Search Results (641)

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

Atherosclerosis is a chronic inflammatory cardiovascular disease that may result from the interaction between oxidative stress, immune dysregulation, and metabolic disorders. Recent studies indicate that the well-known phenolic compounds, hydroxytyrosol (HTyr) and tyrosol (Tyr) present in extra virgin olive oil, confer cardioprotection through various mechanisms of action that include antioxidant, anti-inflammatory, and metabolic regulatory properties. The gut microbiota modulates the structure, bioavailability, and bioactivity of these phenolic compounds, thereby influencing their therapeutic potential. This review explores the intricate interactions between Tyr, HTyr, and gut microbiota within the context of atherosclerosis prevention and management. We explore how gut microbial metabolism can magnify or alter the biological effects of the Tyr and HTyr, and how interindividual differences in microbiota composition may influence their efficacy. A deeper understanding of these mechanisms could support the development of precision nutrition strategies aimed at reducing the risk of atherosclerosis. Full article

The development of bioactive food packaging is an important issue, given its potential to preserve food quality and safety without the use of synthetic preservatives. This study aimed to develop new polystyrene foam (PS) films with hydroxytyrosol (HOxTYR) and eugenol (EUG), alone or in combination, as bioactive molecules to preserve sliced sponge cake during long-term storage. The cake samples were analyzed periodically during storage at 15 °C in terms of quality attributes (pH, water activity, height, volume and weight loss, firmness, CIE Lab color, lipid peroxidation products, microbial spoilage, and overall acceptability) and shelf life. The active film containing the combination of 0.6% HOxTYR and 0.6% EUG showed the strongest antioxidant activity, which was attributed to a potential synergism between the compounds, resulting in lower lipid oxidation rates (TBARS). The combination of HOxTYR and EUG also offered the greatest reduction in bacterial load (62% for S. aureus and 58% for E. coli), suggesting a synergistic effect on microbial inhibition. Likewise, samples packaged in a modified atmosphere (MAP) with the active film containing the combination of HOxTYR and EUG showed the best performance, including a smoother texture and greater volume, more stable color, lower microbial counts, and greater overall acceptability, and, consequently, a longer shelf life of up to 70 days at room temperature. Furthermore, the results of this study could contribute to environmental protection by reducing food waste, and suggest that the developed active packaging technique represents a promising and innovative approach to the preservation of bakery products. Full article

Acteoside (ACT), a prominent compound of the hydroxytyrosol-type phenylethanol glycoside (HPG) class, is present in plants and holds significant potential for food and pharmaceutical applications. However, the limited production of ACT in plants restricts its broader utilization. Although the biosynthetic pathways of ACT are increasingly understood, its transport mechanisms within plants remain unclear. RgMATE6, a vacuolar-type Multidrug and Toxic Compound Extrusion (MATE) transporter identified in Rehmannia glutinosa (a plant known for ACT p roduction), was selected for investigation. This study aims to elucidate the role of RgMATE6 in ACT transport and its impact on ACT biosynthesis. Our study utilized a multidisciplinary approach, including in silico analysis to predict substrate specificity, quantitative real-time PCR (qRT-PCR) to quantify gene expression, HPLC to measure HPG levels, vacuolar membrane vesicle uptake assays to validate RgMATE6 transport activity in vitro, and genetic transformation in R. glutinosa to assess its functional roles in vivo. In silico analysis identified RgMATE6 as a phenolic compound transporter, and correlation analysis revealed a strong positive association between the HPG accumulation and RgMATE6 expression in R. glutinosa. Functional validation through vacuolar membrane vesicle uptake assays in Nicotiana benthamiana confirmed RgMATE6’s role as an HPG transporter, demonstrating a significant preference for ACT. Overexpression and repression experiments in R. glutinosa further demonstrated that RgMATE6 facilitates ACT import into vacuoles and enhances its production. Additionally, tissue-specific expression analysis revealed the coordinated expression patterns between RgMATE6 and six ACT biosynthetic genes in the transgenic plants. RgMATE6 facilitates the transport and accumulation of ACT within vacuoles, and its expression might synergize with ACT biosynthesis. These findings establish a framework for improving ACT and other HPG production through targeted manipulation of plant MATE transporters. Full article

