Search Results (652)

Olive pomace, a byproduct of olive oil production, is a rich source of bioactive phenolic compounds with potential health benefits. This study aimed to characterize the chemical composition and evaluate the metabolic effects of a subcritical water extract from California olive pomace (SWE COP) obtained from Arbequina olives. The extract was mainly composed of carbohydrates (72.81%) and contained 66.62 ± 1.22 mg gallic acid equivalents/g of phenolics, with 3,4-DHPEA-EDA, hydroxytyrosol, and verbascoside identified as the predominant compounds. Male C57BL/6N mice were fed a standard diet (SD; n = 7), a high-fat and high-sugar diet (HFSD; n = 7), which was used to induce features of diet-associated metabolic syndrome, or an HFSD supplemented with 3% (w/w) SWE COP (n = 7) for 16 weeks. Supplementation with SWE COP significantly reduced plasma triglycerides and increased HDL cholesterol levels compared with the HFSD group. Moreover, SWE COP improved glucose tolerance, enhanced insulin sensitivity, and reduced mesenteric and epididymal adiposity. Histological analysis showed that SWE COP alleviated hepatic steatosis and lowered the NAFLD activity score. These findings demonstrate that phenolic-rich SWE COP exerts beneficial effects on glucose and lipid metabolism and reduces liver fat accumulation in diet-induced obese mice. Overall, SWE COP represents a promising functional ingredient derived from olive industry byproducts for mitigating metabolic dysfunctions associated with obesity. Full article

Background/Objectives: The consumption of olive oil and olives has been steadily increasing, leading to growing interest in the sustainable management of by-products such as olive stones. This work aimed to contribute to the development of valorization strategies by studying the chemical composition and biological potential of olive stone extracts, using both conventional and eco-friendly extraction methods with various solvents. Methods: Several extracts were prepared and chemically characterized regarding their fatty acid and phenolic profiles by GC-FID and HPLC-DAD-MS/MS, respectively. Their antioxidant, cytotoxic and antiproliferative activities were also evaluated. Results: n-Hexane Soxhlet extract yielded higher concentrations and a broader range of fatty acids when compared to the chloroform-methanol Folch extract. Oleic, palmitic, and linoleic acids were the predominant fatty acids in the extracts. A large variety of phenolic compounds were identified in extracts obtained by microwave-assisted extraction (MAE), including several flavonoids, small phenolic compounds, secoiridoids (nuezhenide and oleuropein), and hydroxytyrosol. MAE hydroalcoholic extracts showed high total phenolic content (TPC), antioxidant activity by the oxygen radical absorption capacity (ORAC) and hydroxyl radical scavenging capacity (HOSC) assays. Moreover, the aqueous ethanol (50%) and aqueous methanol (80%) extracts displayed low cytotoxicity toward the non-malignant Caco-2 cell line (IC₅₀ values of 1.29 and 1.40 mg/mL, respectively), while both induced complete loss of viability in the HT-29 human colon adenocarcinoma cell line at 0.63 mg/mL. Conclusions: These findings highlight the potential of olive stone as a valuable source of bioactive compounds with antioxidant and selective antiproliferative properties. The results support their further exploration in the development of sustainable valorization strategies for olive industry by-products. Full article

Background: Hydroxytyrosol (HT) is a phenolic compound found in extra virgin olive oil that modulates oxidative and inflammatory status. However, clinical trials evaluating HT as a stand-alone supplement remain scarce, and its underlying mechanisms and pathway modulation are not yet fully understood. This study aimed to investigate the metabolic effects of HT supplementation in individuals with overweight and prediabetes using an untargeted metabolomics approach. Methods: An untargeted liquid chromatography–mass spectrometry (LC–MS)-based metabolomics analysis was performed on serum samples from 49 participants with overweight and prediabetes enrolled in a randomized controlled trial. Participants received either HT (15 mg/day for 16 weeks; n = 24) or placebo (n = 25). Global metabolomic profiling was used to compare metabolic changes between the two groups. Results: HT supplementation induced a distinct metabolic profile compared with placebo. Participants in the HT group showed reduced levels of nitrogenous base derivatives and arachidonic acid, together with increased concentrations of phosphatidylcholines, lysophosphatidylcholines and sphingomyelins. These alterations suggest modulation of two key metabolic pathways including purine degradation and arachidonic acid metabolism. Conclusions: These findings provide mechanistic insights into the biological effects of HT and support the integration of metabolomics and multi-omics approaches in future clinical studies to validate these pathways in larger populations. Full article

