Free Radical Formation Research Articles

Dynamic formation mechanism of persistent free radicals driven by water-phase oxidation-dependent heterogeneity of the carbon−silicon coupling structure in biochar

The formation of persistent free radicals (PFRs) in biochar (BC) is closely related to the structural characteristics and reactivity of BC, which have toxic effects on the environment. However, the mechanisms driving PFRs formation through structural evolution during oxidative aging of BC remain unclear. Herein, we propose a novel dynamic mechanism for BC-PFRs formation driven by oxidation-dependent heterogeneity in carbon−silicon coupling structures by evaluating their heterogeneous correlations, sequential responses, and synergistic relations. The sequential destruction of the “outer carbon−middle silicon−inner carbon” spatial layer and the transformation of molecular components caused by continuous oxidation of BC contributed to the formation of BC-PFRs with two concentration peaks. Moreover, two-dimensional correlation spectroscopy combined with infrared spectroscopy and high-resolution mass spectrometry revealed the sequential responses of carbon−silicon functional groups in BC (Si−O−Si groups → silicon enclosed structures → carbon groups) and BC-derived dissolved organic molecules (lipid-/aliphatic-/carbohydrate-like molecules → lignin-/tannin-like molecules → condensed aromatic molecules), leading to the staged formation of BC-PFRs. High molecular-weight lignin-/tannin-like and condensed aromatic molecules in the carbon layer contributed to BC-PFRs formation, whereas crystalline silicon components hindered the oxidative degradation of inner aromatic carbon and subsequent PFRs formation. Our findings help elucidate potential environmental behaviors and risks associated with BC-PFRs.

Exploring Neuroprotection against Radiation-Induced Brain Injury: A Review of Key Compounds.

Brain radiation is a crucial tool in neuro-oncology for enhancing local tumor control, but it can lead to mild-to-profound and progressive impairments in cognitive function. Radiation-induced brain injury is a significant adverse effect of radiotherapy for cranioencephalic tumors, primarily caused by indirect cellular damage through the formation of free radicals. This results in late neurotoxicity manifesting as cognitive impairment due to free radical production. The aim of this review is to highlight the role of different substances, such as drugs used in the clinical setting and antioxidants such as ascorbate, in reducing the neurotoxicity associated with radiation-induced brain injury. Currently, there is mainly preclinical and clinical evidence supporting the benefit of these interventions, representing a cost-effective and straightforward neuroprotective strategy.

Exploring the Potential of Biomimetic Peptides in Targeting Fibrillar and Filamentous Alpha-Synuclein-An In Silico and Experimental Approach to Parkinson's Disease.

Alpha-synuclein (ASyn) is a protein that is known to play a critical role in Parkinson's disease (PD) due to its propensity for misfolding and aggregation. Furthermore, this process leads to oxidative stress and the formation of free radicals that cause neuronal damage. In this study, we have utilized a biomimetic approach to design new peptides derived from marine natural resources. The peptides were designed using a peptide scrambling approach where antioxidant moieties were combined with fibrillary inhibition motifs in order to design peptides that would have a dual targeting effect on ASyn misfolding. Of the 20 designed peptides, 12 were selected for examining binding interactions through molecular docking and molecular dynamics approaches, which revealed that the peptides were binding to the pre-NAC and NAC (non-amyloid component) domain residues such as Tyr39, Asn65, Gly86, and Ala85, among others. Because ASyn filaments derived from Lewy body dementia (LBD) have a different secondary structure compared to pathogenic ASyn fibrils, both forms were tested computationally. Five of those peptides were utilized for laboratory validation based on those results. The binding interactions with fibrils were confirmed using surface plasmon resonance studies, where EQALMPWIWYWKDPNGS, PYYYWKDPNGS, and PYYYWKELAQM showed higher binding. Secondary structural analyses revealed their ability to induce conformational changes in ASyn fibrils. Additionally, PYYYWKDPNGS and PYYYWKELAQM also demonstrated antioxidant properties. This study provides insight into the binding interactions of varying forms of ASyn implicated in PD. The peptides may be further investigated for mitigating fibrillation at the cellular level and may have the potential to target ASyn.