Kinetic evolution of quality parameters in 21 extra-virgin olive oils (EVOOs) from Coratina cultivar was evaluated during 18 months of dark storage at room temperature (RT) and 4 °C (LT). The aim was to identify the most discriminating variables—fatty acids, peroxide value, spectrophotometric indices, and phenolic compounds—using kinetic analysis and multivariate statistics. Fatty acids remained stable, while peroxide value and ultraviolet absorbance indices increased significantly at RT, following zero-order kinetics. Polyphenols declined markedly after 6 months, especially at RT, with degradation rates influenced by initial concentrations. Hydroxytyrosol and tyrosol followed pseudo-zero-order kinetics, whereas secoiridoids and lignans followed second-order kinetics. Discriminant analysis achieved 90% accuracy (p = 0.000012) in classifying oils by storage condition. The most relevant discriminants were associated with phenolic degradation and oxidative changes. These findings support the importance of low-temperature storage in preserving the biochemical quality and shelf life of EVOOs. Full article

Extra virgin olive oil (EVOO) polyphenols are recognized for their beneficial effects on human health, yet how their concentration shapes biological outcomes remains insufficiently explored. While a daily intake of 25 mL EVOO is generally regarded as beneficial for cardiovascular protection, the high-phenolic EVOO examined in this study contains markedly higher levels of polyphenols than most EVOOs reported previously. This suggests that oils richer in polyphenols may exert distinct biological effects. To investigate this, we compared extracts from a standard EVOO and a naturally high-phenolic EVOO, along with their key phenolic compounds, hydroxytyrosol (HT) and tyrosol (Tyr). Antioxidant effects were assessed by quantifying intracellular reactive oxygen species (ROS) and lipid peroxidation. Anti-inflammatory activity was evaluated in THP-1-derived macrophages stimulated with LPS by analyzing inflammatory surface markers’ expression, cytokines’ production, and the NLRP3-inflammasome pathway. Atheroprotective potential was investigated by measuring cholesterol efflux in J774 macrophages. Both EVOO polyphenols extracts and (HT and Tyr) significantly reduced ROS and lipid peroxidation. High phenolic EVOO extract (EVOOPE+) displayed superior antioxidant activity at lower concentrations, while standard EVOO phenolic extract (EVOOPE) showed more consistent effects across doses. Both extracts favored an anti-inflammatory macrophage phenotype, as indicated by increased CD163 and IL-10 expression and reduced CD86, IFN-α, and NLRP3. Moreover, all treatments enhanced cholesterol efflux in a dose-dependent manner, with EVOOPE+ and HT producing the strongest effects. Collectively, these results highlight the capacity of EVOO polyphenols to modulate, through key bioactivity mechanisms, cardioprotective effects and emphasize the importance of polyphenols concentration in their biological efficacy. Full article

Olive mill wastewater (OMW), a by-product of olive oil extraction, poses significant environmental challenges due to its toxicity and heterogeneity. This study evaluates the phenolic and mineral composition of OMW and alpechin sludges from abandoned ponds in Spain, and establishes a standardized conventional method to recover phenolic fractions and promote their safe valorization as bioactive ingredients. Phenolic compounds were identified by triple-TOF-LC-MS/MS, and minerals and heavy metals were quantified by ICP-MS. Across thirteen ponds analyzed, samples from Cordoba, Tarragona, Alicante and Toledo showed higher phenolic levels, ranging from 7.2 g GAE/kg to 18.9 g GAE/kg, with methanolic extracts reaching 10.98–15.67 mg GAE/mL. Thirty-one phenolic compounds were identified, predominantly luteolin, apigenin, quercetin, and secoiridoid derivatives, notably hydroxytyrosol and tyrosol, supporting their functional potential as natural antioxidants. The mineral profile was dominated by K and Ca and showed negligible carryover to the phenolic organic fraction (<1%). Heavy metal concentrations in fresh OMW were 0.32–1.06 µg/kg for Cd and Hg and 9–43.9 µg/kg for As and Pb. In OMW sludge, they ranged between 0.033 and 0.19 mg/kg for Cd, 0.01 and 0.12 mg/kg for Hg, 5.45 and 8.06 mg/kg for As, and 4.45 and 23.70 mg/kg for Pb, whereas phenolic extracts contained only 0.15–21.50 µg/kg, remaining below EU food safety limits. This work presents one of the first integrated approaches to risk-benefit mapping of abandoned ponds in Spanish soils and advances extraction standardization by jointly considering functional potential, contaminant profiles, and matrix location. Full article

