Polyphenols are a large group of secondary plant metabolites that can be employed as preservatives, antioxidants, and additives. Fumaria officinalis L. (fumitory, Fumariaceae family) is an annual scramblingplant, disturbed and cultivated throughout Europe, and several studies have shown its antimicrobial, antioxidant, antispasmodic, laxative, anthelmintic, anticoagulant, cholagogue, cytotoxic, and sedative potential. The present research aimed to extract antioxidants from the fumitory aerial part of the plant by performing traditional and novel extraction procedures (maceration and ultrasound- and microwave-assisted extractions, UAE and MAE, respectively) and determine the antioxidant capacity of the obtained extracts (ABTS, DPPH, CUPRAC, and FRAP assays). Fumitory macerate showed significantly lower ABTS radical scavenging activity, expressed as a higher IC₅₀ value (the concentration of extract required to neutralize 50% of radicals, 11.4±0.1 mg/mL), in comparison to the other two extracts, whose IC₅₀ values varied over a narrow range (8.6-9.5 mg/mL). However, in the DPPH assay, the trend was different: MAE (11.4±0.3 mg/mL)≥UAE (12.0±0.8 mg/mL)≥macerate (12.8±0.1 mg/mL). In the CUPRAC assay, the trend was as follows: UAE and MAE (17.84±0.85 and 18.05±0.71 µmol Trolox equivalent (TE)/g, respectively)>macerate (16.43±0.45 µmol TE/g). Regarding the results of the FRAP method, there was no statistically significant difference in terms of ferric ion reduction between the macerate, UAE, and MAE extracts (3.00-3.27 µmol Fe²⁺/g). An LC-MS analysis of the fumitory extracts revealed the presence of protopine-type (protopine, oxo-, methyl and/or acetyl protopine derivatives and cryptopine) and spirobenzylisoquinoline-type alkaloids (fumariline and fumarophycine). Chlorogenic and caffeoylmalic acids were also identified, as well as quercetin trihexoside, rutin, methylquercetin pentoside hexoside, isoquercitrin, quercetin, and kaempferol deoxyhexosylhexoside. The presence or absence of significant differences among the fumitory extracts that show the highest antioxidant potential in the various employed tests can be explained by the fact that different secondary metabolites, and their interactions, can significantly affect the overall antioxidant activity of fumitory extracts.

The green kiwi (Actinidia deliciosa) is originally from China and is widely known and consumed worldwide for its outstanding nutritional and functional properties that give it a high presence of antioxidant compounds. The high consumption level of this fruit, both in its native form and in products derived from its industrialization, including juices, wines, jams, and dehydrated fruits, among others, produces by-products such as skin (GKS) and bagasse (GKB). These were traditionally used for the generation of compost, discarded, or burned. However, current research indicates that they constitute a natural source of antioxidant compounds with broad beneficial potential for health. In this sense, GKS and GKB are characterized from nutritional and chemical points of view. Nutritional characterization (proteins, lipids, and minerals) was carried out following the international standards of the AOAC International. For chemical characterization, heat-assisted extraction (HAE) was applied followed by a metabolomic study by HPLC-ESI-QqQ-MS/MS that allowed us to identify and quantify the metabolites. This study reports that GKS and GKB constitute a source of nutrients, with GKB highlighting 8.62 g/100 dw of protein and 8.60 g/100 dw of lipids, of which 42% corresponds to polyunsaturated fatty acids. In contrast, GKS stands out for its high content of K+, Ca+, P+, and Mg+ minerals. This metabolomic study reports GKS 48.5% of phenolic acids, 29.8% of flavonoids, and 21.7% of other polyphenols, while GKB contains 60.5% of phenolic acids, 15.4% of flavonoids, and 24.1% of other polyphenols. These findings reinforce the theory that GKS and GKB constitute a natural source of compounds with antioxidant properties, which may have food, pharmaceutical, and cosmetic applications, providing benefits for human health.

