Cardioprotective potential of oleuropein, hydroxytyrosol, oleocanthal and their combination: Unravelling complementary effects on acute myocardial infarction and metabolic syndrome.

Clinical studies have previously established the role of olive products in cardiovascular disease (CVD) prevention, whilst the identification of the responsible constituents for the beneficial effects is still pending. We sought to assess and compare the cardioprotective potential of oleuropein (OL), hydroxytyrosol (HT), oleocanthal (OC) and oleanolic Acid (OA), regarding Ischemia/Reperfusion Injury (IRI) and CVD risk factors alleviation. The scope of the study was to design a potent and safe combinatorial therapy for high-cardiovascular-risk patients on a bench-to-bedside approach. We evaluated the IRI-limiting potential of 6-weeks treatment with OL, HT, OC or OA at nutritional doses, in healthy and metabolic syndrome (MS)-burdened mice. Three combinatorial regimens were designed and the mixture with preponderant benefits (OL-HT-OC, Combo 2), including infarct sparing and antiglycemic potency, compared to the isolated compounds, was further investigated for its anti-atherosclerotic effects. In vivo experiments revealed that the combination regimen of Combo 2 presented the most favorable effects in limiting infarct size and hyperglycemia, which was selected to be further investigated in the clinical setting in Chronic Coronary Artery Syndrome (CCAS) patients. Cardiac function, inflammation markers and oxidative stress were assessed at baseline and after 4 weeks of treatment with the OL-HT-OC supplement in the clinical study. We found that OL, OC and OA significantly reduced infarct size in vivo compared to Controls. OL exhibited antihyperglycemic properties and OA attenuated hypercholesterolemia. OL-HT-OA, OL-HT-OC and OL-HT-OC-OA combination regimens were cardioprotective, whereas only OL-HT-OC mitigated hyperglycemia. Combo 2 cardioprotection was attributed to apoptosis suppression, enhanced antioxidant effects and upregulation of antioxidant enzymes. Additionally, it reduced atherosclerotic plaque extent in vivo. OL-HT-OC supplement ameliorated cardiac, vascular and endothelial function in the small-scale clinical study. Conclusively, OL-HT-OC combination therapy exerts potent cardioprotective, antihyperglycemic and anti-atherosclerotic properties in vivo, with remarkable and clinically translatable cardiovascular benefits in high-risk patients.

Evaluation of the antibacterial and antifungal properties of oleuropein, olea Europea leaf extract, and thymus vulgaris oil.

BACKGROUND: Although synthetic preservatives and antioxidants may have high antimicrobial and antioxidant activity, they are usually associated with adverse effects on human health. Currently, there is a growing interest in natural antimicrobial and antioxidant agents. This study aimed to evaluate the antimicrobial activity of two medicinal plant extracts and one active compound. Olive leaf extracts (0.2, 0.3, and 0.4% w/v), oleuropein (0.2, 0.4, and 0.6% w/v), thyme oil (0.1%), and oleuropein in combination with thyme oil (0.4% w/v and 0.1% v/v) were used against three bacterial strains (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) and two fungal strains (Candida albicans and Aspergillus niger). RESULTS: The use of oleuropein resulted in complete antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In this context, a reduction of 7 logs was achieved during the storage period (4 weeks). Oleuropein showed no fungal activity at low concentrations (0.2%), but Aspergillus niger was reduced by 2.35 logs at higher concentrations (0.6% w/v). Similar antibacterial and antifungal properties were observed for the olive leaf extracts. Oleuropein at a concentration of 0.4 w/v and a mixture of oleuropein and thyme at concentrations of 0.4 and 0.1 (v/v) showed strong antimicrobial activity against the studied microorganisms. CONCLUSION: Olive leaf extract, thyme oil, and oleuropein have strong antibacterial and weak antifungal properties. There was a good synergistic effect between oleuropein and thymol.

Use of Olives-derived Phytochemicals for Prevention and Treatment of Atherosclerosis: An Update.