The valorization of olive oil production residues represents an innovative and sustainable strategy aligned with circular economy principles and the United Nations Sustainable Development Goals. In this study, we aimed to explore the phytochemical composition and neuroprotective potential of organic extracts obtained from olive pomace of the Arbequina and Arbosana cultivars. Extracts were prepared through solid–liquid extraction and analyzed by high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS), enabling the comprehensive identification of bioactive metabolites. The analysis revealed a diverse profile of phenolic compounds, including hydroxytyrosol, tyrosol, and multiple oleuropein derivatives, as well as triterpenic acids such as oleanolic and maslinic acids. These compounds are widely recognized for their antioxidant, anti-inflammatory, and neuroprotective activities. The antioxidant potential of the extracts was evaluated in vitro using DPPH and ABTS radical scavenging assays, showing significant activity comparable to that of standard antioxidants. Moreover, cholinesterase inhibitory assays demonstrated moderate to strong inhibition of acetylcholinesterase, an enzyme implicated in neurodegenerative diseases such as Alzheimer’s disease. To further elucidate the molecular basis of these effects, in silico molecular docking studies were performed on the most abundant compounds, revealing favorable binding affinities and interactions with key active site residues of acetylcholinesterase. Overall, these findings highlight olive pomace as a promising, underutilized source of bioactive compounds with potential applications in the development of functional foods, nutraceuticals, and neuroprotective therapeutic agents. The integration of in vitro and in silico approaches strengthens the evidence supporting the use of these extracts in future biomedical and industrial applications. Full article

Phenolic compounds are regarded as one of the components responsible for olive oil’s functional properties and health benefits. These chemicals act as antioxidants and anti-inflammatories, and prevent chronic diseases. The Folin–Ciocalteu reagent or HPLC procedures are commonly used to determine the concentration of total phenolic compounds in olive oil. The use of ethyl lactate or lactic acid ethyl ester (LAEE) instead of methanol (MeOH) was examined in terms of green chemistry. Six extra virgin olive oils (EVOOs) with phenolic content ranging from 20 to 350 mg/L, were first extracted with 1:4, 2:3, 3:2, 4:1, and 5:0 MeOH or LAEE/water, (v/v), to determine total phenolic content (TPC) and antiradical activity (%RSA) using the Folin–Ciocalteu reagent and DPPH assay, respectively. The concentration of extracted phenolics or extracts’ RSA increased as the water content in the organic solvent mixture decreased. Also, TPC values were greater when extracted with LAEE than MeOH, while the differences were modest. The HPLC profiles of EVOO phenolic extracts produced by 4:1 MeOH or LAEE/water, (v/v), were indistinguishable in principal component analysis. Simplification of the phenolic profile via acid hydrolysis, resulting in increased hydroxytyrosol and tyrosol content liberated from the corresponding bound forms, showed that both organic solvents equally recovered the predominating phenols of the polar fraction. A noted limitation of LAEE extraction is the need for freeze-drying to remove it prior to HPLC analysis of aqueous extracts. Nonetheless, these findings support LAEE as an effective and environmentally friendly alternative to MeOH for EVOO phenolic extraction in both analytical and industrial contexts. Full article