Oxidative stress, an imbalance between reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) and the antioxidants present in the organism, has a significant role in the pathogenesis of various illnesses. Moreover, this process contributes to cellular damage, affecting DNA, proteins, and lipids, inducing cellular aging and age-related diseases such as cancer, cardiovascular diseases, and neurodegenerative disorders [1]. Brown macroalgae have been demonstrated to be significant potential ROS and RNS scavengers, primarily due to their rich antioxidant properties. Various studies have highlighted the ability of brown algae extracts to neutralize ROS and RNS, including superoxide (O₂^●-) and hydroxyl (^●OH) radicals, hydrogen peroxide (H₂O₂), and nitric oxide (^●NO), which are known to contribute to oxidative stress. This antioxidant capability of these extracts is attributed to the presence of bioactive compounds such as polyphenols, specifically phlorotannins, among other secondary metabolites found in these marine species. In this work, six brown algae species, i.e., Himanthalia elongata, Undaria pinnatifida, Sargassum muticum, Bifurcaria bifurcata, Fucus spiralis, and Ascophylum nodosum, were studied, aiming to assess their ability to promote ROS and RNS scavenging. The bioactive compounds were extracted by microwave-assisted extraction [2–5], and the scavenging activity was tested by in vitro spectrophotometric methods [6]. The results showed that concerning the ^●NO scavenging activity, the EC₅₀ varied from 74 µg/mL to 2000 µg/mL for Fucus spiralis and Himanthalia elongata, respectively. The EC₅₀ regarding the O₂^●- scavenging activity ranged from 16 µg/mL (Sargassum muticum) to 279 µg/mL (Undaria pinnatifida), while for H₂O₂ scavenging, the best result was achieved by Fucus spiralis (EC50 =39 µg/mL). The radical ^●OH was the reactive species that required the highest quantity of algae extract to achieve the 50% depletion, averaging 1240 µg/mL. These results highlight the activity of the algae extracts as antioxidants, showing their potential to reduce oxidative stress.

Parmelia is a genus of foliose lichens belonging to the Parmeliaceae family, distributed worldwide, and includes approximately 300 species. Along with other lichen groups, it reports a highly varied chemical composition with multiple biological activities. A compilation and analysis of recent research on the bioactive compounds present in species of the genus Parmelia and the results of their antioxidant properties were carried out. The characterization of the chemical constituents of 24 species revealed the presence of atranorin, chloratranorin, leucotylin, alectorialic, atraric, baeomycesic, caperatic, diffractaic, divaricatic, evernic, glomelliferic, gyrophoric, isonephrosterinic, isousnic, lecanoric, leucotylic, lichesterinic, nephrosterinic, norstictic, orsellinic, oxyphysodic, protocetraric, protolichesterinic, salazinic, stenosporic, stictic, usnic, 2-hydroxy-4-methoxy-3,6-dimethylbenzoic acids, arabinitol, zeorin, ethyl haematommate, ethyl orsellinate, ethyl-2,4-dihydroxy-6-methylbenzoate, methyl-β-orsellinate, orcinol, β-sitosterol, and α-tocopherol, among others. Extracts prepared with solvents and aqueous extracts from species such as P. sulcata, P. caperata, P. saxatilis, P. omphalodes, P. perlata, P. conspersa, P. arseneana, P. pertusa, P. cirrhatum, P. crinita, and P. erumpens have shown outstanding antioxidant activity in a variety of tests, including DPPH, ABTS, and total phenolic and flavonoid content measurements. The results of these tests indicated moderate-to-high antioxidant activities, depending on the concentration of the extracts used. Likewise, the major isolated compounds from these species showed significant antioxidant activity, which compares favorably with the reference standards used in the research, and in some cases, the results were even superior. In assays with cell lines of human colon carcinoma, the human lung, breast cancer, malignant melanoma, and chronic myelogenous leukemia, some extracts show high cytotoxic effects that are proportional to the concentration of the phenolic content. The genus Parmelia exhibits remarkable chemical diversity, with the presence of secondary metabolites that have demonstrated significant antioxidant properties, supporting its potential use in the prevention and treatment of diseases related to oxidative stress and the development of pharmaceutical products.

