Antioxidant BHT Research Articles

The Effectiveness of Extracts of Spent Grape Pomaces in Improving the Oxidative Stability of Grapeseed Oil

Spent grape pomace is a by-product of Grappa production that is usually considered waste. Therefore, in this study, in order to promote the sustainable use of by-products from the food industry, we aimed to optimize the extraction of antioxidants from spent grape pomace and their use to improve the oxidative stability of grapeseed oil. Ultrasound-assisted extraction maximized the total phenolic content and antioxidant activity, with the latter measured according to the ferric reducing antioxidant power. The best extraction conditions identified for spent grape pomace from red and white grapes were an amplitude of 40%, a duration of 22 min and a ratio of 1:37 and an amplitude of 40%, a duration of 25 min and a ratio of 1:45, respectively. Grapeseed oil, which is rich in polyunsaturated fatty acids and susceptible to rancidity, fortified with 10%, 20% and 30% of these extracts was evaluated in terms of its oxidative stability using the Rancimat method and compared with a control oil and an oil fortified with the synthetic antioxidant BHT at the highest legal level (200 ppm). For oil fortified with 30% of the extracts obtained from red and white pomace under the best conditions, increases in the induction time of 39% and 25% compared to the control and 23.01% and 10.62% compared to the BHT-fortified oil, respectively, were reported. This study highlights the potential of using grape pomace extracts as eco-friendly antioxidants to stabilize oil and contribute to the sustainability of the food industry at the same time.

Electrochemical determination of phenolic antioxidant BHT in cosmetic, food and water samples

BHT, an antioxidant often employed in several industries such as food, cosmetics, and food packaging, has raised public health concerns due to its possible toxicological consequences. These concerns originate from both the inherent properties of BHT itself as a result of its usage as an antioxidant. This research presents a novel sensor that uses a combination of a rare lanthanide element and a metal oxide as substrate modifiers on graphene nanopowder. Three independent electrochemical methods, cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy, were used to analyze the electrode modification process. Excellent linearity in the concentration range of 1.0 × 10−12–1.0 × 10−7 M was obtained under the optimal conditions of the technique, with a detection limit of 3.0 × 10−13 M. Repeatability, reproducibility, and stability studies were performed using the proposed sensor. The RSD value for the reproducibility study was 2.91 %. For the within-day repeatability, the repeatability was determined to be 1.97 % for the sensor. After 7 days, the stability studies indicated a decrease up to a value of 90.89 % of the initial value from the first day of assessment.

Research on Compatibility of Packaging Materials of High-Risk Cephalosporin Powder Injection and Establishment of Indicator Component Evaluation Method

aims: To establish a GC-MS method for the determination of extractable substances in the stoppers of Ceftriaxone sodium bottles for injection; To establish a HPLC method for the determination of vulcanizing agent and antioxidant in Ceftriaxone sodium for injection bottle stopper and to analyze the correlation between the volatile substances of rubber stopper and the clarity of solution. objective: To establish a GC-MS method for the determination of extractable substances in the stoppers of Ceftriaxone sodium bottles for injection; To establish a HPLC method for the determination of vulcanizing agent and antioxidant in Ceftriaxone sodium for injection bottle stopper and to analyze the correlation between the volatile substances of rubber stopper and the clarity of solution. method: GC-MS method was used with capillary column Rtx-5MS (30.0 m×0.25 mm, 0.25 µm), the carrier gas was He at the flow rate of 1.8mL·min-1, the temperature of injection port was 200 ℃, shunt ratio was 10∶l, the column temperature was programmed temperature(initial column temperature was 40 ℃ and kept for 15 min, and with the speed of 10 ℃ upping to 100 ℃ and kept for 2 min, and with the speed of 25 ℃ upping to 230 ℃ and kept for 10 min), the interface temperature was 250 ℃, and the scanning range was from 29 to 600(m·z-1), and the volatile substances were using full scan. An inertsil ODS-3 column(250 mm×4.6 mm, 5 µm) was used for the HPLC analysis. The mobile phase A consisted of water containing 0.04% trifluoroacetic and the mobile phase B consisted of acetonitrile containing 0.04% trifluoroacetic acid, the gradient elution was used and the flow rate was set as 1.0 mL·min-1. The column temperature was 30 ℃, the detection wavelength was 210 nm and the injection volume was 10 µL. result: Antioxidant BHT(264), silicone oil and other organic compounds in rubber stopper permeated and migrated to the sample with acceleration time by GC-MS. A good linearity was observed over the range of 0.5-100 μg·mL-1(r＞0.999). The detection limits of vulcanizing agent and antioxidant were about 0.03 μg·mL-1, and the quantitation limits were about 0.1 μg·mL-1. The average recoveries (low, medium and high) of antioxidant (168, 264, 330, 1076, 1010) and vulcanizing agents (carbon disulfide, sulfur) were between 90.0% and 110.0%, and the corresponding RSD were less than 5% (n=9) by adding standard recovery experiments. The stability test showed that the antioxidant and the vulcanizing agent solution had good stability and was stable within 24 hours. conclusion: the GC-MS/HPLC method can be used for the quality control of rubber stopper of cefuroxime Sodium for Injection.The compatibility study and comprehensive evaluation system of Ceftriaxone sodium for injection packaging materials have been initially formed.

