Individual Antioxidants Research Articles

Association between composite dietary antioxidant index and kidney stone prevalence in adults: data from National Health and Nutrition Examination Survey (NHANES, 2007-2018).

The high prevalence of kidney stones in adults worldwide has prompted research into potential interventions, one of which involves exploring the consumption of antioxidants that may confer protective effects. However, the relationship between the composite dietary antioxidant index (CDAI), a crucial measure used to assess an individual's overall antioxidant capacity from daily dietary intake, and kidney stones remains unclear. Therefore, we conducted cross-sectional analysis to examine the association between CDAI and kidney stone prevalence. The analysis was conducted utilizing data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2018. Antioxidant intake was derived from two 24-h dietary recalls surveys, while CDAI, a comprehensive measure that includes antioxidants like vitamins A, C, and E, zinc, selenium, and carotenoids, was calculated. Multivariate logistic regression and restricted cubic spline (RCS) regression were utilized to examine the association between CDAI and the prevalence of kidney stones. The study included a total of 28,516 participants, with 2,748 individuals having a history of kidney stones. The median of CDAI was -0.01 (-2.02, 2.37). Individuals in the fourth quartile of CDAI exhibited a significantly lower prevalence of kidney stones compared to those in the first quartile (Odds Ratio [OR] = 0.769 [0.633-0.935]), even after adjusting for potential confounding factors (including age, sex, race, education level, poverty income ratio, smoking status, drinking status, body mass index (BMI), energy intake levels, physical activity level, serum calcium concentration, estimated glomerular filtration rate (eGFR), hypertension, diabetes and supplement use). The RCS analysis revealed a non-linear relationship between CDAI and kidney stone prevalence, with inflection points identified at 0.06 (p for non-linearity = 0.039). Subgroup analysis demonstrated consistent CDAI-kidney stone prevalence associations across all subsets. Furthermore, a significant inverse correlation was observed between CDAI and inflammatory markers. This study provides evidence supporting a reciprocal correlation between adult dietary antioxidant intake, as measured by CDAI, and kidney stone prevalence. These findings emphasize the potential benefits of consuming dietary antioxidants in lowering the risk of kidney stone formation.

Multiple online-HPLC methodologies and biological properties of leaves and stem barks extracts of Chrysanthellum indicum

Chrysanthellum indicum, an annual herb with yellow flowers, is used as a functional food in Asia and Africa for health purposes. In this study, we thoroughly investigated the characterization of phytochemicals within C. indicum's ethyl acetate, water, and methanolic extracts from both its bark and leaves. This was achieved through the utilization of the Folin Ciocalteu and aluminum trichloride assays. Moreover, the antioxidant properties of these extracts were comprehensively assessed employing microplate-based assays including ABTS, DPPH, CUPRAC, FRAP, MCA, and PBD, alongside online HPLC-based assays namely ABTS, DPPH, CUPRAC, and FRAP. Furthermore, the inhibitory activity against a range of enzymes, including AChE, BChE, tyrosinase, α-amylase, and α-glucosidase, was ascertained. The tested ethyl acetate extracts from bark and leaves had higher content of total phenolic and flavonoid compared to methanol and water extracts. Additionally, the bark extract exhibited superior antioxidant properties in the in vitro antioxidant assays. Meanwhile, in the realm of online HPLC antioxidant analysis, an effective method has been discovered for swiftly determining the individual antioxidant capacity of compounds within both standard solutions and extract. Within the entirety of the samples subjected to scrutiny, rutin surfaced as the foremost antioxidant, exhibiting its prominence at wavelengths of 280 nm, 595 nm, and 450 nm. Following suit, quercetin emerged as the second most abundant antioxidant, noticeable at wavelengths of 517 nm and 734 nm, both in leaves and bark extracts. Significantly, the extracts derived from both bark and leaves demonstrated noteworthy effectiveness in inhibiting the tyrosinase enzyme. Thus, our study indicates that Chrysanthellum indicum could serve as a promising reservoir of natural bioactive compounds, making it suitable for the formulation of health-promoting applications.

Exploring for HPLC-MS/MS Profiles and Biological Activities of Different Extracts from Allium lycaonicum Siehe ex Hayek from Turkey Flora.