Towards the Development of Novel, Point-of-Care Assays for Monitoring Different Forms of Antioxidant Activity: The RoXstaTM System.

(1) Background: This study set out to develop a series of simple, novel, rapid methods for assessing different forms of antioxidant activity. (2) Methods: An ABTS platform was used to engineer: (i) an electrochemical post-activation assay to assess free radical scavenging activity; (ii) an electrochemical pre-activation strategy to assesses the suppression of free radical formation; (iii) a horseradish peroxidase-mediated oxidation system to monitor hydrogen peroxide scavenging activity and (iv) a cumene peroxide-hematin system to determine the ability of samples to scavenge the mixture of organic peroxides and peroxyl and alkoxyl radicals generated in the presence of these reagents. Each assay was assessed against a panel of candidate antioxidant compounds to determine their relative activities and specificities. In addition, human semen samples were analyzed to determine how the results of these antioxidant assays correlated with semen quality. (3) Results: All 4 assays revealed dose-dependent antioxidant activity on the part of vitamin C, N-acetyl cysteine, hypotaurine, BSA, melatonin, glutathione, resveratrol and epigallocatechin gallate. The other compounds tested either completely lacked antioxidant activity or were only active in one of the assays. Using unfractionated human semen as an exemplar of biological fluids rich in antioxidants, the outputs from the individual assays were found to reflect different aspects of semen quality. When the data from all 4 assays were combined, accurate predictions were generated reflecting the importance of oxidative stress in defining semen quality as reflected by sperm count, seminal lipid aldehyde content, sperm DNA damage and free radical generation by the sperm mitochondria. (4) Conclusions: The methodologies described in this paper constitute the basis for rapid, point-of-care assessments of oxidative stress.

Formation of Both Free Hydroxyl Radicals and Surface Oxygen During Catalytic Ozonation by Single-Atom Iron: An Overlooked Pollutant-Dependent Oxidation Mechanism

Formation of Both Free Hydroxyl Radicals and Surface Oxygen During Catalytic Ozonation by Single-Atom Iron: An Overlooked Pollutant-Dependent Oxidation Mechanism

Photoprotection and its implications for drug safety

Appropriate photoprotection plays a key role in the safety of using medicinal preparations whose active substances may induce photosensitivity reactions. This aspect applies not only to drugs applied topically to the skin, but also systemically. Drug-induced photosensitivity reactions to light depend on the active substance contained in the medicinal product and its dose, which translates into the concentration in the skin, the type of ultraviolet radiation, its intensity and exposure time. The chemical structure of phototoxic drugs contains unsaturated chemical bonds and aromatic groups, which are responsible for the absorption of radiation, the formation of degradation products and/or free radicals and hypersensitivity reactions. Therefore, in order to prevent hypersensitivity reactions, it is necessary to use appropriate sun protection and/or avoid exposure to solar radiation during pharmacotherapy with selected groups of drugs. The paper presents the latest research results on the impact of drug-induced photohypersensitivity on the increased likelihood of skin cancer. Drugs with the potential to induce photohypersensitivity reactions are discussed, including information on the relationship between their long-term use and the incidence of skin cancer. Based on the data contained in the Product Characteristics, exemplary indications regarding the appropriate photoprotection method to ensure the safe use of the medicinal product are presented. Med Pr Work Health Saf. 2024;75(5).

Unveiling the antibacterial and antioxidant capabilities of Diospyros buxifolia leaf and stem extracts via GC-MS analysis

Drug-resistant microorganisms pose a significant threat to public health as they can undermine the effectiveness of existing antibiotics and other medications. Additionally, the formation of free radicals, can contribute to various health problems. Diospyros buxifolia (D. buxifolia) belonging to Ebenaceae family is a large tropical evergreen tree utilised in traditional medicine to cure several health ailments. The present study was set out to separate bioactive speciation of aqueous and methanolic extracts of stem and leaves from D. buxifolia by using Gas Chromatography-Mass Spectrometry (GC-MS) followed by evaluation of its antimicrobial and antioxidant capabilities. GC-MS identified 14 different bioactive compounds, with four compounds common for both (leaf and stem) extracts. The methanolic extracts of leaf demonstrated significant antibacterial activity) while stem extracts exhibited notable antioxidant potential. Thus, D. buxifolia is proved source of natural antimicrobial and antioxidant agent, that could address the challenges posed by drug-resistant microorganisms and oxidative stress in global health.

