Expression of Na+/Ca2+ exchangers was enhanced following pre-treatment of olive leaf extract and olive oil in animal model of ischemic stroke.

BACKGROUND: Neuroprotective role of olive and its natural products can introduce them as alternative candidates for the management of neurodegenerative diseases including stroke. The present study was designed to evaluate whether pretreatment of olive oil and leaf extract can attenuate the most important destructive processes in cerebral ischemia called excitotoxicity. MATERIAL AND METHODS: The male rats were categorized into control, virgin olive oil (OVV), MCAO, MCAO + OVV (with doses of 0.25, 0.50 and 0.75 ml/kg as treatment groups), olive leaf extract, MCAO + olive leaf extract (with doses 50, 75 and 100 mg/kg as treatment groups) groups. Rats of treatment groups received gastric gavage with olive oil or leaf extract for 30 consecutive days. After pretreatment, the intraluminal filament technique was used to block middle cerebral artery (MCA) transiently. Neurological deficits, infarct volume and expression of Na+/Ca2+ exchangers (NCX1, NCX2 and NCX3) proteins were measured. RESULTS: The results revealed that olive oil at doses of 0.50 and 0.75 ml/kg reduced the infarction and neurological score and upregulated NCXs expression in rat brain. In addition, olive leaf extract at doses of 75 and 100 mg/kg attenuated the infarction and neurological score and enhanced NCXs expression in rat brain. CONCLUSION: These findings support the view that olive oil and leaf extract play the neuroprotective role in cerebral ischemia due to the upregulation of NCXs protein expression.

Effects of Enriched-in-Oleuropein Olive Leaf Extract Dietary Supplementation on Egg Quality and Antioxidant Parameters in Laying Hens.

The objective of the present study was to evaluate the effects of an olive leaf extract obtained with an up-to-date laboratory method, when supplemented at different levels in laying hens' diets, on egg quality, egg yolk antioxidant parameters, fatty acid content, and liver pathology characteristics. Thus, 96 laying hens of the ISA-Brown breed were allocated to 48 experimental cages with two hens in each cage, resulting in 12 replicates per treatment. Treatments were: T1 (Control: basal diet); T2 (1% olive leaf extract); T3 (2.5% olive leaf extract); T4 (Positive control: 0.1% encapsulated oregano oil). Eggshell weight and thickness were improved in all treatments compared to the control, with T2 being significantly higher till the end of the experiment (p < 0.001). Egg yolk MDA content was lower for the T2 and T4 groups, while total phenol content and Haugh units were greater in the T2. The most improved fatty acid profile was the one of T3 yolks. The α-tocopherol yolk content was higher in all groups compared to T1. No effect was observed on cholesterol content at any treatment. Based on the findings, it can be inferred that the inclusion of olive leaf extract at a concentration of 1% in the diet leads to enhancements in specific egg quality attributes, accompanied by an augmentation of the antioxidant capacity.

Hematinic Potential of Olive Leaf Extract: Evidence from an In Vivo Study in Mice and a Pilot Study in Healthy Human Volunteers.

Natural resources have recently received considerable attention as complementary or alternative hematinic agents. In this regard, olive leaf extract, which is rich in bioactive phenolic compounds, has been reported to induce erythroid differentiation in human hematopoietic stem cells. Therefore, in the present study, we aimed to explore the potential hematinic properties of aqueous olive leaf extract (WOL) in vivo. After 24 days of administering WOL to healthy mice orally, red blood cell (RBC), hematocrit, reticulocyte, and reticulocyte hemoglobin content (CHr) showed a significant increase. Additionally, WOL promoted plasma iron levels and the expression of splenic ferroportin (Fpn), an iron transporter. Additionally, a single-arm pilot study involving a limited number of healthy volunteers was conducted to assess WOL's feasibility, compliance, and potential benefits. Following an 8-week intervention with WOL, RBC count and hemoglobin level were significantly increased. Notably, there were no significant changes in the safety measures related to liver and kidney functions. Furthermore, we identified oleuropein and oleuroside as the active components in WOL to induce erythroid differentiation in the K562 cell line. Altogether, our study presents evidence of the hematinic potential of WOL in the in vivo studies, opening up exciting possibilities for future applications in preventing or treating anemia.

