Antiangiogenic Potential of an Olive Oil Extract: Insights from a Proteomic Study.

Extra virgin olive oil (EVOO), a staple of the Mediterranean diet, is rich in phenolic compounds recognized for their potent bioactive effects, including anticancer and anti-inflammatory properties. However, its effects on vascular health remain relatively unexplored. In this study, we examined the impact of a "picual" EVOO extract from Jaén, Spain, on endothelial cells. Proteomic analysis revealed the modulation of angiogenesis-related processes. In subsequent in vitro experiments, the EVOO extract inhibited endothelial cell migration, adhesion, invasion, ECM degradation, and tube formation while inducing apoptosis. These results provide robust evidence of the extract's antiangiogenic potential. Our findings highlight the potential of EVOO extracts in mitigating angiogenesis-related pathologies, such as cancer, macular degeneration, and diabetic retinopathy.

Dietary oleacein, a secoiridoid from extra virgin olive oil, prevents collagen-induced arthritis in mice.

Olacein (OLA), one of the main secoiridoids derived from extra virgin olive oil (EVOO), has been shown to modulate oxidative and inflammatory responses in various pathological conditions; however, its potential benefit in joint disorders such as rheumatoid arthritis (RA) is unknown. Therefore, this study was designed to evaluate the preventive role of the effects of an OLA-supplemented diet in the murine model of collagen-induced arthritis (CIA), delving into the possible mechanisms and signaling pathways involved. Animals were fed an OLA-enriched preventive diet for 6 weeks prior to CIA induction and until the end of the experimental time course. On day 43 after the first immunization, mice were sacrificed: blood was collected, and paws were histologically and biochemically processed. Dietary OLA prevented collagen-induced rheumatic bone, joint and cartilage conditions. Circulating matrix metalloproteinase (MMP)-3 and proinflammatory cytokine (IL-6, IL-1ß, TNF-α, IL-17) levels were significantly decreased in the joint, as well as MMP-9 and cathepsin-K (CatK) expression in secoiridoid-fed animals. In addition, dietary OLA was able to decrease COX-2, mPGES-1 and iNOS protein expressions and, also, PGE2 levels. The mechanisms possibly involved in these protective effects could be related to the activation of the Nrf-2/HO-1 axis and the inhibition of proinflammatory signaling pathways, including JAK-STAT, MAPKs and NF-κB, involved in the production of inflammatory and oxidative mediators. These results support the interest of OLA, as a nutraceutical intervention, in the management of RA.

Anti-angiogenic effects of oleacein and oleocanthal: New bioactivities of compounds from Extra Virgin Olive Oil.

Phenolic compounds play a key role in the health benefits of Extra Virgin Olive Oil (EVOO). Among these molecules, the focus has been recently put on (-)-oleocanthal and (-)-oleacein, for which anti-cancer and angiogenesis-related findings have been reported. Here, we explored the modulatory action of (-)-oleocanthal and (-)-oleacein on angiogenesis, the process by which new vessels are created from pre-existent ones, which is directly linked to tumor progression and other pathological conditions. Two in vivo models strongly sustained by angiogenesis, and an in vitro model of endothelial cells to study different steps of angiogenesis, were used. In vivo evidence pointed to the anti-angiogenic effects of both compounds in vivo. In vitro, (-)-oleacein and (-)-oleocanthal inhibited the proliferation, invasion, and tube formation of endothelial cells, and (-)-oleacein significantly repressed migration and induced apoptosis in these cells. Mechanistically, the compounds modulated signaling pathways related to survival and proliferation, all at concentrations of physiological relevance for humans. We propose (-)-oleacein and (-)-oleocanthal as good candidates for angioprevention and for further studies as modulators of angiogenesis in clinical interventions, and as interesting functional claims for the food industry. Chemical compounds studied in this article: Oleocanthal (PubChem CID: 11652416); Oleacein (PubChem CID: 18684078).

Proanthocyanidins in Pruning Wood Extracts of Four European Plum (Prunus domestica L.) Cultivars and Their hLDHA Inhibitory Activity.

