Structural Features of Small Molecule Antioxidants and Strategic Modifications to Improve Potential Bioactivity

Exploring the links between polyphenols, Nrf2, and diabetes: A review

Diabetes mellitus, a complex metabolic disorder, is marked by chronic hyperglycemia that drives oxidative stress and inflammation, leading to complications such as neuropathy, retinopathy, and cardiovascular disease. The Nrf2 pathway, a key regulator of cellular antioxidant defenses, plays a vital role in mitigating oxidative damage and maintaining glucose homeostasis. Dysfunction of Nrf2 has been implicated in the progression of diabetes and its related complications. Polyphenols, a class of plant-derived bioactive compounds, have shown potential in modulating the Nrf2 pathway. Numerous compounds have been found to activate Nrf2 through mechanisms including Keap1 interaction, transcriptional regulation, and epigenetic modification. Preclinical studies indicate their ability to reduce reactive oxygen species (ROS), improve insulin sensitivity, and attenuate inflammation in diabetic models. Clinical trials with certain polyphenols, such as resveratrol, have demonstrated improvements in glycemic parameters, though results remain inconsistent. While polyphenols show promise as a component of non-pharmacological approaches to diabetes management, challenges such as bioavailability, individual variability in response, and limited clinical evidence highlight the need for further investigation. Continued research could enhance understanding of their mechanisms and improve their practical application in mitigating diabetes-related complications.

Sauchinone Ameliorates Senescence Through Reducing Mitochondrial ROS Production

One of the major causes of senescence is oxidative stress caused by ROS, which is mainly generated from dysfunctional mitochondria. Strategies to limit mitochondrial ROS production are considered important for reversing senescence, but effective approaches to reduce them have not yet been developed. In this study, we screened the secondary metabolites that plants produce under oxidative stress and discovered sauchinone as a potential candidate. Sauchinone induced mitochondrial function recovery, enabling efficient electron transport within the electron transport chain (ETC). This led to a decrease in ROS production, a byproduct of inefficient electron transport. The reduction in ROS by sauchinone rejuvenated senescence-associated phenotypes. To understand the underlying mechanism by which sauchinone rejuvenates senescence, we carried out RNA sequencing and found VAMP8 as a key gene. VAMP8 was downregulated by sauchinone. Knockdown of VAMP8 decreased mitochondrial ROS levels and subsequently rejuvenated mitochondrial function, which was similar to the effect of sauchinone. Taken together, these studies revealed a novel mechanism by which sauchinone reduces mitochondrial ROS production by regulating mitochondrial function and VAMP8 expression. Our results open a new avenue for aging research to control senescence by regulating mitochondrial ROS production.

Identification of senescence rejuvenation mechanism of Magnolia officinalis extract including honokiol as a core ingredient

Reactive oxygen species (ROS) contribute to aging by mainly damaging cellular organelles and DNA. Although strategies to reduce ROS production have been proposed as important components of anti-aging therapy, effective mechanisms to lower ROS levels have not yet been identified. Here, we screened natural compounds frequently used as cosmetic ingredients to find substances that reduce ROS levels. Magnolia officinalis (M. officinalis) extract significantly lowered the levels of ROS in senescent fibroblasts. A novel mechanism by which M. officinalis extract restores mitochondrial function to reduce ROS, a byproduct of inefficient electron transport, was discovered. The reduction of ROS by M. officinalis extracts reversed senescence-associated phenotypes and skin aging. Then, honokiol was demonstrated as a core ingredient of M. officinalis extract that exhibits antioxidant effects. Honokiol functions as an oxygen radical scavenger through redox processes, also significantly reduced ROS levels by restoring mitochondrial function. In summary, our study identified a novel mechanism by which M. officinalis extract reverses aging and skin aging by reducing ROS through restoring mitochondrial function. These new findings will not only expand our understanding of aging and associated diseases, but also provide new approaches to anti-aging treatments.

Gamma-Tocopherol: A Comprehensive Review of Its Antioxidant, Anti-Inflammatory, and Anticancer Properties

Gamma-tocopherol (γ-tocopherol), a major isoform of vitamin E, exhibits potent antioxidant, anti-inflammatory, and anticancer properties, making it a promising therapeutic candidate for treating oxidative stress-related diseases. Unlike other tocopherol isoforms, γ-tocopherol effectively neutralizes reactive oxygen species (ROS) and reactive nitrogen species (RNS), providing robust cellular protection against oxidative damage and lipid peroxidation. Its anti-inflammatory effects are mediated through the modulation of pathways involving cyclooxygenase-2 (COX-2) and tumor necrosis factor-alpha (TNF-α), reducing chronic inflammation and its associated risks. In cancer therapy, γ-tocopherol demonstrates multifaceted activity, including the inhibition of tumor growth, induction of apoptosis, and suppression of angiogenesis, with significant efficacy observed in cancers such as prostate, lung, and colon. Preclinical and clinical studies support its efficacy in mitigating oxidative stress, inflammation, and cancer progression, with excellent tolerance at physiological levels. However, high doses necessitate careful evaluation to minimize adverse effects. This review consolidates current knowledge on γ-tocopherol's biological activities and clinical implications, underscoring its importance as a natural compound for managing inflammation, oxidative stress, and cancer. As a perspective, advancements in nanoformulation technology could enhance γ-tocopherol's bioavailability, stability, and targeted delivery, offering the potential to optimize its therapeutic application in the future.

Ethyl Acetate Extract of Cichorium glandulosum Activates the P21/Nrf2/HO-1 Pathway to Alleviate Oxidative Stress in a Mouse Model of Alcoholic Liver Disease

BACKGROUND

Alcoholic liver disease (ALD) is a significant global health concern, primarily resulting from chronic alcohol consumption, with oxidative stress as a key driver. The ethyl acetate extract of Cichorium glandulosum (CGE) exhibits antioxidant and hepatoprotective properties, but its detailed mechanism of action against ALD remains unclear. This study investigates the effects and mechanisms of CGE in alleviating alcohol-induced oxidative stress and liver injury.

METHODS

Ultra-Performance Liquid Chromatography coupled with Quadrupole-Orbitrap Mass Spectrometry (UPLC-Q-Orbitrap-MS) was used to identify CGE components. A C57BL/6J mouse model of ALD was established via daily oral ethanol (56%) for six weeks, with CGE treatment at low (100 mg/kg) and high doses (200 mg/kg). Silibinin (100 mg/kg) served as a positive control. Liver function markers, oxidative stress indicators, and inflammatory markers were assessed. Transcriptomic and network pharmacology analyses identified key genes and pathways, validated by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting.

