Search Results (438)

Salinization of olive orchards constitutes a front-line agronomic challenge for farmers, consumers, and the scientific community as food security, olive logistics, and land use become more unsustainable and problematic. Plantlets of two olive varieties (var. Kalamon and var. Koroneiki) were tested for their performance under soil saline conditions, in which L-methionine, choline-Cl, and L-proline betaine were applied foliarly to alleviate adverse effects. The ‘Kalamon’ variety ameliorated its photosynthetic rates when L-proline betaine and L-methionine were administered at low saline exposure. The stressed varieties achieved higher leaf transpiration rates in the following treatment order: choline-Cl > L-methionine > L-proline betaine. Choline chloride supported stomatal conductance in stressed var. Kalamon olives without this pattern, which was also followed by var. Koroneiki. Supplementation regimes created a mosaic of responses on varietal water use efficiency under stress. The total phenolic content in leaves increased in both varieties after exogenous application only at the highest levels of saline stress. None of the substances applied to olive trees could stand alone as a tool to mitigate salinity stress in order to be recommended as a solid agronomic practice. The residual exploitation of amino acids by the olive orchard microbiome must also be considered as part of an environmentally friendly, integrated strategy to mitigate salinity stress. Full article

Olive tree leaf is a phenol-rich, high-potential-value biomass that can be used to formulate food additives and supplements. Leaf phenolic content varies depending on numerous factors, like cultivar, geographical origin, year, and season of harvest. The aim of this research was to evaluate the variations in phenolic profile of four major Tuscan cultivars (Frantoio, Leccio del Corno, Leccino, and Moraiolo) over four different phenological phases and across two years. All 96 olive leaf samples were harvested from trees grown in the same orchard located in Florence. After drying, their phenolic profile was characterized using HPLC-DAD-MS, and the obtained data were processed by ANOVA, GA-LDA, and RF methods. A total of 25 phenolic derivatives were analyzed, with total contents ranging 16,674.0–50,594.3 mg/kg and oleuropein (4570.0–27,547.7 mg/kg) being the predominant compound regardless of cultivar, year, and season of harvest. Oleuropein and hydroxytyrosol glucoside showed inverse proportionality and similar behavior across years in all cultivars, and therefore were highlighted as main phenolic compounds correlated with the seasonal variability in studied cultivars. Interesting behavior was also pointed out for apigenin rutinoside. Application of GA-LDA and RF methods allowed pointing out the excellent performance of leaf phenols in discriminating samples based on cultivar, harvest year, and harvesting season. Full article

Knowledge about the composition (volatile and non-volatile) and functionality of natural extracts from Mediterranean plants serves as a basis for their further application. In this study, five selected plants were used for the extraction of plant metabolites. Leaves and flowers of Critmum maritimum, Rosmarinus officinalis, Olea europea, Phylliera latifolia and Mellisa officinalis were collected, and a total of 12 extracts were prepared. Extractions were performed under microwave-assisted conditions, with two solvent types: water (W) and a hydroalcoholic (ethanolic) solution (HA). Detailed extract analysis was conducted. Phenolics were analyzed by detecting individual bioactive compounds using high-performance liquid chromatography and by calculating total phenolic and total flavonoid content through spectrophotometric analysis. Higher concentrations of total phenolics and total flavonoids were obtained in the hydroalcoholic extracts, with the significantly highest total phenolic and flavonoid values in the rosemary hydroalcoholic extract (3321.21 mg_GAE/L) and sea fennel flower extract (1794.63 mg_QE/L), respectively; and the lowest phenolics in the water extract of olive leaves (204.55 mg_GAE/L) and flavonoids in the water extracts of sea fennel leaves, rosemary, olive and mock privet (around 100 mg_QE/L). Volatile organic compounds (VOC) were detected using HS-SPME/GC–MS (Headspace Solid-Phase Microextraction coupled with Gas Chromatography-Mass Spectrometry), and antioxidant capacity was estimated using DPPH (2,2-diphenyl-1-picrylhydrazyl assay) and FRAP (Ferric Reducing Antioxidant Power) methods. HS-SPME/GC–MS analysis of samples revealed that sea fennel had more versatile profile, with the presence of 66 and 36 VOCs in W and HA sea fennel leaf extracts, 52 and 25 in W and HA sea fennel flower extracts, 57 in rosemary W and 40 in HA, 20 in olive leaf W and 9 in HA, 27 in W mock privet and 11 in HA, and 35 in lemon balm W and 10 in HA extract. The lowest values of chlorophyll a were observed in sea fennel leaves (2.52 mg/L) and rosemary (2.21 mg/L), and chlorophyll b was lowest in sea fennel leaf and flower (2.47 and 2.25 mg/L, respectively), while the highest was determined in olive (6.62 mg/L). Highest values for antioxidant activity, determined via the FRAP method, were obtained in the HA plant extracts (up to 11,216 mg_AAE/L for lemon balm), excluding the sea fennel leaf (2758 mg_AAE/L) and rosemary (2616 mg_AAE/L). Considering the application of these plants for fresh fish preservation, antimicrobial activity of water extracts was assessed against Vibrio fischeri JCM 18803, Vibrio alginolyticus 3050, Aeromonas hydrophila JCM 1027, Moraxella lacunata JCM 20914 and Yersinia ruckeri JCM 15110. No activity was observed against Y. ruckeri and P. aeruginosa, while the sea fennel leaf showed inhibition against V. fisheri (inhibition zone of 24 mm); sea fennel flower was active against M. lacunata (inhibition zone of 14.5 mm) and A. hydrophila (inhibition zone of 20 mm); and rosemary and lemon balm showed inhibition only against V. fisheri (inhibition zone from 18 to 30 mm). This study supports the preparation of natural extracts from Mediterranean plants using green technology, resulting in extracts rich in polyphenolics with strong antioxidant potential, but with no clear significant antimicrobial efficiency at the tested concentrations. Full article

