Oleuropein-Enriched Olive Leaf Extract Affects Calcium Dynamics and Impairs Viability of Malignant Mesothelioma Cells

Leptospermum extract (QV0) suppresses pleural mesothelioma tumor growth in vitro and in vivo by mitochondrial dysfunction associated apoptosis

Pleural mesothelioma (PM) is a highly aggressive, fast-growing asbestos-induced cancer with limited effective treatments. There has been interest in using naturally occurring anticancer agents derived from plant materials for the treatment of PM. However, it is unclear if an aqueous extract from Leptospermum polygalifolium (QV0) has activity against PM. Here we investigated the anti-cancer properties of QV0 and Defender^® (QV0 dietary formula) in vitro and in vivo, respectively. QV0 suppressed the growth of eight PM cell lines in a dose-dependent manner, effective at concentrations as low as 0.02% w/v (equivalent to 0.2 mg/ml). This response was found to be associated with inhibited cell migration, proliferation, and colony formation but without evident cell cycle alteration. We observed mitochondrial dysfunction post-QV0 treatment, as evidenced by significantly decreased basal and maximal oxygen consumption rates. Ten SCID mice were treated with 0.25 mg/g Defender^® daily and exhibited reduced tumor size over 30 days, which was associated with an average extension of seven days of mouse life. There was no evidence of liver toxicity or increased blood glucose post-treatment in animals treated with Defender^®. Significantly enhanced tumor apoptosis was observed in the Defender^®-treated animals, correlating to mitochondrial dysfunction. Lastly, the high levels of polyphenols and antioxidant properties of QV0 and Defender^® were detected in HPLC analysis. To the best of our knowledge, this study constitutes the first demonstration of an improved host survival (without adverse effects) response in a QV0-treated PM mouse model, associated with evident inhibition of PM cell growth and mitochondrial dysfunction-related enhancement of tumor apoptosis.

Prophylactic role of olive fruit extract against cigarette smoke-induced oxidative stress in Sprague-Dawley rats

Cigarette smoke exposure increases the production of free radicals leading to initiation of several pathological conditions by triggering the oxidative stress and inflammatory cascade. Olive fruit owing to its unique phytochemical composition possesses antioxidant, immune modulatory, and anti-inflammatory potential. Considering the compositional alterations in olive fruits during ripening, the current experimental trail was designed to investigate the prophylactic role of green and black olives against the oxidative stress induced by cigarette smoke exposure in rats. Purposely, rats were divided into five different groups: NC (negative control; normal diet), PC [positive control; normal diet + smoke exposure (SE)], drug (normal diet + SE + citalopram), GO (normal diet + SE + green olive extract), and BO (normal diet + SE + black olive extract). Rats of all groups were exposed to cigarette smoke except "NC" and were sacrificed for collection of blood and organs after 28 days of experimental trial. The percent reduction in total oxidative stress by citalopram and green and black olive extracts in serum was 29.72, 58.69, and 57.97%, respectively, while the total antioxidant capacity increased by 30.78, 53.94, and 43.98%, accordingly in comparison to PC. Moreover, malondialdehyde (MDA) was reduced by 29.63, 42.59, and 45.70% in drug, GO, and BO groups, respectively. Likewise, green and black olive extracts reduced the leakage of hepatic enzymes in sera, alkaline phosphatase (ALP) by 23.44 and 25.80% and 35.62 and 37.61%, alanine transaminase (ALT) by 42.68 and 24.39% and 51.04 and 35.41%, and aspartate transaminase (AST) by 31.51 and 16.07% and 40.50 and 27.09% from PC and drug group, respectively. Additionally, olive extracts also maintained the antioxidant pool, i.e., superoxide dismutase, catalase, and glutathione in serum. Furthermore, histological examination revealed that olive extracts prevented the cigarette smoke-induced necrosis, pyknotic alterations, and congestion in the lung, hepatic, and renal parenchyma. Besides, gene expression analysis revealed that olive extracts and citalopram decreased the brain and lung damage caused by stress-induced upregulation of NRF-2 and MAPK signaling pathways. Hence, it can be concluded that olives (both green and black) can act as promising antioxidant in alleviating the cigarette smoke-induced oxidative stress.

