Search Results (269)

Background/Objectives: Oleuropein is a bioactive phenolic compound from olive leaves with antimicrobial and antioxidant activity. This study aimed to develop a sprayable oral gel containing an oleuropein-rich aqueous extract and to evaluate its pharmaceutical performance antimicrobial efficacy and in ovo biological response. Methods: Oleuropein content was quantified using a validated chromatographic method. Polymeric systems were screened to select an optimized sprayable formulation. Physicochemical stability, dose uniformity, and antimicrobial activity against major cariogenic bacteria were evaluated. In ovo biological evaluation was conducted using the chick chorioallantoic membrane angiogenesis model together with histopathological examination of embryonic heart and liver tissues. Results: Oleuropein content was determined as 288.6 µg/mL in the olive leaf extract and 255.1 µg/mL in the final formulation. The optimized oral spray showed stable physicochemical properties, with pH maintained at 6.90 ± 0.02 and no relevant changes in viscosity during storage. The mean delivered dose per actuation was 0.128 ± 0.015 g, corresponding to 32.6 µg oleuropein per spray. The formulation exhibited inhibitory activity against all tested cariogenic microorganisms, with MIC values ranging from 13.3 to 170.7 µg/mL and MBC values generally two-fold higher. In the CAM assay, significant concentration- and time-dependent antiangiogenic effects were observed after 24–48 h at moderate and higher concentrations. Histopathological evaluation revealed dose-dependent acute degenerative and congestive changes in heart and liver tissues without evidence of fibrosis or steatosis. Conclusions: The oleuropein-based sprayable oral gel is a promising localized delivery system with adequate stability dose uniformity and antimicrobial efficacy. In ovo findings provide a conservative assessment of systemic exposure and support further development for oral biofilm and caries-related applications. Full article

The nutritional composition of insect-derived meals is strongly influenced by insect diet, while defatting can further modulate nutritional quality. However, some defatting methods, such as supercritical CO₂ extraction, depend on sample properties, including density and macromolecule distribution. Therefore, diet-induced changes may affect lipid extraction efficiency and kinetics, a relationship that remains unexplored. This study evaluated the impact of feeding Hermetia illucens larvae with by-products from olive oil industry (olive leaves, OL, at 15, 30 or 50%; dry full-fat olive pomace, OP, at 30, 50, 70, 90%) or quinoa processing (husk, QH, at 15, 30 or 50%) on supercritical CO₂ defatting performance, meal composition, amino acid profile and digestibility. Despite diet-induced variations in lipid accumulation, defatted kinetics mainly depended on the content and solubility of extractable material, while differences in packed bed microstructure had a minor effect. Protein-rich meals were obtained (25–35%), although most diets reduced protein content, except OP50. QH15 and OP30 worsened essential amino acids in meals, whereas OP50 improved them. Chitin content increased, especially for OP-based meals. Digestibility slightly improved with OP30, OP70, QH15, and QH50. These results show the potential of olive oil and quinoa by-products to be up-cycled by H. illucens into high-value insect meals, without compromising the processing by supercritical CO₂ defatting, supporting sustainable insect-based food and feed production. Full article

Olive leaf phenols are recognized for their antioxidant and anti-inflammatory properties. A hydroalcoholic extract of Olea europaea L. cv. Ogliarola leaves was recovered with an ultrasound-assisted extraction using green solvents. Phenol content was investigated by means of liquid chromatography coupled with photodiode array and mass spectrometer detectors. Extract cytotoxicity was determined in SH-SY5Y neuroblastoma cells by the MTT assay to establish non-cytotoxic concentrations. The effects of the extract under lipopolysaccharide-induced conditions were investigated by assessing oxidative stress and lipid peroxidation through malondialdehyde quantification using the thiobarbituric acid assay. Antiglycation capacity was examined with a BSA methylglyoxal model. In parallel, quantitative real-time PCR was employed to assess the modulation of inflammation- and oxidative stress-related genes (TLR4, NF-κB, IL-6, IL-8, Nrf2, and HO-1), providing molecular insights into the extract’s bioactivity. The extract did not exert cytotoxic effects at the selected concentrations and with modulated oxidative stress, lipid peroxidation, protein glycation, and gene expression profiles associated with inflammatory and redox pathways in neuronal cells. These data demonstrated that olive leaf extract, rich in phenols, influenced multiple biochemical and molecular endpoints relevant to neuronal physiology, supporting its potential application as a nutraceutical ingredient for the modulation of oxidative and glycation-related processes. Full article