European plum tree (Prunus domestica L.) is cultivated in many countries for its delicious and nutritive fruit and, accordingly, certain amounts of wood (from pruning works) are generated every year. The main objective of this work was to value this agricultural woody residue, for which the chemical composition of pruning wood extracts from four European plum cultivars was investigated, and the human lactate dehydrogenase A (hLDHA) inhibitory activity of plum wood extracts and pure proanthocyanidins present in those extracts was measured. For the chemical characterization, total phenolic content and DPPH radical-scavenging assays and HPLC-DAD/ESI-MS analyses were performed, the procyanidin (-)-ent-epicatechin-(2α→O→7,4α→8)-catechin (4), the phenolic glucoside (-)-annphenone (3) and the flavan-3-ol catechin (1) being the major components of the wood extracts. Some quantitative and qualitative differences were found among plum cultivars, and the content of proanthocyanidins ranged from 1.51 (cv. 'Claudia de Tolosa') to 8.51 (cv. 'De la Rosa') mg g-1 of dry wood. For the hLDHA inhibitory activity, six wood extracts and six proanthocyanidins were evaluated by a UV spectrophotometric assay, compound 4 showing the highest inhibitory activity (IC50 3.2 µM) of this enzyme involved on the excessive production of oxalate in the liver of patients affected by the rare disease Primary Hyperoxaluria.

Oleocanthal supplemented diet improves renal damage and endothelial dysfunction in pristane-induced systemic lupus erythematosus in mice.

Systemic lupus erythematosus (SLE) is a multiorgan disorder with a deregulated immune-inflammatory response. Nutritional therapy has been considered a promising approach to SLE management. Oleocanthal (OLE), the main extra virgin olive oil (EVOO)-derived secoiridoid, has shown to regulate the immune-inflammatory response in various disease contexts; however, its possible beneficial effects on SLE remain unclear. This study sought to evaluate the effects of OLE enriched diet on renal damage and aortic endothelial dysfunction in murine pristane-induced SLE, focusing on the action mechanisms and signaling pathways involved. BALB/c mice were injected with pristane and fed with OLE supplemented diet (0.01 % (w/w)) for six months. Levels of cytokines were measured by ELISA in lipopolysaccharide (LPS)-stimulated peritoneal macrophages and splenocytes. Presence of immunoglobulin G (IgG) and IgM immune complexes were examined by immunofluorescence and immunohistochemistry. Thoracic aortas were used to evaluate endothelial dysfunction. Western blotting was employed to detect signaling pathways and oxidative-inflammatory-related mediators. Dietary OLE supplementation reduced Th1/Th17 pro-inflammatory cytokines production and alleviated renal damage by decreasing immunoglobulin complexes deposition, and inflammation-mediating enzymes expression. The mechanisms underlying these protective effects could be related to the regulation of nuclear factor erythroid 2-related factor 2/Haem oxygenase 1 (Nrf-2/HO-1), mitogen-activated protein kinases (MAPKs), signal transducer and transcription activator of transcription (STAT-3), inflammasome and, nuclear factor kappa B (NF-κB) signaling pathways. Also, dietary OLE improved aortic endothelial dysfunction and vascular reactivity, normalizing endothelial nitric oxide synthase (eNOS) uncoupling, and NADPH oxidase-1 (NOX-1) overexpression. This study shows the immunomodulatory effects of OLE in an in vivo model of SLE by improving renal damage and regulating aortic endothelial dysfunction. These preliminary results provide OLE as a new therapeutic strategy in SLE management.

Effects of Oleacein, a New Epinutraceutical Bioproduct from Extra Virgin Olive Oil, in LPS-Activated Murine Immune Cells.

The present study was designed to evaluate the immunomodulatory effects of the secoiridoid from extra virgin olive oil, oleacein (OLA), deepening into the possible signaling pathways involved in LPS-activated murine peritoneal macrophages. Moreover, we have explored OLA-induced epigenetic changes in histone markers and related cytokine production in murine LPS-stimulated murine splenocytes. Murine cells were treated with OLA in the presence or absence of LPS (5 µg/mL) for 18 or 24 h. OLA modulated the oxidative stress and the inflammatory response produced by LPS stimulation in murine peritoneal macrophages, by the inhibition of pro-inflammatory cytokines (TNF-α, IL-6, IL-1ß, IFN-γ, IL-17 and IL-18) and ROS production and the expression of pro-inflammatory enzymes such as iNOS, COX-2 and m-PGES1. These protective effects could be due to the activation of the Nrf-2/HO-1 axis and the inhibition of JAK/STAT, ERK and P38 MAPKs and inflammasome canonical and non-canonical signaling pathways. Moreover, OLA modulated epigenetic modifications throughout histone methylation deacetylation (H3K18ac) and (H3K9me3 and H3K27me) in LPS-activated spleen cells. In conclusion, our data present OLA as an interesting anti-inflammatory and antioxidant natural compound that is able to regulate histone epigenetic markers. Nevertheless, additional in vivo studies are required to further investigate the beneficial effects of this EVOO secoiridoid, which might be a promising epinutraceutical bioproduct for the management of immune-related inflammatory diseases.