Mediterranean diet is frequently associated with longevity and a lower incidence of adverse cardiovascular events because of the biological activities and health effects of olives - its key component. Olive oil, olive leaf extract, fruits and different by-products contain many bioactive components that exert anti-oxidant, anti-inflammatory and anti-apoptotic activities. In this review, we focus on the recent studies exploring molecular mechanisms underlying the cardioprotective properties of different olive oils, olive leave extracts, and specific micro-constituents (such as oleuropein, tyrosol, hydroxytyrosol and others) in vitro on rodent models and in clinical trials on human subjects. Particularly, hydroxytyrosol and oleuropein were identified as the major bioactive compounds responsible for the antioxidant, anti-inflammatory, anti-platelet aggregation and anti-atherogenic activities of olive oil. In total, the discussed results demonstrated a positive association between the consumption of olive oil and improvement in outcomes in atherosclerosis, diabetes, myocardial infarction, heart failure, hypertension and obesity.

Pretreatment with oleuropein protects the neonatal brain from hypoxia-ischemia by inhibiting apoptosis and neuroinflammation.

Hypoxic-ischemic (HI) encephalopathy is a cerebrovascular injury caused by oxygen deprivation to the brain and remains a major cause of neonatal mortality and morbidity worldwide. Therapeutic hypothermia is the current standard of care but it does not provide complete neuroprotection. Our aim was to investigate the neuroprotective effect of oleuropein (Ole) in a neonatal (seven-day-old) mouse model of HI. Ole, a secoiridoid found in olive leaves, has previously shown to reduce damage against cerebral and other ischemia/reperfusion injuries. Here, we administered Ole as a pretreatment prior to HI induction at 20 or 100 mg/kg. A week after HI, Ole significantly reduced the infarct area and the histological damage as well as white matter injury, by preserving myelination, microglial activation and the astroglial reactive response. Twenty-four hours after HI, Ole reduced the overexpression of caspase-3 and the proinflammatory cytokines IL-6 and TNF-α. Moreover, using UPLC-MS/MS we found that maternal supplementation with Ole during pregnancy and/or lactation led to the accumulation of its metabolite hydroxytyrosol in the brains of the offspring. Overall, our results indicate that pretreatment with Ole confers neuroprotection and can prevent HI-induced brain damage by modulating apoptosis and neuroinflammation.

IL-17A Drives Oxidative Stress and Cell Growth in A549 Lung Epithelial Cells: Potential Protective Action of Oleuropein.

IL-17A drives inflammation and oxidative stress, affecting the progression of chronic lung diseases (asthma, chronic obstructive pulmonary disease (COPD), lung cancer, and cystic fibrosis). Oleuropein (OLP) is a polyphenolic compound present in olive oil and widely included in the Mediterranean diet. It exerts antioxidant and anti-inflammatory activities, oxidative stress resistance, and anticarcinogenic effects with a conceivable positive impact on human health. We hypothesized that OLP positively affects the mechanisms of oxidative stress, apoptosis, DNA damage, cell viability during proliferation, and cell growth in alveolar epithelial cells and tested its effect in a human alveolar epithelial cell line (A549) in the presence of IL-17A. Our results show that OLP decreases the levels of oxidative stress (Reactive Oxygen Species, Mitochondrial membrane potential) and DNA damage (H2AX phosphorylation-ser139, Olive Tail Moment data) and increases cell apoptosis in A549 cells exposed to IL-17A. Furthermore, OLP decreases the number of viable cells during proliferation, the migratory potential (Scratch test), and the single cell capacity to grow within colonies as a cancer phenotype in A549 cells exposed to IL-17A. In conclusion, we suggest that OLP might be useful to protect lung epithelial cells from oxidative stress, DNA damage, cell growth, and cell apoptosis. This effect might be exerted in lung diseases by the downregulation of IL-17A activities. Our results suggest a positive effect of the components of olive oil on human lung health.

In vitro Effects of Olive Leaf Extract (Oleuropein) on Human Sperm Parameters and Oxidative Stress Induced by Bacterial Lipopolysaccharide (LPS).

