Search Results (76)

Cerebral ischemic reperfusion injury (CIRI) induces irreversible neurological dysfunction with high morbidity and mortality, yet effective clinical interventions remain limited. This study focused on ferroptosis in CIRI and explored the neuroprotective components and mechanisms of Pomelo peel essential oil (PPEO)—a product derived from Guangxi’s characteristic Shatian pomelo. Sprague-Dawley rats were used to establish two CIRI models: focal CIRI via Middle Cerebral Artery Occlusion (MCAO) and global CIRI via Cardiac Arrest/Cardiopulmonary Resuscitation (CA/CPR). Analyses were conducted using metabolomics, transcriptomics, histopathological staining, biochemical assays, RT-qPCR, Western blotting (WB), and molecular docking. Metabolomic results showed altered lipid-related metabolites in both models, predominantly unsaturated fatty acids and components of the arachidonic acid (AA) metabolic pathway. Transcriptomic analysis revealed significant upregulation of PTGS1/2 in the MCAO model. Nootkatone and β-pinene improved neuronal morphology, increased glutathione peroxidase 4 (GPX4) levels, and enhanced neurological scores. Notably, Nootkatone exhibited strong binding affinity to ALOX15, and reduced lipid metabolic disturbances in the CA/CPR model. AA metabolism varies with CIRI severity: it is inflammation-driven in focal CIRI and ferroptosis-associated in global CIRI. As a key component of PPEO, Nootkatone antagonizes ferroptosis via the ACSL4-LPCAT3-ALOX15 axis, offering a novel therapeutic target for global CIRI after CA/CPR. Full article

Traumatic optic neuropathy (TON) causes vision loss through compression and contusion, yet there is no consensus on the most effective treatment. Polyunsaturated fatty acid (PUFA)-derived bioactive lipids metabolized by lipoxygenase (LOX), cytochrome P450 (CYP), and cyclooxygenase (COX) enzymes are known mediators of inflammation and neurodegeneration. However, their role in TON-related retinal pathology remains unclear. Controlled orbital impact (COI) was used to induce unilateral TON in mice with controlled velocity (2–3 m/s), with the fellow eye serving as an internal control. Retina tissues were collected three days post-injury and analyzed by LC/MS to quantify bioactive lipid metabolites from ω−6 and ω−3 PUFAs. Statistical analysis was performed using paired, nonparametric Wilcoxon signed-rank tests with Benjamini–Hochberg false discovery rate (FDR) correction. Results showed that among 38 reliably detected metabolites, no individual lipid showed a statistically significant difference between TON and control eyes after FDR correction (q < 0.05). However, both individual and pathway-level analysis revealed consistent trends toward increased expression of LOX- and CYP-derived metabolites across FDA PUFA substrates, including arachidonic acid (AA), linoleic acid (LA), and docosahexaenoic acid (DHA). These findings support further investigation into lipid-mediated inflammation in TON and its potential as a therapeutic target, particularly through expanding both the sample size and the post-TON time periods. Full article

Ischemic stroke is a leading cause of mortality and disability in adults. The inflammatory cascade is driven by various inflammatory molecules, such as interleukin-1β (IL-1β), and counteracted by its antagonist, interleukin-1 receptor antagonist (IL-1Ra). Eicosanoids are inflammatory derivatives of free fatty acids. Arachidonic acid (AA) derivatives exhibit pro-inflammatory activity, while eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) derivatives, known as specialized pro-resolving mediators, have anti-inflammatory properties. This study aimed to analyze potential associations between eicosanoids and key inflammatory molecules, including IL-1β and its antagonist IL-1Ra. In this prospective study, we investigated inflammatory molecules in 73 ischemic stroke patients. We analyzed interactions between IL-1β, IL-1Ra, and eicosanoids as follows: resolvin E1, prostaglandin E2, resolvin D1, lipoxin A4 (5S, 6R, 15R), protectin DX, maresin 1, leukotriene B4, 18RS-HEPE, 13S-HODE, 9S-HODE, 15S-HETE, 17 HDHA, 12S-HETE, 5-oxo-ETE, and 5-HETE. In 73 ischemic stroke patients, mean IL-1β was 1.31 ± 1.54 pg/mL and IL-1Ra 810.8 ± 691.0 pg/mL. Spearman correlations showed positive associations between IL-1β and protectin DX (ρ = 0.56, p < 0.001), and 17 HDHA (ρ = 0.26, p < 0.05) and 5-oxo-ETE (ρ = 0.27, p < 0.05). IL-1Ra correlated negatively with protectin DX (ρ = −0.58, p < 0.001) and 17 HDHA (ρ = −0.29, p < 0.05), and positively with leukotriene B4 (ρ = 0.34, p < 0.005). After multivariable adjustment, associations with IL-1β lost statistical significance, whereas the inverse relationships between IL-1Ra and protectin DX/17 HDHA remained significant (p < 0.005). Despite the known anti-inflammatory roles of protectin DX and 17 HDHA, and the pro-inflammatory role of leukotriene B4, their activity in the early subacute phase of ischemic stroke appears to be influenced by complex interplays, possibly mediated by IL-1β and IL-1Ra. The activity of protectin DX, 17 HDHA, and leukotriene B4 is correlated with IL-1β and IL-1Ra levels in the early subacute phase of stroke. Full article