Hydroxytyrosol (HXT), a phenolic compound from olive, shows great potential as a neuroprotective agent and a translational target for claim-ready nutrition and food products. Human studies increasingly report benefits for vascular function, inflammatory tone, and early cognitive/psychomotor outcomes, consistent with engagement of redox and signalling pathways (Keap1–Nrf2–ARE, PI3K/Akt–ERK, and AMPK–SIRT1–PGC-1α). HXT is rapidly absorbed and likely reaches the brain, acting on endothelial and microglial targets. On the neurovascular axis, it reduces oxidative stress, preserves nitric-oxide bioavailability, lower inflammatory markers, and favourable intrinsic connectivity. For product development, bitterness from oleuropein-rich inputs can be mitigated by hydrolysis, followed by structure-guided delivery to balance sensory quality with exposure. Viable formats include cyclodextrin inclusion, microencapsulation, and (micro)emulsions in lipid matrices, plus stability engineering for aqueous systems (acidification, chelation, low-oxygen handling, or barrier packaging). Matrix effects are consequential; some proteins and fibers may decrease HXT bioaccessibility, whereas lipid phases and microstructured carriers often enhance it. Clinically, recommended doses are ~7–15 mg/day chronically and ~30–60 mg acutely. As conclusions of this review, future work should prioritize harmonized pharmacokinetics–pharmacodynamics readouts, cognition anchored to a compact neurovascular/blood–brain barrier biomarker core, and head-to-head comparisons of manufacturable delivery formats. Full article

Background/Objectives: Atherosclerosis remains a leading cause of morbidity and mortality worldwide, with an urgent need for novel preventive and therapeutic strategies. Sirtuin 1 (SIRT1), an NAD⁺-dependent deacetylase, has emerged as a central regulator of vascular homeostasis, modulating oxidative stress, inflammation, lipid metabolism, and endothelial function. Increasing evidence highlights that some natural activators of SIRT1 may be interesting in mitigating the development of cardiovascular diseases. Methods: Searching in the main databases PubMed and Scopus, we made a literature revision, including studies from January 2000 to June 2025, of the major natural SIRT1 activators involved in vascular impairment in order to investigate their potential therapeutic use in atherosclerosis. Results: Among them, resveratrol, quercetin, naringenin, and hydroxytyrosol show the strongest evidence in activating SIRT1 and modulating the essential molecular pathways involved in atherosclerotic disease. These findings span from preclinical to clinical studies, with limited randomized clinical trial data for hard cardiovascular outcomes. Conclusions: This review synthesizes current knowledge on natural SIRT1 activators in the context of atherosclerosis, emphasizing their molecular mechanisms and clinical perspectives. The concept of using nutraceuticals-based interventions targeting SIRT1 may pave the way for innovative strategies in cardiovascular diseases. Full article

The olive fruit is recognized for being a significant source of phenolic compounds, including hydroxytyrosol (H-tyr), tyrosol (Tyr), oleuropein (Ole), and verbascoside (Verb). The maturity index (MI) significantly influences the phenolic profile, which is a cultivar-specific trait. A study was conducted to assess the evolution of the phenolic profile in seven olive cultivars during ripening: ‘Galega vulgar’ (Gv), ‘Azeiteira’ (Az), ‘Cobrançosa’ (Cob), ‘Picual’ (Pic), ‘Carrasquenha’ (Car), ‘Redondil’ (Red), and ‘Arbequina’ (Arb). The results indicate a declining trend in total phenolic compounds (TPC) across all cultivars, with Cob and Car exhibiting the highest values, over 60 g GAE kg⁻¹ at T1 and above 30 g GAE kg⁻¹ at T7, respectively. In Ole quantitation, Red demonstrated the highest values, recording 39 g kg⁻¹ in T1 and 15 g kg⁻¹ at T7, with per olive fruit unit measurements ranging from 19.7 mg at T1 to 22.7 mg at T7. These findings underscore olive fruit as an exceptional source of bioactive compounds and their advantageous health-promoting effects, which might be utilized as a functional food source, validating the unique phenolic profiles of each cultivar in relation to ripening. Full article