Recently, biomolecules from natural products have paved the way for novel drug in the treatment of some diseases in vitro and in vivo models as diabetes, cancer and infertility. As such, we aimed to evaluate the capacity of Oleuropein (OLE), the major bio-phenol in olive leaf, to protect human sperm against bacterial lipopolysaccharide (LPS) inducing sperm oxidative stress and defective sperm functions. The toxic effect of OLE on human sperm was firstly investigated by evaluating sperm parameters after incubation during 60 minutes with different concentrations. Determined non-toxic concentration was then used to evaluate the capacity of OLE to protect sperm against LPS oxidative damages and sperm parameters alterations. Thus, sperms were consecutively incubated with LPS (10 µg/mL) and OLE (40 µg/mL) during 60 minutes, then submitted to sperm parameters analysis and oxidative stress assessment by measuring malondialdehyde (MDA), carbonyl groups (CG) levels and the activity of some antioxidant enzymes: superoxide dismutase (SOD) and catalase (CAT). A significant decrease of sperm parameters as well as a significant increase in MDA levels, CG levels, SOD and CAT activities was found after stimulation by LPS. However, a non-significant difference was shown comparing sperms treated by LPS and OLE with LPS-treated control sperms. Consequently, despite the high antioxidant and anti-inflammatory capacity of OLE reported in diverse cells, this phenolic compound seems to be not appropriate to protect human sperm in vitro against induced LPS oxidative stress and seems to have a "double-edged sword" behavior.

Silver Nanoparticles Loaded With Oleuropein Alleviates LPS-Induced Acute Lung Injury by Modulating the TLR4/P2X7 Receptor-Mediated Inflammation and Apoptosis in Rats.

Toll-like receptor 4 (TLR-4) ligands were initially shown to be the source of lipopolysaccharide (LPS), a gram-negative bacterium's cell wall immunostimulatory component. Oxidative stress, apoptosis, and inflammation are all potential effects of LPS treatment on the lungs. By triggering oxidative stress and inflammation, these negative effects could be avoided. Robust flavonoid oleuropein (OLE) exhibits anti-inflammatory, antiproliferative, and antioxidative properties. A nanodelivery system could improve its low bioavailability, making it more effective and useful in treating chronic human ailments. This study evaluates the effects of AgNP-loaded OLE on LPS-induced lung injury in rats in terms of TLR4/P2X7 receptor-mediated inflammation and apoptosis. Forty-eight male albino rats were randomly divided into eight groups. Drugs were administered to the groups in the doses specified as follows: Control, LPS (8 mg/kg ip), OLE (50 mg/kg) AgNPs (100 mg/kg), OLE + AgNPs (50 mg/kg), LPS + OLE (oleuropein 50 mg/kg ig + LPS 8 mg/kg ip), LPS + AgNPs (AgNPs 100 mg/kg ig + LPS 8 mg/kg ip), and LPS + OLE + AgNPs (OLE + AgNPs 50 mg/kg + LPS 8 mg/kg ip). After the applications, the rats were decapitated under appropriate conditions, and lung tissues were obtained. Oxidative stress (SOD, MDA, and GSH), and inflammation (IL-6, IL-1ß, TNF-α, Nrf2, P2X7R, AKT, and TLR4) parameters were evaluated in the obtained lung tissues. Additionally, histopathology studies were performed on lung tissue samples. The data obtained were evaluated by comparison between groups. Both OLE and OLE + AgNPs showed potential in reducing oxidative stress, inflammation, and apoptosis (p < 0.05). These findings were supported by histopathological analysis, which revealed that tissue damage was reduced in OLE and OLE + AgNPs-treated groups. According to the results, LPS-induced lung injury can be reduced by using nanotechnology and producing OLE + AgNP.

Oleuropein mitigates non-alcoholic fatty liver disease (NAFLD) and modulates liver metabolites in high-fat diet-induced obese mice via activating PPARα.