Research on the Influence of Fault Structure on Physical and Chemical Structure of Coking Coal During Spontaneous Combustion

ABSTRACT The spontaneous combustion tendency and oxidation combustion properties of coking coal in fault fracture zone and primary coking coal are different. Accordingly, this study uses Thermogravimetric analysis, in-situ Fourier transform infrared spectroscopy, Scanning electron microscope, low-temperature N2 adsorption and Electron spin resonance techniques were used to study the difference of macroscopic and microscopic structural characteristics between coking coal and primary coking coal in fault fracture zone. The results show that: The oxygen absorption capacity of coking coal in fault fracture zone is enhanced and the thermogravimetric characteristic temperature is advanced, and the ignition point temperature is advanced by 5.36°C; the maximum weight loss temperature of coking coal in fault fracture zone is 3.32°C lower than that of primary coking coal. The apparent activation energy of coking coal in oxidation stage and pyrolytic combustion stage decreased by 4.88 and 5.03 kJ/mol, respectively. Compared with primary coking coal, the pore structure of coking coal in fault fracture zone is more complex, which increases the roughness of coal surface and is conducive to oxygen adsorption. In addition, fault tectonics promotes the separation and cracking of oxygen-containing functional groups into small molecules, and the polycondensation of aliphatic hydrocarbon structure promotes the formation of active free radicals, thus promoting spontaneous combustion. This study provides an important reference and theoretical support for further understanding of the structural evolution and oxidation kinetics of highly metamorphic coking coal induced by fault tectonics, which is helpful for fire prevention and control in fault structure-developed mining areas and safe production of coal industry.

Novel Methods for the Formation of Free Carbyne Radicals in Solution.

Carbyne free radicals (RC) are usually associated with high-energy processes, thus research on their preparation, chemical reactivity, and prevalence under mild conditions is scarce. Recently, it was reported that metallo-complexes containing CR ligands may undergo spontaneous degradation in aqueous solutions to produce free RC radicals. These highly reactive species may react with each other to form the corresponding alkyne and other products. The reaction of 1,1,1 halo-carbo-hydrates with Cr(II) ions also forms RC radicals under mild conditions. Herein, we report two additional synthetic routes that produce free RC radicals under mild conditions. First, the reaction between metallic zinc and acetic anhydride produces 2-butyne and several other C2, C3, and C4 compounds. Isotopic-labeling experiments indicate that the formation of 2-butyne results from an inter-molecular reaction in which two RC moieties from two acetic anhydride molecules combine in solution. In addition, the degradation of the tri-molybdenum complex [Mo3(H3CC≡CCH3)(OAc)(H2O)2Br7], in which a 2-butyne ligand is coordinated to the Mo3 framework in a μ3-η2 (⊥) binding mode in aqueous solution produces several C2, C3, C4 and C5 molecules. This indicates the formation of free CH3C radicals by a homolytic cleavage of the carbon-carbon triple bond.

ESR spectroscopic analysis of fructose as a dosimeter for gamma radiation

In this research, fructose was used as a dosimeter, and ESR examined the influence of radiation dose on the dosimeter’s properties. Microwave power, g-value, and decay of response tests were carried out at doses of 1, 5, and 10 kGy. The results show that fructose possesses linearity at doses of 5 × 10−2–30 kGy. The radiation detection sensitivity of fructose is better than sucrose’s but less than alanine’s over the entire dose range. The irradiation dose influences microwave saturation on ESR intensity, occurring at 5 and 10 kGy. The microwave power for irradiated fructose ranges from 1.00 to 2.46 mW. The ESR signal intensity increases with higher radiation doses, primarily due to the formation of more free radicals. Additionally, higher radiation doses lead to faster decay of the fructose dosimeter’s response. The fructose ESR intensity stability compared to alanine and sucrose at 1, 5, and 10 kGy are alanine > sucrose > fructose, alanine > fructose > sucrose, and alanine > fructose ≈ sucrose, respectively.