(-)-Oleocanthal induces death preferentially in tumor hematopoietic cells through caspase dependent and independent mechanisms.

Olive oil is a key component of the highly cardiovascular protective Mediterranean diet. (-)-Oleocanthal (OLC) is one of the most interesting phenolics present in virgin olive oil, and is formed from secoiridoid ligustroside during the processing of olives to yield the oil. Anti-inflammatory and anti-oxidant properties were identified shortly after OLC isolation, followed by the discovery of anti-tumor activities in a few non-hematopoietic cell lineages. Because of the scarcity of tissues potentially targeted by OLC analyzed so far and the unresolved mechanism(s) for OLC anti-tumor properties, we used a panel of 17 cell lines belonging to 11 tissue lineages to carry out a detailed examination of targets and pathways leading to cell growth inhibition and death. We found that OLC inhibits cell proliferation and induces apoptotic death as revealed by sub-G1 cell cycle analyses and Annexin-V staining in all lineages analyzed except lung carcinoma cell lines. Hematopoietic tumor cell lines, untested until now, were the most sensitive to OLC treatment, whereas non-transformed cells were significantly resistant to cell death. The specificity of OLC-mediated caspase activation was confirmed by blocking experiments and the use of transfectants overexpressing anti apoptotic genes. OLC triggers typical mediators of the intrinsic apoptotic pathway such as production of reactive oxygen species and mitochondrial membrane depolarization (Δψm). Complete blockade of caspases, however, did not result in parallel abrogation of Annexin-V staining, thus suggesting that complex mechanisms are involved in triggering OLC-mediated cell death. Our results demonstrate that OLC preferentially targets hematopoietic tumor cell lines and support that cell death is mediated by caspase-dependent and independent mechanisms.

Ligstroside aglycon, an extra virgin olive oil secoiridoid, prevents inflammation by regulation of MAPKs, JAK/STAT, NF-κB, Nrf2/HO-1, and NLRP3 inflammasome signaling pathways in LPS-stimulated murine peritoneal macrophages.

Ligstroside aglycon (LA) is one of the main polyphenols in extra virgin olive oil (EVOO); nevertheless, it is scarcely investigated. The aim of this study was to evaluate the immunomodulatory and anti-inflammatory effects of LA on lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages, as well as the potential signaling pathways involved. Isolated macrophages were treated with LA (50, 25, and 12.5 µM) in the presence or absence of LPS (5 µg ml-1) for 18 h. Cell viability was determined using the sulforhodamine B (SRB) assay. Nitric oxide (NO) and pro-inflammatory cytokine production was analyzed by the Griess method and enzyme-linked immunosorbent assay (ELISA), respectively. Protein expression of pro-inflammatory markers and signaling pathways were evaluated by western blot analysis. LA showed significant antioxidant and anti-inflammatory effects through decreasing oxidative stress markers such as NO production, inducible nitric oxide synthase (iNOS) and NADPH oxidase-1 (NOX-1) protein expression. Besides, LA was able to reduce pro-inflammatory cytokine levels and modulate cyclo-oxygenase-2 (COX-2), and microsomal prostaglandin E synthase-1 (mPGEs-1) protein overexpression. The mechanisms underlying these protective effects could be related via activation of nuclear factor (erythroid-derived 2)-like (Nrf2)/heme oxygenase 1 (HO-1) and inhibition of nuclear factor kappa-B (NF-κB), mitogen-activated protein kinases (MAPKs), and Janus kinase/signal transducer and activation of transcription (JAK2/STAT3) signaling pathways. In addition, LA inhibited non-canonical and canonical activation of a nucleotide-binding (NOD)-like receptor (NLRP3) inflammasome. We conclude that LA showed significant antioxidant and anti-inflammatory activities in LPS-stimulated murine peritoneal macrophages. However, further in vivo studies are warranted to further investigate the bioactivity of this interesting compound that might be a promising natural agent for the treatment of immune-inflammatory diseases.