Postprandial dysmetabolism, which refers to the impaired regulation of glucose and lipid levels after meals, is recognized as an independent risk factor for cardiovascular diseases (CVDs). Diets rich in polyphenols have demonstrated potential in improving postprandial hyperglycemia and hyperlipidemia. This study investigates the effects of olive leaf polyphenols on postprandial metabolic outcomes following a high-fat and high-carbohydrate meal. A total of 36 healthy adults participated in a three-arm randomized crossover trial. They ingested either a biscuit made from olive leaf powder (OLB), olive leaf tea (OLT), or a placebo meal (CTRL) to assess the impact of olive leaf polyphenols on postprandial glycemia, lipid levels, platelet aggregation factor (PAF), and plasma antioxidant status (TAC). Although no statistically significant differences were observed in the primary biomarkers, including glucose and lipid profiles, a delayed insulin response was noted in the interventions involving olive leaf. These findings suggest that while acute olive leaf supplementation did not significantly alter postprandial glycemia or lipidemia, it may subtly influence insulin kinetics. Further research is needed to explore the long-term effects of olive leaf polyphenols on metabolic health, especially in populations at risk for CVDs. Full article

The distinctive leaf and twig heteromorphism in Euphrates poplar (Populus euphratica Oliv.) reflects its adaptive strategies to cope with arid environments across ontogenetic stages. In the key distribution area of P. euphratica forests in China, we sampled P. euphratica twigs (which grow in the current year) at different age classes (1-, 3-, 5-, 8-, and 11-year-old trees), then analyzed their morphological traits, biomass allocation, as well as allometric relationships. Results revealed significant ontogenetic shifts: seedlings prioritized vertical growth by lengthening stems (32.06 ± 10.28 cm in 1-year-olds) and increasing stem biomass allocation (0.36 ± 0.14 g), while subadult trees developed shorter stems (6.80 ± 2.42 cm in 11-year-olds) with increasesd petiole length (2.997 ± 0.63 cm) and lamina biomass (1.035 ± 0.406 g). Variance partitioning showed that 93%–99% of the trait variation originated from age and individual differences. Standardized major axis analysis demonstrated a consistent “diminishing returns” allometry in biomass allocation (lamina–stem slope = 0.737, lamina–petiole slope = 0.827), with age-modulated intercepts reflecting developmental adjustments. These patterns revealed an evolutionary trade-off strategy where subadult trees optimized photosynthetic efficiency through compact architecture and enhanced hydraulic safety, while seedlings prioritized vertical space occupation. Our findings revealed that heteromorphic twigs play a pivotal role in modular trait coordination, providing mechanistic insights into P. euphratica’s adaptation to extreme aridity throughout its lifespan. Full article