Capillary electrophoretic method for the simultaneous determination of nitrate, nitrite and bromate ions in some selected plants

BACKGROUND

Teas and traditional herbs are taken as health remedies in most cultures worldwide. Plants often used in the manufacture of teas and herbal remedies can comprise carcinogenic contaminates, such as nitrates, nitrites and bromate ions. In the present study, a quick method was applied for the simultaneous determination of nitrate (NO₃ ^- ), nitrite (NO₂ ^- ) and bromate (BrO₃ ^- ) ions in some selected plants and tea samples using capillary electrophoresis and a Box-Behnken response surface design for method optimization.

RESULTS

Optimal conditions of 60 mmol L^-1 phosphate buffer solution at pH 3.5, a capillary temperature of 40 °C, applied voltage of -22.5 kV, total capillary length of 61.5 cm (effective length 53.5 cm) with capillary internal diameter of 50 μm, and an injection pressure of 50 mbar for 30 s were selected. The limits of detection for nitrate, bromate and nitrite were 0.49, 1.25 and 0.11 mg L^-1 , whereas linearity values were determined as 0.998, 0.996 and 0.999, respectively.

CONCLUSION

A quick and easy applicable method was developed and the detection of the anions was achievable within 6 min of analysis. From the studied samples (cherry stalk, a dry mixed herbal tea; cherry stalk, dry sticks; dry pomegranate flower; dry olive leaves; and black tea), dry pomegranate flower (13.10 ± 0.62 mg L^-1 ) and cherry stalk, dry mix herbal tea (13.10 ± 0.62 mg L^-1 ) had the highest nitrate content. © 2021 Society of Chemical Industry.

Olive Leaf Extract (OLE) impaired vasopressin-induced aquaporin-2 trafficking through the activation of the calcium-sensing receptor

Vasopressin (AVP) increases water permeability in the renal collecting duct through the regulation of aquaporin-2 (AQP2) trafficking. Several disorders, including hypertension and inappropriate antidiuretic hormone secretion (SIADH), are associated with abnormalities in water homeostasis. It has been shown that certain phytocompounds are beneficial to human health. Here, the effects of the Olive Leaf Extract (OLE) have been evaluated using in vitro and in vivo models. Confocal studies showed that OLE prevents the vasopressin induced AQP2 translocation to the plasma membrane in MCD4 cells and rat kidneys. Incubation with OLE decreases the AVP-dependent increase of the osmotic water permeability coefficient (Pf). To elucidate the possible effectors of OLE, intracellular calcium was evaluated. OLE increases the intracellular calcium through the activation of the Calcium Sensing Receptor (CaSR). NPS2143, a selective CaSR inhibitor, abolished the inhibitory effect of OLE on AVP-dependent water permeability. In vivo experiments revealed that treatment with OLE increases the expression of the CaSR mRNA and decreases AQP2 mRNA paralleled by an increase of the AQP2-targeting miRNA-137. Together, these findings suggest that OLE antagonizes vasopressin action through stimulation of the CaSR indicating that this extract may be beneficial to attenuate disorders characterized by abnormal CaSR signaling and affecting renal water reabsorption.

Effects of oleuropein on rat's atria and thoracic aorta: a study of antihypertensive mechanisms

Oleuropein (OLE) is the main bioactive ingredient in the leaves of the olive plant Olea europaea L. (Oleaceae), which has proven beneficial due to the antiinflammatory, antiatherogenic, anticancer, antimicrobial, and antiviral effects. This study aimed to investigate the antihypertensive and vasodilator potential of OLE by analyzing its acute effects on spontaneous atrial contractions and vasomotor responses of the isolated thoracic aorta in rats. We showed that the application of OLE induces negative chronotropic and inotropic effects on the heart. OLE also causes mild aortic vasodilation given that the maximal reduction in tension of intact aortic rings precontracted with phenylephrine was approximately 30%. This vasodilation is likely dependent on the nitric oxide released from the endothelium based on the effect obtained on denuded and phenylephrine precontracted aortic rings and responses reordered following vasoconstriction induced by high concentrations of K⁺ and heparin. Our findings provide a basis for further testing of OLE cardiovascular effects, which may lead to subsequent clinical research for its application in the treatment of hypertension and heart disease.