The present study was designed to determine the phenolic constituents, antioxidant, and enzyme inhibition activities of aerial parts and bulbs of Allium lycaonicum (family Amaryllidaceae). Extracts were prepared by maceration and Soxhlet/infusion using hexane, methanol, and water as extraction solvents. Generally, extracts from the aerial parts showed higher total phenolic and individual components and antioxidant activity than their respective bulb extracts. Maceration with water was the best to extract total phenolic content from the aerial parts (29.00 mg gallic acid equivalents (GAE)/g), while the Soxhlet extraction with hexane (22.29 mg GAE/g) was the best for the bulb. Maceration with methanol recovered the highest total flavonoid content from both the aerial parts (41.95 mg (rutin equivalents (RE)/g) and bulb (1.83 mg RE/g). Polar extracts of aerial parts were characterized by higher abundance of kaempferol-3-glucoside (≤20,624.27 µg/mg), hyperoside (≤19,722.76 µg/g), isoquercitrin (≤17,270.70 µg/g), delphindin-3,5-diglucoside (≤14,625.21 µg/g), and rutin (≤10,901.61 µg/g) than the bulb. Aerial parts' aqueous extract, prepared by maceration, exerted the highest anti-ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical activity (64.09 mg trolox equivalents (TE)/g), Cu++ (83.03 mg TE/g) and Fe+++ (63.03 mg TE/g) reducing capacity while that prepared by infusion recorded the highest anti-DPPH (2,2-diphenyl-1-picrylhydrazyl) radical (31.70 mg TE/g) and metal chelating (27.66 mg EDTAE/g) activities. The highest total antioxidant activity (1.46 mmol TE/g) was obtained by maceration of the bulb with water. Extracts obtained by organic solvents showed remarkable enzyme inhibition properties against the tested enzymes. Soxhlet extraction of the bulb with hexane and methanol recorded the highest acetylcholinesterase inhibition (4.75 mg galanthamine equivalents (GALAE)/g) and tyrosinase inhibition (139.95 mg kojic acid equivalents/g) activities, respectively. Extracts obtained by maceration of the bulb with methanol and the aerial parts with hexane exerted the highest glucosidase inhibition (3.25 mmol acarbose equivalents/g) and butyrylcholinesterase inhibition (20.99 mg GALAE/g) activities, respectively. These data indicated that A. lycaonicum is a source of bioactive molecules with potential antioxidant and enzyme inhibition properties. Nonetheless, the extracts obtained through various solvents and extraction techniques showed variations in their phytoconstituent composition and biological properties.

The Impact of Antioxidants on Vitiligo and Melasma: A Scoping Review and Meta-Analysis.

Reactive oxygen species (ROS) generated during melanogenesis make melanocytes particularly vulnerable to oxidative stress, influencing their survival and melanin synthesis. Oxidative stress, significantly present in vitiligo and recently also detected in melasma, triggers inflammatory cascades and melanogenesis, making antioxidants a promising therapeutic avenue. A systematic search was conducted on Embase and Pubmed to study the efficacy of antioxidants for treating vitiligo and/or melasma. Meta-analysis was performed to assess the difference in Melasma Severity Index (MASI) scores between baseline and follow-up. Various antioxidants like polypodium leucotomos, ginkgo biloba, catalase/superoxide dismutase, and vitamin E have potential in vitiligo. For melasma, vitamin C, silymarin, and niacinamide were among those showing promise in reducing pigmentation, with vitamin C displaying significant effects in meta-analysis. Different antioxidants improve both vitiligo and melasma, with an increased minimal erythema dose (MED) following UV exposure being significant for vitiligo and tyrosinase inhibition being crucial for melasma. However, the efficacy of individual antioxidants varies, and their exact mechanisms, especially in stimulating melanocyte proliferation and anti-inflammatory pathways, require further investigation to understand better and optimize their use.