Olive Leaf Extract (OLE) as a Novel Antioxidant That Ameliorates the Inflammatory Response in Cystic Fibrosis.

The deletion of phenylalanine at position 508 (F508del) produces a misfolded CFTR protein that is retained in the ER and degraded. The lack of normal CFTR channel activity is associated with chronic infection and inflammation which are the primary causes of declining lung function in Cystic Fibrosis (CF) patients. Moreover, LPS-dependent oxidative stress downregulates CFTR function in airway epithelial cells. Olive leaf extract (OLE) is used in traditional medicine for its effects, including anti-oxidant and anti-inflammatory ones. We found that OLE decreased the intracellular ROS levels in a dose-response manner in CFBE cells. Moreover, OLE attenuates the inflammatory response to LPS or IL-1ß/TNFα stimulation, mimicking the infection and inflammatory status of CF patients, in CFBE and primary nasal epithelial (HNE) cells. Furthermore, we demonstrated that OLE restored the LPS-mediated decrease of TrikfaftaTM-dependent F508del-CFTR function in CFBE and HNE cultures. These findings provide strong evidence of OLE to prevent redox imbalance and inflammation that can cause chronic lung damage by enhancing the antioxidant activity and attenuating inflammation in CF airway epithelial cells. Additionally, OLE might be used in combination with CFTR modulators therapy to improve their efficacy in CF patients.

Development of Pegylated Nano-Phytosome Formulation with Oleuropein and Rutin to Compare Anti-Colonic Cancer Activity with Olea Europaea Leaves Extract.

Olive leaf extract is a valuable source of phenolic compounds; primarily, oleuropein (major component) and rutin. This natural olive leaf extract has potential use as a therapeutic agent for cancer treatment. However, its clinical application is hindered by poor pharmacokinetics and low stability. To overcome these limitations, this study aimed to enhance the anticancer activity and stability of oleuropein and rutin by loading them into PEGylated Nano-phytosomes. The developed PEGylated Nano-phytosomes exhibited favorable characteristics in terms of size, charge, and stability. Notably, the anticolonic cancer activity of the Pegylated Nano-phytosomes loaded with oleuropein (IC50=0.14 µM) and rutin (IC50=0.44 µM) surpassed that of pure oleuropein and rutin alone. This outcome highlights the advantageous impact of Nano-phytosomes to augment the anticancer potential of oleuropein and rutin. These results present a promising pathway for the future development of oleuropein and rutin Nano-phytosomes as effective options for passive tumor-targeted therapy, given their improved stability and efficacy.

Low Dose Monacolin K Combined with Coenzyme Q10, Grape Seed, and Olive Leaf Extracts Lowers LDL Cholesterol in Patients with Mild Dyslipidemia: A Multicenter, Randomized Controlled Trial.

Certain nutraceuticals, mainly containing red yeast rice, might be considered as an alternative therapy to statins in patients with dyslipidemia, although there is still insufficient evidence available with respect to long-term safety and effectiveness on cardiovascular disease prevention and treatment. The aim of this study was to assess the lipid-lowering activity and safety of a dietary supplement containing a low dose of monacolin K combined with coenzyme Q10, grape seed and olive tree leaf extracts in patients with mild hypercholesterolemia. In total, 105 subjects with mild hypercholesterolemia (low-density lipoprotein cholesterol LDL-C levels 140-180 mg/dL) and low CV risk were randomly assigned into three treatment groups: lifestyle modification (LM), LM plus a low dosage of monacolin K (3 mg), and LM plus a high dosage of monacolin K (10 mg) and treated for 8 weeks. The primary endpoint was the reduction of LDL-C and total cholesterol (TC). LDL-C decreased by 26.46% on average (p < 0.001) during treatment with 10 mg of monacolin and by 16.77% on average during treatment with 3 mg of monacolin (p < 0.001). We observed a slight but significant reduction of the triglyceride levels only in the high-dose-treated group (mean -4.25%; 95% CI of mean -11.11 to 2.61). No severe adverse events occurred during the study. Our results confirm the LDL-C-lowering properties of monacolin are clinically meaningful even in lower doses of 3 mg/day.