Gene Expression Alterations Associated with Oleuropein-Induced Antiproliferative Effects and S-Phase Cell Cycle Arrest in Triple-Negative Breast Cancer Cells

It is known that the Mediterranean diet is effective in reducing the risk of several chronic diseases, including cancer. A critical component of the Mediterranean diet is olive oil, and the relationship between olive oil consumption and the reduced risk of cancer has been established. Oleuropein (OL) is the most prominent polyphenol component of olive fruits and leaves. This compound has been shown to have potent properties in various types of cancers, including breast cancer. In the present study, the molecular mechanism of OL was examined in two racially different triple-negative breast cancer (TNBC) cell lines-African American (AA, MDA-MB-468) and Caucasian American (CA, MDA-MB-231). The data obtained showed that OL effectively inhibits cell growth in both cell lines, concomitant with S-phase cell cycle arrest-mediated apoptosis. The results also showed that OL-treated MDA-MB-468 cells were two-fold more sensitive to OL antiproliferative effect than MDA-MB-231 cells were. At lower concentrations, OL modified the expression of many apoptosis-involved genes. OL was more effective in MDA-MB-468, compared to MDA-MB-231 cells, in terms of the number and the fold-change of the altered genes. In MDA-MB-468 cells, OL induced a noticeable transcription activation in fourteen genes, including two members of the caspase family: caspase 1 (CASP1) and caspase 14 (CASP14); two members of the TNF receptor superfamily: Fas-associated via death domain (FADD) and TNF receptor superfamily 21 (TNFRSF21); six other proapoptotic genes: growth arrest and DNA damage-inducible 45 alpha (GADD45A), cytochrome c somatic (CYCS), BCL-2 interacting protein 2 (BNIP2), BCL-2 interacting protein 3 (BNIP3), BH3 interacting domain death agonist (BID), and B-cell lymphoma/leukemia 10 (BCL10); and the CASP8 and FADD-like apoptosis regulator (CFLAR) gene. Moreover, in MDA-MB-468 cells, OL induced a significant upregulation in two antiapoptotic genes: bifunctional apoptosis regulator (BFAR) and B-Raf proto-oncogene (BRAF) and a baculoviral inhibitor of apoptosis (IAP) repeat-containing 3 (BIRC3). On the contrary, in MDA-MB-231 cells, OL showed mixed impacts on gene expression. OL significantly upregulated the mRNA expression of four genes: BIRC3, receptor-interacting serine/threonine kinase 2 (RIPK2), TNF receptor superfamily 10A (TNFRSF10A), and caspase 4 (CASP4). Additionally, another four genes were repressed, including caspase 6 (CASP6), pyrin domain (PYD), and caspase recruitment domain (CARD)-containing (PAYCARD), baculoviral IAP repeat-containing 5 (BIRC5), and the most downregulated TNF receptor superfamily member 11B (TNFRSF11B, 16.34-fold). In conclusion, the data obtained indicate that the two cell lines were markedly different in the anticancer effect and mechanisms of oleuropein's ability to alter apoptosis-related gene expressions. The results obtained from this study should also guide the potential utilization of oleuropein as an adjunct therapy for TNBC to increase chemotherapy effectiveness and prevent cancer progression.