RESULTS

UPLC-Q-Orbitrap-MS identified 81 CGE compounds, mainly including terpenoids, flavonoids, and phenylpropanoids. CGE significantly ameliorated liver injury by reducing alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels and enhancing antioxidative markers such as total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) while lowering hepatic malondialdehyde (MDA) levels. Inflammation was mitigated through reduced levels of Tumor Necrosis Factor Alpha (TNF-α), Interleukin-1 Beta (IL-1β), and C-X-C Motif Chemokine Ligand 10 (CXCL-10). Transcriptomic and network pharmacology analysis revealed seven key antioxidant-related genes, including HMOX1, RSAD2, BCL6, CDKN1A, THBD, SLC2A4, and TGFβ3, validated by RT-qPCR. CGE activated the P21/Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1) signaling axis, increasing P21, Nrf2, and HO-1 protein levels while suppressing Kelch-like ECH-associated Protein 1 (Keap1) expression.

CONCLUSIONS

CGE mitigates oxidative stress and liver injury by activating the P21/Nrf2/HO-1 pathway and regulating antioxidant genes. Its hepatoprotective effects and multi-target mechanisms highlight CGE's potential as a promising therapeutic candidate for ALD treatment.

Enhancing the Oxidative Stability of Beeswax-Canola Oleogels: Effects of Ascorbic Acid and Alpha-Tocopherol on Their Physical and Chemical Properties

The choice of antioxidant to be used in the formulation of an oleogel is crucial to determine its oxidative stability and functionality, as these factors can also affect the physical, chemical, and rheological properties of the oleogel. In this study, the effect of two antioxidants (ascorbic acid, AA, and alpha-tocopherol, AT) and their concentration (0.01, 0.02, and 0.03%) on the physical and chemical properties of beeswax and canola oil oleogels were evaluated. The results show that the type and concentration of antioxidants did not affect the thermal properties of the samples, and in FTIR analyses, no noticeable changes in spectra patterns are observed. Rheological analyses showed that the oleogels containing AA exhibited higher elasticity and resistance to deformation. Accelerated oxidative stability tests (storage at 50 °C and the Rancimat test) showed that AA effectively delayed oxidation. The induction time increased by 2.61-fold at higher concentrations, while AT did not significantly affect oxidation resistance. Overall, it was observed that AA improved oleogel firmness and OBC (up to 1.75-fold and 2.8%, respectively), whereas AT resulted in a softer and less stable gel structure. These results show the importance of antioxidant selection, indicating that hydrophilic antioxidants have promising applications in the formulation of beeswax oleogels.

Correlation of physicochemical properties with antioxidant activity in phenol and thiophenol analogues

Oxidative stress, associated with excessive production of reactive oxygen and nitrogen species (ROS, RNS), contributes to the development and progression of many ailments, such as aging, cardiovascular diseases, Alzheimer's disease, Parkinson's disease, diabetes, cancer, preeclampsia or multiple sclerosis. While phenols and polyphenols are the most studied antioxidants structurally similar compounds such as anilines or thiophenols are sporadically analyzed despite their radical scavenging potential. This work assesses the impact of structural features of phenols and thiophenols on their antioxidant activity. Seventeen pairs of phenol/thiophenol analogues, possessing both electron-donating and withdrawing groups were selected for this study. Several physicochemical properties of the compounds were determined by density functional theory (DFT) calculations at the (U)B3LYP/6-311++G(d,p) level of theory for gas phase calculations and at the (U)B3LYP/6-311++G(d,p) scrf = (smd, solvent = water) level for the solvated ones. Correlations between calculated properties and experimental radical scavenging activities were investigated to identify the pivotal physical characteristics contributing to antioxidant efficiency. These include S-H and O-H bond distances and bond dissociation enthalpies (BDE), dipole moments, logP values, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) orbital energies, and the HOMO-LUMO gap energies that were calculated at the M06-2X/6-311++G(d,p) level of theory, and Fukui functions. The experimental activity was evaluated using the 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl-1picrylhydrazyl (DPPH) radical scavenging assays. Several compounds exhibited superior scavenging abilities, surpassing that of the reference antioxidant Trolox. The extensive DFT calculations revealed that in the gas phase, lower BDE values, compared to IP and PA, suggested that the HAT mechanism predominates in case of these compound groups. In contrast, in water, significant reductions in PA due to solvent effects suggested that the SPLET mechanism is dominant under aqueous conditions.

A comprehensive DFT-based study of the antioxidant properties of monolignols: Mechanism, kinetics, and influence of physiological environments

Monolignols, p-coumaryl alcohol (CouA), coniferyl alcohol (ConiA), and sinapyl alcohol (SinA), are the fundamental materials for lignin biosynthesis, a major component of lignocellulosic biomass. In the present study, we report a comprehensive analysis of the antioxidant properties of monolignols, using density functional theory (DFT) calculations. Under model physiological conditions, monolignols demonstrated a high hydroperoxyl radical scavenging capacity in polar media, with overall rate constants (koverall) ranging from 5.80 × 106 to 1.15 × 107 M-1 s-1. In contrast, this activity was less pronounced in lipid media, with koverall in the range of 2.66 × 102 to 2.61 × 104 M-1 s-1. The single electron transfer (SET) mechanism was found to play a decisive role in water at physiological pH and under basic conditions, whereas the formal hydrogen transfer (FHT) mechanism was the exclusive pathway in aqueous acid conditions and lipid media. Furthermore, the monolignols ConiA and SinA, demonstrated a strong capacity to chelate Cu(II) and Fe(III) ions in water, with apparent equilibrium constants in the range of 9.21 × 1014 to 5.93 × 1021 M-1 s-1. Their complexes were also found to be highly effective in blocking the reduction of Cu(II)-to-Cu(I) and Fe(III)-to-Fe(II) via the ascorbic acid anion pathway.

Stilbene production as part of drought adaptation mechanisms in cultivated grapevine (Vitis vinifera L.) roots modulates antioxidant status

Stilbenes, naturally occurring polyphenolic secondary metabolites, play a pivotal role in adaptation of various plant species to biotic and abiotic factors. Recently, increased attention has been directed toward their potential to enhance plant stress tolerance. We evaluated drought tolerance of three grapevine varieties grown with different levels of water deficit. Throughout, we studied physiological mechanisms associated with drought stress tolerance, particularly stilbene accumulation in root tissues, using HPLC. Additionally, we explored the possible relationship between antioxidant potential and stilbene accumulation in response to water deficit. The results underscore the detrimental impact of water deficit on grapevine growth, water status, and membrane stability index, while revealing varying tolerance among the studied genotypes. Notably, Syrah variety had superior drought tolerance, compared to Razegui and Muscat d'Italie grapes. Under severe water deficit, Syrah exhibited a substantial increase in levels of stilbenic compounds, such as t-resveratrol, t-piceatannol, t-ɛ-viniferin, and t-piceid, in root tissues compared to other genotypes. This increase was positively correlated with total antioxidant activity (TAA), emphasizing the active role of resveratrol and its derivatives in total antioxidant potential. This demonstratres the potential involvement of resveratrol and its derivatives in enhancing antioxidant status of the drought-tolerant Syrah grape variety. Our findings suggest that these stilbenes may function as valuable markers in grapevine breeding programs, offering novel insights for the sustainable cultivation of grapevines in water-limited environments.