Antioxidant supplements as a means to prevent Alzheimer’s disease following COVID-19 infection

Oxidative stress has been proposed as a factor in many conditions, such as Alzheimer’s disease. Moreover, there is a link between oxidative stress and a variety of COVID-19 symptoms. The occurrence of multiple diseases can be ascribed to long-term exposure to heightened oxidative stress impeding the body’s normal homeostatic function. Complications arising from elevated levels of oxidative stress include lipid peroxidation, mitochondrial dysfunction, protein oxidation, damage to deoxyribonucleic acid (DNA), glycoxidation, weakened antioxidant defence, and impaired amyloid clearance. Moreover, oxidative stress leads to the onset of inflammation through an increase in the levels of active inflammatory factors. It is widely accepted that the prolongation of this detrimental cycle contributes to the development of pathological states. Consequently, interruption of the cycle of oxidative stress is imperative to prevent disease onset. Research has primarily focused on individual antioxidants, with an emphasis on vitamins C and E, owing to their significant properties as antioxidants that help reduce oxidative stress. Compared to individual antioxidants, supplements encompassing a harmonious assortment mixture of multiple antioxidants may be more effective in combating various symptoms associated with pre-existing conditions and current health concerns like COVID-19 and Alzheimer’s disease. This review explores the correlation between oxidative stress, COVID-19 infection, and Alzheimer’s disease. Additionally, we suggest the use of Twendee X, a remarkably powerful antioxidant compound, to reduce the rate of cognitive decline in individuals with Alzheimer’s disease. Moreover, Twendee X can prevent and alleviate COVID-19 and its associated symptoms.

Application of ultrasound in wood chips on the accelerated aging of apple liqueur

SummaryThe practice of aging beverages, such as fruit liqueur, incorporates phenolic compounds from wood, contributing to sensorial enhancement with new aromas and flavours. The apple liqueurs were prepared with 100 g L−1 of sugar, 20°GL and the addition of oak chips (toasted or untoasted) was previously treated with ultrasound (bath or probe). The content of total and individual phenolic compounds, antioxidant activity (FRAP, DPPH and ABTS) and colour were evaluated. A Ranking Descriptive Analysis was performed to evaluate the characteristics of each apple liqueur. The apple liqueur that received chips pre‐treated with an ultrasonic probe presented 116.5% more phenolic compounds, on average 4.9 times more antioxidant activity, and greater variation in total colour ΔE 7.03 than the control apple liqueur. The pre‐treatment with an ultrasonic probe accelerated the extraction process in approximately 60 days. The untoasted chips contributed by adding 17.4% more total phenols than the toasted chips, due to the significant presence of gallic acid. The pre‐treatment on wood chips accelerated the aging of apple liqueurs, increased phenolics compounds. Sensorially, the woody descriptors (taste, aroma and residual) were more intensely perceived and with the best acceptance scores among the judges.

Insights into the Structure-Capacity of Food Antioxidant Compounds Assessed Using Coulometry.

CDAC (coulometrically determined antioxidant capacity) involves the determination of the antioxidant capacity of individual compounds or their mixtures using constant-current coulometry, with electrogenerated Br2 as the titrant, and biamperometric detection of the endpoint via Br2 excess. CDAC is an accurate, sensitive, rapid, and cheap measurement of the mol electrons (mol e-) transferred in a redox process. In this study, the CDAC of 48 individual antioxidants commonly found in foods has been determined. The molar ratio CDAC (CDACχ, mol e- mol-1) of representative antioxidants is ranked as follows: tannic acid > malvidin-3-O-glucoside ≃ curcumin > quercetin > catechin ≃ ellagic acid > gallic acid > tyrosol > BHT ≃ hydroxytyrosol > chlorogenic acid ≃ ascorbic acid ≃ Trolox®. In many cases, the CDACχ ranking of the flavonoids did not comply with the structural motifs that promote electron or hydrogen atom transfers, known as the Bors criteria. As an accurate esteem of the stoichiometric coefficients for reactions of antioxidants with Br2, the CDACχ provides insights into the structure-activity relationships underlying (electro)chemical reactions. The electrochemical ratio (ER), defined as the antioxidant capacity of individual compounds relative to ascorbic acid, represents a dimensionless nutritional index that can be used to estimate the antioxidant power of any foods on an additive basis.

Polyphenolic Composition, Antioxidant and Antiproliferative Activity of Edible and Inedible Parts of Cultivated and Wild Pomegranate (Punica granatum L.).