Background/Objectives: Lichen simplex chronicus (LSC) of the vulva is a chronic dermatologic disorder characterized by persistent pruritus, compulsive scratching, and progressive thickening of the vulvar skin. Currently, LSC diagnosis primarily relies on clinical presentation, with histopathological examination performed when the diagnosis is unclear. However, the precise pathogenic mechanisms driving the disease remain poorly understood. This study aimed to investigate the pathogenesis of LSC and evaluate the feasibility of tape stripping as a non-invasive diagnostic technique. Methods: Skin specimens were obtained using both traditional biopsy and tape stripping methods, and the metabolites and oxidized lipids in these samples were analyzed using advanced mass spectrometry techniques. Results: Our findings suggest that 20-hydroxyeicosatetraenoic acid (20-HETE), an oxidized derivative of arachidonic acid (AA), activates the TRPV1 receptor, thereby exacerbating the itch–scratch cycle. This activation upregulates energy metabolism and promotes epidermal hyperplasia, providing new insights into the disease’s pathophysiology. Conclusions: Our study suggests that tape stripping could serve as a viable non-invasive diagnostic tool for LSC, with linoleic acid (LA) and AA potentially acting as biomarkers for the disease. Full article

Background/Objectives: Localized provoked vulvodynia (LPV) is characterized by chronic vulvar pain upon light touch to the vestibule, a specialized ring of tissue immediately surrounding the vaginal opening. LPV affects about 14 million people in the US, yet the etiopathology of the disease is unknown. In LPV, the vestibule expresses elevated levels of the pro-nociceptive pro-inflammatory mediators prostaglandin E₂ (PGE2) and interleukin-6 (IL-6), which corresponds to lower pain thresholds. Previous studies have shown reduced amounts of arachidonic acid (AA)-derived pro-resolving lipid mediators in tissue biopsies from LPV patients that might impede the resolution of inflammation. AA is obtained from dietary linoleic acid, pointing to a defect in the metabolism of dietary polyunsaturated fatty acids in LPV. We aimed to further explore the involvement of AA metabolism in LPV, which appears dysregulated in the vestibule of LPV patients and culminates in chronic inflammation and chronic pain. Methods: Vestibular and vulvar tissue biopsies obtained from LPV and non-LPV patients were used to generate fibroblast strains and assessed for COX/LOX expression using qRT-PCR. Fibroblast strains were treated with inflammatory stimuli, and then COX-1 and COX-2 expression was assessed using Western blot analysis. Pro-inflammatory mediator production was assessed using enzyme-linked immunosorbent assays (ELISAs). ALOX5 and ALOX12 expression was assessed using qRT-PCR. Finally, lipidomic analysis was carried out to screen for 143 lipid metabolites following inflammatory challenge. Results: Tissue and fibroblasts from LPV patients exhibited altered expression of COX/LOX enzymes and production of AA-derived lipid mediators compared to non-LPV patients. Conclusions: Lipid profiles of tissue and vestibular fibroblasts from LPV patients differed from non-LPV patients, and this difference was attributed to differential COX/LOX expression and activity, which metabolizes AA derived from dietary linoleic acid. This dysregulation fosters chronic inflammation and reduced resolution capacity in LPV patients, causing chronic pain. While further work is needed, these findings suggest that dietary modifications could impact the LPV mechanism. Full article