Optimization of UAE-NADES green extraction of bioactive compounds from chickpea (Cicer arietinum L.) sprouts using simplex lattice mixture design methodology

In the present study, a statistical tool called the simplex lattice mixture design method was used to create a new formulation of Natural Deep Eutectic Solvent (NADES), which is derived from a combination of three compounds (citric acid, glycerol, and water) to extract bioactive compounds from chickpea (Cicer arietinum L.) sprouts. The mixture (natural deep eutectic solvent) was formulated by combining three solvents including citric acid, glycerol, and water. The extraction was performed in a sonication bath for 30 min. The simultaneous optimization was performed to obtain the highest total polyphenol content (TPC), total flavonoid content (TFC) and antioxidants activity. The highest values of total polyphenol content (TPC), total flavonoid content (TFC) and antioxidant activity were 128.0 ± 0.2 mg GAE/100 g, 38.61 ± 0.03 mg CE/100 g and 2117 ± 1.8 µmol TE/100 g respectively. HPLC-DAD of the optimized extract was utilized for quantification of polyphenol compounds showing catechin as the main compound followed by chlorogenic acid, epicatechin, syringic acid, rutin, gallic acid, kaempferol 3-glucoside, ferulic acid, and coumaric acid. These findings may represent a significant advancement in the management of phenolic compound extraction for targeted uses, such as serving as alternatives to traditional antioxidants primarily employed in the food industry to improve nutritional quality. Furthermore, our research has shown that mixture designs are an efficient and useful method for structuring and optimizing experimental parameters to achieve the most accurate results with the minimum number of experiments.

Unveiling Anthraquinones: Diverse Health Benefits of an Essential Secondary Metabolite

Since ancient times, plants have been used as a remedy for numerous diseases. The pharmacological properties of plants are due to the presence of secondary metabolites like terpenoids, flavonoids, alkaloids, etc. Anthraquinones represent a group of naturally occurring quinones found generously across various plant species. Anthraquinones attract a significant amount of attention due to their reported efficacy in treating a wide range of diseases. Their complex chemical structures, combined with inherent medicinal properties, underscore their potential as agents for therapy. They demonstrate several therapeutic properties such as laxative, antitumor, antimalarial, antibacterial, antifungal, antioxidant, etc. Anthraquinones are found in different forms (derivatives) in plants, and they exhibit various medicinal properties due to their structure and chemical nature. The precursors for the biosynthesis of anthraquinones in higher plants are provided by different pathways such as plastidic hemiterpenoid 2-C-methyl-D-erthriol4-phosphate (MEP), mevalonate (MVA), isochorismate synthase and polyketide. Anthraquinones possess several medicinal properties and a complex biosynthetic pathway, making them good candidates for patenting new products, synthesis methods, and biotechnological production advancements. By conducting a thorough analysis of scientific literature, this review provides insights into the intricate interplay between anthraquinone biosynthesis and its broad-ranging contributions to human health.

Effect of the Type of Herbal Preparations (Powdered Plant Material vs. Dry Ethanolic Extracts) on the Bioaccessibility of Bearberry (Arctostaphylos uva-ursi (L.) Spreng.) Phytochemicals in Simulated Digestion Conditions

The main aim of this study was to determine the potential bioaccessibility of bearberry phytochemicals influenced by the type of herbal preparations. Herbal preparations-powdered plant materials and dry extracts obtained using various ethanol concentrations (0%, 20%, 40%, 60%, 80%, and 100%) were subjected to simulated gastric or gastrointestinal digestion for the evaluation of the bioaccessibility of the phytochemicals. The phytochemical characterization of the plant material, dry extracts, and potentially bioaccessible fractions was performed using high-performance liquid chromatography (HPLC) and spectrophotometric assays. The content of the main compounds, i.e., arbutin, hydroquinone, hyperoside, pentagalloylglucose, and picein, as well as the total phenolic content and in vitro antioxidant activity through the ABTS•+-scavenging activity and Fe3+-reducing power were determined. The bioaccessibility of arbutin, i.e., the main compound in bearberry, was high, in most cases exceeding 95%, and was generally unaffected by the experimental factors; however, the changes in the content of the other compounds, the total phenolic content, and the antioxidant activity were more prominent and influenced by the type of the herbal preparation and the stage of digestion. Given the compromise between the abundance of the bearberry phytochemicals, the antioxidant activity, and the resulting potential bioaccessibility of these phytochemicals, the dry extracts prepared with 40% ethanol seem to be the most promising for phytopharmaceutical purposes and functional food applications.

Al-Dahwi R, Georgieva E, Karamalakova Y, Nikolova G. Preeclampsia Treatment Aspirin/Clampsilin: Oxidative Stress, sFlt-1/PIGF Soluble Tyrosine Kinase 1, and Placental Growth Factor Monitoring

The present study aimed to investigate and compare oxidative stress biomarkers and antioxidant enzyme activity in the serum of women at risk of developing preeclampsia (PE) to prevent adverse pregnancy outcomes through early intervention. Changes in soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) levels were measured between 11 and 13 gestational weeks (gw.) before the onset of preeclampsia and its associated complications. This study evaluated the feasibility of the sFlt-1/PlGF biomarker ratio in predicting preeclampsia and adverse pregnancy outcomes, with the goal of preventive therapy with acetylsalicylic acid (150 mg daily), with acetylsalicylic acid (75 mg daily) and Clampsilin. For this purpose, the following were evaluated: (1) the levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) as parameters of oxidative stress; (2) lipid oxidation; (3) antioxidant enzyme activity; and (4) cytokine production. Analysis of the results showed that pregnant women at risk of preeclampsia had significantly higher levels of ROS, lipid oxidation, and superoxide anion radical (•O2-) levels compared to normal pregnancies. In PE, depleted levels of nitric oxide (NO), impaired NO synthase system (NOS), and reduced antioxidant enzyme activity (p < 0.03) suggest that PE patients cannot compensate for oxidative stress (OS). In conclusion, oxidative stress in PE plays a key role, which arises from placental problems and affects both mother and baby. The groups with acetylsalicylic acid therapy (150 mg and 75 mg) were better affected compared to those on Clampsillin.