Hepatoprotective effect of silymarin-chitosan nanocomposite against aluminum-induced oxidative stress, inflammation, and apoptosis

Aluminum (Al) is abundant in the environment, and its toxicity is attributed to free radical formation and subsequent oxidative stress. While silymarin is a well-known antioxidant, its low water solubility and bioavailability limit its therapeutic effects. This study was designated to formulate silymarin chitosan nanoparticles (SM-CS-NPs) and evaluate its ameliorative effect against hepatotoxicity induced by aluminum chloride (AlCl3). SM-CS-NPs were prepared by ionotropic gelation method and characterized using different techniques. Rats were distributed into six groups (n=7/group), control, silymarin (SM; 15 mg/kg B.W), silymarin-chitosan nanoparticles (SM-CS-NPs; 15 mg/kg), aluminum chloride (AlCl3, 34 mg/kg), SM or SM-CS-NPs administrated orally one hour before the treatment with AlCl3 for 30 days, respectively. Results showed that supplementation of SM-CS-NPs or SM solo improved the antioxidant state and reduced oxidative stress. On the other hand, the pretreatment with SM-CS-NPs or SM followed by AlCl3 significantly restored liver functions (AST, ALT, ALP, LDH, total protein, albumin, globulin, and bilirubin) and modulated oxidative stress biomarkers (TBARS and H2O2), with improved cellular antioxidant defense (SOD, CAT, GPx, GR, GST, and GSH) and maintained normal liver histological structure compared to rats treated with AlCl3 alone. Furthermore, they alleviated the inflammation and apoptosis by downregulating the expression level of COX-2, caspase-3, and TNFα. This ameliorative effect was stronger with silymarin nanoform than in bulk-state silymarin. According to the findings, silymarin preparation in nanoform boosts its ameliorative and protective effects against AlCl3 hepatotoxicity.

Enhancing oil shale pyrolysis using metal-doped carbon quantum dot catalysts: A comprehensive behavioral, kinetic, and mechanistic analysis

Current oil shale extraction technologies face significant challenges, including high heating costs, slow pyrolysis reaction rates, and low efficiency, which hinder effective resource exploitation. To address these issues, this study synthesized three types of metal-doped carbon quantum dot (M/CQD) catalysts—Co/CQDs, Ni/CQDs, and Mn/CQDs—and tested their effects on the pyrolysis of oil shale. The introduction of these catalysts resulted in a notable enhancement of the pyrolysis process, reducing the required activation energy by approximately 40 % and lowering the initiation temperatures for Co/CQDs, Ni/CQDs, and Mn/CQDs by 64 °C, 62 °C, and 94 °C, respectively. Consequently, the yield of shale oil increased significantly by 23.1 %, 13.3 %, and 19.8 % for each catalyst. Kinetic and product analyses indicate that these catalysts facilitate electron transfer from organic molecules, promoting the formation of free radicals and the cleavage of C–C bonds. This enhancement leads to an increased production of short-chain hydrocarbons and a reduction in oxygenates and esters, thereby improving the quality of the shale oil. Further insights from Density Functional Theory (DFT) calculations suggest that the catalysts enhance pyrolysis by promoting the formation of carbocations and synergizing with radicals released from the shale, intensifying the pyrolysis process. This study not only elucidates the catalytic mechanisms that enhance oil shale pyrolysis but also offers a promising approach to overcome technological challenges in shale resource recovery, such as high heating costs and low efficiency, paving the way for more efficient and cleaner shale oil production.

Exploration of the regulatory mechanism of pulsed electric field on the aggregation behavior of soybean protein isolates