The aim of this study is to determine and compare the antioxidant and antiproliferative activities of juices and extracts of the peel, aril and membrane of the cultivated and wild pomegranate fruits. The content of total phenols, total flavonoids, total flavonols, total flavan-3-ols and total anthocyanins was determined spectrophotometrically. The individual phenolics were quantified by HPLC. Antioxidant activity was determined by DPPH and ABTS tests and neutralisation of hydroxyl radical, while the antiproliferative activity was measured in vitro by sulforhodamine B (SRB) assay. Total phenolics were statistically highest in wild pomegranate peel extract, expressed in gallic acid equivalents, 340.92 mg/g (p<0.05), while total flavonoid content was the highest in cultivated pomegranate peel extract, expressed in quercetin equivalents, 31.84 mg/g (p<0.05). The sample of wild pomegranate peel extract showed the highest antioxidant activity with respect to free DPPH and ABTS radicals. The samples of cultivated pomegranate peel and membrane extracts had almost identical and the strongest effect on the inhibition of hydroxyl radicals (41.24 and 41.23 μg/mL, respectively). The sample of wild pomegranate peel extract showed the strongest effect on the growth inhibition of all tested tumour cell lines. In this study, the bioactivity of different parts of cultivated and wild pomegranates was determined and compared. In the available literature, the individual antioxidant and antiproliferative activity of only some parts of the pomegranate fruit was investigated. All parts of the pomegranate fruit were investigated, including the membrane, which was barely analysed in other works. The wild pomegranate has also been less analysed in previous studies. Future research should focus on in vivo studies of the obtained pomegranate samples.

Bone mineral density is associated with composite dietary antioxidant index among US adults: results from NHANES.

While individual dietary antioxidants have shown beneficial effects on bone metabolism, the diverse and potentially interacting nature of dietary components may limit the accuracy of evaluating their impact on bone health. Thus, this study aims to investigate the association between CDAI and BMD. Additionally, we explore the relationship between the intake of individual components of the CDAI and BMD. The CDAI is a novel index evaluating total dietary antioxidant intake, considering vitamins A, C, and E, zinc, selenium, and carotenoids. A cross-sectional analysis was conducted using data from participants aged ≥ 20 in the National Health and Nutrition Examination Survey (2005-2010, 2013-2014, and 2017-2018). We utilized multivariate linear regression models to examine the relationship between CDAI, individual dietary antioxidants, including vitamins A, C, and E, zinc, selenium, carotenoids, and femoral BMD. The final analysis included 10,584 participants with a mean age of 50.73 ± 16.65years. After multivariate adjustment, the second to fourth quartiles of CDAI (- 2.00-0.04, 0.04-2.54, and 2.54-70.78) exhibited higher femoral BMD compared to the first quartile of CADI (- 7.34 to - 2.00). Multiple regression analysis revealed that higher intakes of vitamin C, vitamin E, selenium, zinc, and carotenoids were associated with higher femoral BMD. CDAI serves as a comprehensive tool for evaluating the overall antioxidant capacity of antioxidants in diets. Additionally, our study shows a positive correlation between CDAI and BMD, which indicates that the combined intake of dietary antioxidants may help reduce the risk of osteoporosis in adults.

Absorbent bioactive aerogels based on germinated wheat starch and grape skin extract

This study aimed to produce water-absorbent bioactive aerogels using biodegradable raw materials, wheat starch and poly ethylene oxide (PEO), and derived from agro-industrial residues (grape skin) obtained in the wine industry. The aerogels were produced using germinated wheat starch (GWS), with and without PEO, and incorporating grape skin extract (GSE) at concentrations of 5 and 10 % (w/w). The GSE was evaluated for total and individual phenolic compounds, anthocyanins, and antioxidant activity. The starch aerogels were characterized for morphology, density, porosity, functional groups by FT-IR, relative crystallinity and diffraction pattern, water absorption capacity, antioxidant activity, and in vitro release profile of phenolic compounds in food simulant medium. The total phenolic compounds in GSE was 226.25 ± 0.01 mg equivalent of gallic acid/g GSE. The aerogels showed low density and high porosity. All aerogels demonstrated high water absorption capacity (581.4 to 997.5 %). The antioxidant activity of the aerogels increased with increasing GSE concentration and the addition of PEO. The aerogels could release GSE gradually for up to 120 days in the hydrophilic simulant medium and 240 h for the hydrophobic medium. Starch-based aerogels with GSE showed potential to be applied as exudate absorbers with antioxidant activity to develop active food packaging.