Bioavailability of Phenolic Compounds in Californian-Style Table Olives with Tunisian Aqueous Olive Leaf Extracts.

Recent advances in biotechnology have ensured that one of the main olive tree by-products is olive leaf extract (OLE), a rich source in bioactive compounds. The aim of this work was to study the phenolic composition in different OLEs of three Tunisian varieties, namely, 'Sayali', 'Tkobri', and 'Neb Jmel'. The in vitro biodigestibility effect after 'Sayali' OLE addition to Californian-style 'Hojiblanca' table olives was also studied. This OLE contained bioactive molecules such as hydroxytyrosol, tyrosol, oleropeine, Procianidine B1 (PB1), and p-cumaric acid. These compounds were also found in fresh olives after OLE was added. Furthermore, from fresh extract to oral digestion, the detected amount of bioavailable phenol was higher; however, its content decreased according to each phase of gastric and intestinal digestion. In the final digestion phase, the number of phenols found was lower than that of fresh olives. In addition, the phenolic content of Californian-style 'Hojiblanca' table olives decreased during the in vitro digestion process. The antioxidant activity of this variety decreased by 64% and 88% after gastrointestinal digestion, being the highest antioxidant capacity found in both simulated gastric and intestinal fluid, respectively. The results show us that the 'Sayali' variety is rich in phenolic compounds that are bioavailable after digestion, which could be used at an industrial level due to the related health benefits.

Antioxidant and anti-inflammatory effect of olive leaf extract treatment in diabetic rat brain.

OBJECTIVES: Olive (Olea europaea L.) plays a promising role in pharmaceutical, nutraceutical, and cosmetic production. On the other hand, olive leaf is widely used in folk medicine due to its antihyperglycemic activity. For this aim, possible effects of olive leaf extract (OLE) in the brain tissue of streptozotocin-induced diabetic rats were investigated. METHODS: A total of 28 male rats were divided into four equal groups as control, diabetic (single dose of 45 mg/kg streptozotocin, i.p.), OLE (500 mg/kg/day), and diabetic + OLE groups. The study was terminated 21 days after the diabetes model was formed. At the end of the study, all the animals were sacrificed and blood and brain tissues were isolated. Relative brain weights, complete blood count, blood glycated hemoglobin, serum glucose, total protein, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, insulin, gonadal hormone levels, production and messenger ribonucleic acid (mRNA) levels of proinflammatory cytokines and mediators, total thiol, total oxidative stress, and total antioxidant status levels and fatty acid composition in brain tissue were measured in all study groups. RESULTS: In diabetic rats, relative brain weight and serum insulin level decreased, glycated hemoglobin, oxidative stress, production and mRNA level of proinflammatory cytokines and mediators increased, hyperglycemia, hypercholesterolemia and hypertriglyceridemia, degraded fatty acid composition, anemia, leukopenia, and thrombocytopenia occurred. After OLE treatment, a remarkable improvement in most of these parameters, except gonadal hormones, has been observed in diabetic rats. CONCLUSIONS: This study suggests that olive leaf can be a precious neuroprotective agent in diabetes.

Neuroprotective Panel of Olive Polyphenols: Mechanisms of Action, Anti-Demyelination, and Anti-Stroke Properties.