This study involved 45 finishing Limousin young bulls (initial BW 350 ± 15 kg; aged 250 ± 20 days) reared under commercial conditions and randomly assigned for 250 days to three dietary treatments: a control diet without olive cake (CTR), and diets including partially destoned dried olive cake at 10% (OC10) or 15% (OC15) of dry matter. The effects of the dietary inclusion of partially destoned dried olive cake (DOC) on the physicochemical properties, intramuscular fatty acid composition, nutritional lipid indices, and antioxidant profile of the Longissimus dorsi muscle were evaluated. Meat pH was measured at 45 min, 24 h, and 7 days of aging. Instrumental color, proximate composition, fatty acid profile, lipid nutritional indices, total phenolic content (TPC), individual polyphenols, and antioxidant capacity were determined. Data were analyzed by ANOVA using PROC GLIMMIX in SAS, with orthogonal contrasts to evaluate linear and quadratic responses to olive cake inclusion. Treatments did not affect post mortem pH, and color differences observed at 24 h were not present after 7 days of aging. Crude protein content was lower in OC-fed groups, while total lipid content tended to increase; sodium chloride concentration was higher in OC15 meat. Olive cake supplementation reduced hypercholesterolemic saturated fatty acids and increased stearic, oleic, and polyunsaturated fatty acids, including α-linolenic acid, EPA, and DPA, improving PUFA/SFA and UFA/SFA ratios and reducing atherogenic and thrombogenic indices. Despite a higher peroxidability index, OC groups showed greater muscle TPC and antioxidant capacity, the presence of detectable hydroxytyrosol and tyrosol suggests a possible contribution of dietary olive phenolics or their metabolites, although the exact mechanisms underlying their appearance in muscle tissue remain to be fully elucidated. Overall, partially destoned DOC can be included up to 15% of the finishing diet to improve beef nutritional and functional quality within sustainable circular systems. Full article

This study aimed to evaluate the aqueous extraction of phenolic compounds from olive tree pruning. Soxhlet extraction and aqueous extraction at 120 °C were performed in two types of pressurized reactors and different scales. The highest total phenolic content was obtained using Soxhlet (3809.8 mg/100 g biomass), followed by the other extraction strategies (up to 1500 mg/100 g). The content of 3,4-dihydroxyphenylglycol, hydroxytyrosol, and oleuropein also varied depending on the extraction conditions. Overall, aqueous extraction at 120 °C can be used to partially recover phenolic compounds, albeit in a shorter time compared to Soxhlet extraction and using higher solid loads to facilitate scaling up. This type of extraction can be applied in the future to recover these high-value compounds from olive tree pruning, a common agricultural byproduct of the Mediterranean region. Full article

Adulteration of high-value oils such as olive and camellia oil poses serious challenges to market integrity and consumer safety. This study develops a comprehensive, model-free marker library for high-throughput detection of single and multivariate adulteration across nine vegetable oils (olive, camellia, sesame, rapeseed, flaxseed, soybean, peanut, industrial hemp seed, and sunflower seed oils) using untargeted metabolomics via UHPLC-Q-TOF-MS. We identified 34 characteristic markers, including 9 confirmed by reference standards, such as hydroxytyrosol in olive oil, camelliasaponins in camellia oil, and sesamin in sesame oil, which are uniquely present in specific oils and absent in others. The method enables reliable qualitative screening of adulteration at levels as low as 5% without dependence on chemometric models. Validation using binary and multicomponent blends confirmed its robustness and specificity. In commercial sample analysis, adulteration was detected in 16.0% of olive oils (4/25) and 12.7% of camellia oils (7/55), with results consistent with regulatory findings. This work establishes the first integrated marker library for simultaneous screening of nine vegetable oils, offering a standardized, high-throughput tool for large-scale market surveillance that bridges the gap between discovery-based omics and routine regulatory practice. Full article

Recovery of nutritional and bioactive molecules by pomegranate peel (PP) has found wide applications in food and pharmaceutical industries. We investigated protective effects of a PP extract (PPE) from Mediterranean (Mazara del Vallo, Italy) on intestinal inflammation by using in vitro and ex vivo models. Reactive oxygen species (ROS) and lactate dehydrogenase (LDH) levels, as well as tight junction protein-1 (ZO-1) expression, were determined in lipopolysaccharide (LPS)-injured Caco-2 cells treated with PPE. We evaluated anti-inflammatory and antioxidant effects of PPE in isolated colon specimens of adult male mouse (C57/BL6) stimulated by LPS. Cyclooxygenase-2 (COX-2), nuclear factor-kB (NF-kB), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), as well as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX), and inducible nitric oxide synthase (i-NOS) gene expression was determined. We also characterized phytochemical composition of the extract through chromatographic (HPLC-UV) and spectrophotometric techniques. PPE was rich in punicalagins A and B, along with other polyphenols such as hydroxytyrosol (HT), catechin, p-coumaric acid, and rosmarinic acid. In Caco-2 cells, PPE reduced ROS generation and LDH release, restoring intestinal barrier integrity by upregulating ZO-1 expression. In addition, PPE increased SOD, CAT, and GPX and suppressed COX-2, NF-kB, TNF-α, IL-1β and i-NOS LPS-induced gene expression in colon. PPE mitigates inflammation and oxidative stress, restoring intestinal barrier function. The beneficial effects induced by the extract could be related to the pattern of polyphenolic composition, with particular regard to HT, rosmarinic acid, p-coumaric acid, catechin, as well as punicalagins A and B. Full article

