The Antioxidant Properties of Salvia verbenaca Extract Contribute to Its Intestinal Antiinflammatory Effects in Experimental Colitis in Rats.

Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammation with unpredictable symptom fluctuations. While there is no effective cure for IBD, various treatments aim to manage symptoms and improve the quality of life for affected individuals. In recent years, there has been growing interest in the potential benefits of certain natural plants and herbs in the management of IBD. In this regard, this study aimed to evaluate the immunomodulatory and anti-inflammatory effects of a well-characterized extract of Salvia verbenaca (S. verbenaca) in an experimental model of colitis in rats. Interestingly, the daily administration of S. verbenaca (10 and 25 mg/kg) effectively alleviated colitis symptoms, as evidenced by reduced weight/length ratio and colonic damage. Moreover, it reduced oxidative stress markers (MPO and GSH), decreased pro-inflammatory cytokine expression (Il-6, Il-12a, Il-1ß, Il-23, Icam-1, Mcp-1, Cinc-1), and preserved the integrity of the intestinal barrier (Villin, Muc-2, Muc-3). These effects suggest S. verbenaca extract could represent a potential complementary candidate to treat gastrointestinal disorders. Its beneficial actions can be related to its antioxidant properties as well as the downregulation of the immune response, which can result in the improvement in the intestine epithelial barrier.

Tigecycline reduces tumorigenesis in colorectal cancer via inhibition of cell proliferation and modulation of immune response.

BACKGROUND: and Purpose: Colorectal cancer (CRC) is one of the cancers with the highest incidence in which APC gene mutations occur in almost 80% of patients. This mutation leads to ß-catenin aberrant accumulation and an uncontrolled proliferation. Apoptosis evasion, changes in the immune response and microbiota composition are also events that arise in CRC. Tetracyclines are drugs with proven antibiotic and immunomodulatory properties that have shown cytotoxic activity against different tumor cell lines. EXPERIMENTAL APPROACH: The effect of tigecycline was evaluated in vitro in HCT116 cells and in vivo in a colitis-associated colorectal cancer (CAC) murine model. 5-fluorouracil was assayed as positive control in both studies. KEY RESULTS: Tigecycline showed an antiproliferative activity targeting the Wnt/ß-catenin pathway and downregulating STAT3. Moreover, tigecycline induced apoptosis through extrinsic, intrinsic and endoplasmic reticulum pathways converging on an increase of CASP7 levels. Furthermore, tigecycline modulated the immune response in CAC, reducing the cancer-associated inflammation through downregulation of cytokines expression. Additionally, tigecycline favored the cytotoxic activity of cytotoxic T lymphocytes (CTLs), one of the main immune defenses against tumor cells. Lastly, the antibiotic reestablished the gut dysbiosis in CAC mice increasing the abundance of bacterial genera and species, such as Akkermansia and Parabacteroides distasonis, that act as protectors against tumor development. These findings resulted in a reduction of the number of tumors and an amelioration of the tumorigenesis process in CAC. CONCLUSION AND IMPLICATIONS: Tigecycline exerts a beneficial effect against CRC supporting the use of this antibiotic for the treatment of this disease.

Genetically encoded Runx3 and CD4+ intestinal epithelial lymphocyte deficiencies link SKG mouse and human predisposition to spondyloarthropathy.