Effect of combinations of 3,4‐dihydroxyphenylacetic acid and its esters on the oxidative stability of fish oil–containing trace water

AbstractThe current study aims to comprehend the effect of the various combinations of 3,4‐dihydroxyphenylacetic acid (3,4‐DHPA) and its esters in varying molar ratios on retarding oxidation in bulk refined fish oil in the presence of 0.3% w/w water. All the esters and 3,4‐DHPA exhibited better performance than the synthetic antioxidant butylated hydroxytoluene. In the presence of trace water, the parent compound was found to have a synergistic effect with hexyl ester when used at a molar ratio of 2:1, respectively, exhibiting a higher percent reduction among all the esters and their combinations. The study also showed that the presence of extraneous water can significantly accelerate the oxidation (twofold) in a bulk fish oil system. This suggests that the microenvironment of the oil is altered when water is present and that association colloids play a key role in enhancing the rate of oxidation. Thus, while designing a competent mixture of antioxidants, the specific site of oxidation involved and the surface‐active components should be taken into consideration to efficiently retard oxidation.Practical Applications: Analyzing the impact of trace amounts of water on the efficiency of natural antioxidants, including 3,4‐DHPA and its lipophilic esters, helps to comprehend the required optimal antioxidant concentrations for such a dynamic bulk oil system. The study finds application in controlling oxidation in PUFA‐rich oils containing surface‐active minor components that can accelerate oxidation. The results of the study show that 3,4‐DHPA and its esters could be a potential replacement for the synthetic antioxidant BHT in all aspects.

Shelf Life Enhancement of Structured Lipids Rich in Omega-3 Fatty Acids Using Rosemary Extract: A Sustainable Approach.

This study investigates the efficacy of rosemary extract (RE) in stabilizing structured lipids (SL) developed using perilla seed oil (PSO) and palmolein (PO) under accelerated storage conditions. The oil samples, comprising PSO, Blend, and SL formulations with and without RE (1500 ppm) and BHT (200 ppm), were studied for their storage stability during a 30 day storage period at 65 °C, with the analysis carried out at 6 day intervals. Oxidative properties were comprehensively assessed, including both physical attributes (color, viscosity, and refractive index) and chemical parameters (peroxide value, free fatty acid (FFA), p-anisidine value, TOTOX value, conjugated dienes, and trienes). The results demonstrated that RE-enriched oil samples exhibited significantly higher oxidative stability (p < 0.05) compared to the control group. SL added with 1500 ppm of RE exhibited notable enhancements in quality parameters, showcasing reductions in FFA, TOTOX value, conjugated diene, and triene value by 44.01%, 35.42, 39.03, and 47.36, respectively, when compared to SL without any antioxidant. The RE at 1500 ppm concentration showed a similar effect as the synthetic antioxidant BHT at 200 ppm. Also, the RE demonstrated potent inhibition of the oxidation of polyunsaturated fatty acids, thereby contributing to the improved oxidative stability of the SLs. Furthermore, SL with RE also exhibited reduced degradation of the tocopherol content and total phenolic content during the storage period. Principal component analysis demonstrated that SL and blend followed similar oxidative characteristics as they fell within the same quadrant. These findings underscore RE as a potent source of antioxidants capable of scavenging free radicals and enhancing the oxidative stability of omega-3 fatty acid-rich SLs.