The Combination of Bioactive Herbal Compounds with Biomaterials for Regenerative Medicine

Regenerative medicine aims to restore the function of diseased or damaged tissues and organs by cell therapy, gene therapy, and tissue engineering, along with the adjunctive application of bioactive molecules. Traditional bioactive molecules, such as growth factors and cytokines, have shown great potential in the regulation of cellular and tissue behavior, but have the disadvantages of limited source, high cost, short half-life, and side effects. In recent years, herbal compounds extracted from natural plants/herbs have gained increasing attention. This is not only because herbal compounds are easily obtained, inexpensive, mostly safe, and reliable, but also owing to their excellent effects, including anti-inflammatory, antibacterial, antioxidative, proangiogenic behavior and ability to promote stem cell differentiation. Such effects also play important roles in the processes related to tissue regeneration. Furthermore, the moieties of the herbal compounds can form physical or chemical bonds with the scaffolds, which contributes to improved mechanical strength and stability of the scaffolds. Thus, the incorporation of herbal compounds as bioactive molecules in biomaterials is a promising direction for future regenerative medicine applications. Herein, an overview on the use of bioactive herbal compounds combined with different biomaterial scaffolds for regenerative medicine application is presented. We first introduce the classification, structures, and properties of different herbal bioactive components and then provide a comprehensive survey on the use of bioactive herbal compounds to engineer scaffolds for tissue repair/regeneration of skin, cartilage, bone, neural, and heart tissues. Finally, we highlight the challenges and prospects for the future development of herbal scaffolds toward clinical translation. Overall, it is believed that the combination of bioactive herbal compounds with biomaterials could be a promising perspective for the next generation of regenerative medicine. Impact statement This article reviews the combination of bioactive herbal compounds with biomaterials in the promotion of skin, cartilage, bone, neural, and heart regeneration, due to the anti-inflammatory, antibacterial, antioxidative, and proangiogenic effects of the herbal compounds, but also their effects on the improvement of mechanic strength and stability of biomaterial scaffolds. This review provides a promising direction for the next generation of tissue engineering and regenerative medicine.

Unveiling the role of gut microbiota in curcumin metabolism using antibiotic-treated mice

Curcumin might exert its therapeutic effects by interacting with gut microbiota. However, the role of gut microbiota in curcumin metabolism in vivo remains poorly understood. To address this, we used antibiotics to deplete gut microbiota and compared curcumin metabolism in control and antibiotic-treated mice. Using Q-TOF and triple quadrupole mass spectrometry, we identified and quantified curcumin metabolites, revealing distinct metabolic pathways in these two mice groups. The novel metabolites, hexahydro-dimethyl-curcumin and hexahydro-didemethyl-curcumin were exclusively derived from gut microbiota. Additionally, gut bacteria deconjugated curcumin metabolites back into their bioactive forms. Moreover, control mice exhibited significantly lower curcumin degradation, suggesting a protective role of gut microbiota against degradation. In conclusion, our results indicated that gut microbiota might enhance the effectiveness of curcumin by deconjugation, production of active metabolites, and protection against degradation in the large intestine. This study enhances our understanding of the interactions between curcumin and gut microbiota.

Exploring the Therapeutic Potential of BBB-Penetrating Phytochemicals With p38 MAPK Modulatory Activity in Addressing Oxidative Stress-Induced Neurodegenerative Disorders, With a Focus on Alzheimer's Disease

Oxidative stress plays an important role in the occurrence of neurodegenerative diseases. Previous studies indicate a strong connection between oxidative stress, inappropriate activation of the p38 MAPK signaling pathway, and the pathogenesis of neurodegenerative diseases. Although antioxidant therapy is a valid strategy to alleviate these problems, the most important limitation of this approach is the ineffectiveness of drug administration due to the limited permeability of the BBB. Therefore, BBB-penetrating p38 MAPK modulators with proper antioxidant capacity could be useful in preventing/reducing the complications of neurodegenerative disorders. The current manuscript aims to review the therapeutic capabilities of some recently reviewed naturally occurring p38 MAPK inhibitors in the management of neurodegenerative problems such as Alzheimer's disease. In data collection, we tried to use more recent studies published in high-quality journals indexed in databases Scopus, Web of Science, PubMed, and so on, but no specific time frame was considered due to the nature of the study. Our evaluations indicate that natural compounds tanshinones, protoberberines, pinocembrin, osthole, rhynchophylline, oxymatrine, schisandrin, piperine, paeonol, ferulic acid, 6-gingerol, obovatol, and trolox have significant potential for use as supplements/adjuvants in the reduction of neurodegenerative-related problems. Our findings emphasize the usefulness of BBB-penetrating phytochemicals with p38 MAPK modulatory activity as potential therapeutic options against neurodegenerative disorders. Of course, the proper use of these compounds depends on considering their toxicity/safety profile and pharmacokinetic characteristics as well as the clinical conditions of users.

Applications of Tert-Butyl-Phenolic Antioxidants in Consumer Products and Their Potential Toxicities in Humans

Tert-butyl phenolic antioxidants (TBP-AOs) are employed to inhibit oxidation and function as stabilizers and protectants in a broad spectrum of consumer products, such as food packaging, adhesives, lubricants, plastics, and cosmetics. The extensive utilization of TBP-AOs results in human exposure through various pathways. Furthermore, some TBP-AOs have been identified as potential endocrine disruptors and may cause liver and lung damage, as well as allergic reactions. Considering their varied applications and potential toxicity, a detailed evaluation of their safety profiles is imperative. However, existing research is often segmented and tends to focus narrowly on specific compounds. Consequently, this review collates recent data on TBP-AOs regarding their production, exposure, and toxicity, incorporating different databases and prior studies, as well as predictions of toxicity using ADMET. Our review strives to offer a comprehensive overview of the characteristics and health effects of TBP-AOs to guide future research and inform policy decisions.

Solvent- and Catalyst-Free Environmentally Benign High Hydrostatic Pressure-Assisted Synthesis of Bioactive Hydrazones and the Evaluation of Their Stability Under Various Storage Conditions

Our group has seen great promise in using substituted diaryl-hydrazones to alleviate oxidative stress in preeclampsia. Specifically, fluorinated diaryl-hydrazones have shown great efficacy, confirmed via antioxidant assays and animal trials using pregnant mice. In addition to efficient antioxidant properties, these diaryl-hydrazones are also considered non-toxic. While the synthesis of these compounds is relatively simple, it commonly utilizes undesirable solvents and glacial acetic acid as the catalyst; additional solvents are needed for the isolation of the desired products, which negatively affects the green synthesis of the hydrazones. To combat this possible industrial roadblock, we have begun incorporating the use of hydrostatic high pressure (HHP) in the synthesis. The use of HHP allowed us to synthesize substituted diaryl-hydrazones in a 1:1 molar ratio without the need for solvents or acid catalysts. The optimized procedure can produce nearly quantitative yields, leading to an easier isolation of the products. Different HHP methodologies, such as constant high-pressure treatment and cycling (with different number of cycles, holding and decompression times) were applied and cycling was observed to be the most efficient activation for the majority of the reactions. Stability experiments were also conducted with one of the products and observed that although the solid-state storage does not alter the hydrazone, storing it in various solvents may significantly decrease the concentration of the active component which should be considered when performing the biochemical/biological assays.