Disturbances in immune regulation, intestinal dysbiosis and inflammation characterize ankylosing spondylitis (AS), which is associated with RUNX3 loss-of-function variants. ZAP70W163C mutant (SKG) mice have reduced ZAP70 signaling, spondyloarthritis and ileitis. In small intestine, Foxp3+ regulatory T cells (Treg) and CD4+CD8αα+TCRαß+ intraepithelial lymphocytes (CD4-IEL) control inflammation. TGF-ß and retinoic acid (RA)-producing dendritic cells and MHC-class II+ intestinal epithelial cells (IEC) are required for Treg and CD4-IEL differentiation from CD4+ conventional or Treg precursors, with upregulation of Runx3 and suppression of ThPOK. We show in SKG mouse ileum, that ZAP70W163C or ZAP70 inhibition prevented CD4-IEL but not Treg differentiation, dysregulating Runx3 and ThPOK. TGF-ß/RA-mediated CD4-IEL development, T-cell IFN-γ production, MHC class-II+ IEC, tissue-resident memory T-cell and Runx3-regulated genes were reduced. In AS intestine, CD4-IEL were decreased, while in AS blood CD4+CD8+ T cells were reduced and Treg increased. Thus, genetically-encoded TCR signaling dysfunction links intestinal T-cell immunodeficiency in mouse and human spondyloarthropathy.

Pro-resolving and anti-arthritic properties of the MC1 selective agonist PL8177.

Background: Melanocortins are peptides endowed with anti-inflammatory and pro-resolving activities. Many of these effects are mediated by the Melanocortin receptor 1 (MC1) as reported in several experimental settings. As such, MC1 can be a viable target for the development of new therapies that mimic endogenous pro-resolving mediators. The aim of this study was to assess the immunopharmacology of a selective MC1 agonist (PL8177) in vitro and in a mouse model of inflammatory arthritis. Methods: PL8177 and the natural agonist αMSH were tested for activation of mouse and human Melanocortin receptors (MC1,3,4,5), monitoring cAMP accumulation and ERK1/2 phosphorylation, using transiently transfected HEK293A cells. The anti-inflammatory and pro-resolving effects of PL8177 and αMSH were evaluated using mouse peritoneal Macrophages. Finally, a model of K/BxN serum transfer induced arthritis was used to determine the in vivo potential of PL8177. Results: PL8177 activates mouse and human MC1 with apparent EC50 values of 0.01 and 1.49 nM, respectively, using the cAMP accumulation assay. Similar profiles were observed for the induction of ERK phosphorylation (EC50: 0.05 and 1.39 nM). PL8177 displays pro-resolving activity (enhanced Macrophage efferocytosis) and counteracts the inflammatory profile of zymosan-stimulated macrophages, reducing the release of IL-1ß, IL-6, TNF-α and CCL-2. In the context of joint inflammation, PL8177 (3mg/kg i.p.) reduces clinical score, paw swelling and incidence of severe disease as well as the recruitment of immune cells into the arthritic joint. Conclusion: These results demonstrate that the MC1 agonism with PL8177 affords therapeutic effects in inflammatory conditions including arthritis. Significance: Drugs targeting the Melanocortin system have emerged as promising therapeutics for several conditions including inflammation or obesity. Multiple candidates are under clinical development, and some have already reached approval. Here we present the characterization of a novel drug candidate, PL8177, selective for the Melanocortin 1 receptor (MC1), demonstrating its selectivity profile on cAMP and ERK1/2 phosphorylation signaling pathways, of relevance as selective drugs will translate into lesser off-target effect. PL8177 also demonstrated, not only anti-inflammatory activity, but pro-resolving actions due to its ability to enhance efferocytosis (i.e. the phagocytosis of apoptotic cells), endowing this molecule with therapeutic advantages compared to classical anti-inflammatory drugs. Using a mouse model of inflammatory arthritis, the compound demonstrated in vivo efficacy by reducing clinical score, paw swelling and overall disease severity. Taken together, these results present Melanocortin-based therapies, and specifically targeting MC1 receptor, as a promising strategy to manage chronic inflammatory diseases.

T cell Repertoire Profiling and the Mechanism by which HLA-B27 Causes Ankylosing Spondylitis.