Synthesis, characterization, and comprehensive computational analysis of aromatic hydrazone compounds: Unveiling quantum parameters, evaluating antioxidant activity, and investigating molecular docking interactions

This study presents a synergistic approach encompassing experimental synthesis, computational analysis, and antioxidant activity evaluation of two aromatic hydrazone compounds, namely 4-[(2E)-2-(2-nitrobenzylidene) hydrazinyl] benzoic acid (NBHZ) and 4-[(2E)-2-(2-hydroxybenzylidene) hydrazinyl] benzoic acid (HBHZ). Efficient synthesis yielded impressive quantities (70 % and 58 %, respectively), and structural characterization employed IR, UV–Vis, and NMR spectroscopy. Antioxidant potential was assessed using the DPPH free radical scavenging assay, revealing distinct capabilities of NBHZ and HBHZ, each featuring a nitro (NO2) and a hydroxy (OH) group, respectively, at the ortho position. HBHZ exhibited superior efficacy (IC50 = 1.15 μg/mL) compared to NBHZ (IC50 = 2.1 μg/mL) and the standard antioxidant BHT (IC50 = 1.83 μg/mL). Computational analyses using Gaussian 09 at the B3LYP/6–311 G(d,p) level elucidated electronic characteristics, molecular electrostatic potential (MEP), HOMO-LUMO energies, and global reactivity descriptors. VEDA 4 further investigated vibrational behavior and potential energy distribution (PED), topological analyses electron localization function (ELF), localized orbital locator (LOL), average localized ionization energy (ALIE), and reduced density gradient (RDG) were identified to evaluate their interactions. Thermochemical parameters explored antioxidant mechanisms (hydrogen atom transfer (HAT), single electron transfer–proton transfer (SET–PT), and sequential proton loss electron transfer (SPLET)). Molecular docking via iGEMDOCK revealed binding interactions with the target NADPH oxidase. These findings not only provide insights into the compounds' antioxidant potential but also underscore the impact of specific molecular features on their properties. This integrated approach contributes to advancing the understanding of hydrazone compounds, guiding the design of materials with tailored functionalities for applications in oxidative stress mitigation.

The key factors of solid nanodispersion for promoting the bioactivity of abamectin

Solid nanodispersion (SND) is an important variety of nanopesticides which have been extensively studied in recent years. However, the key influencing factors for bioactivity enhancement of nanopesticides remain unclear, which not only limits the exploration of relevant mechanisms, but also hinders the precise design and development of nanopesticides. In this study, we explored the potential of SND in enhancing the bioactivity of nanopesticides, specifically focusing on abamectin SND prepared using a self-emulsifying-carrier solidifying technique combined with parameter optimization. Our formulation, consisting of 8% abamectin, 1% antioxidant BHT (2,6-di-tert-butyl-4-methylphenol), 12% complex surfactants, and 79% sodium benzoate, significantly increased the pseudo-solubility of abamectin by at least 3300 times and reduced its particle size to a mere 15 nm, much smaller than traditional emulsion in water (EW) and water-dispersible granule (WDG) forms. This reduction in particle size and increase in surface activity resulted in improved foliar adhesion and retention, enabling a more efficient application without the need for organic solvents. The inclusion of antioxidants also enhanced photostability compared to EW, and overall stability tests confirmed SND's resilience under various storage conditions. Bioactivity tests demonstrated a marked increase in toxicity against diamondback moths (Plutella xylostella L.) with abamectin SND, which exhibited 3.7 and 7.6 times greater efficacy compared to EW and WDG, respectively. These findings underscore the critical role of small particle size, high surface activity, and strong antioxidant properties in improving the performance and bioactivity of abamectin SND, highlighting its significance in the design and development of high-efficiency, eco-friendly nanopesticides and contributing valuably to sustainable agricultural practices.