This research focuses on the additional valorization of olive leaves, a by-product of regular olive pruning, by increasing their secondary metabolite content through the combined application of biochar and a phenolic extract from olive leaves. A suspension of biochar, obtained by the pyrolysis of grapevine pruning residues, was prepared by mixing it in demineralized water (1.5 g; 5 L; 24 h). The phenolic extract was obtained by extracting lyophilized and ground olive leaves in demineralized water (50 g; 5 L; 24 h), while the combined preparation was obtained in an analogous manner (1.5 g biochar; 50 g olive leaf powder; 5 L water; 24 h). Treatments were applied at the beginning of July, 50 days after anthesis (May 16th) and included the following: (i) control treatment (demineralized water), (ii) biochar solution, (iii) phenolic extract solution, and (iv) a combined aqueous preparation of biochar and phenolic extract, all with the addition of a wetting agent. Trees of the olive cultivars Leccino and Istarska bjelica were sprayed with the corresponding preparation until runoff. Olive leaves were sampled three weeks after treatment (July 26th) and, after washing and drying, and were prepared for LC-MSMS analysis. Both biochar-based treatments induced the most potent effects, although responses differed between cultivars. In particular, apigenin derivatives, hydroxytyrosol, luteolin-7-rutinoside, and the secoiridoid oleacein showed apparent differences between biochar treatments and the control. Overall, higher concentrations of the sum of detected secoiridoids were observed in the leaf samples of ‘Istarska bjelica’ under BCH and BCH+PH treatments, whereas no such differences were found for ‘Leccino’ cultivar. Further research is needed to clarify the cultivar-dependent response of secondary metabolism in these olive cultivars and the mechanisms by which biochar foliar application modulates metabolite profiles. Full article

Background: Acute pancreatitis is a significant global disease. This study investigated the phytochemical composition and potential protective effects of Equisetum arvense L. (horsetail) ethanol extract and Olea europaea L. (olive leaves) aqueous extract against metronidazole (MTZ)-induced pancreatic damage in rats. Materials and Methods: Rats were randomly divided into six groups: Group I (control) received saline; Group II (Metronidazole) received only MTZ (400 mg/kg). Group III (Equisetum arvense group) received E. arvense 100 mg/kg. Group IV (Olea europaea) received 400 mg/kg of O. europaea. Group V (MTZ + E. arvense) received both MTZ (400 mg/kg) and E. arvense (100 mg/kg). Group VI (MTZ + O. europaea) received MTZ (400 mg/kg) and O. europaea (400 mg/kg). All treatments were delivered daily via the oral route. After 60 days, serum amylase, lipase, protease, and glucose levels, oxidative parameters “malondialdehyde (MDA), catalase (CAT), mRNA relative expression of pancreatic Pik3ca (phosphatidylinosi-tol-4,5-bisphosphate 3-kinase, catalytic subunit alpha), AKT (AKT Serine/Threonine Kinase 1), Nrf-2 (Nuclear factor, erythroid 2-like 2), TNFα (tumor necrosis factor alpha), and IL-1β (interleukin-1 beta genes, an apoptotic marker “caspase-3,” and histopathological changes were estimated. Results: HPLC analysis revealed that horsetail extract contained caffeic acid, catechin, rutin, and kaempferol, while olive leaf extract was dominated by oleuropein. MTZ administration significantly elevated serum levels of pancreatic enzymes (lipase, amylase, and protease) and glucose and increased oxidative stress markers, such as MDA, while reducing catalase (CAT) activity. Co-treatment with MTZ and horsetail, or MTZ and olive extracts, mitigated these effects, especially horsetail, which restored CAT levels and reduced MDA concentrations. qPCR analysis showed MTZ upregulated inflammatory genes (TNFα, IL-1β) and downregulated antioxidant and survival-related genes (Pik3ca, AKT, Nrf-2). Horsetail co-treatment significantly reversed these gene expression patterns. Histopathological and immunohistochemical analyses confirmed MTZ-induced pancreatic tissue degeneration and increased cleaved caspase-3 expression, both of which were notably alleviated by horsetail extract. Conclusions: These findings highlight the superior protective efficacy of Equisetum arvense over Olea europaea in ameliorating MTZ-induced pancreatic toxicity, potentially through anti-inflammatory, antioxidant, and anti-apoptotic mechanisms. Full article