Biological effects of olive oil phenolic compounds on mitochondria.

Phenolic compounds derived from olive oil have beneficial health properties against cancer, neurodegenerative, and metabolic diseases. Therefore, there are discrepancies in their impact on mitochondrial function that result in changes in oxidative capacity, mitochondrial respiration, and energetic demands. This review focuses on the versatile role of oleuropein, a potent antioxidant that regulates the AMPK/SIRT1/mTOR pathway to modulate autophagy/mitophagy and maintain metabolic homeostasis.

Recovery and Seasonal Variation of Cinnamtannin B-1 from Laurel (Laurus nobilis L.) Pruning Wood Wastes.

Cinnamtannin B-1 (C-B1) is a commercially-available trimeric A-type procyanidin with remarkable cellular actions mainly derived from its high radical scavenging activity. C-B1 is the main phenolic compound of laurel wood, which has previously been isolated by a combination of conventional chromatographic techniques. The first aim of this work was to find laurel trees containing as much C-B1 as possible, and learn about the influence of variables, such as gender and harvest time, on the production of C-B1 by the tree. It was found that all studied trees tend to give higher C-B1 percentages in the May-July period, from 6 % to 18 %, and lower ones around March (spring) and November (fall), from 1 % to 8 %. In a general way, it also seems that the female trees tend to produce a bit more C-B1 (from 2.8 % to 17.3 %) than male ones (from 1.7 % to 13.4 %). In addition, eight minor phenolic compounds [(-)-ent-catechin (1), (-)-ent-epicatechin-(4α→8)-ent-epicatechin (2), (epi)catechin-(4→8)-(epi)afzelechin-(4→8)-(epi)catechin (3), (+)-epiafzelechin-(4ß→8)-epicatechin (4), (-)-epicatechin (5), (-)-afzelechin-(4α→8)-epicatechin (6), (epi)afzelechin-(4→8)-(epi)afzelechin-(4→8)-(epi)catechin (7) and (+)-epicatechin-(4ß→8,2ß→O-7)-epicatechin-(4ß→8)-catechin (C-D1)] were found and quantified in the ethyl acetate extract of the wood samples. The second aim of this work was to improve the recovery of C-B1 from laurel wood. The use of the fast centrifugal partition chromatography (FCPC) technique has allowed for a recovery of 96 % of a technical-grade C-B1 (64 % in a previous protocol using conventional column chromatography on silica gel and size-exclusion chromatography).

(-)-Methyl-Oleocanthal, a New Oleocanthal Metabolite Reduces LPS-Induced Inflammatory and Oxidative Response: Molecular Signaling Pathways and Histones Epigenetic Modulation.

The antioxidant and anti-inflammatory responses of (-)-methyl-oleocanthal (met-OLE), a new metabolite of the extra virgin olive oil (EVOO) phenolic oleocanthal (OLE), were explored in lipopolysaccharide (LPS)-induced murine peritoneal macrophages. Possible signaling pathways and epigenetic modulation of histones were studied. Met-OLE inhibited LPS-induced intracellular reactive oxygen species (ROS) and nitrite (NO) production and decreased the overexpression of the pro-inflammatory enzymes COX-2, mPGES-1 and iNOS in murine macrophages. In addition, met-OLE was able to significantly decrease the activation of p38, JNK, and ERK mitogen-activated protein kinases (MAPKs) and blocked canonical and non-canonical inflammasome signaling pathways. On the contrary, met-OLE upregulated haem oxigenase 1 (HO-1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) expression in treated cells. Finally, met-OLE pretreated spleen cells counteracted LPS induction, preventing H3K18 acetylation or H3K9 and H3K27 demethylation. Overall, these results provide novel mechanistic insights into the beneficial effects of met-OLE regarding the regulation of the immune-inflammatory response through epigenetic changes in histone markers. This revealing evidence suggests that the methylated metabolite of OLE may contribute significantly to the beneficial effects that are associated with the secoiridoid-related compound and the usual consumption of EVOO.