Neurological diseases such as stroke and multiple sclerosis are associated with high morbidity and mortality, long-term disability, and social and economic burden. Therefore, they represent a major challenge for medical treatment. Numerous evidences support the beneficial effects of polyphenols from olive trees, which can alleviate or even prevent demyelination, neurodegeneration, cerebrovascular diseases, and stroke. Polyphenols from olive oils, especially extra virgin olive oil, olive leaves, olive leaf extract, and from other olive tree derivatives, alleviate inflammation and oxidative stress, two major factors in demyelination. In addition, they reduce the risk of stroke due to their multiple anti-stroke effects, such as anti-atherosclerotic, antihypertensive, antioxidant, anti-inflammatory, hypocholesterolemic, hypoglycemic, and anti-thrombotic effects. In addition, olive polyphenols have beneficial effects on the plasma lipid profiles and insulin sensitivity in obese individuals. This review provides an updated version of the beneficial properties and mechanisms of action of olive polyphenols against demyelination in the prevention/mitigation of multiple sclerosis, the most common non-traumatic neurological cause of impairment in younger adults, and against cerebral insult with increasing incidence, that has already reached epidemic proportions.

Valorization of the Photo-Protective Potential of the Phytochemically Standardized Olive (Olea europaea L.) Leaf Extract in UVA-Irradiated Human Skin Fibroblasts.

Leaves of Olea europaea are a by-product of the olive oil industry and a dietary supplement with acknowledged antioxidant and anti-inflammatory activity but underestimated photoprotective potential. We investigated the protective effects of the LC-PDA-MS/MS standardized ethanol-water extract of olive leaves (OLE), containing 26.2% total phenols and 22.2% oleuropein, with underlying mechanisms against the UVA-induced oxidative damage in human dermal fibroblasts. Hs68 cells were pre-treated (24 h) with OLE (2.5-25 µg/mL) or the reference antioxidants, quercetin and ascorbic acid (25 µg/mL), followed by irradiation (8 J/cm2). OLE significantly reduced the UVA-induced DNA damage and reactive oxygen species (ROS) overproduction and increased the thioredoxin reductase (TrxR) expression and post-radiation viability of fibroblasts by inhibiting their apoptosis. Both intrinsic and extrinsic apoptotic signaling pathways appeared to be inhibited by OLE, but the activity of caspase 9 was the most reduced. We hypothesized that the TrxR up-regulation by OLE could have prevented the UVA-induced apoptosis of Hs68 cells. In addition, a significant decrease in UVA-induced secretion levels of tumor necrosis factor (TNF-α) and interleukin-2 (IL-2) was shown in human lymphocyte culture in response to OLE treatment. In summary, our results support the beneficial effect of OLE in an in vitro model and indicate its great potential for use in the cosmetic and pharmaceutical industry as a topical photoprotective, antioxidant, and anti-inflammatory agent.

Immunotherapeutic potential of ethanolic olive leaves extract (EOLE) and IL-28B combination therapy in ENU induced animal model of leukemia.

Cytokine therapies have shown promising results against cancers. Cytokines are secreted naturally from different bodily cells. These have fewer side effects but higher specificity than chemotherapy and radiation therapy. In leukemia, changes in normal hematopoiesis and defective leukocyte production limit the efficacy of immunotherapy by reducing the count of functional immune cells. Therefore, the treatment of leukemia needs advanced therapeutics that can target multiple cancer sustaining mechanisms. In combination therapy, using two different therapeutic agents affect cancer growth in many ways and sometimes gives synergistic effects. Here, we examined the effect of the ethanolic olive leaf extract (EOLE) and IL-28B in combination. N-N' Ethyl-nitrosourea (ENU) induced leukemia in Swiss albino mice was treated with EOLE for four weeks and IL-28B for one week after confirming the development of leukemia. The combination of EOLE and IL-28B significantly reduced the blast cell and total WBC counts in the peripheral blood, altered the levels of various cytokines in plasma, and induced the functional activity of NK cells in leukemic mice. The induced NK activity correlates with increased expression of perforin and granzyme studied at the gene level through real-time (RT)-PCR. The treatment of leukemic mice with combined EOLE and IL-28B has also caused an increased serum IL-10 and IFN-γ level, and reduced serum TGF-ß indicates improved overall immunity. Altogether, the combination of EOLE and IL-28B has given substantial therapeutic activity against leukemia.

The Potential of Olive Leaf Extract as a Functional Ingredient in Yoghurt Production: The Effects on Fermentation, Rheology, Sensory, and Antioxidant Properties of Cow Milk Yoghurt.