As an emerging protein modification technology, pulsed electric field (PEF) technology in modifying soybean protein isolates (SPI) suffers from unclear mechanism and controversial changes in aggregation structure. To address these issues, the effects of PEF treatment with different electric field intensities (5–30 kV/cm) on the aggregation behavior and spatial structure of SPI were investigated. The results showed that the SPI aggregates exhibited a trend of depolymerization followed by reaggregation with the increase of PEF intensity. At 10 and 15 kV/cm, the polarization effect of PEF induced the unfolding of the tertiary structure of SPI, leading to the enhancement of the electronegativity of the side chains, and the electrostatic repulsive force between the molecules promoted the depolymerization of SPI aggregates. However, with the withdrawal of PEF, the structure of the SPI was partially reversible, resulting in a limited depolymerization effect. When the PEF intensity reached 20 kV/cm and above, SPI underwentstructure unfolding, subunit dissociation, continuous exposure of hydrophobic groups and sulfhydryl groups, and ultimately reaggregation mediated by hydrophobic interactions and disulfide bonding, resulting in the formation of high molecular weight soluble and insoluble protein aggregates. In addition, the formation of free radicals under strong electric fields (≥20 kV/cm) accelerated the oxidation of SPI and promoted the rapid formation of disulfide bonds. This study provides a theoretical basis for the targeted regulation of SPI aggregation structure by PEF.

Free-radical triggered formation of dioxins from 2-chlorophenol pyrolysis investigated by synchrotron radiation photoionization mass spectrometry

Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated naphthalenes (PCNs) are a category of highly toxic and environmentally persistent pollutants released particularly via thermal processes of chlorine-containing materials. However, the detailed reaction mechanism, especially the evolution of related radicals remains elusive for decades. Herein we have for the first time characterized the radicals and intermediates during pyrolysis of 2-chlorophenol resulting in PCDD/Fs and PCNs, using a flow tube reactor coupled with in-situ synchrotron radiation photoionization mass spectrometry (SR-PIMS). Transient species including 2-chlorophenoxy (C6H4ClO•), phenoxy (C6H5O•), chloro-cyclopentadienyl (•C5H4Cl), chloro-cyclopentadiene (C5H5Cl), fulvenone ketene (C6H4O) and o-benzyne (o-C6H4), were identified via m/z and photoionization efficiency profile. Potential energy surfaces of the early-stage mechanism and the associated rate constants and branching ratios were elucidated. Successively, the formation mechanisms of PCDD/Fs and PCNs from these transient intermediates at high temperatures were proposed which have experimentally validated and refined the previous mechanism. The results suggested that the combination of 2-chlorophenoxy radicals with another 2-chlorophenoxy, phenoxy, phenyl, or o-benzyne leads to the formation of PCDD/Fs, while PCNs are generated from the self-coupling of chloro-cyclopentadienyl.

Electron Paramagnetic Resonance Analysis of Hydroquinone Polymerization Catalyzed by Small Laccase

AbstractLaccases are multi‐copper oxidases (MCOs) that oxidize a broad range of substrates while reducing molecular oxygen to water. Although much effort has been made to elucidate the catalytic mechanism of laccases, information about reactive catalytic intermediates during catalysis is not yet fully understood. Herein, hydroquinone (HQ) polymerization catalyzed by prokaryotic small laccase (SLAC) was investigated by electron paramagnetic resonance (EPR) spectroscopy to provide more information on the catalytic mechanism. Briefly, free radical intermediates during the catalysis were investigated by real‐time in situ EPR measurement to monitor the formation and transformation of free radicals. A paramagnetic species was identified which was attributed to a copolymer formed by hydroquinone, benzoquinone, and semiquinone radical. In addition, the low‐temperature EPR spectrum of the trinuclear copper center during catalysis not only revealed tentative rotational motion of the histidine imidazole rings coordinating the TNC upon electron uptake but also provided evidence of the formation of oxygen bridge at TNC during the reaction, represented by the observation of a new type 2 copper component featured larger g// values and smaller A// values. Together, EPR spectroscopic insights into the catalytic intermediates during enzymatic hydroquinone polymerization have extended the knowledge of the biophysical characteristics and catalytic mechanism of SLAC.