Terpenes represent a structurally diverse class of natural compounds with increasing scientific interest due to their potential anti-inflammatory properties. This study investigates the in silico binding behavior of six plant-derived terpenes—α-pinene, β-pinene, menthol, camphor, limonene, and linalool—against four key enzymes in the arachidonic acid (AA) metabolic pathway: cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), and phospholipase A2 (PLA₂). AA serves as a reference for binding energy comparison. Blind rigid-body molecular docking is performed using AutoDock 4.2 and the Lamarckian Genetic Algorithm, with 100 runs per ligand–enzyme pair and the energy-based selection of optimal poses. The analysis includes binding energy (ΔG), inhibition constants (Ki), root-mean-square deviation (RMSD), and residue-level interactions. Several terpenes exhibit favorable binding energies and inhibition constants across the evaluated enzymes. For COX-1 and COX-2, menthol and camphor show low Ki values, indicating stable binding. Menthol and limonene also show the strongest affinities for PLA₂, exceeding AA. The focus is on compounds with potential to modulate arachidonic acid metabolism. In this context, β-pinene engages the catalytic site of PLA₂, linalool forms multiple contacts within key regions of 5-LOX, and menthol, α-pinene, and β-pinene align with functionally important regions in both COX isoforms. These targeted interactions suggest that the highlighted compounds may selectively interfere with enzymatic activity in inflammation-related pathways. By modulating key steps in AA metabolism, these terpenes may influence the biosynthesis of pro-inflammatory mediators, offering a promising avenue for the development of safer, plant-derived anti-inflammatory agents. The findings lay the groundwork for further experimental validation and the structure-based optimization of terpene-derived modulators. Full article

The purpose of this review is to propose that lipoxin A4 (LXA4), derived from arachidonic acid (AA), a potent anti-inflammatory, cytoprotective, and wound healing agent, may be useful to prevent and manage diabetic retinopathy (DR). LXA4 suppresses inappropriate angiogenesis and the production of pro-inflammatory prostaglandin E2 (PGE2), leukotrienes (LTs), 12-HETE (12-hydroxyeicosatetraenoic acid), derived from AA by the action of 12-lioxygenase (12-LOX)) interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), as well as the expression of NF-κB, inducible NO (nitric oxide) synthase (iNOS), cyclooxygenase-2 (COX-2), intracellular adhesion molecule-1 (ICAM-1), and vascular endothelial growth factor (VEGF)—factors that play a role in DR. Thus, the intravitreal injection of LXA4 may form a new approach to the treatment of DR and other similar conditions such as AMD (age-associated macular degeneration) and SARS-CoV-2-associated hyperinflammatory immune response in the retina. The data for this review are derived from our previous work conducted in individuals with DR and from various publications on LXA4, inflammation, and DR. Full article

Secreted phospholipase 2 (sPLA2) is the largest family of phospholipase A2 (PLA2) enzymes with 11 mammalian isoforms. Each sPLA2 exhibits different localizations and specific properties, being involved in a very wide spectrum of biological processes. The enzymatic activity of sPLA2 has been well described; however, recent findings have shown that they could regulate different signaling pathways by acting directly as ligands. Arachidonic acid (AA) and its derivatives are produced by sPLA2 in collaboration with other molecules in the extracellular space, making important impacts on the cellular environment, being especially relevant in the contexts of immunity and cancer. For these reasons, this review focuses on sPLA2 functions in processes such as the promotion of EMT, angiogenesis, and immunomodulation in the context of tumor initiation and progression. Finally, we will also describe how this knowledge has been applied in the search for new sPLA2 inhibitory compounds that can be used for cancer treatment. Full article

Polyunsaturated fatty acids (PUFAs) are not only structural components of membrane phospholipids and energy storage molecules in cells. PUFAs are important factors that regulate various biological functions, including inflammation, oxidation, and immunity. Both n-3 and n-6 PUFAs from cell membranes can be metabolized into pro-inflammatory and anti-inflammatory metabolites that, in turn, influence cardiovascular health in humans. The role that PUFAs play in organisms depends primarily on their structure, quantity, and the availability of enzymes responsible for their metabolism. n-3 PUFAs, such as eicosapentaenoic (EPA) and docosahexaenoic (DHA), are generally known for anti-inflammatory and atheroprotective properties. On the other hand, n-6 FAs, such as arachidonic acid (AA), are precursors of lipid mediators that display mostly pro-inflammatory properties and may attenuate the efficacy of n-3 by competition for the same enzymes. However, a completely different light on the role of PUFAs was shed due to studies on the influence of PUFAs on new-onset atrial fibrillation. This review analyzes the role of PUFAs and PUFA derivatives in health-related effects, considering both confirmed benefits and newly arising controversies. Full article