Exploring the Redox and pH Dimension of Carbonic Anhydrases in Cancer: A Focus on Carbonic Anhydrase 3

Significance: Both redox and pH are important regulatory processes that underpin cell physiological functions, in addition to influencing cancer cell development and tumor progression. The thioredoxin (Trx) and glutathione redox systems and the carbonic anhydrase (CA) proteins are considered key regulators of cellular redox and pH, respectively, with components of the Trx system and CAs regarded as cancer therapeutic targets. However, the redox and pH axis in cancer cells is an underexplored topic of research. Recent Advances: Structural studies of a CA family member, CA3, localized two of its five cysteine residues to the protein surface. Redox-regulated modifications to CA3 have been identified, including glutathionylation. CA3 has been shown to bind to other proteins, including B cell lymphoma-2-associated athanogene 3, and squalene epoxidase, which can modulate autophagy and proinflammatory signaling, respectively, in cancer cells. Critical Issues: CA3 has also been associated with epithelial-mesenchymal transition processes, which promote cancer cell metastasis, whereas CA3 overexpression activates the phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway, which upregulates cell growth and inhibits autophagy. It is not yet known if CA3 modulates cancer progression through its reported antioxidant functions. Future Directions: CA3 is one of the least studied CA isozymes. Further studies are required to assess the cellular antioxidant role of CA3 and its impact on cancer progression. Identification of other binding partners is also required, including whether CA3 binds to Trx in human cells. The development of specific CA3 inhibitors will facilitate these functional studies and allow CA3 to be investigated as a cancer therapeutic target. Antioxid. Redox Signal. 41, 957-975.

Monoterpene Hydroxy Lactones Isolated from Thalassiosira sp. Microalga and Their Antibacterial and Antioxidant Activities

Two monoterpenoid lactones, loliolide (1) and epi-loliolide (2), were isolated from the crude dichloromethane extract of a microalga, Thalassiosira sp.). The structures of loliolide (1) and epi-loliolide (2) were elucidated by 1D and 2D NMR analysis, as well as a comparison of their 1H or/and 13C NMR data with those reported in the literature. In the case of loliolide (1), the absolute configurations of its stereogenic carbons were confirmed by X-ray analysis, whereas those of epi-loliolide (2) were determined by NOESY correlations. Loliolide (1) and epi-loliolide (2) were tested for their growth inhibitory activity against two Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212) and two Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) bacteria, as well as one clinical isolate (E. coli SA/2, an extended-spectrum β-lactamase producer-ESBL) and two environmental isolates, S. aureus 74/24, a methicillin-resistant (MRSA), and E. faecalis B3/101, a vancomycin-resistant (VRE) isolates. The results showed that none of the tested compounds exhibited antibacterial activity at the highest concentrations tested (325 μM), and both revealed low antioxidant activity, with ORAC values of 2.786 ± 0.070 and 2.520 ± 0.319 µmol TE/100 mg for loliolide (1) and epi-loliolide (2), respectively.

Prospecting Pharmacologically Active Biocompounds from the Amazon Rainforest: In Vitro Approaches, Mechanisms of Action Based on Chemical Structure, and Perspectives on Human Therapeutic Use

The Amazon rainforest is an important reservoir of biodiversity, offering vast potential for the discovery of new bioactive compounds from plants. In vitro studies allow for the investigation of biological processes and interventions in a controlled manner, making them fundamental for pharmacological and biotechnological research. These approaches are faster and less costly than in vivo studies, providing standardized conditions that enhance the reproducibility and precision of data. However, in vitro methods have limitations, including the inability to fully replicate the complexity of a living organism and the absence of a complete physiological context. Translating results to in vivo models is not always straightforward, due to differences in pharmacokinetics and biological interactions. In this context, the aim of this literature review is to assess the advantages and disadvantages of in vitro approaches in the search for new drugs from the Amazon, identifying the challenges and limitations associated with these methods and comparing them with in vivo testing. Thus, bioprospecting in the Amazon involves evaluating plant extracts through bioassays to investigate pharmacological, antimicrobial, and anticancer activities. Phenolic compounds and terpenes are frequently identified as the main bioactive agents, exhibiting antioxidant, anti-inflammatory, and antineoplastic activities. Chemical characterization, molecular modifications, and the development of delivery systems, such as nanoparticles, are highlighted to improve therapeutic efficacy. Therefore, the Amazon rainforest offers great potential for the discovery of new drugs; however, significant challenges, such as the standardization of extraction methods and the need for in vivo studies and clinical trials, must be overcome for these compounds to become viable medications.

Design, synthesis, molecular docking, and dynamics studies of novel thiazole-Schiff base derivatives containing a fluorene moiety and the assessment of their antimicrobial and antioxidant activity

In this study, a series of eighteen fluorene-containing substituted thiazole derivatives were synthesized and characterized via spectral analyses. The proposed compounds were screened for their in vitro antimicrobial activity, and it was found that compound 2a displayed a significant zone of inhibition (20.3 ± 0.6 mm) against B. subtilis and compound 2b exhibited inhibitory activity (30.3 ± 0.6 mm) against a C. albicans fungal strain. Furthermore, antioxidant activity was evaluated for all analogues, where 2f exhibited a four-fold higher antioxidant capability (11.73 ± 1.22 μg mL-1) than the standard ascorbic acid. Oral bioavailability and toxicological parameters were considered, and most of the compounds satisfied Lipinski's rule of five and Veber's rule, except for one violation by a few derivatives. Molecular docking and molecular dynamics simulation were performed, providing more explicit ideas on the binding interaction and stability of compounds that exhibited wet lab activity. Average RMSD and RMSF values ranged between 0.5 Å and 2.5 Å, which indicated the stability of ligands inside the complex, yielding some engrossing insights.

Tanshinone IIA delays liver aging by modulating oxidative stress

Organ-specific aging is increasingly recognized for its research significance, with liver aging demonstrating particular relevance due to its central role in metabolism. We have pioneered the discovery that the expression of ESRRG in the liver positively correlates with age and have established its association with clinical characteristics, including hepatic edema. Our findings link liver aging to a shift in oxidative stress states, where ESRRG, a crucial nuclear receptor responsive to oxidative stress, may be modulated by various small molecules. Through virtual screening of a natural medicinal molecule database followed by further validation, we confirmed that the natural compound Tanshinone IIA mitigates oxidative stress-induced damage in the liver via the ESRRG/Cyp2e1 pathway, thus decelerating liver aging. Importantly, our study also explores the dynamic impact of Tanshinone IIA on ESRRG conformation, providing a profound understanding of its molecular interactions with ESRRG and laying a foundation for the rational design of small molecules based on natural compounds.