A Bioactive Olive Pomace Extract Prevents the Death of Murine Cortical Neurons Triggered by NMDAR Over-Activation

We have recently demonstrated that bioactive molecules, extracted by high pressure and temperature from olive pomace, counteract calcium-induced cell damage to different cell lines. Here, our aim was to study the effect of the same extract on murine cortical neurons, since the preservation of the intracellular Ca²⁺-homeostasis is essential for neuronal function and survival. Accordingly, we treated neurons with different stimuli in order to evoke cytotoxic glutamatergic activation. In these conditions, the high-pressure and temperature extract from olive pomace (HPTOPE) only abolished the effects of N-methyl-d-aspartate (NMDA). Particularly, we observed that HPTOPE was able to promote the neuron rescue from NMDA-induced cell death. Moreover, we demonstrated that HPTOPE is endowed with the ability to maintain the intracellular Ca²⁺-homeostasis following NMDA receptor overactivation, protecting neurons from Ca²⁺-induced adverse effects, including aberrant calpain proteolytic activity. Moreover, we highlight the importance of the extraction conditions used that, without producing toxic molecules, allow us to obtain protecting molecules belonging to proanthocyanidin derivatives like procyanidin B2. In conclusion, we can hypothesize that HPTOPE, due to its functional and nontoxic properties on neuronal primary culture, can be utilized for future therapeutic interventions for neurodegeneration.

Oleuropein: A Potential Inhibitor for Prostate Cancer Cell Motility by Blocking Voltage-Gated Sodium Channels

In this study, we investigated whether olive leaf and oleuropein have the potential to stop cell motility, which a metastatic cell behavior by blocking voltage-gated sodium channels (VGSCs). For this purpose, it was first prepared the aqueous extract of olive leaves (AOLE). Then it was assayed the effect on the motility of MAT-LyLu, a highly metastatic Dunning rat prostate adenocarcinoma cells of this extract. The phenolic content of AOLE was analyzed using LC-MS/MS instrument. It was observed that oleuropein was the most finding compound in AOLE. Therefore, whether oleuropein was responsible for the inhibitory effect of AOLE on the MAT-LyLu cell movement was tested. Nontoxic oleuropein concentrations and those that did not affect proliferation on MAT-LyLu cells were determined. Subsequently, it was examined the effects of oleuropein on the lateral and vertical movement of MAT-LyLu cells. To elucidate the mechanism of oleuropein affecting cell motility, whether it suppressed mRNA expression of SCN9A, which encodes the VGSC was analyzed. Accordingly, oleuropein suppressed the movement of MAT-LyLu cells by reducing SCN9A mRNA expression. In conclusion, we report the first time that oleuropein might be considered as a potential antimetastatic agent for prostate cancer due to its blocking effect on VGSC-mediated cell motility.

Molecular Targets for Combined Therapeutic Strategies to Limit Glioblastoma Cell Migration and Invasion

The highly invasive nature of glioblastoma imposes poor prospects for patient survival. Molecular evidence indicates glioblastoma cells undergo an intriguing expansion of phenotypic properties to include neuron-like signaling using excitable membrane ion channels and synaptic proteins, augmenting survival and motility. Neurotransmitter receptors, membrane signaling, excitatory receptors, and Ca2+ responses are important candidates for the design of customized treatments for cancers within the heterogeneous central nervous system. Relatively few published studies of glioblastoma multiforme (GBM) have evaluated pharmacological agents targeted to signaling pathways in limiting cancer cell motility. Transcriptomic analyses here identified classes of ion channels, ionotropic receptors, and synaptic proteins that are enriched in human glioblastoma biopsy samples. The pattern of GBM-enriched gene expression points to a major role for glutamate signaling. However, the predominant role of AMPA receptors in fast excitatory signaling throughout the central nervous system raises a challenge on how to target inhibitors selectively to cancer cells while maintaining tolerability. This review critically evaluates a panel of ligand- and voltage-gated ion channels and synaptic proteins upregulated in GBM, and the evidence for their potential roles in the pathological disease progress. Evidence suggests combinations of therapies could be more effective than single agents alone. Natural plant products used in traditional medicines for the treatment of glioblastoma contain flavonoids, terpenoids, polyphenols, epigallocatechin gallate, quinones, and saponins, which might serendipitously include agents that modulate some classes of signaling compounds highlighted in this review. New therapeutic strategies are likely to exploit evidence-based combinations of selected agents, each at a low dose, to create new cancer cell-specific therapeutics.