Background: Oxidative degradation during deep frying negatively affects the nutritional quality and stability of edible oils. Rapid, non-destructive methods to monitor oxidation, particularly in antioxidant-enriched oils, are therefore of growing interest. Materials and Methods: This study investigates the potential of near-infrared (NIR) spectroscopy combined with chemometric modeling—specifically the Stepwise Decorrelation of Variables (SELECT) algorithm and Ordinary Least Squares (OLS) regression—to quantitatively assess oxidation dynamics in edible oils enriched with hydroxytyrosol extract from olive fruit during deep frying. Extra virgin olive oil, virgin olive oil, refined olive oil, refined sunflower oil, and high-oleic sunflower oil were evaluated under controlled thermal degradation conditions. Results: Variable selection identified key NIR spectral regions related to acidity, conjugated dienes (K₂₃₂), secondary oxidation indices (K₂₇₀ and ΔK), peroxide value (PV), anisidine value (AnV), and the total oxidation (TOTOX) index. From 700 measured wavelengths, a limited number were sufficient for robust prediction (16–30 wavelengths depending on the parameter), with critical sensitivity observed around 1792 nm and 1392 nm. The optimized NIR–SELECT–OLS models showed strong predictive performance across oil types (R² > 0.90; explained variance > 85%). Conclusions: The results demonstrate that hydroxytyrosol enrichment enhances the oxidative and nutritional stability of edible oils during deep frying. Moreover, the integration of NIR spectroscopy with chemometric modeling provides an effective, non-destructive tool for real-time monitoring of oil oxidation, supporting sustainable quality control, process optimization, and antioxidant fortification in functional edible oils. Full article

Skin photoaging, marked by structural and functional changes, is mainly caused by long-term ultraviolet (UV) exposure. This study sought to create hydroxytyrosol (HT)-loaded soluble microneedles (HT MNs) and thoroughly assess their anti-photoaging effects and underlying mechanisms in vitro and in vivo. The optimized HT MNs, featuring tips with 10% HT + 5% hyaluronic acid (HA) and a backing layer of 10% polyvinyl pyrrolidone (PVP), demonstrated robust mechanical strength (withstanding an axial force of 10 N without fracture), adequate penetration depth (>200 μm), and efficient skin self-recovery post-removal. In vitro, HT MNs notably boosted cell viability, reduced reactive oxygen species (ROS) levels, and suppressed senescence-associated β-galactosidase (A-β-Gal) expression in UVA-exposed human skin fibroblasts (HSF). In vivo, in a UVA + UVB-irradiated mouse model, HT MNs significantly enhanced skin hydration and elasticity, increased collagen density (confirmed by Masson staining), decreased malondialdehyde (MDA) content, and elevated the activities of glutathione (GSH), catalase (CAT), and glutathione peroxidase (GSH-Px). Western blot analysis further revealed that HT MNs upregulated the expression of collagen type I alpha 1 (COL1A1), elastin (ELN), hyaluronan synthase 2 (HAS2), and filaggrin (FLG), while downregulating matrix metalloproteinase 1. Overall, these findings suggest that HT MNs effectively mitigate UV-induced photoaging through antioxidant, anti-senescence, and extracellular matrix (ECM)-regulating mechanisms, underscoring their potential as a novel transdermal anti-photoaging therapy. Full article