Olive leaves are a valuable source of natural bioactive compounds, particularly polyphenols and flavonoids, recognized for their potent antioxidant and health-promoting properties. The extraction of these high-value products has gained increasing attention due to their relevance in food sustainability and the circular economy. However, the concentrations and profiles of these compounds vary substantially depending on the olive variety and the extraction method applied. This study evaluated the influence of extraction method and olive variety on the phenolic composition and antioxidant potential of olive leaf extracts from nine cultivars cultivated in Morocco. Two conventional extraction techniques, maceration and Soxhlet extraction, were compared for their efficiency in recovering extraction yield, total phenolic content, total flavonoid content, and total condensed tannins, along with antioxidant activity measured by DPPH and ABTS radical scavenging assays. Analyses of variance indicated that varietal differences were the predominant source of variation in phenolic composition and antioxidant capacity, whereas the extraction method mainly influenced yield. Soxhlet extraction enhanced phenolic recovery and antioxidant potential, while maceration favored flavonoid extraction. These findings highlight the potential of olive leaf extracts derived from Manzanilla, Haouzia, Picual, and Moroccan Picholine varieties using Soxhlet as sustainable natural antioxidants for functional, cosmetic, and pharmaceutical uses. Full article

The Olea europaea L., commonly known as the European olive, has been recognized for centuries as one of the most valuable species among useful plants. In contemporary applications, the olive tree provides a wide array of raw materials utilized in the food, pharmaceutical, and nutraceutical industries. Extracts derived from the leaves, bark, and fruits of O. europaea have also gained significant relevance in dermatological and cosmetic formulations. The aim of this paper was to review scientific studies published between 2019 and 2025 concerning the application of olive oil and other derivatives of the European olive in the care of skin, hair, and nails. The analysis underscores the role of olive-derived bioactives in wound healing, stretch mark management, and skin regeneration, highlighting compounds such as oleocanthal and oleuropein in hydration, elasticity, wrinkle reduction, and photoprotection relevant to skin aging. The evidence for olive oil in hair and nail care mainly highlights their moisturizing and strengthening effects, though studies remain limited. O. europaea derivatives show a favorable safety profile with low allergenic potential, and their availability and minimal sensitization risk support use in home cosmetics. The importance of the European olive and its products is expected to grow in the coming years. However, the availability of technologies for processing waste materials obtained from this plant, as well as the associated technological costs, remain significant limitations. Full article

In the present study, alginate–silver nanoparticle (Alg-AgNP) nanocomposite hydrogels possessing antibacterial activity were synthesized via an innovative route. A task-specific designed Natural Deep Eutectic Solvent (NADES), composed of glucose, lactic acid, and water, was utilized as a green extraction solvent of bioactive compounds from olive leaves (OLs). The NADES–olive leaf extract (NADES-OLE) was used as obtained for the preparation of the Alg-AgNP nanocomposite hydrogel as a multiple-role component. The NADES-OLE acts (a) as a crosslinking agent for the preparation of the alginate hydrogels, (b) as a reducing agent for the in situ synthesis of AgNPs during hydrogel formation, and (c) as a bioactivity enhancement agent due to the presence of compounds obtained from the olive leaves. The Alg-AgNP hydrogel preparation process was optimized through a Box–Behnken experimental design. The resulting nanocomposite hydrogels were characterized for their swelling capacity and water retention in phosphate buffer (pH 5.5), achieving 538% swelling capacity within 180 min and 90% water retention after 250 min. The AgNPs formed within the hydrogels were found to have an average size of 103.2 ± 5.6 nm, with a concentration of 1.2 10⁸ ± 2.2 ∗ 10⁷ particles/mL. Antibacterial testing of the nanocomposite hydrogels against foodborne pathogens, including Gram-negative (Escherichia coli, Salmonella Typhimurium, Yersinia enterocolitica) and Gram-positive bacteria (Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus), revealed significant antibacterial activity, particularly against E. coli (64.9%), Y. enterocolitica (60.6%), S. aureus (79.1%), and B. cereus (55.3%), at a concentration of 1 mg/mL. Full article

Olive cultivation generates substantial pruning waste, yet current valorization strategies focus solely on leaves despite the logistical challenges of separating them. This study optimized the extraction of bioactive compounds from unseparated pruning waste (branches and leaves) using a D-optimal design of experiments to evaluate solvent composition, temperature, and time effects in thirteen experiments. Optimized conditions were scaled up, and extracts were tested via DPPH, ORAC assays, and ROS inhibition in HaCaT cells. Extracts from unseparated pruning waste demonstrated antioxidant capacity equivalent to isolated leaf extracts, and effectiveness in reducing the oxidative stress by approximately 60% compared to the H₂O₂ condition. This approach eliminates costly leaf separation while maintaining bioactivity, offering a scalable circular economy solution for olive waste management. The practical implications are substantial: whole pruning waste valorization reduces processing costs and time, decreases agricultural waste by utilizing currently discarded branches, and simplifies supply chains for industries requiring olive-derived antioxidants. Our findings challenge the current paradigm in olive waste biorefining, providing a more economically viable and environmentally sustainable pathway for producing antioxidant-rich extracts suitable for cosmetics, nutraceutical, and pharmaceutical applications. Full article