BACKGROUND: This study aimed to elucidate the mechanism of oleuropein (OLE) ameliorates non-alcoholic fatty liver disease (NAFLD) and its underlying mechanisms. RESULTS: Male C57BL/6J mice were fed either a low-fat diet (LFD), a high-fat diet (HFD), or a HFD supplemented with 0.03% (w/w) OLE for 16 weeks. OLE supplementation decreased body weight and liver weight, improved serum lipid profiles, and ameliorated HFD-induced hepatic dysfunction. Liver metabolomics analysis revealed that OLE increased the levels of nicotinamide, tauroursodeoxycholic acid, taurine, and docosahexaenoic acid, which were beneficial for lipid homeostasis and inflammation regulation. OLE exerted its protective effects by activating peroxisome proliferator-activated receptor alpha (PPARα), a key transcription factor that regulates fibroblast growth factor 21 (FGF21) expression and modulates lipid oxidation, lipogenesis and inflammation pathways. Importantly, OLE supplementation did not significantly affect body weight or liver weight in PPARα knockout (PPARα KO) mice, indicating that PPARα is essential for OLE-mediated NAFLD prevention. CONCLUSION: Our results suggest that OLE alleviates NAFLD in mice by activating PPARα and modulating liver metabolites. © 2024 Society of Chemical Industry.

Multiple-heated cooking oil promotes early hepatic and renal senescence in adult male rats: the potential regenerative capacity of oleuropein.

For economic purposes, cooking oil is repeatedly heated in food preparation, which imposes serious health threats. This study investigated the detrimental effects of multiple-heated cooking oil (MHO) on hepatic and renal tissues with particular focusing on cellular senescence (CS), and the potential regenerative capacity of oleuropein (OLE). Adult male rats were fed MHO-enriched diet for 8 weeks and OLE (50 mg/kg, PO) was administered daily for the last four weeks. Liver and kidney functions and oxidative stress markers were measured. Cell cycle markers p53, p21, cyclin D, and proliferating cell nuclear antigen (PCNA) were evaluated in hepatic and renal tissues. Tumor necrosis factor-α (TNF-α) and Bax were assessed by immunohistochemistry. General histology and collagen deposition were also examined. MHO disturbed hepatic and renal structures and functions. MHO-fed rats showed increased oxidative stress, TNF-α, Bax, and fibrosis in liver and kidney tissues. MHO also enhanced the renal and hepatic expression of p53, p21, cyclin D and PCNA. On the contrary, OLE mitigated MHO-induced oxidative stress, inflammatory burden, apoptotic and fibrotic changes. OLE also suppressed CS and preserved kidney and liver functions. Collectively, OLE displays marked regenerative capacity against MHO-induced hepatic and renal CS, via its potent antioxidant and anti-inflammatory effects.

Effect of Oleuropein on Anti-Obesity and Uncoupling Protein 1 Level in Brown Adipose Tissue in Mild Treadmill Walking Rats with Diet-Induced Obesity.

Oleuropein aglycone (OA), which is the absorbed form of oleuropein, is a major phenolic compound in extra virgin olive oil. We analyzed the anti-obesity effect of OA intake combined with mild treadmill walking (MTW, 4 m/min for 20 min/d, 5-6 d/wk, without electric shocks and slope) in rats under a high-fat diet (HF). Four-week-old male Sprague-Dawley rats (n=28) were equally divided into four groups: control (HF), 0.08% oleuropein-supplemented HF (HFO), HF with MTW (HF+W), and HFO with MTW (HFO+W) groups. After 28 d, the inguinal subcutaneous fat content and weight gain were significantly lower in the HFO+W group than in the control group. The HFO+W group also had significantly higher levels of urinary noradrenaline secretion, interscapular brown adipose tissue, uncoupling protein 1, brain transient receptor potential ankyrin subtype 1 (TRPA1), vanilloid subtype 1 (TRPV1), and brain-derived neurotrophic factor (BDNF) than the control group. Especially, the HFO+W group showed a synergistic effect on noradrenaline secretion. Therefore, OA combined with MTW may accelerate the enhancement of UCP1 and BDNF levels in rats with HF-induced obesity by increasing noradrenaline secretion after TRPA1 and TRPV1 activation.