Background: Since breast cancer is a major cause of mortality, investigation of the synergistic effect of Olea europaea L. leaf extract in combination with some cancer medications is important for obtaining cost-effective and high-achieving treatments for breast cancer. This study aims to investigate the potential effects of Olea europaea L. extract in inhibiting breast cancer cell growth and enhancing the efficacy of chemotherapy agents against breast cancer under in vitro conditions. Methods: We conducted an analysis of some minerals and vitamins of three different viscosities (200 V, 300 V, and 400 V as a natural food product) of Olea europaea L. leaf water-based extract (OWE) derived from a natural cold maceration. We investigated the cytotoxic effects of Olea europaea L. extract with different viscosities (200–400 V) and various chemotherapy agents, either alone or in combination, in estrogen receptor-positive MCF-7 human breast carcinoma cells by MTT assay. Olea europaea L. extract treatment of cells resulted in growth inhibition in a dose- and time-dependent manner. Results: The 400 V OWE showed the highest calcium (301 ± 12 mg/100 g), potassium (1744 ± 33 mg/100 g), and vitamin E (0.36 ± 0.01 mg/100 g) amounts. Based on MTT results, combinations of 400V Olea europaea L. extract, which exhibited the strongest inhibitory effect with an IC₅₀ value of 940 µg/mL, and anticancer drugs were next assessed for their synergistic efficacy towards cell growth inhibition. Conclusions: Combinations of the IC₅₀ value of 400 V OWE with docetaxel, paclitaxel, and trastuzumab (1 µg/mL) treatment showed a strong synergistic effect in the growth inhibition of MCF-7 cells. Full article

Domestic food waste and agro-industrial by-products (AIBPs) occurring throughout the food chain, including production, processing, and storage, have become a global sustainability concern. Interestingly, this waste and these by-products contain a significant amount of commercially vital bioactive compounds, including polyphenols and carotenoids. Remarkably, discarded by-products such as fruit and vegetable peels contain more bioactive compounds than edible pulp. Thus, valorizing this waste and these by-products for commercially vital bioactive products can solve their disposal problems and help alleviate climate change crises. Additionally, it can generate surplus revenue, significantly improving food production and processing economics. Interestingly, several bioactive extracts derived from citrus peel, carrot pomace, olive leaf, and grape seed are commercially available, highlighting the importance of agro-food waste and by-product valorization. Considering this background information, this review aims to provide holistic information on major AIBPs; recovery methods of bioactive compounds focusing on polyphenols, carotenoids, oligosaccharides, and pectin; microencapsulation of isolated bioactive for enhanced physical, chemical, and biological properties; and their commercial application. In addition, green extraction methods are discussed, which have several advantages over conventional extraction. The concept of the circular bio-economy approach, challenges in waste valorization, and future perspective are also discussed. Full article

The valorization of by-products in the olive sector has increasingly become the focus of business and research in the context of biorefineries. This work evaluates the recovery of bioactive compounds from olive leaves and their subsequent incorporation into poly(L-lactic- acid-co-caprolactone) (PLCL) filaments through supercritical impregnation. Obtaining an olive leaf extract (OLE) using enhanced solvent extraction at a high pressure (ESE with CO₂/ethanol 1:1 v/v) resulted in higher yields and concentrations of bioactives with high antioxidant and anti-inflammatory activity. No significant differences were found between the extracts obtained with different water regimes (irrigated and dry land). The supercritical impregnation of PLCL filaments showed that a low depressurization rate is essential to avoid material deformation, while the impregnation pressure and temperature influenced the OLE loading and antioxidant activity of the filaments. In vitro release studies showed the prolonged release of active compounds over 90 days, and the kinetics best fit the Korsmeyer–Peppas model, suggesting a diffusion mechanism. These results validate supercritical impregnation as a promising strategy for the development of OLE-active PLCL filaments with potential for biomedical applications requiring sustained therapeutic release. Full article

This study evaluated the potential of pectin (PEC)-based coatings, enhanced with olive leaf extract (OLE) and chitosan nanoparticles (CH-NPs), to mitigate the formation of harmful compounds during the frying of French fries. The research compared deep fat and hot air frying methods. Initial characterization of the coating solutions included assessing zeta potential, Z-Average, polydispersity index, and antioxidant capacity. The inclusion of OLE and CH-NPs significantly boosted antioxidant activity, reaching 78.9%, without substantially altering zeta potential or Z-Average characteristics. Notably, hot air frying induced significantly higher levels of acrylamide (ACR) and hydroxymethylfurfural (HMF) compared to deep fat frying. However, the application of the developed coatings demonstrated a marked reduction in both ACR and HMF across both frying techniques. Furthermore, the coatings, particularly PEC with OLE and CH-NPs, effectively decreased oil absorption by 55% while simultaneously increasing moisture content. The sensory evaluation indicated that the panelists liked the deep-fat-fried fries significantly more compared to hot air frying. Deep-fat frying led to an elevated browning index, which was significantly counteracted by the application of the coatings. These findings underscore the importance of informing consumers about the potential for increased ACR and HMF formation during hot air frying, despite its advantages in reducing fat content, to ensure informed dietary choices. Full article