The olive industry produces large quantities of olive leaves, an agro-industrial byproduct without commercial value and with significant environmental disposal challenges. However, olive leaves are a rich source of antioxidant compounds known for their diverse biological properties. This highlights the need for green processes that utilize environmentally friendly solvents. Thus, this research aimed to evaluate the effectiveness of two different solvents: ethanol (at concentrations of 0%, 15%, and 30%) and glycerol (also at 0%, 15%, and 30%), combined with moderate temperatures (50 °C and 70 °C) using ultrasound-assisted extraction (20 kHz and 60% amplitude for 30 min) to recover antioxidant compounds from olive leaves. Our results showed that 30% glycerol at 70 °C was more effective at recovering polyphenols (14.85 ± 0.09 mg GAE g⁻¹ dw) compared to ethanol (12.26 ± 0.13 mg GAE g⁻¹ dw) under the same conditions. Additionally, the antioxidant capacity, measured using DPPH and ORAC assays, yielded higher results with 30% glycerol, showing values of 2.65 ± 0.16 mg mL⁻¹ and 684.65 ± 20.79 µmol TE g⁻¹ dw, respectively. The polyphenol profile quantified different families of polyphenols like phenolic acids, flavanols, flavonols, stilbenes, and secoiridoids. However, oleuropein, a secoiridoid, was the most predominant polyphenol found in the extracts (1122.52 ± 33.72 μg g⁻¹ dw). Interestingly, the use of 30% ethanol at 70 °C reduced the glucose and fructose content by 48% and 84%, respectively. Therefore, glycerol emerges as an efficient green solvent for the extraction of antioxidant compounds. These findings support the valorization of this agricultural residue by recovering its valuable components, contributing to food sustainability and a circular economy. Full article

The study aimed to identify mineral determinants of potential therapeutic effects of Olea europaea L. leaves from introduced cultivars of the Southern Coast of Crimea and to assess their suitability for functional aqueous tisanes. Using ICP-OES, eighteen macro- and micro-elements were identified in dried leaves, with K and Ca predominant (>10.0 g/kg), followed by P, S, and Mg (>1.0 g/kg). Maximum values occurred in ‘Nikitskaya’ (K 15.6 g/kg; S 2.05 g/kg; and P 1.97 g/kg) and ‘Tlemcen’ (Ca 18.6 g/kg and Mg 1.46 g/kg). Extractability into infusion (2 g/100 mL, 60 min) reached 325 mg/L for K, 26 mg/L for Ca, 48 mg/L for S, 18 mg/L for P, and 9 mg/L for Mg. Potentially toxic elements were below detection limits, indicating the safety of both the raw material and beverage. Principal component, correlation, and Ward clustering analyses highlighted ‘Nikitskaya’, ‘Lomashenskaya’, and ‘Coregiolo’ as having the highest cumulative mineral value among the tested six cultivars. Overall, the findings support the feasibility of olive-leaf tisanes as accessible sources of K, Ca, S, P, and Mg, with potential contributions to antioxidant defense, blood-pressure regulation, and lipid and carbohydrate metabolism. Full article

The diverse phytochemical profile of olive leaves makes them an attractive feedstock for biomass utilization. The main objective of this study was to evaluate the phenolic content and antioxidant activity (AOA) of olive leaf extracts from four varieties cultivated in the Meknes region (Morocco) across two major collection periods: olive harvest (November) and pruning season (March). This study particularly focused on assessing how variety and season affect total phenolic compounds (TPC), ortho-diphenols (ODPC), total flavonoid content (TFC), and antioxidant activity (AOA). The results revealed that olive leaves collected in November exhibited the highest levels of TPC, ODPC, and AOA, while those from March were richer in TFC. Among the studied cultivars, Koroneiki showed the highest TPC and extraction yields in both November (72.08 ± 0.83 mg GAE/g DM; 42.61 ± 6.51%) and March (46.38 ± 0.83 mg GAE/g DM; 41.00 ± 1.84%). In contrast, Picual leaves displayed the highest antioxidant activity across both periods. The mineral profile of November leaves exhibited varietal specificities and a negative correlation between TPC and most nutrients except Fe, Cu, and Mn. These findings underscore the substantial impact of seasonal variation and cultivar differences on biochemicals, AOA, and minerals, and must be carefully considered for further valorization. Full article