Olive pomace (OP), a by-product of olive oil production, is a sustainable resource rich in bioactive compounds with potential applications in cosmetics and pharmaceuticals. This study investigates the protective effects of olive pomace juice (OPJ) against H₂O₂-induced neuronal damage and LPS-induced inflammatory responses in HT22 and BV2 cells, respectively. OPJ suppressed H₂O₂-induced cell death and exerted anti-apoptotic effects by reducing the BAX/BCL2 ratio and caspase-3 cleavage. OPJ also mitigated neurodegenerative hallmarks by decreasing amyloid fibrils formation and inhibiting β-secretase and acetylcholinesterase (AChE) activity. Mechanistically, OPJ enhanced antioxidant response by upregulating Nrf2 and its downstream molecule HO-1, along with increasing mRNA levels of antioxidant enzymes, including catalase, SOD1, and GPx. OPJ further activated AMPKα–SIRT1–PGC1α signaling and CREB–BDNF–TrkB signaling, suggesting modulation of key antioxidant, anti-apoptotic, and neurotrophic pathways. In BV2 cells, OPJ downregulated pro-inflammatory cytokines (IL-6 and IL-1β) and decreased iNOS and COX-2 expression through suppression of NF-κB and MAPK signaling pathways. HPLC analysis identified hydroxytyrosol (10.92%) as the major active compound in OPJ, which compared with tyrosol (2.18%), and hydroxytyrosol exhibited greater neuroprotective and anti-inflammatory effects than tyrosol. This study highlights the potential of OPJ and its major compound, hydroxytyrosol, as functional agents for mitigating neurodegeneration-related cellular response, supporting its application in the food and pharmaceutical industries. Full article

The current study investigates the modulatory effects of gallic acid (GA), 3-hydroxytyrosol (3-HT), and quercetin (QUE) on key cholinesterase enzymes using Drosophila melanogaster (fruit fly) head homogenates as a source of central cholinesterases following in vivo larval exposure. The choice of these plant phenolics was predicated on their cholinesterase (ChE) inhibitory effect reported recently by our group. The study utilized D. melanogaster larvae subjected to varying doses of GA, 3-HT, and QUE, subsequently evaluating enzymatic activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Galanthamine HBr was used as a positive control. All three phenolic compounds exhibited elevated ΔOD/min values for BChE inhibition compared to the negative control (ethanol). GA and QUE inhibited AChE, though with lower potency than galanthamine; at 1 mM, GA and QUE achieved 79.23% and 80.98% inhibition, respectively, compared to 98.34% for galanthamine. Interestingly, the effect of 3-HT on AChE was inversely related to the dose. The results indicate that GA and QUE modulate cholinesterase activity in vivo, consistent with our prior in vitro reports. This study also provides the first in vivo evidence of 3-HT’s ChE-modulating activity in Drosophila within a whole-organism model. Full article

Background: Olive cultivation and olive oil production are key agricultural sectors in the Dalmatia region, where numerous oil mills operate. Analyses have shown that extra virgin olive oils (EVOO) produced in this area contain respectable amounts of polyphenols, which contribute to superior oil quality due to their antioxidant properties. During processing, hydrophilic phenolic compounds predominantly transfer into olive mill wastewater (OMW), making it a concentrated source of valuable bioactive molecules. The antioxidant, anti-inflammatory, and photoprotective effects of these polyphenols are highly relevant for cosmetic and pharmaceutical use. Methods: A total of 186 OMW samples were collected from oil mills in the Split-Dalmatia County across three production seasons (2023–2025). Total polyphenol content (TPC) was measured spectrophotometrically, while polyphenol composition was determined by High Performance Liquid Chromatography (HPLC). Antioxidant activity was evaluated using hydrogen atom transfer (HAT; 2,2-diphenyl-1-picrylhydrazyl) (DPPH), electron transfer (ET; ferric reducing antioxidant power) (FRAP), and oxygen radical absorbance capacity assay (ORAC). Results: The obtained results indicated high total polyphenols concentrations, with values ranging from 111.8 to 6717.2 mg of gallic acid equivalents per L of OMW (mg GAe L⁻¹). In the vast majority of analyzed samples, hydroxytyrosol was the predominant phenol compound. The antioxidant activity of the samples was high. 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

Game meats are particularly prone to oxidation and microbial spoilage due to their specific characteristics and the procedures required to obtain them. Various sustainable bioactive molecules derived from food industry by-products, such as olive mill wastewater, have the potential to enhance the stability and safety of game meats. The use of different levels of polyphenolic extracts from olive mill vegetation water, encapsulated through a freeze-drying process, was tested on wild boar meat patties as an antioxidant and antimicrobial. Two separate trials were performed. Trial 1 was carried out by adding different concentrations of polyphenolic extract (0, 1, and 2%) during the production of wild boar patties, and trial 2 by adding 1.5% salt and adding or not adding 2% polyphenolic extract. The first trial revealed antioxidant effects on the raw patties during storage time, both on colour (increasing in saturation index) and thiobarbituric acid-reactive substances (0.306, 0.268, and 0.254 mg MDA/kg after 5 days of storage in the control with 1% and 2% polyphenolic extract groups, respectively). Oxidation was also reduced during cold storage of cooked patties. Trial 1 also revealed a dose-dependent antimicrobial effect, mainly on Enterobacteriaceae and Pseudomonas spp. Trial 2 confirmed that salt plus extract addition had an overall higher antimicrobial effect than when singularly added, but with a moderate increase in the hardness of the products. Full article