Colombian tropical fruits, such as carambolo (Averrhoa carambola L), mango (Mangifera indica), papaya (Carica papaya), pineapple (Ananas comosus), guayaba (Psidium guajava), golden berries (Physalis peruviana), lulo (Solanum quitoense), gulupa (Passiflora edulis Sims.), tamarillo (Cyphomandra betacea), curuba (Passiflora tripartida), tamarind (Tamarindus indica L.), avocado (Persea americana), and banana (Musa paradisiaca), are known for their high content of bioactive compounds. LDL oxidation is a leading cause of endothelial damage, and antioxidants can inhibit this process by donating hydrogen and capturing lipid radicals, thus protecting against cardiovascular diseases.

Objective

To review the phenolic compound content and antioxidant capacity of Colombian tropical fruits, measured by the DPPH and FRAP methods, it is important to assess their potential as dietary components for reducing the risk of cardiovascular diseases.

Methods

A bibliographic search was conducted in the Medline Elsevier and Scielo databases, including articles published in the last 12 years in English and Spanish.

Results

Phenolic compound content (mg eq of gallic acid/100 gr sample) is as follows: curuba: 638, avocado: 0.20-582.9, tamarillo: 92-300, lulo: 310, gulupa: 270, papaya: 240-263, golden berries: 59.2-265; carambolo: 143, guayaba: 199.21, mango: 217.6-652.6, banana: 302.58-1323.70, pineapple: 159.3-990.76, and tamarind: 10.82-20.23.

By measuring the oxidative capacity with the DPHH method (µmol Trolox/100 g sample), we attained the following results: carambolo: 429.55, gulupa: 366, golden berries: 243.6, tamarillo: 75, avocado: 165.10, lulo: 60, curuba: 55 , guayaba: 26.2, papaya: 14.62, mango: 23.7-174, tamarind: 293.93, pineapple: 34.80–36.45, and banana: 8.79. Meanwhile, using FRAP (µmol Trolox/g sample), we found the following results: carambolo: 7106.72, curuba: 148.1, gulupa: 464, golden berries: 345.2, papaya: 71.77, lulo: 52, tamarillo: 50, guayaba: 48.85, pineapple: 25.60–27.09, tamarind: 12.96, mango: 3.18, banana: 11.5, and avocado: 0.8.

FRAP and DPPH methods measure the antioxidant concentrations that could be used to reduce endothelial oxidative damage, due to the high antioxidant capacity to inhibit LDL oxidation, hydrogen donation, lipid radical capture, and metal ion chelation, and reduce the risk of developing cardiovascular diseases.

This work presents a computational analysis of the antioxidant potential of organic molecular compounds using the DFT (Density Functional Theory) method, a technique that involves using advanced theoretical tools to predict and analyze the antioxidant activity of various organic molecules. This method also allows for the determination of key parameters influencing the antioxidant efficiency of compounds, such as ionization energy, electron affinity, and radical dissociation energy. These properties are essential for predicting the antioxidant behavior of molecules under various biological conditions and help identify which compound is most effective at capturing free radicals and thus preventing oxidative damage. We also demonstrate how these compounds can combat oxidative damage caused by free radicals in the body by using computational simulations and molecular modeling tools to assess the antioxidant potential of these molecular compounds. These compounds are crucial as they can prevent or repair damage caused by free radicals, a process that can lead to chronic diseases, cellular aging, and other serious health issues. In our research, we also studied the three main antioxidant mechanisms—HAT (Hydrogen Atom Transfer), SEP-PT (Sequential Proton Transfer), and SPLET (Single-Electron Transfer Proton Transfer)—in order to evaluate their effectiveness against free radicals. The results of this study highlight the significant impact of free radicals on our health and identify promising compounds for experimental testing, thus contributing to the development of new antioxidants with therapeutic, cosmetic, and nutritional applications. These findings also open new perspectives for future research and the potential application of computational methods in drug design and antioxidant development.