BACKGROUND: Yoghurt has been traditionally consumed for its high nutritional value and health-promoting benefits. The addition of plant extracts as a source of phenolic compounds and bio-flavonoids has attracted much attention recently since milk and dairy products are deficient in these health-protecting components. Accordingly, olive leaf extract (OLE) has been considered due to the presence of bioactive compounds, primarily polyphenols. Thus, the aim of this research was to investigate the possibility of adding OLE into cow milk yoghurt as a potential functional ingredient. METHODS: Yoghurts enriched with OLE (1.5, 3, and 5% v/v) were produced and compared with yoghurt without OLE. In all samples acidity, viscosity, colour, syneresis, water holding capacity (WHC), microbiological parameters, sensory properties, total phenols, and antioxidant activity (DPPH and FRAP methods) were determined. RESULTS: The addition of OLE resulted in shorter fermentation and lower pH, but it had no adverse effect on the viability of yoghurt starter bacteria. OLE-enriched yoghurts showed increased syneresis, higher total phenols content, and antioxidant activity, while WHC and viscosity decreased. Sensory properties were slightly poorer for yoghurts containing higher OLE concentrations. Considering all of the obtained results, the addition of 1.5% OLE appeared to be optimal.

Oleuropein-Rich Olive Leaf Extract Attenuates Neuroinflammation in the Alzheimer's Disease Mouse Model.

Alzheimer's disease (AD) is the most common form of dementia among several neurodegenerative disorders afflicting the elderly. AD is characterized by the deposition of extracellular amyloid-ß (Aß) plaques, disrupted blood-brain barrier (BBB), and neuroinflammation. Several studies have demonstrated the health benefits of olive oil and olive leaf extract (OLE) due to their polyphenolic content. The main phenolic compound in OLE is glycosylated oleuropein (OLG), while the aglycon form of oleuropein (OLA) exists in much lower amounts. This work aimed to evaluate the effect of a low dose of OLG-rich OLE and the mechanism(s) that contributed to the observed beneficial effects against Aß pathology in the homozygous 5xFAD mouse model. Mice were fed with OLE-enriched diet (695 µg/kg body weight/day) for 3 months, starting at 3 months old. Overall findings demonstrated that OLE reduced neuroinflammation by inhibiting the NF-κB pathway and suppressing the activation of NLRP3 inflammasomes and RAGE/HMGB1 pathways. In addition, OLE reduced total Aß brain levels due to increased clearance and reduced production of Aß and enhanced BBB integrity and function, which collectively improved the memory function. Thus, the consumption of OLE as a dietary supplement is expected to stop and/or slow the progression of AD.

Physical, Chemical and Sensory Characterization of Deep-Fried Fresh-Cut Potatoes Coated with Hydrocolloid/Herbal Extracts.

Research background: Recently, natural plant extracts have been used to increase the nutritional value of food and to potentially reduce the absorbed fat and the formation of acrylamide in fried foods. Literature data on the use of edible polymers with nettle or olive leaf extracts are scarce. Experimental approach: The effect of novel coatings on colour, fat absorption, phenolic and sugar content, and acrylamide formation in deep-fat-fried fresh-cut potatoes was evaluated. Extracts of olive and nettle leaves were incorporated in carboxymethyl cellulose (CMC) and gum arabic, used as coatings for potatoes and applied before frying. This aimed to improve the nutritional quality of deep-fat-fried fresh-cut potatoes. Results and conclusions: Enrichment of the edible coatings with extracts resulted in a significant change in the visible colour of the potatoes before frying. Significant effect of the extract amount on the sensory characteristics of potatoes was also observed. Most importantly, the perception of characteristic potato odour and taste was not significantly affected by the coating. Although higher amounts of the extract (1.5%) resulted in higher phenolic mass fraction in fried potatoes, the sensory scores decreased. After frying, fat mass fraction in the coated potatoes was reduced by about 15% compared to the uncoated samples. The type of extract affected the total sugar mass fraction in fried potatoes, which was lower in the samples with coatings enriched with olive leaf than in those with nettle leaf. Only gum arabic coating had a reducing effect on acrylamide mass fraction by 17%. Based on all the obtained results, CMC and gum arabic coatings did not influence sensory properties, so they can be recommended as carriers of functional compounds or as a frying pre-treatment for potatoes with favourable effect on fat and acrylamide content. Novelty and scientific contribution: The knowledge obtained in this study can be exploited for preparation of coatings with functional compounds used as a pre-treatment for fried food with favourable effect on fat and acrylamide content.