Background/Objectives: Olive leaf (Olea europaea L.), a by-product of olive oil production, is rich in bioactive phenolics but limited in application due to poor solubility and stability. To improve their bioavailability, this study presents a comparative encapsulation strategy using three phospholipid-based liposomal systems (AL, PG90, and PH90) loaded with ethanolic olive leaf extract. Methods: Liposomes were characterized by physicochemical parameters, encapsulation efficiency (EE), antioxidant activity, morphology, release kinetics under simulated physiological conditions, and 60-day stability. To the best of our knowledge, this is the first direct comparison of AL, PG90, and PH90 matrices for olive leaf extract encapsulation. Results: HPLC and GC-MS confirmed successful encapsulation, with oleuropein showing the highest EE (up to 76.18%). PH90 favored retention of non-polar triterpenes, while AL and PG90 preferentially encapsulated polar flavonoid glycosides. FT-IR analysis verified extract integration into phospholipid bilayers. Antioxidant activity remained high in all loaded formulations, with negligible activity in empty liposomes. Extract-loaded systems exhibited reduced particle size, higher viscosity, and more negative electrophoretic mobility, enhancing colloidal stability. PG90 liposomes displayed the most stable mobility profile over 60 days. Transmission electron microscopy and nanoparticle tracking analysis revealed formulation-dependent vesicle morphology and concentration profiles. Release studies demonstrated significantly prolonged polyphenol diffusion from PG90 liposomes compared to the free extract. Conclusions: Phospholipid composition critically governs encapsulation selectivity, stability, and release behavior. Tailored liposomal systems offer a promising strategy to enhance the stability and delivery of olive leaf polyphenols, supporting their application in bioactive delivery platforms. Full article

The olive tree (Olea europaea L.) has been cultivated for millennia, with olive oil representing both a cornerstone of the Mediterranean diet and a major agricultural commodity. Its composition, rich in monounsaturated fatty acids, polyphenols, tocopherols and squalene, supports well-documented cardioprotective, antioxidant and anti-inflammatory benefits. Olive oil production generates substantial secondary streams, including pomace, leaves, pits and mill wastewater, which are rich in phenols, triterpenes and fibers. This review consolidates recent advances in their phytochemical characterization, innovative extraction technologies and health-promoting effects, while highlighting the economic and regulatory prospects for industrial adoption. Comparative analysis shows that olive leaves can produce up to 16,674.0–50,594.3 mg/kg total phenolics; oleuropein 4570.0–27,547.7 mg/kg, pomace retains 2.24 g GAE/100 g dried matrix (DM)total phenolics; oil 13.66% DM; protein 6.64% DM, and wastewater contains high concentration of phenolics content of olives. Innovative extraction techniques, such as ultrasound and microwave-assisted methods, allow for a recovery, while reducing solvent use and energy input. The analysis highlights opportunities for integrating these by-products into circular bioeconomy models, supporting the development of functional foods, nutraceutical applications and sustainable waste management. Future research should address techno-economic feasibility, regulatory harmonization and large-scale clinical validation to accelerate market translation. Full article

Olive leaves, a significant source of agri-food waste, can be valorized as feedstock in biorefineries due to their high content of antioxidant compounds, mainly polyphenols. This study aims to valorize olive leaves through an efficient solid/liquid extraction of oleuropein, its main polyphenol, using green solvents and advanced technologies. Accordingly, three natural eutectic solvents formed with 1,2-butanediol and choline chloride, betaine, or proline, which incorporated water or ethanol as cosolvents, and ultrasound-assisted extraction to enhance the process were used in this work. Additionally, the effect of the cosolvent composition on the physical properties of the solvent mixtures (i.e., density and viscosity as a function of temperature) was evaluated. The extraction time was optimized for both conventional and intensified extractions, and the antioxidant activity of the extracts was assessed over time to determine their stability. Measurements through high-performance liquid chromatography and antioxidant activity assays concluded that ultrasound-assisted extraction using the solvent proline:1,2-butanediol prepared with ethanol at 25–75% composition yielded the best results at 37.00 mg of oleuropein per gram of dry sample (g/ds), obtained after just 1 min of intensified extraction, with a notable reduction in both time and energy consumption from conventional extraction, while providing significant antioxidant activity and stability. Full article