Bioprospecting a Film-Forming System Loaded with Eugenia uniflora L. and Tropaeolum majus L. Leaf Extracts for Topical Application in Treating Skin Lesions.

Natural products can be used as complements or as alternatives to synthetic drugs. Eugenia uniflora and Tropaeolum majus are natives of Brazil and have antimicrobial, anti-inflammatory, and antioxidant activities. This study aimed to develop a film-forming system (FFS) loaded with plant extracts with the potential for treating microbial infections. E. uniflora and T. majus leaf extracts were prepared and characterized, and the individual and combined antioxidant and antimicrobial activities were evaluated. The FFS was developed with different concentrations of polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) and analyzed for physicochemical characteristics. The combination of extracts showed a superior antioxidant effect compared to the individual extracts, justifying the use of the blend. FFS prepared with 4.5% PVA, 4.5% PVP, 7.81% E. uniflora extract, and 3.90% T. majus extract was adhesive, lacked scale formation, presented good malleability, and had a suitable pH for topical application. In addition, the viscosity at rest was satisfactory for maintaining stability; water solubility was adequate; skin permeation was low; and the antimicrobial effect was superior to that of the individual extracts. Therefore, the developed FFS is promising for the differentiated treatment of skin lesions through topical application.

Incorporation of natural antioxidants extracted from strawberry, cinnamon, beetroot, and ginger; into virgin coconut oil for expansion of its shelf life

Lipid oxidation significantly deteriorates the quality of edible oils and further leads to changes in flavour, storage properties, and overall nutritional value. Phenolic phytochemicals of strawberry (S), beetroot (B), cinnamon (C), and ginger (G) were extracted into ethanol using the reflux method and evaluated for their total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant potential. These phytochemicals were then incorporated into virgin coconut oil (VCO) as individual antioxidants and combinations, to expand its shelf life and mitigate the negative effects of oxidation. The antioxidant fortified VCO subjected to accelerated oxidation was assessed under the parameters of peroxide value (PV), free fatty acid value (FFA), conjugated dienes (CD), conjugated trienes (CT), and Thiobarbituric acid related substances assay (TBARS) value with comparison to control (VCO), gallic acid, Vitamin E, and BHT. The TPC of strawberry, cinnamon, beetroot, and ginger were 198.00 ± 1.41, 135.00 ± 1.41, 55.00 ± 1.41, and 151.51 ± 0.071 mg GAE/g respectively and their antioxidant potential ranged in the order of S> B> C> G based on their IC50 DPPH value. The PV of (VCO, and VCOGC), VCOSG, VCOSCBG, and VCOBHT have reached the rancid PV of 30–40 meq/Kg range in 12, 24, 48, and 72 h respectively. The FFA of control, VCOVit.E, and VCOBHT was higher than that of VCOGC, VCOSG, and VCOSGBC, after 72 h. The CD and CT values increased with time, similar to PV with storage time. Nevertheless, the combinations SB (1:1) and SGBC (1:1:1:1) at 1500 ppm could be used as natural antioxidant and might be explored to prevent the oxidation of vegetable oils. Therefore, the combination could be used as preservative ingredients in the oil-based food industries.

Characterization of Targeted Phenolic Compounds in Globe Artichoke Heads and Waste from Vegetatively and "Seed"-Propagated Genotypes.