Chimonanthus nitens Oliv. leaves (COL), a commonly used traditional Chinese medicine, are rich in a variety of bioactive components, with flavonoids being one of the most abundant. In the current study, RAW264.7 macrophages were induced by lipopolysaccharide (LPS) and treated with COL flavonoids (COLFs). The results demonstrated that COLFs could inhibit the release of nitric oxide (NO) and related inflammatory factors in macrophages. RNA sequencing (RNA-seq) analysis revealed 627 differentially expressed genes (DEGs) in the COLF group, which were further analyzed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. We found that genes involved in biological processes in the LPS and COLF groups were significantly regulated, as indicated by the GO enrichment analysis. The NF-κB signaling pathway was identified through KEGG enrichment analysis for further exploration of the mechanism by which COLFs affect macrophages. Additionally, Western blotting analysis indicated that COLFs could influence the activity of the NF-κB/MAPK signaling pathway via the TLR4 receptor, thereby modulating its anti-inflammatory function. Overall, our results reveal a novel role for COLFs as natural inflammation regulators and provide a theoretical and molecular basis for their development and utilization. Full article

Medicinal beverages are herbal drinks that are consumed by people in numerous countries including China, India, Brazil, Greece, Turkey, and others. These herbal drinks possess many beneficial properties for human health, such as antioxidant, antimicrobial, anti-inflammatory, anticancer, antiaging, anti-fertility, antitumor properties, and anti-diabetic effects. Flavonoids, phenols, carotenoids, sterols, glucosinolates, alkaloids, polyacetylenes, coumarins, saponins, and terpenoids are the main constituents which offer benefits to human health. In this context, this review aimed to highlight medicinal beverages’ origin, physico-chemical properties, and bio-functionality, focusing mainly on olive leaf extracts and their bioactive components that have not been extensively studied. Full article

Background/Objectives: Prostate cancer (PC) is among the most common malignancy in men. Several newly diagnosed patients have a locally advanced disease and distant metastasis at the initial diagnosis time. Castration-resistant PC (CRPC) patients have 100% recurrence incidence despite completing a therapeutic regimen, leading to high mortality. Androgen deprivation therapy and androgen inhibitors are initially effective, but resistance is inevitably developed. Epidemiological studies indicated that the Mediterranean diet, with high olive phenolic contents, is associated with a lower incidence of certain malignancies. This study aims at exploring the mCRPC progression and recurrence-suppressive and molecular effects of the major olive leaf phenolic glucoside (−)-oleuropein (OLE). Results: OLE downregulated the levels of proprotein convertase subtlisin/klexin type 9 (PCSK9) and normalized the low-density lipoprotein receptor (LDLR) in PC cells in vitro. Thus, a PCSK9-LDLR protein–protein interaction (PPI) in silico model was generated and used to assess OLE and its aglycone (OA) ability to bind at PCSK9 and thereby interfere with PCSK9-LDLR PPI. OLE perfectly filled the PCSK9 interface versus OA. Both OLE and OA showed virtual potential to interfere with PCSK9-LDLR PPI. OLE showed modest in vitro viability, migration, and clonogenicity suppressive effects on diverse human PC cell lines. OLE effectively suppressed mCRPC progression and recurrence in a nude mouse xenograft model. RNA-sequencing results proved the PCSK1, PCSK2, and PCSK9 downregulation in OLE-treated recurrent tumors versus vehicle control. Conclusions: Oleuropein is a novel lead useful for the control of mCRPC progression and the prevention of its recurrence via targeting PCSK9 expression and PPI with LDLR. Full article