Photoactive nanocatalysts as DTT-assisted BSA-AuNCs with enhanced oxidase-mimicking ability for sensitive fluorometric detection of antioxidants

Redox imbalance and oxidative stress are increasingly recognized as significant factors in health disorders such as neurodegenerative disorders, premature aging and cancer. However, detecting antioxidant levels that is crucial for managing oxidative stress, can be challenging due to existing assays' limitations, such as insensitivity to thiol-containing antioxidants. This study presents a simple fluorescence-based assay for antioxidant detection employing the enhanced photocatalytic oxidase-like activity of dithiothreitol (DTT)-assisted bovine serum albumin (BSA)-stabilized gold nanoclusters (DTT@BSA-AuNCs). The reported nanozyme exhibits remarkable stability, versatility, and catalytic activity. Under LED irradiation, DTT@BSA-AuNCs generate singlet oxygen, which converts non-fluorescent thiamine to fluorescent thiochrome, utilizing dissolved oxygen for catalysis. Antioxidants inhibit thiochrome formation, leading to fluorescence quenching. This method enables sensitive detection of antioxidants such as ascorbic acid and glutathione with limits of detection of 0.08 µM and 0.32 µM, respectively, under neutral pH, outperforming previous studies. The assay successfully detects antioxidants in human saliva and cancer cell models. The DTT@BSA-AuNCs-based assay offers a cost-effective, sensitive, and straightforward approach for detecting antioxidants in biological samples, facilitating improved monitoring of oxidative stress in various diseases.

New solvated Mo(VI) complexes of isatin based asymmetric bisthiocarbohydrazones as potent bioactive agent: synthesis, DFT-molecular docking studies, biological activity evaluation and crystal structures

New solvated Mo(VI) complexes were isolated from the reaction of [MoO2(acac)2] with asymmetric isatin bisthiocarbohydrazone ligands. The ligands were obtained from the reaction of isatin monothiocarbohydrazone with 3,5-dibromo salicylaldehyde (L1), 3,5-dichloro salicylaldehyde (L2) and 3-chloro-5-bromo salicylaldehyde (L3), respectively. In the complexes, the ligands serve as ONS donors and coordinate to the [MoO2]2+ nucleus. The bonding sites are azomethine nitrogen atom, phenolic oxygen atom and thiol sulfur atom. The sixth coordination site is completed by an oxygen atom from an ethanol solvent. The ethanol-coordinated Mo(VI) complexes, C1-C3, [MoO2L(EtOH)] (L: L1-L3), were characterized using elemental analysis, IR and 1H NMR spectroscopies, and conductivity measurements. By crystallizing ethanol-solvated solid complexes from an EtOH/DMSO mixture, DMSO-solvated complexes (C4-C6) suitable for X-ray crystallography were obtained. Crystal structure analysis supports the proposed complex structures and geometries, but the ethanol in the sixth coordination site has been replaced by DMSO. When the anticarcinogenic effects of the ligands and complexes (C1-C3) on the C6 cell line were examined, it was found that the complexes showed higher activity than the ligands. The C3 complex appears to have the best anti-cancer activity compared to doxorubicin. Additionally, all compounds were determined to have high total antioxidant capacity. Data obtained from theoretical studies (DFT and docking) support experimental studies.

Nanomedicines as Guardians of the Heart: Unleashing the Power of Antioxidants to Alleviate Myocardial Ischemic Injury

Ischemic heart disease (IHD) is increasingly recognized as a significant cardiovascular disease with a growing global incidence. Interventions targeting the oxidative microenvironment have long been pivotal in therapeutic strategies. However, many antioxidant drugs face limitations due to pharmacokinetic and delivery challenges, such as short half-life, poor stability, low bioavailability, and significant side effects. Fortunately, nanotherapies exhibit considerable potential in addressing IHD. Nanomedicines offer advantages such as passive/active targeting, prolonged circulation time, enhanced bioavailability, and diverse carrier options. This comprehensive review explores the advancements in nanomedicines for mitigating IHD through oxidative stress regulation, providing an extensive overview for researchers in the field of antioxidant nanomedicines. By inspiring further research, this study aims to accelerate the development of novel therapies for myocardial injury.

Potential Role of Dietary Phenolic Compounds in the Prevention and Treatment of Rheumatoid Arthritis: Current Reports

Rheumatoid arthritis (RA) is a complex illness with both hereditary and environmental components. Globally, in 2019, 18 million people had RA. RA is characterized by persistent inflammation of the synovial membrane that lines the joints, cartilage loss, and bone erosion. Phenolic molecules are the most prevalent secondary metabolites in plants, with a diverse spectrum of biological actions that benefit functional meals and nutraceuticals. These compounds have received a lot of attention recently because they have antioxidant, anti-inflammatory, immunomodulatory, and anti-rheumatoid activity by modulating tumor necrosis factor, mitogen-activated protein kinase, nuclear factor kappa-light-chain-enhancer of activated B cells, and c-Jun N-terminal kinases, as well as other preventative properties. This article discusses dietary polyphenols, their pharmacological properties, and innovative delivery technologies for the treatment of RA, with a focus on their possible biological activities. Nonetheless, commercialization of polyphenols may be achievable only after confirming their safety profile and completing successful clinical trials.

Novel acrylonitrile derived imidazo[4,5-b]pyridines as antioxidants and potent antiproliferative agents for pancreatic adenocarcinoma

We present the design, synthesis, computational analysis, and biological assessment of several acrylonitrile derived imidazo[4,5-b]pyridines, which were evaluated for their anticancer and antioxidant properties. Our aim was to explore how the number of hydroxy groups and the nature of nitrogen substituents influence their biological activity. The prepared derivatives exhibited robust and selective antiproliferative effects against several pancreatic adenocarcinoma cells, most markedly targeting Capan-1 cells (IC50 1.2-5.3 μM), while their selectivity was probed relative to normal PBMC cells. Notably, compound 55, featuring dihydroxy and bromo substituents, emerged as a promising lead molecule. It displayed the most prominent antiproliferative activity without any adverse impact on the viability of normal cells. Furthermore, the majority of studied derivatives also exhibited significant antioxidative activity within the FRAP assay, even surpassing the reference molecule BHT. Computational analysis rationalized the results by highlighting the dominance of the electron ionization for the antioxidant features with the trend in the computed ionization energies well matching the observed activities. Still, in trihydroxy derivatives, their ability to release hydrogen atoms and form a stable O-H⋯O•⋯H-O fragment upon the H• abstraction prevails, promoting them as excellent antioxidants in DPPH• assays as well.