PURPOSE OF REVIEW: Ankylosing spondylitis (AS) is strongly associated with the HLA-B27 gene. The canonical function of HLA-B27 is to present antigenic peptides to CD8 lymphocytes, leading to adaptive immune responses. The 'arthritogenic peptide' theory as to the mechanism by which HLA-B27 induces ankylosing spondylitis proposes that HLA-B27 presents peptides derived from exogenous sources such as bacteria to CD8 lymphocytes, which subsequently cross-react with antigens at the site of inflammation of the disease, causing inflammation. This review describes findings of studies in AS involving profiling of T cell expansions and discusses future research opportunities based on these findings. RECENT FINDINGS: Consistent with this theory, there is an expanding body of data showing that expansion of a restricted pool of CD8 lymphocytes is found in most AS patients yet only in a small proportion of healthy HLA-B27 carriers. These exciting findings strongly support the theory that AS is driven by presentation of antigenic peptides to the adaptive immune system by HLA-B27. They point to new potential approaches to identify the exogenous and endogenous antigens involved and to potential therapies for the disease.

The melatonergic agonist agomelatine ameliorates high fat diet-induced obesity in mice through the modulation of the gut microbiome.

BACKGROUND AND PURPOSE: Melatonin has shown beneficial effects on obesity, both in humans and experimental models, via regulating the altered circadian rhythm and thus ameliorating the gut dysbiosis associated with this metabolic condition. However, its clinical use is limited, mostly due to its short half-life. Agomelatine is an agonist of the melatonin receptors that could be used to manage obesity and offer a better profile than melatonin. EXPERIMENTAL APPROACH: Male C57BL/6 mice were fed a high fat diet and orally treated for five weeks with agomelatine, or melatonin or metformin, used as control drugs. Metabolic profile, inflammatory status, vascular dysfunction and intestinal microbiota composition were assessed. KEY RESULTS: Agomelatine lessened body weight gain, enhanced glucose and lipid metabolisms, and improved insulin resistance. It also reduced the obesity-associated inflammatory status and endothelial dysfunction, probably linked to its effect on gut dysbiosis, consisting of the restoration of bacterial populations with key functions, such as short chain fatty acid production. CONCLUSIONS AND IMPLICATIONS: Agomelatine can be considered as a novel therapeutic tool for the management of human obesity and its associated comorbidities.

Disrupted Peyer's Patch Microanatomy in COVID-19 Including Germinal Centre Atrophy Independent of Local Virus.

Confirmed SARS-coronavirus-2 infection with gastrointestinal symptoms and changes in microbiota associated with coronavirus disease 2019 (COVID-19) severity have been previously reported, but the disease impact on the architecture and cellularity of ileal Peyer's patches (PP) remains unknown. Here we analysed post-mortem tissues from throughout the gastrointestinal (GI) tract of patients who died with COVID-19. When virus was detected by PCR in the GI tract, immunohistochemistry identified virus in epithelium and lamina propria macrophages, but not in lymphoid tissues. Immunohistochemistry and imaging mass cytometry (IMC) analysis of ileal PP revealed depletion of germinal centres (GC), disruption of B cell/T cell zonation and decreased potential B and T cell interaction and lower nuclear density in COVID-19 patients. This occurred independent of the local viral levels. The changes in PP demonstrate that the ability to mount an intestinal immune response is compromised in severe COVID-19, which could contribute to observed dysbiosis.

Repurposing tetracyclines for acute respiratory distress syndrome (ARDS) and severe COVID-19: a critical discussion of recent publications.

INTRODUCTION: Drug repurposing can be a successful approach to deal with the scarcity of cost-effective therapies in situations such as the COVID-19 pandemic. Tetracyclines have previously shown efficacy in preclinical acute respiratory distress syndrome (ARDS) models and initial predictions and experimental reports suggest a direct antiviral activity against SARS-CoV2. Furthermore, a few clinical reports indicate their potential in COVID-19 patients. In addition to the scarcity and limitations of the scientific evidence, the effectiveness of tetracyclines in experimental ARDS has been proven extensively, counteracting the overt inflammatory reaction and fibrosis sequelae due to a synergic combination of pharmacological activities. AREAS COVERED: This paper discusses the scientific evidence behind the application of tetracyclines for ARDS/COVID-19. EXPERT OPINION: The benefits of their multi-target pharmacology and their safety profile overcome the limitations, such as antibiotic activity and low commercial interest. Immunomodulatory tetracyclines and novel chemically modified non-antibiotic tetracyclines have therapeutic potential. Further drug repurposing studies in ARDS and severe COVID-19 are necessary.