In the globe artichoke, both the edible portion and the waste biomass are recognized as valuable sources of bioactive compounds. For this study, heads with 30 cm-long floral stems including two to three leaves were harvested from five genotypes, which included two traditional vegetative-propagated varietal types ("Brindisino" and "Violetto di Foggia") and three "seed"-propagated hybrids ("Tempo", "Opal", and "Madrigal"). The study aimed to determine the total and individual polyphenolic concentrations (measured spectrophotometrically and using HPLC) and antioxidant activity (AA) in different artichoke parts, namely the "hearts" (H), head waste (HW), stem waste (SW), and leaf waste (LW). "Brindisino" SW exhibited the highest accumulation of luteolin (26,317 mg kg-1 F.W.), while "Tempo" H displayed the highest cynarin content (190 mg kg-1 F.W.). "Tempo" HW and H showed the highest levels of apigenin (640 mg kg-1 F.W.), and the greatest source of chlorogenic acid was found in the HW of "Opal" and the H of "Brindisino" (4300 mg kg-1 F.W.). The hybrids generally exhibited lower total polyphenolic concentrations than the traditional genotypes, particularly evident in the LW. The SW demonstrated the highest concentration of total polyphenols (18,000 mg kg-1 F.W.), followed by the edible H and non-edible HW (12,000 mg kg-1 F.W.), while the LW exhibited the lowest concentration (2000 mg kg-1 F.W.). Interestingly, the AA did not precisely align with the total polyphenolic concentration, showing slight variations between the examined parts and genotypes.

Association of the composite dietary antioxidant index with bone mineral density in the United States general population: data from NHANES 2005-2010.

There is evidence that individual antioxidants may increase bone mineral density (BMD) in patients with low BMD. However, the association between overall dietary antioxidant intake and BMD is unclear. The objective of this study was to examine how overall dietary antioxidant intake is related to BMD. A total of 14,069 people participated in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2010. Dietary Antioxidant Index (DAI) was calculated from the intake of vitamins A, C, E, zinc, selenium, and magnesium, which indicates a nutritional tool to assess the overall antioxidant properties of the diet. The correlation between the Composite Dietary Antioxidant Index (CDAI) and BMD was examined using multivariate logistic regression models. In addition to fitting smoothing curves, we fitted generalized additive models as well. Furthermore, to ensure data stability and avoid confounding factors, subgroup analysis was also conducted on gender and body mass index (BMI). A significant association was demonstrated by the study between CDAI and total spine BMD (β = 0.001, 95% CI 0-0.001, P = 0.00039). And just like that, CDAI was positively correlated with femoral neck (β = 0.003, 95% CI 0.003-0.004, P < 0.00001) and trochanter (β = 0.004, 95% CI 0.003-0.004, P < 0.00001). In the gender subgroup analysis, CDAI maintained a strong positive correlation with femoral neck and trochanter BMD in males and females. Nevertheless, the link with total spine BMD was only observed in males. In addition, in the subgroup analysis stratified by BMI, CDAI showed a significantly positive relation to BMD of the femoral neck and trochanter in each group. However, the significant relationship between CDAI and BMD of the total spine was only maintained when BMI was above 30kg/m2. This study found that CDAI correlated positively with femoral neck, trochanter, and total spine BMD. This suggests that intake of a diet rich in antioxidants can reduce the risk of low bone mass and osteoporosis.

Assessment of glutathione peroxidase enzyme response and total antioxidant status in oral cancer - Systematic review and meta-analysis.

Oxidative stress induced by free radical accumulation contributes to many pathologies, including cancer. Antioxidant defense system fails to scavenge free radicals when it is excessively accumulated. Assessing individual antioxidant enzymes and total antioxidant capacity could direct the customized therapeutic strategies. Evaluation of total antioxidant status and enzyme glutathione peroxidase activity in the oral cancer group compared to the healthy control group. The literature search included databases PubMed, Science Direct, Wiley Online Library, Cochrane and Cross Reference between 1999 and 2021. The database search was completed in the month of August 2022. The extracted data were analyzed by Comprehensive Meta-Analysis (CMA) version 3 software (Biostat Inc. Englewood, NJ). Based on search strategies, 1435 articles have been retrieved from the database. In the segregated articles, 1365 were excluded due to duplicated articles, animal studies, low-quality studies, articles unrelated to the research question, and with unmatched objectives. Based on inclusion criteria, 70 articles were selected for full-text valuation. However, 33 articles were found highly suitable for inclusion and data extraction. Finally, 11 articles were selected for meta-analysis. The meta-analysis of four included studies of tissue samples showed a significantly (p < .001) increased GPx activity in the oral cancer group, when compared to the control group, whereas three included studies of erythrocyte samples displayed a significantly (p < .001) decreased GPx activity in the oral cancer group than the control group with the pooled standardized mean difference value of -2.766 moles/min/g Hb at 95% CI (-3.297 to -2.234). The meta-analysis of the included studies depicted an insignificant (p = .947) reduction of salivary TAS levels in the oral cancer group when compared to the control group. Our systematic review and meta-analysis depict antioxidant GPx enzyme activity in the regional tissue samples of the oral cancer group differs from other systemic biological fluid samples compared to the healthy control group.