Modification of activated carbon through chemical-physical activation method with KOH and 60Co gamma irradiation from banana leaf waste

Abstract Until now waste is still a problem in many big cities in Indonesia. In addition, the amount of waste increases as the population increases. Banana leaf waste is no exception, which is included in other types of waste, which accounts for 6.33% of the total waste in Indonesia in 2022. Utilization of banana leaf waste as a raw material for activated carbon production can also be an alternative to reducing the amount of wasted banana leaf waste because they contain various kinds of organic compounds. Activated carbon is widely used as an adsorbent in various sectors, especially in the industrial sector. Production of activated carbon must go through an activation process to enlarge the surface pores either chemically or physically, or even both. This study aims to compare the results of activated carbon surface area and functional groups using the chemical-physical activation method from banana leaf biomass raw materials with KOH and gamma irradiation at various doses. The research method used is an experimental method consisting of 4 stages: dehydration, carbonization, activation, and characterization. The research was started by dehydrating the leaves and continued with the carbonization stage at 350°C for 30 minutes. Carbon was divided into four samples that consisted of 1 blank and 3 test materials that activated with 30% (w/v) KOH solution for 24 hours and gamma-irradiated with a dose of 10, 30, and 50 kGy. Results were characterized using FTIR and BET. The effect of gamma 60Co irradiation on the activated carbon material from banana leaf waste can increase the peak transmittance value of the activated carbon functional group due to the formation and reaction of free radicals on its surface. Increase in the surface area (from 6.504 to 24.04 m2/g) is also associated with an increase in the absorbed dose due to the formation of more free radicals. However, the surface area obtained is not as expected due to the possibility of pore blockage and excessive activation time, which causes the surface area of the material to be small.

Investigation of the Effect of Nano-melatonin on Oxidative Stress in Sera of Patients with Polycystic Syndrome

Background: The association between polycystic ovary syndrome (PCOS) and oxidative stress in women, the possible causes of PCOS, insulin resistance (IR), obesity, and oxidative stress. Oxidants are chemical elements that tend to gain electrons, losing positive charge. The Oxidative Stress (OS) is defined as an imbalance between the formation and synthesis of free radicals and the antioxidant defense system, which results in oxidative damage. Objective: The purpose of this research is to investigate the effect of nano-melatonin on oxidative stress in the sera of patients with polycystic syndrome. Methods: The study includes 120 Iraqi women, divided into two groups: 60 PCOS patients and 60 healthy control patients. Sample Analysis Biochemistry analyses the hormonal profile and determines the hormonal levels (LH, FSH, Testosterone, and Prolactin) that were identified for all controls and patients. Hormones analysis was performed using the enzyme-linked fluorescent assay (ELFA) technique. Synthesized ML nanoparticles by ultrasonic sonication. Results: The results indicate that the mean of serum LH significantly increased (P<0.02) in PCOS BMI ≥ 25 patients G1 (6.19±3.13) mIU/mL compared with controls C1 (4.504±1.591) mIU/mL, while a nonsignificant difference (P>0.05) when compared the BMI<25 kg/m2 for G2 (5.55±1.93) with control group C2 (6.31±2.58) of luteinizing hormone in G1 and G2. Conclusions: An increased ratio of LH to FSH was shown to be characteristic of PCOS. For PCOS, high LH values are crucial. For the purpose of diagnosing PCOS, high LH values are crucial release of gonadotropin hormones (LH, FSH) from the pituitary. To higher the production of androgen in ovarian theca cells, The LH receptor is activated by the luteinizing hormone (LH). The nano Mel was higher in the inhibition of Oxidative stress two causes nano-melatonin high surface area and small size.

Iron supplementation post-blood donation in Vietnam: Impact on hemoglobin, red cell indices, and iron reserves

Background. Regular blood donation plays a pivotal role in mitigating the formation of free radicals by regulating iron accumulation. However, frequent blood donation can lead to chronic iron deficiency. In this study, we aimed to evaluate the effectiveness of daily iron supplementation as an intervention to expedite hemoglobin (Hb) recovery among frequent blood donors at a hospital in Vietnam. Methodology. Conducted longitudinally within the Hematology Department of a Hanoi hospital from February to July 2023, our study involved 104 eligible participants. They received a daily iron supplement comprising 100 mg of elemental iron, 0.75 mg of folic acid, and 5 mg of zinc sulfate for a minimum of 8 weeks. Blood samples were collected at three key time points: before blood donation during recruitment, immediately after donation, and at least 8 weeks post-donation. Results. Our findings revealed moderate, statistically significant positive correlations between elemental iron administration and changes in platelet count (PLT), hematocrit (HCT), and mean corpuscular hemoglobin (MCH) (r = 0.753, p <0.001; r = 0.887, p <0.001; and r = 0.703, p <0.001, respectively). Additionally, weak but significant correlations were observed between elemental iron administration and red blood cell count (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width coefficient of variation (RDWC), and red cell distribution width standard deviation (RDWS) (r = 0.260, p = 0.002; r = 0.302, p = 0.005; r = 0.160, p = 0.010; r = 0.120, p = 0.020; and r = 0.400, p <0.001, respectively). Conclusion. Over an eight-week duration, the regimen of daily iron supplementation yielded significant improvements in both red cell variables, red cell indices, and iron study variables, demonstrating its potential clinical impact.