Quercetin is a plant-derived flavonoid found in various fruits, vegetables, and beverages, and it is known for its potent antioxidant, anti-inflammatory, and immune-modulating properties. Its role in managing chronic diseases has been widely studied, showing promise in several areas. Quercetin and quercetin-rich foods have been reported to have a wide range of health-promoting effects, especially in the prevention and management of several diseases; however, its solubility and bioavailability have limited its use. It is beneficial in diseases with an inflammatory component, such as rheumatoid arthritis, inflammatory bowel disease (IBD), and asthma, inhibiting the inflammatory pathways by suppressing pro-inflammatory cytokines (e.g., TNF-α, IL-6) and enzymes (e.g., COX-2). It prevents or reduces oxidative stress-linked conditions like cardiovascular diseases (CVDs), neurodegenerative disorders (e.g., Alzheimer's), and diabetes, as Quercetin neutralizes free radicals and upregulates antioxidant defenses (e.g., glutathione). It has a potential role in managing hypertension, atherosclerosis, and heart disease as it improves endothelial function, reduces blood pressure, and lowers LDL cholesterol by enhancing nitric oxide bioavailability and reducing lipid peroxidation. It is a proven fact that the consumption of Quercetin improves insulin sensitivity, lowers blood glucose levels, reduces complications by modulating glucose transporters, inhibits α-glucosidase enzymes, and protects pancreatic β-cells from oxidative damage. Due to its multifunctional biological effects, Quercetin holds significant potential in managing chronic diseases. While it is not a substitute for standard medical treatments, it can be an effective complementary approach under professional guidance. This review explores the current literature surrounding quercetin’s versatile properties, mechanisms of action, and its role in the prevention and treatment of conditions such as cardiovascular diseases, diabetes, cancer, and other diseases.

Herbal decoctions are widely consumed for their health benefits and flavour. These beverages are known for their natural antioxidant properties, primarily linked to their phytochemical and nutrient content, including amino acids. This study investigated the amino acid composition of four multicomponent decoctions (with nine to twenty-eight different plants), focusing on their antioxidant potential and relevance to chronic disease prevention. The main objective was to analyze the amino acid profiles of selected decoctions to evaluate their contribution to oxidative stress reduction and their role as functional beverages. After an aqueous extraction with boiling water, decoctions were lyophilized before re-dissolution in water for derivatization using OPA/3-MPA and FMOC-Cl. Analysis was performed using high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Antiradical activity, a reliable indicator of oxidative stress reduction, was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+) and nitric oxide radical (•NO) assays. The results revealed that all decoctions contain high levels of histidine (2.31 ± 0.18 μg/g to 5.75 ± 0.55 μg/g) and arginine (10.0 ± 0.7 μg/g to 32.5 ± 2.2 μg/g). Both amino acids are essential in free radical scavenging and oxidative stress reduction and in preventing chronic diseases such as cardiovascular disorders, diabetes, and obesity. A decoction with 28 components exhibited the highest activity against ABTS•+ and •NO, while the 14-component decoction showed the highest DPPH• scavenging capacity. Furthermore, two decoctions contained cysteine (0.99 ± 0.09 μg/g and 1.78 ± 0.83 μg/g), an important amino acid with potent antioxidant properties due to its ability to interact with redox reactions. Additionally, glutamine, a precursor for glutathione synthesis and essential for antioxidant defence, was present in all the samples. Multicomponent decoctions offer functional beverages with amino acid-driven antioxidants, supporting oxidative stress reduction and health promotion. They support sustainable food systems and serve as dietary strategies for chronic disease prevention and management, highlighting their potential in nutrition-based health interventions.