Glutathione Depletion Disrupts Redox Homeostasis in an Anoxia-Tolerant Invertebrate.

The upregulation of endogenous antioxidants is a widespread phenomenon in animals that tolerate hypoxia/anoxia for extended periods. The identity of the mobilized antioxidant is often context-dependent and differs among species, tissues, and stresses. Thus, the contribution of individual antioxidants to the adaptation to oxygen deprivation remains elusive. This study investigated the role of glutathione (GSH) in the control of redox homeostasis under the stress of anoxia and reoxygenation in Helix aspersa, an animal model of anoxia tolerance. To do so, the total GSH (tGSH) pool was depleted with l-buthionine-(S, R)-sulfoximine (BSO) before exposing snails to anoxia for 6 h. Then, the concentration of GSH, glutathione disulfide (GSSG), and oxidative stress markers (TBARS and protein carbonyl) and the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione transferase, glutathione reductase, and glucose 6-phosphate dehydrogenase) were measured in foot muscle and hepatopancreas. BSO alone induced tGSH depletion by 59-75%, but no other changes happened in other variables, except for foot GSSG. Anoxia elicited a 110-114% increase in glutathione peroxidase in the foot; no other changes occurred during anoxia. However, GSH depletion before anoxia increased the GSSG/tGSH ratio by 84-90% in both tissues, which returned to baseline levels during reoxygenation. Our findings indicate that glutathione is required to withstand the oxidative challenge induced by hypoxia and reoxygenation in land snails.

Assessing radical scavenging capacity of Sempervivum tectorum L. leaf extracts: An integrated high-performance thin-layer chromatography/in silico/chemometrics approach

High-Performance Thin-Layer Chromatography (HPTLC)-radical scavenging capacity (RSC) assays are standard techniques for the separation and identification of antioxidants from complex mixtures. HPTLC coupled with DPPH· visualization of chromatograms allows for the detection of individual antioxidants. However, other HPTLC-RSC assays that recognize compounds exhibiting different mechanisms of radical-scavenging activity are rarely reported. In this study, we developed an integrated approach that combines five HPTLC-RSC assays, principal component analysis (PCA) and quantum chemical calculations to assess the antioxidant capacity of Sempervivum tectorum L. leaf extracts. Two HPTLC assays - potassium hexacyanoferrate(III) total reducing power assay (TRP) and total antioxidant capacity by phosphomolybdenum method (TAC) - were developed for the first time. The method supports a more in-depth study of the RSC of natural products, as it compares the radical scavenging fingerprints of S. tectorum leaf extracts and recognizes differences in their individual bioactive constituents. Kaempferol, kaempferol 3-O-glucoside, quercetin 3-O-glucoside, caffeic acid, and gallic acid were identified as the compounds that discriminate HPTLC-RSC assays according to their mechanism of action and capture the similarities between 20 S. tectorum samples. Additionally, DFT calculations on M06–2X/6–31+G(d,p) level were applied to map thermodynamic feasibility of hydrogen atom transfer (HAT) and single electron transfer (SET) mechanisms of the identified compounds. Based on experimental and theoretical results, a combination of HPTLC-ABTS and HPTLC-TAC assays were proposed as the optimal method for mapping the antioxidants from S. tectorum. This study represents a step forward in identifying and quantifying individual antioxidants from complex food and natural product matrices in a more rational manner.