Design, synthesis, and biological evaluation of novel pyrrolidinone small-molecule Formyl peptide receptor 2 agonists.

A series of Formyl peptide receptor 2 small molecule agonists with a pyrrolidinone scaffold, derived from a combination of pharmacophore modelling and docking studies, were designed and synthesized. The GLASS (GPCR-Ligand Association) database was screened using a pharmacophore model. The most promising novel ligand structures were chosen and then tested in cellular assays (calcium mobilization and ß-arrestin assays). Amongst the selected ligands, two pyrrolidinone compounds (7 and 8) turned out to be the most active. Moreover compound 7 was able to reduce the number of adherent neutrophils in a human neutrophil static adhesion assay which indicates its anti-inflammatory and proresolving properties. Further exploration and optimization of new ligands showed that heterocyclic rings, e.g. pyrazole directly connected to the pyrrolidinone scaffold, provide good stability and a boost in the agonistic activity. The compounds of most interest (7 and 30) were tested in an ERK phosphorylation assay, demonstrating selectivity towards FPR2 over FPR1. Compound 7 was examined in an in vivo mouse pharmacokinetic study. Compound 7 may be a valuable in vivo tool and help improve understanding of the role of the FPR2 receptor in the resolution of inflammation process.

Autophagy modulates endothelial junctions to restrain neutrophil diapedesis during inflammation.

The migration of neutrophils from the blood circulation to sites of infection or injury is a key immune response and requires the breaching of endothelial cells (ECs) that line the inner aspect of blood vessels. Unregulated neutrophil transendothelial cell migration (TEM) is pathogenic, but the molecular basis of its physiological termination remains unknown. Here, we demonstrated that ECs of venules in inflamed tissues exhibited a robust autophagic response that was aligned temporally with the peak of neutrophil trafficking and was strictly localized to EC contacts. Genetic ablation of EC autophagy led to excessive neutrophil TEM and uncontrolled leukocyte migration in murine inflammatory models, while pharmacological induction of autophagy suppressed neutrophil infiltration into tissues. Mechanistically, autophagy regulated the remodeling of EC junctions and expression of key EC adhesion molecules, facilitating their intracellular trafficking and degradation. Collectively, we have identified autophagy as a modulator of EC leukocyte trafficking machinery aimed at terminating physiological inflammation.

Allium-Derived Compound Propyl Propane Thiosulfonate (PTSO) Attenuates Metabolic Alterations in Mice Fed a High-Fat Diet through Its Anti-Inflammatory and Prebiotic Properties.

BACKGROUND: Propyl propane thiosulfonate (PTSO) is an organosulfur compound from Allium spp. that has shown interesting antimicrobial properties and immunomodulatory effects in different experimental models. In this sense, our aim was to evaluate its effect on an experimental model of obesity, focusing on inflammatory and metabolic markers and the gut microbiota. METHODS AND RESULTS: Mice were fed a high-fat diet and orally treated with different doses of PTSO (0.1, 0.5 and 1 mg/kg/day) for 5 weeks. PTSO lessened the weight gain and improved the plasma markers associated with glucose and lipid metabolisms. PTSO also attenuated obesity-associated systemic inflammation, reducing the immune cell infiltration and, thus, the expression of pro-inflammatory cytokines in adipose and hepatic tissues (Il-1ẞ, Il-6, Tnf-α, Mcp-1, Jnk-1, Jnk-2, Leptin, Leptin R, Adiponectin, Ampk, Ppar-α, Ppar-γ, Glut-4 and Tlr-4) and improving the expression of different key elements for gut barrier integrity (Muc-2, Muc-3, Occludin, Zo-1 and Tff-3). Additionally, these effects were connected to a regulation of the gut microbiome, which was altered by the high-fat diet. CONCLUSION: Allium-derived PTSO can be considered a potential new tool for the treatment of metabolic syndrome.