Oleuropein, a Bioactive Compound from Olea europaea L., as a Potential Preventive and Therapeutic Agent in Non-Communicable Diseases

Growing scientific literature data suggest that the intake of natural bioactive compounds plays a critical role in preventing or reducing the occurrence of human chronic non-communicable diseases (NCDs). Oleuropein, the main phenolic component of Olea europaea L., has attracted scientific attention for its several health beneficial properties such as antioxidant, anti-inflammatory, cardio- and neuro-protective, and anti-cancer. This article is a narrative review focused on the current literature concerning the effect of oleuropein in NCDs, such as neuro- and cardiovascular diseases, diabetes mellitus, chronic kidney diseases, and cancer, by its putative antioxidant and anti-inflammatory activity, but also for its other peculiar actions such as an autophagy inducer and amyloid fibril growth inhibitor and, finally, for its anti-cancer effect. Despite the increasing number of published studies, looking at the beneficial effects of oleuropein, there is limited clinical evidence focused on the benefits of this polyphenol as a nutraceutical product in humans, and many problems are still to be resolved about its bioavailability, bioaccessibility, and dosage. Thus, future clinical randomized trials are needed to establish the relation between the beneficial effects and the mechanisms of action occurring in the human body in response to the intake of oleuropein.

Safety and efficacy of hydroxytyrosol-based formulation on skin inflammation: in vitro evaluation on reconstructed human epidermis model

BACKGROUND

Atopic dermatitis is a multifactorial immune-mediated skin disorder characterized by an alteration of epidermal barrier function and onset of skin lesions, which range from mild erythema to severe lichenification. Treatment consists in hydration with possible use of topical or immunomodulatory corticosteroids, which, however sometimes showed side effects. Recently, the interest in natural compounds has grown significantly and among these, hydroxytyrosol (HT) plays a pivotal role due to its strong and well-known anti-inflammatory activity.

OBJECTIVES

The aim of this study was to investigate the safety and efficacy of Fenolia® Eudermal Cream 15 (HT-based formulation) on epidermal barrier impaired as consequence of skin injury.

METHODS

Whit this purpose, morphologic and structural as well as anti-inflammatory evaluations, after treatment with pro-inflammatory mediators (PBS 1 X and LPS) and HT-based formulation on reconstructed human epidermis (RHE) were carried out by qualitative (hematoxylin/eosin- and immunostaining) and quantitative (MTT assay, IL-1α and IL-8 release by ELISA) techniques. Furthermore, HT absorption through the epidermal barrier was evaluated by RP-LC-DAD analysis.

RESULTS

A rise in the thickness of the epidermis as well as an appropriate maturation and protein expression (Loricrin, Fillagrin, E-Cadherin and Cytokeratins 5&6) were detected in treated RHE samples. In particular, the HT-based formulation was found to stimulate cell proliferation, as evidenced by the significant increase in Ki67 expression, which suggests the involvement of repair mechanisms, increasing epithelial regeneration and differentiation and improving the epidermal barrier effect. Furthermore, HT-based formulation showed a statistically significant anti-inflammatory activity by reducing both IL-1α and IL-8 release by RHE tissues, greater than the reference drug dexamethasone. Finally, excellent transcutaneous absorption values were found for HT, demonstrating how this new formulation increases the availability of the bioactive compound.

CONCLUSIONS

In light of these results, Fenolia® Eudermal Cream 15 could be an effective agent to counteract atopic dermatitis. Graphical abstract Safety and efficacy of hydroxytyrosol-based formulation on skin inflammation: in vitro evaluation on reconstructed human epidermis model.