Essential Oil of Origanum vulgare var. aureum L. from Western Romania: Chemical Analysis, In Vitro and In Silico Screening of Its Antioxidant Activity

This investigation aims to assess the chemical composition and antioxidant properties of Origanum vulgare var. aureum L. essential oil (OEO). The oil was obtained with a 0.34% (v/w dried weight) yield and investigated by gas chromatography-mass spectrometry (GC–MS) analysis. The main compounds of the OEO were found to be gamma-terpinene (22.96%), para-cymene (14.72%), germacrene (11.64%), beta-trans-ocimene (9.81%), and cis-beta-ocimene (7.65%). Furthermore, individual antioxidant assays 1,1-diphenyl-2-picrylhydrazyl (DPPH) and [2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium] (ABTS) radical scavenging activities and beta-carotene/linoleic acid bleaching were carried out. OEO demonstrated better scavenging effects on the DPPH (IC50 93.12 ± 0.03 μg/mL) and ABTS (IC50 27.63 ± 0.01 μg/mL) assays (significantly lower IC50 values; p ≤ 0.001) than ascorbic acid (IC50 127.39 ± 0.45 μg/mL). In the beta-carotene/linoleic acid bleaching assay, the OEO exhibited a higher Relative antioxidant activity (RAA %) (82.36 ± 0.14%) but lower compared with butylated hydroxyanisole (BHA) (100%), with no significant differences (p &gt; 0.05) observed. According to molecular docking results, the first two main compounds of the OEO, para-cymene, and gamma-terpinene, may potentially contribute to the biological antioxidant activity of the oil by inhibiting ROS (reactive oxygen species)-producing enzymes such as lipoxygenase and xanthin oxidase. These experimental data suggest that OEO could represent a valuable new natural antioxidant source with functional properties in the food or pharmaceutical industries.

Effect of Gallic Acid Pretreatment and SGK1 Enzyme Inhibition on Cardiac Function and Inflammation in a Rat Model of Ischemia-Reperfusion Injury.

Serum and glucocorticoid-induced kinase 1 (SGK1) is an enzyme that may play an important role in ischemic-reperfusion (I/R) injury and myocardial dysfunction. Although many studies have been conducted on individual antioxidants, little attention has been paid to the effects of co-administration of an antioxidant with an SGK1 inhibitor on cardiac function after I/R. This study aimed to determine the effects of gallic acid (as an antioxidant) combined with an SGK1 inhibitor on I/R-induced cardiac dysfunction and inflammation. Sixty male Wistar rats were randomized into 6 groups, pretreated with gallic acid or vehicle for 10 days. Subsequently, the heart was isolated and exposed to I/R. In groups that received the SGK1 inhibitor, the heart was perfused with the SGK1 inhibitor GSK650394, 5 min before induction of ischemia. After that, cardiac function, inflammatory factors, and myocardial damage were evaluated. The combination of these two compounds improved cardiac contractility, heart rate, rate pressure product, left ventricular developed pressure, left ventricular systolic pressure, perfusion pressure, and QRS voltage significantly (P < 0.05). In addition, concomitant therapy of these two agents reduced tumor necrosis factor-alpha and interleukin-6, and the activity of creatine kinase-MB, lactate dehydrogenase, and troponin-I (P < 0.05). The results indicated that administration of gallic acid with the SGK1 inhibitor may have a potentiating effect on the improvement of cardiac dysfunction and I/R-induced inflammation.

Food Antioxidants and Their Interaction with Human Proteins.

Common to all biological systems and living organisms are molecular interactions, which may lead to specific physiological events. Most often, a cascade of events occurs, establishing an equilibrium between possibly competing and/or synergistic processes. Biochemical pathways that sustain life depend on multiple intrinsic and extrinsic factors contributing to aging and/or diseases. This article deals with food antioxidants and human proteins from the circulation, their interaction, their effect on the structure, properties, and function of antioxidant-bound proteins, and the possible impact of complex formation on antioxidants. An overview of studies examining interactions between individual antioxidant compounds and major blood proteins is presented with findings. Investigating antioxidant/protein interactions at the level of the human organism and determining antioxidant distribution between proteins and involvement in the particular physiological role is a very complex and challenging task. However, by knowing the role of a particular protein in certain pathology or aging, and the effect exerted by a particular antioxidant bound to it, it is possible to recommend specific food intake or resistance to it to improve the condition or slow down the process.