Influence of Drying Temperature and Harvesting Season on Phenolic Content and Antioxidant and Antiproliferative Activities of Olive (Olea europaea) Leaf Extracts.

Interest in plant compounds has increased, given recent evidence regarding their role in human health due to their pleiotropic effects. For example, plant bioactive compounds present in food products, including polyphenols, are associated with preventive effects in various diseases, such as cancer or inflammation. Breast and colorectal cancers are among the most commonly diagnosed cancers globally. Although appreciable advances have been made in treatments, new therapeutic approaches are still needed. Thus, in this study, up to 28 olive leaf extracts were obtained during different seasons and using different drying temperatures. The influence of these conditions on total polyphenolic content (measured using Folin-Ciocalteu assays), antioxidant activity (using Trolox Equivalent Antioxidant Capacity and Ferric Reducing Ability of Plasma assays) and antiproliferative capacity (using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assays) was tested in breast and colorectal cancer cells. Increased phenolic composition and antioxidant and antiproliferative capacity are noted in the extracts obtained from leaves harvested in autumn, followed by summer, spring and winter. Regarding drying conditions, although there is not a general trend, conditions using the highest temperatures lead to the optimal phenolic content and antioxidant and antiproliferative activities in most cases. These results confirm previously published studies and provide evidence in support of the influence of both harvesting and drying conditions on the biological activity of olive leaf extracts.

Chemical composition, antioxidant activities, in an allergic asthma model, of Olea europaea L. leaf extracts from Collo (Skikda, Algeria).

This study is an attempt to characterize the chemical composition and antioxidant activity of olive leaves variety (namely Bouricha variety) that is very widespread in the East of Algeria. The aqueous extract (AE) of leaves was initially analyzed for its phenolic profile. Using the liquid chromatography coupled to tandem mass spectrometry analysis, it was possible to identify the predominant components in the AE of the leaves. This extract was hydrolyzed with acid and gave hydroxytyrosol (HT). AE and HT were evaluated for their 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity, ferric reducing antioxidant power and total antioxidant activity by phosphomolybdenum method. The antioxidant and anti-asthmatic activities of these extracts were examined in a model of experimental asthma in Wistar rats. For measuring the intensity of the airway inflammation, oxidative stress parameters were analyzed in lungs and a histological study of this tissue was performed. The obtained results showed that the sensitization of the ovalbumin (OVA) group induced lung inflammation and severe lipid peroxidation (LPO) revealed by a significant increase in malondialdehyde (MDA) levels and a decrease in the non-enzymatic and enzymatic antioxidant systems. However, the administration of AE and HT extracts significantly improved the antioxidant state in asthma disease and provided evidence for the relation between phenolic compounds and the high antioxidant activity of olive leaves extracts, especially HT more than AE.

The efficacy of olive leaf extract on healing herpes simplex virus labialis: A randomized double-blind study.