1H NMR and UV-Vis as Analytical Techniques to Evaluate Biodiesel Conversion and Oxidative Stability

The present study evaluated the applicability of 1H NMR and UV-Vis spectroscopies as analytical techniques for the characterization and determination of biodiesel conversion and for monitoring the oxidative stability of biodiesel samples with antioxidants. For this study, safflower and babassu biodiesels were obtained through transesterification, and physicochemical properties confirmed the success of both reactions. A bench-top accelerated oxidation system was used as an alternative to the Rancimat® method, with samples of 6.0 g heated at 110 ± 5 °C and collected every 2 h for 12 h. The agreement for biodiesel conversions was good, with divergences between 2% and 0.4% for safflower biodiesel and 1.9% for babassu biodiesel. As for UV-Vis spectroscopy, the technique showed the same trend as the Rancimat® method, showing efficiency in evaluating the oxidative stability of safflower biodiesel and in the performance of antioxidants BHT and DMP-30. The accuracy of NMR signals integration for mixtures of safflower oil and safflower biodiesel and the use of UV-Vis spectroscopy associated with a bench-top accelerated oxidation system to investigate the performance of phenolic and amine antioxidants in safflower and babassu biodiesel were explored for the first time, showing results close to the standard methods. Therefore, 1H NMR and UV-Vis spectroscopies could be applied as alternatives to the GC and Rancimat® methods to determine conversion and monitor the oxidative stability of biodiesel rapidly and practically.

Organic wastes of Citrus sinensis Peels- a source of eco-friendly and sustainable bioactive compounds for promoting health

To determine the phytochemicals, radical scavenging and antioxidant potential of orange peel extract. Citrus sinensis were subjected to extraction with ethanol. Gas chromatography (GC) was utilized to determine the phytochemical composition of orange peel extract. Hydrogen peroxide, superoxide, nitric oxide, and hydroxyl radical scavenging assays were conducted to assess radical scavenging potential of the extract. Antioxidant activities of the peel extracts were determined via the 2,2-diphenylpicrylhydrazyl (DPPH) free radical scavenging activity, ferric reducing antioxidant power (FRAP) assay, ABTS scavenging, and total antioxidant capacity (TAC) assay. The GC-FID analysis revealed the presence of alkaloids, flavonoids, polyphenols, tannins, sapogenin, and steroids in the orange peel extract. The results of radical scavenging assays demonstrated the extract’s ability to scavenge hydrogen peroxide, superoxide, nitric oxide and hydroxyl radicals. The scavenging capacity of the extract was observed to be concentration-dependent, with comparisons made to standard antioxidants ascorbic acid and BHT. Peels from citrus sinensis represent a valuable source of phytochemicals, demonstrating significant antioxidant and radical scavenging activities.

New Garden Rose (Rosa × hybrida) Genotypes with Intensely Colored Flowers as Rich Sources of Bioactive Compounds

Garden roses, known as Rosa × hybrida, hold a prominent position as one of the most important and economically valuable plants in horticulture. Additionally, their products—essential oil, rose water, concrete, and concentrate—find extensive use in the cosmetic, pharmaceutical, and food industries, due to their specific fragrances and potential health benefits. Rose flowers are rich in biologically active compounds, such as phenolics, flavonoids, anthocyanins, and carotenoids. This study aims to investigate the potential of five new garden rose genotypes with intensely colored flowers to serve as sources of biologically active compounds. Phenolic profile was evaluated by determination of total phenolic (TPC), flavonoid (TFC), and monomeric anthocyanins (TAC) contents and LC-MS/MS analysis of selected compounds. Antioxidant activity was evaluated via DPPH and FRAP assays, neuroprotective potential via acethylcholinesterase inhibition assay, and antidiabetic activity viaα-amylase and α-glucosidase inhibition assays. The flowers of investigated genotypes were rich in phenolics (TPC varied from 148 to 260 mg galic acid eq/g de, TFC from 19.9 to 59.7 mg quercetin eq/g de, and TAC from 2.21 to 13.1 mg cyanidin 3-O-glucoside eq/g de). Four out of five genotypes had higher TPC than extract of R. damascene, the most famous rose cultivar. The dominant flavonoids in all investigated genotypes were glycosides of quercetin and kaempferol. The extracts showed high antioxidant activity comparable to synthetic antioxidant BHT, very high α-glucosidase inhibitory potential, moderate neuroprotective activity, and low potential to inhibit α-amylase.