Polyphenols are natural compounds found in a variety of plants and are widely recognized for their antioxidant properties and potential health benefits, particularly in relation to inflammation and neuroprotection. Among these, oleuropein aglycone (OleA) and its main metabolite hydroxytyrosol (HT) from extra virgin olive oil (EVOO) and olives have the potential to counteract pro-inflammatory signals in the brain, including those triggered by fibrinogen, a key protein involved in blood clotting. Fibrinogen is known to activate microglia, the resident immune cells of the central nervous system, leading to the production of inflammatory cytokines that exacerbate neuroinflammatory conditions.

The aim of our study was to enhance the understanding of the molecular mechanisms underlying the protective effects of EVOO polyphenols at different concentrations on fibrinogen-induced damage by conducting in vitro experiments using the human microglia C13NJ and SH-SY5Y neuronal cell models, where cellular viability and oxidative stress were assessed. Additionally, immunofluorescence analysis was performed to measure the levels of neuroinflammatory markers, and we investigated the mitochondrial efficiency in microglia and neuronal cells treated with C13NJ-conditioned medium.

Our results indicate that both OleA and HT prevent the activation of TRL4 and p-NF-κB and the release of pro-inflammatory chemokines and cytokines, as evidenced by conditioned medium treatments on SH-SY5Y cells. Moreover, OleA and HT promote an increase in TREM2 levels and act as epigenetic modulators on histone 4 lactylation while also increasing the mitochondrial function.

The ability of OleA and HT to promote an anti-inflammatory microglial phenotype positions them as promising molecules for reducing neuroinflammation, protecting neurons from damage, and supporting overall brain health. Dietary or supplemental strategies incorporating these polyphenols could provide preventive approaches and strategies aimed at mitigating inflammation before the onset of neurodegenerative diseases. Additionally, they may serve as complementary therapies to existing treatments that focus on managing neuroinflammation and supporting neuronal health.

Introduction: Friedreich’s Ataxia (FRDA) is an autosomal recessive neurodegenerative disorder characterized by impaired muscle coordination and hypertrophic cardiomyopathy, affecting 1 in 50,000 individuals worldwide. It results from GAA triplet expansion in the FXN gene, reducing frataxin levels and causing mitochondrial dysfunction, oxidative stress and oxytosis/ferroptosis, a form of iron-dependent regulated cell death. Although the FDA-approved omaveloxolone slows disease progression via NRF2 activation, its association with elevated liver enzymes limits its clinical use, and no treatments currently effectively address the underlying causes of FRDA. Rationale: Deferiprone (DFP), an iron chelator, has demonstrated potential in managing FRDA by crossing physiological barriers and targeting intracellular iron pools. However, DFP lacks mitochondrial specificity and results from its phase II trial for FRDA (NCT00897221) remain unpublished. Therefore, we hypothesize that selectively targeting iron chelators to mitochondria can prevent iron-induced toxicity, mitochondrial dysfunction and oxytosis/ferroptosis. Objectives: We aimed to design and synthesize DFP-based compounds to improve mitochondrial targeting, combining iron chelating and antioxidant properties to address mitochondrial dysfunction and prevent oxytosis/ferroptosis in FRDA. Methods: DFP derivatives were synthesized and evaluated for antioxidant activity using the ORAC assay to measure the peroxyl radical scavenging activity. Iron chelating properties were recorded using UV-Vis spectroscopy in the absence/presence of FeSO_4. The active compounds were further tested for their ability to protect neuronal cells (HT22) from oxytosis/ferroptosis induced by glutamate, erastin or RSL3 insults. Results: DFP derivatives exhibited similar antioxidant activity to the parent DFP, indicating that structural modifications did not alter peroxyl radical neutralization and effectively chelated Fe²⁺. Some compounds showed significant protection against oxytosis/ferroptosis in HT22 cells, with the best compound presenting EC₅₀s of 5.10 µM, 6.0 µM and 5.8 µM against glutamate, erastin and RSL3, respectively. Conclusions: Novel DFP derivatives provide a multitarget strategy to address mitochondrial dysfunction in FRDA, offering a promising new safety class of therapeutic agents with combined iron chelation, antioxidant and neuroprotective properties.