A Kinetic Approach to Oxygen Radical Absorbance Capacity (ORAC): Restoring Order to the Antioxidant Activity of Hydroxycinnamic Acids and Fruit Juices

This study introduces a kinetic model that significantly improves the interpretation of the oxygen radical absorbance capacity (ORAC) assay. Our model accurately simulates and fits the bleaching kinetics of fluorescein in the presence of various antioxidants, achieving high correlation values (R2 > 0.99) with the experimental data. The fit to the experimental data is achieved by optimizing two rate constants, k5 and k6. The k5 value reflects the reactivity of antioxidants toward scavenging peroxyl radicals, whereas k6 measures the ability of antioxidants to regenerate oxidized fluorescein. These parameters (1) allow the detailed classification of cinnamic acids based on their structure-activity relationships, (2) provide insights into the interaction of alkoxyl radicals with fluorescein, and (3) account for the regeneration of fluorescein radicals by antioxidants. The application of the model to different antioxidants and fruit extracts reveals significant deviations from the results of traditional ORAC tests based on the area under the curve (AUC) approach. For example, lemon juice, rich in 'fast' antioxidants such as ascorbic acid, shows a high k5 value, in contrast to its low AUC values. This finding underscores the limitations of the AUC approach and highlights the advantages of our kinetic model in understanding antioxidative dynamics in food systems. This study presents a comprehensive, quantitative, mechanism-oriented approach to assessing antioxidant reactivity, demonstrating a significant improvement in ORAC assay applications.

Emerging Role of Plant-Based Bioactive Compounds as Therapeutics in Parkinson's Disease

Neurological ailments, including stroke, Alzheimer's disease (AD), epilepsy, Parkinson's disease (PD), and other related diseases, have affected around 1 billion people globally to date. PD stands second among the common neurodegenerative diseases caused as a result of dopaminergic neuron loss in the midbrain's substantia nigra regions. It affects cognitive and motor activities, resulting in tremors during rest, slow movement, and muscle stiffness. There are various traditional approaches for the management of PD, but they provide only symptomatic relief. Thus, a survey for finding new biomolecules or substances exhibiting the therapeutic potential to patients with PD is the main focus of present-day research. Medicinal plants, herbal formulations, and natural bioactive molecules have been gaining much more attention in recent years as synthetic molecules orchestrate a number of undesired effects. Several in vitro, in vivo, and in silico studies in the recent past have demonstrated the therapeutic potential of medicinal plants, herbal formulations, and plant-based bioactives. Among the plant-based bioactives, polyphenols, terpenes, and alkaloids are of particular interest due to their potent anti-inflammatory, antioxidant, and brain-health-promoting properties. Further, there are no concise, elaborated articles comprising updated mechanism-of-action-based reviews of the published literature on potent, recently investigated (2019-2023) medicinal plants, herbal formulations, and plant based-bioactive molecules, including polyphenols, terpenes, and alkaloids, as a method for the management of PD. Therefore, we designed the current review to provide an illustration of the efficacious role of various medicinal plants, herbal formulations, and bioactives (polyphenols, terpenes, and alkaloids) that can become potential therapeutics against PD with greater specificity, target approachability, bioavailability, and safety to the host. This information can be further utilized in the future to develop several value-added formulations and nutraceutical products to achieve the desired safety and efficacy for the management of PD.

A Novel Dual-Function Redox Modulator Relieves Oxidative Stress and Anti-Angiogenic Response in Placental Villus Explant Exposed to Hypoxia-Relevance for Preeclampsia Therapy

BACKGROUND

Preeclampsia (PE) is a severe, life-threatening complication during pregnancy (~5-7%), and no causative treatment is available. Early aberrant spiral artery remodeling is associated with placental stress and the release of oxygen radicals and other reactive oxygen species (ROS) in the placenta. This precedes the production of anti-angiogenic factors, which ultimately leads to endothelial and trophoblast damage and the key features of PE. We tested whether a novel dual-function redox modulator-AKT-1005-can effectively reduce placental oxidative stress and alleviate PE symptoms in vitro.

METHOD

Isolated human villous explants were exposed to hypoxia and assessed to determine whether improving cell-redox function with AKT-1005 diminished ROS production, mitochondrial stress, production of the transcription factor HIF1A, and downstream anti-angiogenic responses (i.e., sFLT1, sEng production). MitoTEMPO was used as a reference antioxidant.

RESULTS

In our villous explant assays, pretreatment with AKT-1005 reduced mitochondrial-derived ROS production, reduced HIF-1A, sFLT1, and sEng protein expression, while increasing VEGF in hypoxia-exposed villous trophoblast cells, with better efficiency than MitoTEMPO. In addition, AKT-1005 improved mitochondrial electron chain enzyme activity in the stressed explant culture.

CONCLUSIONS

The redox modulator AKT-1005 has the potential to intervene with oxidative stress and can be efficacious for PE therapy. Future studies are underway to assess the in vivo efficacy of HMP.

Featured Reviews in Organic Chemistry

The field of Organic Chemistry represents one of the most traditional areas of chemistry that has delivered many benefits to the community of chemists [...].

Nitroxide-HMP-Protects Human Trophoblast HTR-8/SVneo Cells from H2O2-Induced Oxidative Stress by Reducing the HIF1A Signaling Pathway

Preeclampsia (PE) is a pregnancy-specific syndrome affecting 5-7% of patients. There is no effective treatment available. Early abnormal placental development is associated with oxidative stress (OS) and a release of reactive oxygen species (ROS) in the placenta. This phenomenon leads to downstream signaling, Hypoxia Inducible Factor 1A (HIF1A) stabilization and transcription of the anti-angiogenic factors soluble fms-like tyrosine kinase 1 (sFLT1) and soluble endoglin (sEng), which are known to cause endothelial and trophoblast dysfunction and cardinal features of PE: hypertension, proteinuria and, in severe cases, eclampsia. We tested whether 3-(Hydroxymethyl)-1-oxy-2,2,5,5-tetramethylpyrrolidine (HMP)-a nitroxide-type antioxidant molecule-can reduce placental OS and mitigate PE symptoms in vitro. We induced OS in human trophoblast (HTR-8/SVneo) cells with hydrogen peroxide (H2O2) and assessed whether modulating cell redox function with HMP reduces cell injury, mitochondrial stress and HIF1A and sFLT1 production. Pre-treatment with HMP reduced mitochondrial-derived ROS production, restored LC3B expression and reduced HIF1A and sFLT1 expression in H2O2-exposed HTR-8/SVneo trophoblast cells. HMP improved the mitochondrial electron chain enzyme activity, indicating that a reduction in OS alleviates mitochondrial stress and also reduces anti-angiogenic responses. In reducing placental trophoblast OS, HMP presents a potential novel therapeutic approach for the treatment of PE. Future investigation is warranted regarding the in vivo use of HMP.