Characterization of the bark of Protium tenuifolium Engl. from the Amazonian biome as a source of natural antioxidants

Abstract The bark anatomy was analysed, as was the overall chemical composition (extractives, lignin, suberin, ash and polysaccharides), and a quantitative elemental analysis was performed of the bark and two tannin extracts (extracted with water only and with a mixture of water and Na2SO3). The phenolic composition and antioxidant activity of the bark extracts were quantified. The results indicated that the bark is composed of conductive phloem, nonconductive phloem, rhytidome, crystals and secretory cells. The average chemical composition was 15.9 % extractives, 35.3 % total lignin, 1.9 % suberin, 15.4 % ash and 31.5 % polysaccharides. The condensed tannin yield in the extract obtained with water alone was 5.1 %, and that in the treatment with water and Na2SO3 was 8.1 %. The ethanol-water extract had a high phenolic content (112.6 mg GAE g−1 extract). The bark extract showed strong antioxidant activity, reaching 83.5 % inhibition of DPPH free radicals, which was higher than the value of 75.0 % for the commercial antioxidant BHT at the same concentration. These results demonstrate that Protium tenuifolium is a potential natural Amazonian source of phenolic compounds and antioxidants and can be used for medicinal purposes and the production of various sustainable products, such as cosmetics.

Variations in Oxidative Stability of Walnut Oil with Rosmarinic Acid Added under Different Ultraviolet Radiations

Rosmarinic acid (RA) is a natural phenolic compound extracted from the Labiatae family and is a natural antioxidant. In this study, walnut oil added with RA was treated with different ultraviolet radiations, and stabilization effects in terms of the same conditions (0.2 mg/g) were compared with synthetic antioxidant (BHT). In order to compare the effectiveness of three UV treatments, different lab tests were conducted, namely, the acid value, peroxide value, iodine value, anisidine value, DPPH free radical scavenging rate, and malondialdehyde content. The enhanced UV-A, UV-B, and UV-C radiation intensities have increased the oxidation stability of RA-added walnut oil, of which UV-B has the greatest influence on the oxidative stability of walnut oil. When both RA and BHT were added at 0.2 mg/g, the antioxidant effect of RA is superior to the general antioxidant BHT.

Some characteristics of tomato lycopene and the possibility of its use in fresh milk fortification

The results showed that lycopene dye was highly effective in reducing the peroxide number value, as adding 1 mg of the dye to fresh milk led to the lowest peroxide number (0.497 - 2.483) compared to (0.543 - 4.943) of milk with artificial antioxidant BHT and milk without addition, which scored (0.567 - 11.997) for eleven days of storage at 4 °C. Lycopene dye reduced the values of thiobarbituric acid (TBA) in milk stored at 4°C for seven days compared to regular milk without addition. The results also proved that the dry lycopene dye extracted from the fruits of the tomato plant, when dissolved in buffer solutions with different pHs ranging from (3-8), did not have a significant effect on the dyes, as the pH factor on the measured wavelengths ranged from 370.0-370.5 As for the effect of the number of days factor, it ranged from 369.7-370.6 nanometers. It was found that low temperatures did not affect the lycopene pigment extracted from tomato fruits. The results of the sensory evaluation indicate that the total sum of sensory evaluation scores (taste, texture, and appearance) was higher (23.8) in the treatment of lycopene-free milk compared to the milk fortified with lycopene tomato, which scored 22.6. Keywords: plant pigments, lycopene, fresh milk

Lignin recovery from a mixture of SIX lignocellulosic biomasses within a biorefinery scheme based on a sequential process of autohydrolysis and organosolv

A mixture of six lignocellulosic biomasses could be a solution for sustainable biorefinery supply throughout the year compared with seasonal feedstock. In this study, a sequential process of autohydrolysis and organosolv was used for this mixture. To optimize lignin extraction, an experimental design was used to study the impacts of temperature, ethanol concentration, and time on lignin yield and related characteristics of the organosolv process. A highly pure organosolv lignin (OL) (ca. 90% Klason lignin) was recovered. FTIR analysis showed the main lignin structure was almost unchanged. NMR confirmed this and revealed the presence of guaiacyl-syringyl type with small amounts of p-hydroxyphenyl units (25% G, 70% S, and 5% H), predominantly presenting β-O-4 units (ca. 80%). Tg from 73 to 85 °C was detected. OL showed radical scavenging activity as high as the commercial antioxidant BHT. Moreover, enzymatic susceptibility of delignified biomass was accessed, in which 50% glucose yield was achieved.