Introduction: Obesity is characterized by low-grade chronic inflammation, which can be modulated by lipid mediators derived from omega-3 (n-3) polyunsaturated fatty acids (PUFA). Obesity is a multifactorial disease, where genetic and environmental factors strongly interact to increase its development. In this context, the FADS1 gene encodes the delta-5 desaturase protein, which catalyzes the desaturation of PUFA. The rs174547 genetic variant of FADS1 has been associated with alterations in lipid metabolism, particularly with decreases in eicosapentaenoic acid (EPA) and arachidonic acid (AA) concentrations. Objective: To analyze the effect of an n-3-supplemented diet on the fatty acid profile and composition in red blood cells (RBCs) of obese subjects carrying the rs174547 variant of the FADS1 gene. Methodology: Seventy-six subjects with obesity were divided into two groups: omega-3 (1.5 g of n-3/day) and placebo (1.5 g of sunflower oil/day). The dietary intervention consisted of a four-month follow-up. Anthropometric, biochemical, and dietary variables were evaluated monthly. The total fatty acid profile in RBC was determined using gas chromatography. The rs174547 variant was analyzed through allelic discrimination. Results: The n-3 index (O3I) increased at the end of the intervention in both groups. Subjects carrying the CC genotype showed significant differences (minor increase) in n-6, n-3, total PUFA, EPA, DHA, and the O3I in RBCs compared to TT genotype carriers in the n-3 group. Conclusions: The diet supplemented with EPA and DHA is ideal for providing the direct products that bypass the synthesis step affected by the FADS1 rs174547 variant in subjects carrying the CC genotype. The O3I confirmed an increase in n-3 fatty acids in RBCs at the end of the intervention. Full article

In obesity, circulating saturated fatty acids (SFAs) and inflammatory cytokines interfere with skeletal muscle insulin signaling, leading to whole body insulin resistance. Further, obese skeletal muscle is characterized by macrophage infiltration and polarization to the inflammatory M1 phenotype, which is central to the development of local inflammation and insulin resistance. While skeletal muscle-infiltrated macrophage–myocyte crosstalk is exacerbated by SFA, the effects of other fatty acids, such as n-3 and n-6 polyunsaturated fatty acids (PUFAs), are less studied. Thus, the objective of this study was to determine the effects of long-chain n-3 and n-6 PUFAs on macrophage M1 polarization and subsequent effects on myocyte inflammation and metabolic function compared to SFA. Using an in vitro model recapitulating obese skeletal muscle cells, differentiated L6 myocytes were cultured for 24 h with RAW 264.7 macrophage-conditioned media (MCM), followed by insulin stimulation (100 nM, 20 min). MCM was generated by pre-treating macrophages for 24 h with 100 μM palmitic acid (16:0, PA–control), arachidonic acid (20:4n-6, AA), or docosahexaenoic acid (22:6n-3, DHA). Next, macrophage cultures were stimulated with a physiological dose (10 ng/mL) of lipopolysaccharide for an additional 12 h to mimic in vivo obese endotoxin levels. Compared to PA, both AA and DHA reduced mRNA expression and/or secreted protein levels of markers for M1 (TNFα, IL-6, iNOS; p < 0.05) and increased those for M2 (IL-10, TGF-β; p < 0.05) macrophage polarization. In turn, AA- and DHA-derived MCM reduced L6 myocyte-secreted cytokines (TNFα, IL-6; p < 0.05) and chemokines (MCP-1, MIP-1β; p < 0.05). Only AA-derived MCM increased L6-myocyte phosphorylation of Akt (p < 0.05), yet this was inconsistent with improved insulin signaling, as only DHA-derived MCM improved L6 myocyte glucose uptake (p < 0.05). In conclusion, dietary n-3 and n-6 PUFAs may be a useful strategy to modulate macrophage–myocyte inflammatory crosstalk and improve myocyte insulin sensitivity in obesity. Full article

Chronic exposure to harmful pollutants, chemicals, and pathogens from the environment can lead to pathological changes in the epithelial barrier, which increase the risk of developing an allergy. During allergic inflammation, epithelial cells send proinflammatory signals to group 2 innate lymphoid cell (ILC2s) and eosinophils, which require energy and resources to mediate their activation, cytokine/chemokine secretion, and mobilization of other cells. This review aims to provide an overview of the metabolic regulation in allergic asthma, atopic dermatitis (AD), and allergic rhinitis (AR), highlighting its underlying mechanisms and phenotypes, and the potential metabolic regulatory roles of eosinophils and ILC2s. Eosinophils and ILC2s regulate allergic inflammation through lipid mediators, particularly cysteinyl leukotrienes (CysLTs) and prostaglandins (PGs). Arachidonic acid (AA)-derived metabolites and Sphinosine-1-phosphate (S1P) are significant metabolic markers that indicate immune dysfunction and epithelial barrier dysfunction in allergy. Notably, eosinophils are promoters of allergic symptoms and exhibit greater metabolic plasticity compared to ILC2s, directly involved in promoting allergic symptoms. Our findings suggest that metabolomic analysis provides insights into the complex interactions between immune cells, epithelial cells, and environmental factors. Potential therapeutic targets have been highlighted to further understand the metabolic regulation of eosinophils and ILC2s in allergy. Future research in metabolomics can facilitate the development of novel diagnostics and therapeutics for future application. Full article