Probiotic and Functional Properties of Limosilactobacillus reuteri INIA P572.

Limosilactobacillus reuteri INIA P572 is a strain able to produce the antimicrobial compound reuterin in dairy products, exhibiting a protective effect against some food-borne pathogens. In this study, we investigated some probiotic properties of this strain such as resistance to gastrointestinal passage or to colonic conditions, reuterin production in a colonic environment, and immunomodulatory activity, using different in vitro and in vivo models. The results showed a high resistance of this strain to gastrointestinal conditions, as well as capacity to grow and produce reuterin in a human colonic model. Although the in vitro assays using the RAW 264.7 macrophage cell line did not demonstrate direct immunomodulatory properties, the in vivo assays using a Dextran Sulphate Sodium (DSS)-induced colitic mice model showed clear immunomodulatory and protective effects of this strain.

Intestinal anti-inflammatory effects of probiotics in DNBS-colitis via modulation of gut microbiota and microRNAs.

PURPOSE: Probiotics have been shown to exert beneficial effects in IBD although their exact mechanisms are not completely understood. The aim of the present study was to assess the intestinal anti-inflammatory activity of different probiotics (Lactobacillus fermentum CECT5716, Lactobacillus salivarius CECT5713, Escherichia coli Nissle 1917, Saccharomyces boulardii CNCMI-745 in the dinitrobenzene sulfonic acid (DNBS) model of mouse colitis and correlate it with the modifications of the gut microbiota and the immune response, focusing on miRNA expression. METHODS: The probiotics were daily administered orally for 25 days. On day 19 colitis was induced by rectal installation of DNBS. At the end of the treatment, mice were sacrificed and the colonic damage was assessed biochemically by analysing the expression of different markers involved in the immune response, including miRNAs; and the colonic microbiota by pyrosequencing. Probiotics properties were also evaluated in vitro in different immune cell types (CMT-93 intestinal epithelial cells and bone marrow-derived macrophages), where the expression of different mRNAs and miRNAs was examined. RESULTS: All the probiotics displayed intestinal anti-inflammatory effects but slightly different, especially regarding miRNAs expression. Likewise, the probiotics ameliorated the colitis-associated dysbiosis, although showing differences in the main bacterial groups affected. CONCLUSION: Among the probiotics assayed, Lactobacillus fermentum CECT5716 and Escherichia coli Nissle 1917 appear to present the best intestinal anti-inflammatory effects, being the latter one of the few probiotics with reputed efficacy in human IBD. Therefore, Lactobacillus fermentum CECT5716 could be considered as a complementary nutritional strategy for IBD treatment.

The Beneficial Effects of Red Sun-Dried Capsicum annuum L. Cv Senise Extract with Antioxidant Properties in Experimental Obesity are Associated with Modulation of the Intestinal Microbiota.

SCOPE: Capsicum annuum L. cv Senise is a sweet pepper containing health promoting compounds that can be modified by ripening and drying. This study focuses on finding the peppers with the best antioxidant properties, which are evaluated on an experimental model of obesity. METHODS AND RESULTS: Phytochemical profile and antioxidant activity are evaluated on several peppers obtained from the same cultivar at different ripening stages. Red sweet peppers show the highest content in polyphenols, ß-carotene, lycopene, and capsinoids, and demonstrate the best antioxidant activity in vitro. Mice fed a high fat diet are orally treated with an extract from these peppers (Capsicum annuum extract [CAE]) (1, 10, and 25 mg/kg/day). It promotes weight loss and improves plasma markers related to glucose and lipid metabolisms. CAE also ameliorates obesity-associated systemic inflammation reducing the expression of pro-inflammatory cytokines in adipose and hepatic tissues and improving the expression of different markers involved in the gut epithelial barrier function. These effects are associated with a modulation of the intestinal microbiome, which appears altered. CONCLUSIONS: The extract can be considered a new potential approach for the treatment of obesity, complementary to dietary restrictions.