Harmonizing In Vitro Techniques for Anti-Aging Cosmetic Ingredient Assessment: A Comprehensive Review

Skin grows old due to intrinsic factors, such as age and associated hormonal changes, and external factors, like solar radiation and chemical substances to which we are exposed. With age, skin shows thinning, laxity, pallor, increased dryness, and the appearance of wrinkles, attributed to a decrease in collagen and elastin produced by fibroblasts. Several theories explain skin aging, including the free radical formation, neuroendocrine, and mitochondrial decline theories. Based on a scientific understanding of skin behavior, different in vitro methods are used to evaluate the effects of new ingredients in cosmetics. Commonly used methods include anti-collagenase, anti-elastase, and anti-hyaluronidase activity alongside techniques utilizing skin cells or 3D models. Although these methods are recognized and widely used, they lack standardization. In this review, a literature search has been conducted to examine the characteristics and variations of these methods across the laboratories. A key issue identified in this review is that many papers provide insufficient detail regarding their protocols. Moreover, the number of studies using cells is less significant than the ones determining enzyme inhibition. Our findings revealed that, in many cases, there is limited information available, underscoring the urgent need to initiate a comprehensive standardization process for the methodologies used to demonstrate anti-aging activity.

Protective effect of long-chain polyunsaturated fatty acids on hepatorenal syndrome in rats.

Hepatorenal syndrome (HRS) is the most prevalent form of acute kidney injury in cirrhotic patients. It is characterized by reduced renal blood flow and represents the most severe complication in cirrhotic patients with advanced disease. Previous research has indicated that antioxidants can delay the onset of a hyperdynamic circulatory state in cirrhosis and improve renal function in HRS patients. Regular omega-3 supplementation has significantly reduced the risk of liver disease. This supplementation could represent an additional therapy for individuals with HRS. To evaluated the antioxidant effect of omega-3 polyunsaturated fatty acid supplementation on the kidneys of cirrhotic rats. Secondary biliary cirrhosis was induced in rats by biliary duct ligation (BDL) for 28 d. We used 24 male Wistar rats divided into the following groups: I (control); II (treated with omega-3, 1 g/kg of body weight); III (BDL treated with omega-3, 1 g/kg of body weight); and IV (BDL without treatment). The animals were killed by overdose of anesthetic; the kidneys were dissected, removed, frozen in liquid nitrogen, and stored in a freezer at -80℃ for later analysis. We evaluated oxidative stress, nitric oxide (NO) metabolites, DNA damage by the comet assay, cell viability test, and apoptosis in the kidneys. Data were analyzed by one-way analysis of variance, and means were compared using the Tukey test, with P ≤ 0.05. Omega-3 significantly decreased the production of reactive oxygen species (P < 0.001) and lipoperoxidation in the kidneys of cirrhotic rats treated with omega-3 (P < 0.001). The activity of the antioxidant enzymes superoxide dismutase and catalase increased in the BDL+omega-3 group compared to the BDL group (P < 0.01). NO production, DNA damage, and caspase-9 cleavage decreased significantly in the omega-3-treated BDL group. There was an increase in mitochondrial electrochemical potential (P < 0.001) in BDL treated with omega-3 compared to BDL. No changes in the cell survival index in HRS with omega-3 compared to the control group (P > 0.05) were observed. The study demonstrates that omega-3 can protect cellular integrity and function by increasing antioxidant enzymes, inhibiting the formation of free radicals, and reducing apoptosis.