The food industry generates large quantities of biowaste, including olive (Olea europaea L.) leaves, which are rich in phenolic compounds with proven antioxidant and antimicrobial activity. In this study, a microwave-assisted olive leaf extract was produced and evaluated. Antioxidant potential (20.23 ± 0.31 µmol TE g⁻¹), antimicrobial activity against Staphylococcus aureus (MIC 17.62 mg GAE g⁻¹), and cytotoxic effects in breast (MDA-MB-231 (IC₅₀ = 38.9 ± 1.8 µg mL⁻¹), MCF-7 (IC₅₀ = 58.9 ± 5.4 µg mL⁻¹) and prostate cancer PC-3 (IC₅₀ = 69.2 ± 7.6 µg mL⁻¹) cell models were confirmed. Further, the extract was incorporated into a whey protein isolate (WPI) edible coating mixture and applied to semi-hard cheese over a 60-day ripening period. When applied to cheese, WPI-based coatings enriched with OLE contributed to an improved antioxidant potential (289.79 ± 16.16 µmol TE L⁻¹), elevated retention of total phenols and flavonoids, and slightly reduced microbial growth without compromising cheese safety. Compared to the uncoated control, coated samples showed higher total solids (up to 62.87 ± 0.13%, CWPIM) and fat contents (up to 26.59 ± 0.17%, CWPIM), moderated proteolysis (WSN in CWPIM: 3.15 ± 0.09% vs. 4.48 ± 0.02% in C0), maintained cohesiveness and resilience compared to the control, and exhibited less pronounced color deviation (ΔE) in some coated samples during ripening. These results highlight the potential of olive leaf extract as a bioactive, sustainable ingredient for functional edible coatings that improve the nutritional, technological, and microbiological quality of ripened cheese. Full article

Secondary metabolites in olive (Olea europaea L.) leaves constitute a complex framework wherein phenylpropanoids, terpenoids, and secoiridoids in particular, serve as major contributors to olive plant resilience. Silicon (Si) stands as a mediator of defense mechanisms in plants, enhancing their protective responses and adaptability. A field trial on one-year-old plantlets of two metabolically distinct olive genotypes was conducted to investigate the effects of foliar-applied Si on the phytochemical profiles of locally treated leaves. Silicon’s systemic effects in juvenile leaves were also appraised. We accounted for intervarietal differences in nutrient uptake and conducted in situ measurements of physiological indices. The peak of the summer season and the onset of autumn were chosen as the two sampling time points. Intense summer conditions prompted metabolic adjustments that resulted in phytochemical profiles unique to each cultivar. These profiles were further significantly altered by Si while remaining genotype-specific, with substantial increases in prominent compounds like oleuropein (105% and 252%) and verbascoside (62% and 126%), depending on the genotype. As the pressure from environmental factors eased, the differences in Si-mediated phytochemical responses emerged. Silicon had a limited effect on the phytochemical profile of the resilient cultivar which acquired a metabolic steady-state, while it significantly altered the profile of its metabolically more versatile counterpart, resulting with a progressive increase in its oleuropein (37%) and verbascoside (26%) levels. These effects extended to untreated, juvenile leaves as well. While effective in altering and improving the phytochemical composition of olive leaves, Si acted in a manner that adhered to each genotype’s metabolic foundation. The intensity of environmental constraints, along with each cultivar’s inherent sensitivity to them, seems to be tied to silicon’s capacity to mediate significant phytochemical alterations. The extent of silicon’s prophylactic function may therefore be dependent on a genotype’s metabolic foundation and overall sensitivity, and as such it seems inseparable from stress and its intensity. Full article

Background: Consumer demand for plant-based milk alternatives, particularly oat-based milk, has increased due to perceived health benefits and environmental sustainability. However, challenges remain in improving their nutritional profile and physical stability while promoting the use of local agricultural resources and reducing food waste. Methods: This study developed and evaluated fortified oat-based milk formulations using locally sourced oats cultivated in central Italy. Two valorization strategies were tested: (i) the addition of raspberry powder derived from juice processing byproducts and (ii) the substitution of water with infusions of raspberry and olive leaves. The nutritional composition, antioxidant activity, physical stability, and sensory properties were assessed. Results: Replacing water with leaf infusions significantly increased total polyphenol content (up to 688 mg GAE/100 g DW) and antioxidant activity but compromised physical stability, resulting in higher separation indexes during refrigerated storage. Conversely, adding raspberry powder moderately enhanced antioxidant properties while maintaining emulsion stability. Sensory evaluation showed that enriched formulations reduced undesirable attributes (e.g., floury and cereal notes), although higher concentrations of leaf infusions increased astringency and bitterness. Conclusions: The fortification of oat-based milk with locally sourced raspberry powders and leaf infusions effectively enhances its nutritional and antioxidant properties while influencing its physical and sensory characteristics. This strategy supports the valorization of local agricultural byproducts and promotes the development of sustainable, functional plant-based beverages. Full article