Anti-Inflammatory and Proresolving Effects of the Omega-6 Polyunsaturated Fatty Acid Adrenic Acid.

Polyunsaturated fatty acids (PUFAs) and their metabolites are potent regulators of inflammation. Generally, omega (n)-3 PUFAs are considered proresolving whereas n-6 PUFAs are classified as proinflammatory. In this study, we characterized the inflammatory response in murine peritonitis and unexpectedly found the accumulation of adrenic acid (AdA), a poorly studied n-6 PUFA. Functional studies revealed that AdA potently inhibited the formation of the chemoattractant leukotriene B4 (LTB4), specifically in human neutrophils, and this correlated with a reduction of its precursor arachidonic acid (AA) in free form. AdA exposure in human monocyte-derived macrophages enhanced efferocytosis of apoptotic human neutrophils. In vivo, AdA treatment significantly alleviated arthritis in an LTB4-dependent murine arthritis model. Our findings are, to our knowledge, the first to indicate that the n-6 fatty acid AdA effectively blocks production of LTB4 by neutrophils and could play a role in resolution of inflammation in vivo.

Intestinal anti-inflammatory activity of the total alkaloid fraction from Fumaria capreolata in the DSS model of colitis in mice.

Fumaria genus has been traditionally used for managing inflammatory and gastrointestinal disorders. The study evaluates the immunomodulatory potential of the total alkaloid fraction from Fumaria capreolata L. (AFC) in primary macrophages and the intestinal anti-inflammatory effect in a dextran sodium sulphate-induced colitis in mice. AFC inhibited LPS-stimulated bone marrow-derived macrophages gene expression program dose-dependently. In vivo, AFC markedly reduced macroscopic and microscopic signs of intestinal inflammation. Besides, it restored the colonic expression of pro-inflammatory and anti-inflammatory mediators, as well as enhanced the expression of intestinal barrier markers. These results demonstrate the potential of AFC extract as a therapeutic tool for the management of inflammatory bowel disease.

The Beneficial Effects of Lippia Citriodora Extract on Diet-Induced Obesity in Mice Are Associated with Modulation in the Gut Microbiota Composition.

SCOPE: Obesity is characterized by a dysfunction in the adipose tissue and an inflammatory subclinical state leading to insulin resistance and increased risk of cardiovascular diseases. It is also associated with intestinal dysbiosis that contributes to inflammation development. Lippia citriodora (LCE) contains high levels of polyphenolpropanoids and has shown promising results in obesity. The aim of this study is to investigate a well-characterized extract of LCE in a model of metabolic syndrome in mice, focusing on its effects on metabolic tissues, endothelial dysfunction, and microbiome. METHODS: Mice are fed a high fat diet (HFD) for six weeks and treated daily with LCE (1, 10, and 25 mg kg-1 ). Glucose and lipid metabolism is investigated. The inflammatory state in the metabolic tissues and the intestinal microbiota composition are characterized, as well as the endothelium-dependent vasodilator response to acetylcholine. RESULTS: LCE reduces fat accumulation and improves plasma glycemic and lipid profiles, as well as the inflammatory process and vascular dysfunction. Moreover, LCE lessens intestinal dysbiosis, as it reduces the Firmicutes/Bacteroidetes ratio and increases Akkermansia abundance in comparison with untreated HFD mice. CONCLUSION: The antiobesity therapeutic properties of LCE are most probably mediated by the synergic effects of its bioactive compounds.