Antioxidant Potential of Spray- and Freeze-Dried Extract from Oregano Processing Wastes, Using an Optimized Ultrasound-Assisted Method.

Origanum vulgare is recognized worldwide for its numerous applications, in the food industry and beyond. However, the extraction of its essential oils generates a significant amount of waste. The aim of this research was to achieve the valorization of solid waste from oregano hydro-distillation, by (i) optimizing the ultrasound extraction of antioxidants, (ii) evaluating the effect of spray and freeze drying on the extract's physicochemical properties, and (iii) characterizing the obtained powder by its antioxidant capacity. A central composite design of experiments was used to optimize the sample/solvent ratio, ethanol/water ratio, and extraction time. The extract was analyzed for its antioxidant potential by determining the percentage of DPPH inhibition, FRAP, and total phenolic content (TPC). The GAB model best fit the data for the moisture sorption isotherm of the resulting powder. The antioxidant activity of the powders was tested in a ground-beef food system. The TPC was maximized at times longer than 58 min, a sample/solvent ratio between 0.058 and 0.078, and a ratio of ethanol/water around 1. Neither drying method significantly affected the antioxidant properties of the extract, even though the resulting powders from each showed a different morphology (determined using SEM). Encapsulation with maltodextrin protected the spray-dried extract during a 6-month storage period. Powders from both drying methods equally retarded lipid oxidation, and were comparable to the synthetic antioxidant BHT. It is concluded that oregano processing waste is a potent source of antioxidants, and that its dried extract, via an ultrasound-assisted process, can potentially be used as a natural alternative to synthetic antioxidants.

Pistacia lentiscus extracts as a valuable source of antioxidant compounds

Medicinal plants produced many secondary metabolites which constituted an important source of bioactive molecules. This study aims to determine organic extracts (EOs) antioxidant activity extracted from terminal branches of Pistacia lentiscus (P. lentiscus) collected at three different phenological stages (vegetative, flowering and fructification). For this, different extracts were prepared by maceration in various solvents with increasing polarity notably diethyl ether, ethyl acetate, dichloromethane, methanol and water. Antioxidant activity was reported by DPPH free radical scavenging, iron reducing capacity and total antioxidant capacity tests. Results showed that phenological stages and solvent polarities affected significantly P. lentiscus antioxidant activity. Furthermore, aqueous and methanolic extracts from vegetative stage present the highest total polyphenols, total flavonoids and condensed tannins contents. Methanolic extract from vegetative stage exhibited the greatest antioxidant activity and even exceeded that of synthetic antioxidants BHT and ascorbic acid. In this study, P. lentiscus represents an important source of antioxidant molecules. As a result, extracts of this plant could replace synthetic antioxidants in e food, pharmaceutical and cosmetic fields.

Structural Characterization of Acid DES-Modified Alkaline Lignin and Evaluation of Antioxidant Properties

Lignin is an abundant and environmentally friendly biopolymer that contains a large number of phenolic hydroxyl functional group. In this paper, alkaline lignin was modified using different acidic DES (choline chloride/p-toluenesulfonic acid and choline chloride/lactic acid) at 130 ℃ (TC-lignin and LC-lignin) and the conformational relationship between the modified products and the antioxidant activity was investigated. Lignin was characterized by 31P NMR, gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FT-IR), and its antioxidant activity was evaluated. The results showed that the alkaline lignin products modified by acidic DES formed relatively homogenous dispersions and were characterized by a relatively low molecular weight and a high content of phenolic hydroxyl groups (e.g., TC-lignin, aliphatic-OH: 3.52 mmol/g, G-OH: 4.18 mmol/g, Mw: 3726, Mn: 2053, PDI: 1.81). The antioxidant activity (free radical scavenging rate, 90.35%) of TC-lignin was somewhat higher than that of LC-lignin (free radical scavenging rate, 89.12%) and both were higher than that of the commercially available antioxidant BHT (free radical scavenging rate, 88.79%). More specifically, we discussed the possible mechanisms of antioxidant reactions of lignin model substances in DPPH solutions. In addition, LC-lignin has an excellent UV-blocking capacity due to the specific phenolic hydroxyl and phenyl propane structure. A simple method is proposed for the modification of industrial lignin to make it suitable for use as an antioxidant and UV-resistant product.