Interface interactions driven antioxidant properties in olive leaf extract/cellulose nanocrystals/poly(butylene adipate-co-terephthalate) biomaterials.

Functional packaging represents a new frontier for research on food packaging materials. In this context, adding antioxidant properties to packaging films is of interest. In this study, poly(butylene adipate-co-terephthalate) (PBAT) and olive leaf extract (OLE) have been melt-compounded to obtain novel biomaterials suitable for applications which would benefit from the antioxidant activity. The effect of cellulose nanocrystals (CNC) on the PBAT/OLE system was investigated, considering the interface interactions between PBAT/OLE and OLE/CNC. The biomaterials' physical and antioxidant properties were characterized. Morphological analysis corroborates the full miscibility between OLE and PBAT and that OLE favours CNC dispersion into the polymer matrix. Tensile tests show a stable plasticizer effect of OLE for a month in line with good interface PBAT/OLE interactions. Simulant food tests indicate a delay of OLE release from the 20 wt% OLE-based materials. Antioxidant activity tests prove the antioxidant effect of OLE depending on the released polyphenols, prolonged in the system at 20 wt% of OLE. Fluorescence spectroscopy demonstrates the nature of the non-covalent PBAT/OLE interphase interactions in π-π stacking bonds. The presence of CNC in the biomaterials leads to strong hydrogen bonding interactions between CNC and OLE, accelerating OLE released from the PBAT matrix.

Oleuropein has hypophagic effects in broiler chicks.

Oleuropein, a phenolic compound derived from olives, has known glucoregulatory effects in mammalian models but effects in birds are unknown. We investigated effects of dietary supplementation and exogenous administration of oleuropein on broiler chick feed intake and glucose homeostasis during the first 7 days post-hatch. One hundred and forty-eight day-of-hatch broiler chicks were randomly allocated to one of four dietary treatments with varying oleuropein concentrations (0, 250, 500, or 1,000 mg/kg). Body weight and breast muscle and liver weights were recorded on day 7. In the next experiment, chicks received intraperitoneal (IP) injections of oleuropein at doses of 0 (vehicle), 50, 100, or 200 mg/kg on day 4 post-hatch, with feed intake and blood glucose levels measured thereafter. Lastly, chicks fed a control diet were fasted and administered intracerebroventricular (ICV) injections of oleuropein at doses of 0, 50, 100, or 200 µg, after which feed intake was recorded. Results indicated that IP and ICV injections led to decreased feed intake, primarily at 60 min post-injection, with effects diminishing by 90 min in the IP study. Blood glucose levels decreased 1-h post-IP injection at higher oleuropein doses. These findings suggest that oleuropein acts as a mild appetite suppressant and influences energy metabolism in broiler chickens.

Polyphenol-Rich Extracts from Agroindustrial Waste and Byproducts: Results and Perspectives According to the Green Chemistry and Circular Economy.

Polyphenols are natural secondary metabolites found in plants endowed with multiple biological activities (antioxidant, anti-inflammatory, antimicrobial, cardioprotective, and anticancer). In view of these properties, they find many applications and are used as active ingredients in nutraceutical, food, pharmaceutical, and cosmetic formulations. In accordance with green chemistry and circular economy strategies, they can also be recovered from agroindustrial waste and reused in various sectors, promoting sustainable processes. This review described structural characteristics, methods for extraction, biological properties, and applications of polyphenolic extracts obtained from two selected plant materials of the Mediterranean area as olive (Olea europaea L.) and pomegranate (Punica granatum L.) based on recent literature, highlighting future research perspectives.

Effects of Olea oleaster leaf extract and purified oleuropein on ethanol-induced gastric ulcer in male Wistar rats.