OBJECTIVE: Herpes simplex virus (HSV), as a common infection in healthy individuals, is treated symptomatically, but drug resistance and the side effects of drugs have drawn the attention of researchers to complementary medicine. Olive Leaf Extract (OLE) has antiviral effects that may treat HSV. The current study aimed to compare the clinical effects of OLE and Acyclovir on HSV-1. METHODS: This randomized double-blind clinical trial was conducted on 66 patients who had already been diagnosed with HSV-1. The participants were randomized into two groups, receiving 2% OLE cream or 5% acyclovir cream five times a day for six days. The symptoms were evaluated before, and three and six days after the interventions. Data were analyzed using the SPSS software through the Kolmogorov-Smirnov test, chi-squared, t-test, and repeated measures ANOVA. RESULTS: The results showed clinical symptoms decreased in both groups during the study and both medications were effective in the treatment of HSV-1. However, the OLE group experienced less bleeding (P = 0.038), itching (P = 0.002), and pain (P = 0.001) on the third day as well as less irritation (P = 0.012), itching (P = 0.003) and color change (P = 0.001) on the sixth day compared to the acyclovir group. The treatment course for participants in the OLE group was shorter than in the acyclovir group (P = 0.001). CONCLUSION: The evidence from these trials suggests the OLE cream is superior in the healing of episodes of HSV-1 over the acyclovir cream. Future studies are recommended to investigate if OLE could be an adjunct to acyclovir treatment.

Anti-influenza virus activity of the elenolic acid rich olive leaf (Olea europaea L.) extract Isenolic®.

Seasonal flu is caused by influenza infection, a virus that spreads easily in human population with periodical epidemic outbreaks. The high mutational rate of influenza viruses leads to the emergence of strains resistant to the current treatments. Due to that, scientific research is focusing on the development of new anti-influenza agents as alternative or complementary treatments. Olive tree (Olea europaea L.) has been a source of ancestral remedies due to its antimicrobial activity. Thus, the aim of this study was to test the anti-influenza activity of a standardized olive leaf extract rich in elenolic acid (EA), Isenolic®, compared with oseltamivir. Isenolic® extract was characterized by High Performance Liquid Chromatography (HPLC)-Mass Spectrometry and its content in EA was determined by HPLC. Cytotoxicity, viral neuraminidase inhibitor activity and cell viability protection against influenza infection of Isenolic® were tested in vitro using sialic acid overexpressing Madin-Darby Canine Kidney cells. Isenolic® formulations showed a 4% and 8% dry basis. Oseltamivir and Isenolic® extracts showed anti-influenza activity. The 8% Isenolic® formulation showed a dose-dependent neuraminidase inhibitor activity higher than the 4% formulation, and preserved cell viability under viral infection. Thus, Isenolic® become a promising natural alternative to existing influenza treatments.

Olive leaf-derived PPAR agonist complex induces collagen IV synthesis in human skin models.

INTRODUCTION: Peroxisome proliferator-activated receptor (PPAR) agonists are known to modulate the synthesis of dermal lipids and proteins including collagens. Olive (Olea europaea) leaves have been reported to contain PPAR-binding ligands. Collagen IV, a major dermal-epidermal junction (DEJ) protein, degrades with both age and disease. Here, we report the formulation of a novel multi-ligand complex, Linefade, and its effects on collagen IV synthesis. METHODS: Linefade prepared from the leaves of Olea europaea contains 2% w/w plant extract solids dissolved in a mixture of glyceryl monoricinoleate and dimethyl isosorbide. In silico docking was performed with PPAR-α (PDB ID: 2P54). Linefade was evaluated for PPAR-α-dependent transcription in a luciferase reporter assay system. Cell viability and collagen IV levels in human dermal fibroblast cultures were measured using the MTT method and ELISA assay, respectively. Transcriptome analysis was conducted on a full-thickness reconstituted human skin (EpiDermFT) model. Ex vivo cell viability and collagen IV immunostaining were performed on human skin explants. RESULTS: In silico docking model of the major constituents (oleanolic acid and glyceryl monoricinoleate) produced a co-binding affinity of -6.7 Kcal/mole. Linefade significantly increased PPAR-α transcriptional activity in CHO cells and collagen IV synthesis in adult human dermal fibroblasts. Transcriptome analysis revealed that 1% Linefade modulated the expression of 280 genes with some related to epidermal differentiation, DEJ, PPAR, Nrf2 and retinoid pathways. An ex vivo human explant study showed that 1% Linefade, delivered via a triglycerides excipient, increased collagen IV levels along the dermal-epidermal junction by 52%. CONCLUSION: In silico modelling and in vitro and ex vivo analyses confirmed Linefade-mediated activation of PPAR-α and stimulation of collagen IV synthesis.