Simultaneous downregulation of miR-21 and miR-155 through oleuropein for breast cancer prevention and therapy

Breast cancer (BC) is the leading cause of cancer mortality in women worldwide. It recently was proven that miRNAs play a critical role in BC development. The use of natural agents for control of cancer by modulating miRNAs is promising. Oleuropein is a natural polyphenolic agent with anti-neoplastic properties and is well tolerated by humans. This study was undertaken to determine the therapeutic effects of oleuropein through modulation of master oncomiRs (miR-21 and miR-155) in BC cells. The present study provides the first link between miRNA and oleuropein as a mechanism in BC. MCF-7 cells were tested with and without oleuropein and the cell viability, apoptosis, and migration were examined. The effect of oleuropein on miR-21 and miR-155 expression was assessed through qRT-PCR. It was found that oleuropein induced apoptosis and retarded cell migration and invasion in a dose-dependent manner in the human MCF7 BC cell line. It was observed that oleuropein significantly decreased expression of both miR-21 and miR-155 over time in a dose-dependent manner. These results demonstrate that oleuropein is a potential therapeutic and preventive agent for BC. Oleuropein exhibits an anti-cancer effect by modulation of tumor suppressor gene expression, which is targeted by oncomiRs.

Dandelion Root Extract Induces Intracellular Ca2+ Increases in HEK293 Cells

Dandelion (Taraxacum officinale Weber ex F.H.Wigg.) has been used for centuries as an ethnomedical remedy. Nonetheless, the extensive use of different kinds of dandelion extracts and preparations is based on empirical findings. Some of the tissue-specific effects reported for diverse dandelion extracts may result from their action on intracellular signaling cascades. Therefore, the aim of this study was to evaluate the effects of an ethanolic dandelion root extract (DRE) on Ca²⁺ signaling in human embryonic kidney (HEK) 293 cells. The cytotoxicity of increasing doses of crude DRE was determined by the Calcein viability assay. Fura-2 and the fluorescence resonance energy transfer (FRET)-based probe ERD1 were used to measure cytoplasmic and intraluminal endoplasmic reticulum (ER) Ca²⁺ levels, respectively. Furthermore, a green fluorescent protein (GFP)-based probe was used to monitor phospholipase C (PLC) activation (pleckstrin homology [PH]–PLCδ–GFP). DRE (10–400 µg/mL) exposure, in the presence of external Ca²⁺, dose-dependently increased intracellular Ca²⁺ levels. The DRE-induced Ca²⁺ increase was significantly reduced in the absence of extracellular Ca²⁺. In addition, DRE caused a significant Ca²⁺ release from the ER of intact cells and a concomitant translocation of PH–PLCδ–GFP. In conclusion, DRE directly activates both the release of Ca²⁺ from internal stores and a significant Ca²⁺ influx at the plasma membrane. The resulting high Ca²⁺ levels within the cell seem to directly stimulate PLC activity.

Cell protection from Ca2+-overloading by bioactive molecules extracted from olive pomace

We are reporting in the present study that molecules extracted from olive pomace prevent cell death induced by Ca²⁺-overloading in different cell types. Exposure of cells to these molecules counteracts the Ca²⁺-induced cell damages by reducing the activation of the Ca²⁺-dependent protease calpain, acting possibly through the modification of the permeability to Ca²⁺ of the plasma membrane. The purification step by RP-HPLC suggests that effective compound(s), differing from the main biophenols known to be present in the olive pomace extract, could be responsible for this effect. Our observations suggest that bioactive molecules present in the olive pomace could be potential candidates for therapeutic applications in pathologies characterised by alterations of intracellular Ca²⁺ homeostasis.