The prebiotic properties of Hibiscus sabdariffa extract contribute to the beneficial effects in diet-induced obesity in mice.

The metabolic syndrome has been associated with an alteration of intestinal microbiota, which can be considered as a target for the management of these patients. Phenolic extracts from Hibiscus sabdariffa have shown beneficial effects on obesity and its related complications. However, their effects on gut microbiota have not been investigated yet. This study evaluates the effects of a chemically characterized polyphenolic extract of H. sabdariffa (HSE) in an experimental model of diet-induced obesity (DIO) in mice. HSE was administered daily by oral gave for 42 days. HSE reduced weight increase in high fat diet (HFD)-fed mice, and improved glucose tolerance, insulin sensitivity and normalized LDL/HDL cholesterol ratio. It also enhanced the inflammatory state in the liver, reducing the expression of different adipokines and proinflammatory mediators, and reinforced gut integrity by increasing the expression of mucins and proteins involved in the maintenance of mucosal barrier. Moreover, HSE had a prebiotic effect, ameliorating the changes in the gut microbiota induced by the HFD. Thus, HSE improved the Firmicutes/Bacteroidetes ratio, which may contribute to the beneficial effects. Consequently, HSE could be considered for the development of a complementary treatment for the metabolic syndrome due to its beneficial properties.

The metabolic and vascular protective effects of olive (Olea europaea L.) leaf extract in diet-induced obesity in mice are related to the amelioration of gut microbiota dysbiosis and to its immunomodulatory properties.

INTRODUCTION: Many studies have showed the beneficial effects of the olive (Olea europaea) leaf extract (OLE) in experimental models of metabolic syndrome, which have been ascribed to the presence of phenolic compounds, like oleuropeoside. This study evaluated the effects of a chemically characterized OLE in high fat diet (HFD)-induced obesity in mice, describing the underlying mechanisms involved in the beneficial effects, with special attention to vascular dysfunction and gut microbiota composition. METHODS: C57BL/6J mice were distributed in different groups: control, control-treated, obese and obese-treated with OLE (1, 10 and 25 mg/kg/day). Control mice received a standard diet, whereas obese mice were fed HFD. The treatment was followed for 5 weeks, and animal body weight periodically assessed. At the end of the treatment, metabolic plasma analysis (including lipid profile) as well as glucose and insulin levels were performed. The HFD-induced inflammatory status was studied in liver and fat, by determining the RNA expression of different inflammatory mediators by qPCR; also, different markers of intestinal epithelial barrier function were determined in colonic tissue by qPCR. Additionally, flow cytometry of immune cells from adipose tissue, endothelial dysfunction in aortic rings as well as gut microbiota composition were evaluated. Faecal microbiota transplantation (FMT) to antibiotic-treated mice fed with HFD was performed. RESULTS: OLE administration reduced body weight gain, basal glycaemia and insulin resistance, and showed improvement in plasma lipid profile when compared with HFD-fed mice. The extract significantly ameliorated the HFD-induced altered expression of key adipogenic genes, like PPARs, adiponectin and leptin receptor, in adipose tissue. Furthermore, the extract reduced the RNA expression of Tnf-α, Il-1ß, Il-6 in liver and adipose tissue, thus improving the tissue inflammatory status associated to obesity. The flow cytometry analysis in adipose tissue corroborated these observations. Additionally, the characterization of the colonic microbiota by sequencing showed that OLE administration was able to counteract the dysbiosis associated to obesity. The extract reversed the endothelial dysfunction observed in the aortic rings of obese mice. FMT from donors HFD-OLE to recipient mice fed an HFD prevented the development of obesity, glucose intolerance, insulin resistance and endothelial dysfunction. CONCLUSION: OLE exerts beneficial effects in HFD-induced obesity in mice, which was associated to an improvement in plasma and tissue metabolic profile, inflammatory status, gut microbiota composition and vascular dysfunction.