Marine natural products are important sources of novel drugs. In this study, we isolated 4-hydroxyphenylacetic acid (HPA) from the marine-derived fungus Emericellopsis maritima Y39–2. The antithrombotic activity and mechanism of HPA were reported for the first time. Using a zebrafish model, we found that HPA had a strong antithrombotic activity because it can significantly increase cardiac erythrocytes, blood flow velocity, and heart rate, reduce caudal thrombus, and reverse the inflammatory response caused by Arachidonic Acid (AA). Further transcriptome analysis and qRT–PCR validation demonstrated that HPA may regulate autophagy by inhibiting the PI3K/AKT/mTOR signaling pathway to exert antithrombotic effects. Full article

Platelets assume a pivotal role in the pathogenesis of cardiovascular diseases (CVDs), emphasizing their significance in disease progression. Consequently, addressing CVDs necessitates a targeted approach focused on mitigating platelet activation. Eugenol, predominantly derived from clove oil, is recognized for its antibacterial, anticancer, and anti-inflammatory properties, rendering it a valuable medicinal agent. This investigation delves into the intricate mechanisms through which eugenol influences human platelets. At a low concentration of 2 μM, eugenol demonstrates inhibition of collagen and arachidonic acid (AA)-induced platelet aggregation. Notably, thrombin and U46619 remain unaffected by eugenol. Its modulatory effects extend to ATP release, P-selectin expression, and intracellular calcium levels ([Ca²⁺]i). Eugenol significantly inhibits various signaling cascades, including phospholipase Cγ2 (PLCγ2)/protein kinase C (PKC), phosphoinositide 3-kinase/Akt/glycogen synthase kinase-3β, mitogen-activated protein kinases, and cytosolic phospholipase A2 (cPLA2)/thromboxane A2 (TxA₂) formation induced by collagen. Eugenol selectively inhibited cPLA2/TxA₂ phosphorylation induced by AA, not affecting p38 MAPK. In ADP-treated mice, eugenol reduced occluded lung vessels by platelet thrombi without extending bleeding time. In conclusion, eugenol exerts a potent inhibitory effect on platelet activation, achieved through the inhibition of the PLCγ2–PKC and cPLA2-TxA₂ cascade, consequently suppressing platelet aggregation. These findings underscore the potential therapeutic applications of eugenol in CVDs. Full article

Ultraviolet B (UVB) radiation induces oxidative stress in skin cells, generating reactive oxygen species (ROS) and perturbing enzyme-mediated metabolism. This disruption is evidenced with elevated concentrations of metabolites that play important roles in the modulation of redox homeostasis and inflammatory responses. Thus, this research sought to determine the impacts of the lipid extract derived from the Nannochloropsis oceanica microalgae on phospholipid metabolic processes in keratinocytes subjected to UVB exposure. UVB-irradiated keratinocytes were treated with the microalgae extract. Subsequently, analyses were performed on cell lysates to ascertain the levels of phospholipid/free fatty acids (GC-FID), lipid peroxidation byproducts (GC-MS), and endocannabinoids/eicosanoids (LC-MS), as well as to measure the enzymatic activities linked with phospholipid metabolism, receptor expression, and total antioxidant status (spectrophotometric methods). The extract from N. oceanica microalgae, by diminishing the activities of enzymes involved in the synthesis of endocannabinoids and eicosanoids (PLA2/COX1/2/LOX), augmented the concentrations of anti-inflammatory and antioxidant polyunsaturated fatty acids (PUFAs), namely DHA and EPA. These concentrations are typically diminished due to UVB irradiation. As a consequence, there was a marked reduction in the levels of pro-inflammatory arachidonic acid (AA) and associated pro-inflammatory eicosanoids and endocannabinoids, as well as the expression of CB1/TRPV1 receptors. The microalgal extract also mitigated the increase in lipid peroxidation byproducts, specifically MDA in non-irradiated samples and 10-F4t-NeuroP in both control and post-UVB exposure. These findings indicate that the lipid extract derived from N. oceanica, by mitigating the deleterious impacts of UVB radiation on keratinocyte phospholipids, assumed a pivotal role in reinstating intracellular metabolic equilibrium. Full article