Synergistic Interplay between Curcumin and Polyphenol-Rich Foods in the Mediterranean Diet: Therapeutic Prospects for Neurofibromatosis 1 Patients

Neurofibromas are the hallmark lesions in Neurofibromatosis 1 (NF1); these tumors are classified as cutaneous, subcutaneous and plexiform. In contrast to cutaneous and subcutaneous neurofibromas, plexiform neurofibromas can grow quickly and progress to malignancy. Curcumin, a turmeric-derived polyphenol, has been shown to interact with several molecular targets implicated in carcinogenesis. Here, we describe the impact of different dietary patterns, namely Mediterranean diet (MedDiet) compared to the Western diet (WesDiet), both with or without curcumin, on NF1 patients’ health. After six months, patients adopting a traditional MedDiet enriched with 1200 mg curcumin per day (MedDietCurcumin) presented a significant reduction in the number and volume of cutaneous neurofibromas; these results were confirmed in subsequent evaluations. Notably, in one patient, a large cranial plexiform neurofibroma exhibited a reduction in volume (28%) confirmed by Magnetic Resonance Imaging. Conversely, neither unenriched MedDiet nor WesDiet enriched with curcumin exhibited any significant positive effect. We hypothesize that the combination of a polyphenol-rich Mediterranean diet and curcumin was responsible for the beneficial effect observed on NF1. This is, to the best of our knowledge, the first experience with curcumin supplementation in NF1 patients. Our report suggests that an integrated nutritional approach may effectively aid in the management of NF1.

Anticancer effects of oleuropein

Cancer cells exhibit enhanced proliferation rate and a resistance to apoptosis. Epidemiological studies suggest that olive oil intake is associated with a reduced risk of cancer. Olive oil, olives, and olive leaves contain many polyphenols, including oleuropein. Recently, several studies have demonstrated that oleuropein inhibits proliferation and induces apoptosis in different cancer cell lines. In addition, anticancer effects of oleuropein have been seen in animal studies. These effects are associated with oleuropein's ability to modulate gene expression and activity of a variety of different signaling proteins that play a role in proliferation and apoptosis. This article summarizes the existing in vitro and in vivo studies focusing on the anticancer effects of oleuropein and its effects on key signaling molecules. © 2017 BioFactors, 43(4):517-528, 2017.

Anti-inflammatory effect of oleuropein on microglia through regulation of Drp1-dependent mitochondrial fission

Oleuropein is a primary phenolic compound found in olive leaf and Fraxinus rhynchophylla. Here, we investigated the impact of oleuropein on LPS-induced BV-2 microglial cells. Oleuropein suppressed the LPS-induced increase in pro-inflammatory mediators, such as nitric oxide, and pro-inflammatory cytokines, via inhibition of ERK/p38/NF-κB activation and reactive oxygen species (ROS) generation. Furthermore, it suppressed LPS-induced excessive mitochondrial fission, which regulates mitochondrial ROS generation and pro-inflammatory response by diminishing Drp1 dephosphorylation. Collectively, we demonstrated that oleuropein suppresses pro-inflammatory response of microglia by inhibiting Drp1-dependent mitochondrial fission. Our findings suggest a potential role of oleuropein in microglial inflammation-mediated neurodegenerative disorders.

Nutraceutical Properties of Olive Oil Polyphenols. An Itinerary from Cultured Cells through Animal Models to Humans

The increasing interest in the Mediterranean diet hinges on its healthy and anti-ageing properties. The composition of fatty acids, vitamins and polyphenols in olive oil, a key component of this diet, is considered a key feature of its healthy properties. Therefore, it is of significance that the Rod of Asclepius lying on a world map surrounded by olive tree branches has been chosen by the World Health Organization as a symbol of both peace and well-being. This review travels through most of the current and past research, recapitulating the biochemical and physiological correlations of the beneficial properties of olive tree (Olea europaea) polyphenols and their derivatives found in olive oil. The factors influencing the content and beneficial properties of olive oil polyphenols will also be taken into account together with their bioavailability. Finally, the data on the clinical and epidemiological relevance of olive oil and its polyphenols for longevity and against age- and lifestyle-associated pathologies such as cancer, cardiovascular, metabolic and neurodegenerative diseases are reviewed.