Objectives: Evaluating the effect of fresh Oleaster leaf extract (OLE) and purified oleuropein (OLR) on ethanol-induced gastric ulcers in rats. HPLC analysis demonstrates the presence of various polyphenol compounds such as ligstroside, luteolin derivative, oleuropein, and comselogoside. Materials and Methods: Gastric ulcer was induced by administration of ethanol by the gastric gavage route. The olive leaf extract was analyzed by HPLC-PDA-ESI-MS, and OLR was purified. These two compounds were given 2 hr before gastric ulcer induction by ethanol. Results: This study verified that OLE and purified OLR protect from ethanol-induced gastric ulceration and damage, evidenced by the significant decrease in gastric ulcer urea (by 74 and 58% respectively) and stomach mucus content (by 169 and 87% respectively). In addition, the ulcer index (UI) and curative index (CI) levels in the stomach of the rats treated with this supplement were also suppressed by 55 and 46%, respectively. OLE and OLR also decreased the gastric myeloperoxidase (MPO) activity and ameliorated the nitric oxide (NO) content. OLE and OL also ingestion suppressed gastric tumor necrosis factor-alpha (TNF-α) and interleukin (IL-6) rates. Macroscopic and histological findings revealed that OLE and OLR protect from gastric hemorrhage, severe disruption of the gastric mucosa, and neutrophil infiltration. Conclusion: Overall, the findings demonstrate that OLE and OLR have both promising potential with regard to the inhibition of gastric hemorrhage and lesions.

Oleuropein, a Component of Extra Virgin Olive Oil, Improves Liver Steatosis and Lobular Inflammation by Lipopolysaccharides-TLR4 Axis Downregulation.

Gut-dysbiosis-induced lipopolysaccharides (LPS) translocation into systemic circulation has been suggested to be implicated in nonalcoholic fatty liver disease (NAFLD) pathogenesis. This study aimed to assess if oleuropein (OLE), a component of extra virgin olive oil, lowers high-fat-diet (HFD)-induced endotoxemia and, eventually, liver steatosis. An immunohistochemistry analysis of the intestine and liver was performed in (i) control mice (CTR; n = 15), (ii) high-fat-diet fed (HFD) mice (HFD; n = 16), and (iii) HFD mice treated with 6 µg/day of OLE for 30 days (HFD + OLE, n = 13). The HFD mice developed significant liver steatosis compared to the controls, an effect that was significantly reduced in the HFD + OLE-treated mice. The amount of hepatocyte LPS localization and the number of TLR4+ macrophages were higher in the HFD mice in the than controls and were lowered in the HFD + OLE-treated mice. The number of CD42b+ platelets was increased in the liver sinusoids of the HFD mice compared to the controls and decreased in the HFD + OLE-treated mice. Compared to the controls, the HFD-treated mice showed a high percentage of intestine PAS+ goblet cells, an increased length of intestinal crypts, LPS localization and TLR4+ expression, and occludin downregulation, an effect counteracted in the HFD + OLE-treated mice. The HFD-fed animals displayed increased systemic levels of LPS and zonulin, but they were reduced in the HFD + OLE-treated animals. It can be seen that OLE administration improves liver steatosis and inflammation in association with decreased LPS translocation into the systemic circulation, hepatocyte localization of LPS and TLR4 downregulation in HFD-induced mouse model of NAFLD.

An Eco-Friendly Supercritical CO2 Recovery of Value-Added Extracts from Olea europaea Leaves.

An eco-friendly approach towards the recovery of value-added extracts from olive tree leaves with the aid of supercritical CO2 at 30 MPa was carried out. The impact of extraction temperature (35-90 °C) and presence of co-solvents (ethanol, water, and aqueous ethanol) on the total phenolic, flavonoid, and pigment content, as well as oleuropein, hydroxytyrosol, tyrosol, and α-tocopherol content was determined. In addition, the antioxidant activity of extracts from tree leaves using DPPH, ABTS, and CUPRAC assays was investigated. The results of the study showed that the most effective supercritical CO2 extraction was at 90 °C with an addition of ethanol, which enabled the separation of extract with the highest content of tested compounds. Some of the highest recorded values were for oleuropein 1.9 mg/g, for carotenoids 5.3 mg/g, and for α-tocopherol 2.0 mg/g. Our results are expected to contribute to the efforts towards the valorization of olive leaves as a sustainable source of valuable compounds, and boost local economies as well as the interest of pharmaceutical, food, and cosmetic industries for novel food by-product applications.