Protective Effects of 3'-Epilutein and 3'-Oxolutein against Glutamate-Induced Neuronal Damage

Dietary lutein can be naturally metabolized to 3'-epilutein and 3'-oxolutein in the human body. The epimerization of lutein can happen in acidic pH, and through cooking, 3'-epilutein can be the product of the direct oxidation of lutein in the retina, which is also present in human serum. The 3'-oxolutein is the main oxidation product of lutein. Thus, the allylic oxidation of dietary lutein can result in the formation of 3'-oxolutein, which may undergo reduction either to revert to dietary lutein or epimerize to form 3'-epilutein. We focused on the effects of 3'-epilutein and 3'-oxolutein itself and on glutamate-induced neurotoxicity on SH-SY5Y human neuroblastoma cells to identify the possible alterations in oxidative stress, inflammation, antioxidant capacity, and iron metabolism that affect neurological function. ROS measurements were performed in the differently treated cells. The inflammatory state of cells was followed by TNFα, IL-6, and IL-8 cytokine ELISA measurements. The antioxidant status of the cells was determined by the total antioxidant capacity kit assay. The alterations of genes related to ferroptosis and lipid peroxidation were followed by gene expression measurements; then, thiol measurements were performed. Lutein metabolites 3'-epilutein and 3'-oxolutein differently modulated the effect of glutamate on ROS, inflammation, ferroptosis-related iron metabolism, and lipid peroxidation in SH-SY5Y cells. Our results revealed the antioxidant and anti-inflammatory features of 3'-epilutein and 3'-oxolutein as possible protective agents against glutamate-induced oxidative stress in SH-SY5Y cells, with greater efficacy in the case of 3'-epilutein.

Antioxidant capacity of simplified oxygen heterocycles and proposed derivatives by theoretical calculations

CONTEXT

Some structural properties can be involved in the antioxidant capacity of several polyphenol derivatives, among them their simplified structures. This study examines the contribution of simplified structure for the antioxidant capacity of some natural and synthetic antioxidants. The resonance structures were related to the π-type electron system of carbon-carbon double bonds between both phenyl rings. Trans-resveratrol, phenyl-benzofuran, phenyl-indenone, and benzylidene-benzofuranone are the best basic antioxidant templates among the simplified derivatives studied here. Additionally, the stilbene moiety was found on the molecules with the best antioxidant capacity. Furthermore, our investigation suggests that these compounds can be used as antioxidant scaffold for designing and developing of new promising derivatives.

METHODS

To investigate the structure-antioxidant capacity for sixteen simplified natural and proposed derivatives we have employed density functional theory and used Gaussian 09. Our DFT calculations were performed using the B3LYP functional and the 6-31+G(d,p) basis set. All electron transfer mechanisms were investigated by using values of HOMO, ionization potential, energy affinity, stabilization energies, and spin density distributions.

The Cactus (Opuntia ficus-indica) Cladodes and Callus Extracts: A Study Combined with LC-MS Metabolic Profiling, In-Silico, and In-Vitro Analyses

Opuntia ficus-indica (OF) phytochemicals have received considerable attention because of their health benefits. However, the structure-activity relationship between saponin and flavonoid antioxidant compounds among secondary metabolites has rarely been reported. In a molecular docking study, selected compounds from both Opuntia ficus-indica callus (OFC) and OF ethanol extract were found to be involved in Toll-like receptor 4 and mitogen-activated protein kinase (MAPK) signaling pathways. High affinity was specific for MAPK, and it was proposed to inhibit the oxidative and inflammatory responses with poricoic acid H (-8.3 Kcal/mol) and rutin (-9.0 Kcal/mol). The pro-inflammatory cytokine factors at a concentration of 200 μg/mL were LPS-stimulated TNF-α (OFC 72.33 ng/mL, OF 66.78 ng/mL) and IL-1β (OFC 49.10 pg/mL, OF 34.45 pg/mL), both of which significantly decreased OF (p < 0.01, p < 0.001). Taken together, increased NO, PGE₂, and pro-inflammatory cytokines were significantly decreased in a dose-dependent manner in cells pretreated with OFC and the OF extract (p < 0.05). These findings suggest that OFC and OF have important potential as natural antioxidant, anti-inflammatory agents in health-promoting foods and medicine.

Enzymatic Modification of Pomace Olive Oil with Natural Antioxidants: Effect on Oxidative Stability

Enzymatic lipophilization has been proposed as a cost-effective strategy to produce new liposoluble antioxidant compounds. In this study, modified oils rich in structured phenolipids were prepared via one-pot enzymatic acylation of hydroxytyrosol (HTYR), vanillyl alcohol (VA) and homovanillyl alcohol (HVA) with pomace olive oil (POO) in solvent-free conditions using immobilized lipase on biogenic nanoparticles. The effect of temperature (30-70 °C) and enzyme concentration (0.1-1%, w/w) on the efficiency of the bioprocess as well as the reusability of the nanobiocatalyst were thoroughly investigated. The modified oils exhibited increased antioxidant activity compared to the control oil according to DPPH and CUPRAC assays (p < 0.05). The oxidative stability of pomace olive oil was also significantly enhanced after modification, as depicted by the K₂₃₂ values and TBARS contents under accelerated oxidation at 60 °C (p < 0.05). Moreover, a fortified mayonnaise containing modified oil with HTYR was prepared that was noticeably stable compared to the control mayonnaise at 28 °C for 5 months (p < 0.05). Enzymatically modified oils have great potential for application in the nutraceutical and food industry, encouraging the exploitation of immobilized lipases as effective and green catalytic tools.

Antioxidant activity of lidocaine, bupivacaine, and ropivacaine in aqueous and lipophilic environments: an experimental and computational study

Introduction: Local anesthetics are widely recognized pharmaceutical compounds with various clinical effects. Recent research indicates that they positively impact the antioxidant system and they may function as free radical scavengers. We hypothesize that their scavenging activity is influenced by the lipophilicity of the environment. Methods: We assessed the free radical scavenging capacity of three local anesthetics (lidocaine, bupivacaine, and ropivacaine) using ABTS, DPPH, and FRAP antioxidant assays. We also employed quantum chemistry methods to find the most probable reaction mechanism. The experiments were conducted in an aqueous environment simulating extracellular fluid or cytosol, and in a lipophilic environment (n-octanol) simulating cellular membranes or myelin sheets. Results: All local anesthetics demonstrated ABTS˙⁺ radical scavenging activity, with lidocaine being the most effective. Compared to Vitamin C, lidocaine exhibited a 200-fold higher half-maximal inhibitory concentration. The most thermodynamically favorable and only possible reaction mechanism involved hydrogen atom transfer between the free radical and the -C-H vicinal to the carbonyl group. We found that the antioxidant activity of all tested local anesthetics was negligible in lipophilic environments, which was further confirmed by quantum chemical calculations. Conclusion: Local anesthetics exhibit modest free radical scavenging activity in aqueous environments, with lidocaine demonstrating the highest activity. However, their antioxidant activity in lipophilic environments, such as cellular membranes, myelin sheets, and adipose tissue, appears to be negligible. Our results thus show that free radical scavenging activity is influenced by the lipophilicity of the environment.