INTRODUCTION: Les agonistes du récepteur activé par les proliférateurs de peroxysomes (PPAR) sont connus pour moduler la synthèse des lipides cutanés et des protéines du derme, y compris des collagènes. Il a été signalé que les feuilles d'olivier (Olea europaea) contiennent des ligands de liaison aux PPAR. Le collagène IV, une protéine majeure de la jonction dermo-épidermique (DEJ), se dégrade avec l'âge et la maladie. Nous rapportons ici la formulation d'un nouveau complexe multi ligand, Linefade, et ses effets sur la synthèse du collagène IV. MÉTHODES: Le complexe Linefade préparé à partir des feuilles d'Olea europaea contient 2 % p/p de solides d'extraits végétaux dissous dans un mélange de monoricinoléate de glycéryle et d'isosorbide de diméthyle. Un docking in silico a été réalisé avec PPAR-α (PDB ID : 2P54). Linefade a été évalué pour la transcription dépendante du PPAR-α dans un système de test rapporteur à la luciférase. La viabilité cellulaire et les niveaux de collagène IV dans les cultures de fibroblastes dermiques humains ont été respectivement mesurés en utilisant la méthode MTT et le test ELISA. L'analyse du transcriptome a été réalisée sur un modèle de peau humaine reconstitué sur toute son épaisseur (EpiDermFT). La viabilité cellulaire ex vivo et l'immunomarquage du collagène IV ont été réalisés sur des explants de peau humaine. RÉSULTATS: Le modèle de docking in silico des principaux constituants (acide oléanolique et monoricinoléate de glycéryle) a produit une affinité de liaison conjointe de -6,7 Kcal/mole. Linefade a augmenté de manière significative l'activité transcriptionnelle du PPAR-α dans les cellules CHO et la synthèse du collagène IV dans les fibroblastes dermiques humains chez les personnes adultes. L'analyse du transcriptome a révélé que 1% de Linefade modulait l'expression de 280 gènes dont certains étaient liés à la différenciation épidermique, à la DEJ, au PPAR, à la voie Nrf2 et aux voies rétinoïdes. Une étude ex vivo sur des explants humains a montré que 1% de Linefade, délivré via un excipient de triglycérides, augmentait de 52% les niveaux de collagène IV le long de la jonction dermo-épidermique. CONCLUSION: La modélisation in silico et les analyses in vitro et ex vivo ont confirmé l'activation du PPAR-- α et la stimulation de la synthèse du collagène IV par Linefade.

The Olive Leaves Extract Has Anti-Tumor Effects against Neuroblastoma through Inhibition of Cell Proliferation and Induction of Apoptosis.

Neuroblastoma (NB) is the most common extra-cranial solid tumor of pediatric age. The prognosis for high-risk NB patients remains poor, and new treatment strategies are desirable. The olive leaf extract (OLE) is constituted by phenolic compounds, whose health beneficial effects were reported. Here, the anti-tumor effects of OLE were investigated in vitro on a panel of NB cell lines in terms of (i) reduction of cell viability; (ii) inhibition of cell proliferation through cell cycle arrest; (iii) induction of apoptosis; and (iv) inhibition of cell migration. Furthermore, cytotoxicity experiments, by combining OLE with the chemotherapeutic topotecan, were also performed. OLE reduced the cell viability of NB cells in a time- and dose-dependent manner in 2D and 3D models. NB cells exposed to OLE underwent inhibition of cell proliferation, which was characterized by an arrest of the cell cycle progression in G0/G1 phase and by the accumulation of cells in the sub-G0 phase, which is peculiar of apoptotic death. This was confirmed by a dose-dependent increase of Annexin V+ cells (peculiar of apoptosis) and upregulation of caspases 3 and 7 protein levels. Moreover, OLE inhibited the migration of NB cells. Finally, the anti-tumor efficacy of the chemotherapeutic topotecan, in terms of cell viability reduction, was greatly enhanced by its combination with OLE. In conclusion, OLE has anti-tumor activity against NB by inhibiting cell proliferation and migration and by inducing apoptosis.