE was confirmed by lipid analysis, oil red O staining and metabolomics analysis. The mechanism of AEE might be associated with the changes in the metabolism of glycerophospholipid, amino acid, fatty acid, sphingolipid, purine, bile acid and glutathione.

Aspirin eugenol ester (AEE) possesses anti-thrombotic, anti-atherosclerotic and anti-oxidative effects. The study aims to clarify the mechanism underlying the anti-atherosclerotic effects of AEE on vascular endothelial dysfunction. Both the high-fat diet (HFD)-induced atherosclerotic rat model and the H₂O₂-induced human umbilical vein endothelial cells (HUVECs) model were used to investigate the effects of AEE on vascular endothelial dysfunction. UPLC/QTOF-MS coupled with a multivariate data analysis method were used to profile the variations in the metabolites of HUVECs in response to different treatments. Pretreatment of HUVECs with AEE significantly ameliorated H₂O₂-induced apoptosis, the overexpression of E-selectin and VCAM-1, and the adhesion of THP-1 cells. Putative endogenous biomarkers associated with the inhibition of endothelial dysfunction were identified in HUVECs pretreated with AEE in the absence or presence of H₂O₂, and these biomarkers were involved in important metabolic pathways, including amino acid metabolism, carbohydrate metabolism, and glutathione metabolism. Moreover, in vivo, AEE also significantly reduced vascular endothelial dysfunction and decreased the overexpression of VCAM-1 and E-selectin. Based on our findings, the mechanism underlying the anti-atherosclerotic effects of AEE might be related to a reduction in vascular endothelial dysfunction mediated by ameliorating alterations in metabolism, inhibiting oxidative stress, and decreasing the expression of adhesion molecules.

Aspirin eugenol ester (AEE) is a novel compound that is formed from the esterification of aspirin (acetylsalicylic acid (ASA)) and eugenol. This study aimed to investigate the effects of AEE on blood stasis in rats and to characterize the underlying mechanisms using a plasma metabolomic study. The results indicate that AEE and ASA could modulate whole blood viscosity (WBV), plasma viscosity (PV), blood coagulation parameters, platelet count, platelet aggregation, lactate dehydrogenase (LDH), creatinine (CR) and the levels of thromboxane A2 (TXA₂) and 6-keto prostaglandin F1α (6-keto-PGF_1α). The metabolic profiles of the plasma samples from all groups were clearly separated in the score plots. Nineteen potential metabolites were selected and identified, and disordered levels of these metabolites could be regulated by AEE and ASA. Pathway analysis showed that the mechanism of action of AEE on blood stasis might be principally related to the metabolism of amino acid, fatty acid, energy and glycerophospholipid. The above results indicate that AEE protected the rats against blood stasis, and that this effect might have been caused by the anticoagulation activity of AEE and its abilities to maintain a balance between TXA₂ and PGI₂, reduce blood viscosity, inhibit platelet aggregation and normalize the plasma metabolic profile.