Genetic insights and therapeutic potential for colorectal cancer: mutation analysis of KRAS gene and efficacy of Oleuropein-conjugated iron oxide nanoparticles.

This study aimed to address the challenges of treating advanced stages of colon cancer (CRC) by exploring potential therapeutic options. The research focused on the genetic aspects of CRC, specifically the mutation rate of the KRAS gene, along with other genes like TTN, APC, MUC16, and TP53, using the TCGA dataset. Additionally, the study investigated the efficacy of Oleuropein, a polyphenolic compound found in olives, in combating CRC by using iron oxide nanoparticles coated with glucose and conjugated with Oleuropein. The study characterized the physicochemical properties of the nanoparticles, and the cytotoxic effects of the nanoparticles were evaluated on CRC and normal fibroblast cell lines, demonstrating significantly higher cytotoxicity against CRC cells compared to normal cells. Furthermore, the study analyzed gene expression changes using the GSE124627 dataset to understand the influence of KRAS alterations. It identified numerous upregulated and downregulated genes in KRAS-overexpressing samples, suggesting their involvement in critical cancer-related pathways. These findings suggest that KRAS-influenced genes could serve as potential therapeutic targets for CRC treatment. The study also examined the expression levels of identified genes in CRC samples compared to normal samples. Among the upregulated genes, 22 showed significant increases in cancer samples, while 14 downregulated genes exhibited decreased expression in both KRAS-influenced and cancer samples. Cox regression analysis identified specific upregulated genes, including ANKZF1, SNAI1, PPFIA4, SIX4, and NOTUM, associated with poor prognosis. Kaplan-Meier analysis further confirmed the correlation between increased expression of these genes and higher patient mortality rates. In conclusion, this study provided valuable insights into the genetic aspects of CRC and potential therapeutic strategies. The use of Oleuropein-conjugated iron oxide nanoparticles showed promising cytotoxic effects on colon cancer cells. These findings contribute to advancing our understanding of CRC and offer potential targets for further investigation and the development of novel therapeutic approaches.

Gastrointestinal digestion of olive leaf waste from olive mill production chain in a simulator of the gastrointestinal tract.

BACKGROUND: Currently, olive leaves are considered waste, although their high phenolic content makes them a source of antioxidants that could be used directly. The aim of this work was to study the behavior of phenolic compounds contained in olive leaf from the olive mill production chain during their gastrointestinal digestion. RESULTS: Phenolic compounds in the gastric digestion analyzed by high-performance liquid chromatography-diode array detection-mass spectrometry increased by 58% to 314.5% compared to the meal, while in the intestinal stage they ranged from 1.87 to 9.04 times higher. An increase of between 187% and 903% in bioaccessibility of phenolic compounds in the intestinal phase was observed, except for verbascoside. Furthermore, such compounds were fully bioavailable, except for apigenin-7-O-glucoside, which showed a bioavailability of 56%. CONCLUSION: The current study showed that the concentration of oleuropein, apigegin-7-O-glucoside, hydroxytyrosol hexoside and hydroxytyrosol contained in olive leaf continued to be extracted during the gastrointestinal digestion process. Furthermore, the results obtained with respect to their bioaccessibility and bioavailability suggest a good disposition to pass into the bloodstream where they could exert beneficial effects. Therefore, these results are promising for olive leaf becoming a consumable by-product that could be directly ingested through a simple infusion. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Oleuropein impact on colorectal cancer.