Computational assessment of the primary and secondary antioxidant potential of alkylresorcinols in physiological media.

Alkylresorcinols are a group of natural phenolic compounds found in various foods such as whole grain cereals, bread, and certain fruits. They are known for their beneficial health effects, such as anti-inflammatory and anti-cancer properties. This study aimed to evaluate the antioxidant activity of two typical alkylresorcinols namely olivetol and olivetolic acid (Oli and OliA) under physiological conditions. The free radical scavenging capacity of Oli and OliA toward oxygenated free radicals (HO˙ and HOO˙ radicals) was investigated using thermodynamic and kinetic calculations. The results revealed that Oli and OliA are potent scavengers of HO˙ radical in both polar and lipid media, acting exclusively via the FHT (formal hydrogen transfer) mechanism. Moreover, they demonstrated excellent scavenging activity toward HOO˙ radical in water via the SET (single electron transfer) mechanism, outperforming the common antioxidant BHT. In lipid media, Oli and OliA showed moderate scavenging activity toward HOO˙ radical via the FHT mechanism. Significant prooxidant potential of OliA- was also demonstrated through the formation of complexes with copper ions. Additionally, docking studies indicate that the compounds exhibited a good affinity for ROS-producing enzymes, including myeloperoxidase (MP), cytochrome P450 (CP450), lipoxygenase (LOX), and xanthine oxidase (XO), highlighting their potential as natural antioxidants with promising therapeutic applications.

Antimicrobial, antioxidant activity and phytochemical prospection of Eugenia involucrata DC. leaf extracts.

The species Eugenia involucrata DC. is a plant native to Brazil and is traditionally used for intestinal problems, however, little research has documented about its biological potential and phytochemical profile. Thus, the objective of this study was to carry out preliminary phytochemical prospecting, antimicrobial and antioxidant potential of E. involucrata extracts. Using the E. involucrata leaves, aqueous and organic extracts were obtained using the following solvents (ethanol, methanol, hexane, acetone, dichloromethane and ethyl acetate). The phytochemical prospecting detected the presence of saponins, steroids, flavonoids and tannins in the extracts. Ethanolic and methanolic extracts presented antimicrobial activity for most of the bacterial strains tested, as well as for yeast Candida albicans, with concentrations between 3.12 and 50 mg/mL. The ethanolic and metanolic extract presented high free radical sequestration potential (>90%). The methanol extract showed an IC50 value statistically equal to that found for the commercial antioxidant BHT (p <0.05). The crude extracts obtained with ethanol and methanol were the most promising. These results suggest that methanolic, ethanolic and aqueous extracts are a promising source of natural bioactive.

Photosensitization of human skin fibroblasts by vemurafenib promotes pleiotropic effects on membrane-enclosed organelles and apoptosis.

Vemurafenib (VB), a BRAF inhibitor and a first-line treatment for unresectable or metastatic melanoma, is strongly phototoxic towards normal skin cells. Herein, we show that in cultured HS 68 human diploid dermal fibroblasts, low concentrations of VB suffice to promote photosensitization to low doses of UVA (∼ 5J/cm2), as evidenced by a significant decrease in cell viability. In contrast to data obtained in chemico our results support a role for ROS (reactive oxygen species). Indeed, peroxidation of cellular lipids was observed which could be alleviated by the lipophilic antioxidant BHT (2,6-di-tert-butyl-4-methylphenol). Using in vivo confocal laser scanning microscopy and vital fluorescent probes it was shown at the single cell level that the plasma membrane and lipid-rich organelles, namely mitochondria, endoplasmic reticulum, and lysosomes, as well as actin filaments, were severely damaged by the UVA-induced VB-photosensitization. Finally, we showed that mitochondrial impairment was concurrent with caspase 3/7 activation and cell death by apoptosis.