Colorectal cancer (CRC) is considered the third most common cancer in the world. In Mediterranean region, olives and olive oil play a substantial role in diet and medical traditional behaviors. They totally believe that high consumption of olive products can treat a wide range of diseases and decrease risk of illness. Oleuropein is the main active antioxidant molecule found in pre-mature olive fruit and leaves. Recently, it has been demonstrated that oleuropein is used in cancer therapy as an anti-proliferative and apoptotic agent for some cancer cells. In this review, we would like to explore the conclusive effects of oleuropein on CRC with respect to in vitro and in vivo studies.

Targeting resistant breast cancer stem cells in a three-dimensional culture model with oleuropein encapsulated in methacrylated alginate microparticles.

BACKGROUND: Cancer stem cells (CSCs) are a subpopulation of cancer cells that are believed to be responsible for tumor initiation, progression, metastasis, and resistance to conventional therapies. Oleuropein as a natural compound found in olive leaves and olive oil, has potential therapeutic effects in cancer treatment, particularly in targeting CSCs. It induces apoptosis in CSCs while sparing normal cells, inhibit proliferation, migration, and invasion, and suppress the self-renewal ability of CSCs. Additionally, oleuropein has shown synergistic effects with conventional chemotherapy drugs, enhancing their efficacy against CSCs. OBJECTIVES: This study aims to selectively target therapeutically resistant cancer stem cells (CSCs) within a heterogeneous tumor population by utilizing oleuropein (OLE) encapsulated in methacrylated alginate (OLE-mALG) within an in vivo-like microenvironment. PURPOSE: This study aims to target therapeutically resistant cancer stem cells (CSCs) with oleuropein (OLE) encapsulated in the methacrylated alginate (OLE-mALG) in a heterogeneous tumor population with an in vivo-like microenvironment. METHODS: Co-culture of CSCs with non-tumorogenic MCF-12 A cells was performed, the 3D breast cancer model was supported with methocel/matrigel/collagen-I, and vascularization was ensured with human umbilical vein endothelial cells (HUVEC). Then, OLE-loaded methacrylated alginate microparticles (mALG) were formed by dual crosslinking in the presence of both ionic and visible light obtained with a droplet based microfluidic system. The characterization and effectiveness of the produced OLE-mALG were evaluated by the FTIR, swelling/degradation/release analysis. Before producing OLE loaded mALG microparticles, a preliminary study was carried out to determine the effective dose of OLE for cells and the duration of OLE action on MCF-7, CSCs and MCF-12 A. Subsequently, CSC viability (WST-1), apoptosis (Bcl-2, Bax, caspase-3, caspase-9), stemness (OCT3/4, NANOG, SOX2), EMT profile (E-cadherin, Vimentin, Slug) and proliferation (SURVIVIN, p21, CYCLIN D1) after OLE-mALG treatment were all evaluated in the 3D model. RESULTS: OLE was encapsulated in mALG with an efficiency of 90.49% and released 73% within 7 h. OLE-mALG induced apoptosis through the decrease in anti-apoptotic Bcl-2 and an increase in pro-apoptotic Bax, caspase-3, and caspase-9 protein levels. While Vimentin and Slug protein levels decreased after 200 µg/mL OLE-mALG treatment to 3D breast cancer culture, E-cadherin levels increased. OLE-mALG treatment to CSC co-culture led to a decrease in proliferation by triggering p21/SURVIVIN expressions, and also resulted in an increase in stemness genes (OCT3/4/NANOG/SOX2). CONCLUSION: 200 µg/mL OLE-loaded mALG microparticles suppressed epithelial-to-mesenchymal transition by suppressing Vimentin and Slug protein levels, and increased E-cadherin levels in the 3D breast cancer model we created with CSCs, MCF-12 A and HUVECs. This complex system may allow the use of personalized cells for rapid drug screening in preclinical studies compared to animal experiments. OLE-mALG showed apoptotic and metastasis suppressive properties in cancer cells and it was concluded that it can be used in combination with or alternatively with chemotherapeutic agents to target breast cancer stem cells.