Electrochemical Detection of Total Antioxidant Capacity (TAC) in Plant Tissues from Different Origins.

Total antioxidant capacity (TAC) is a reliable indicator of antioxidant content in animal and plant samples. The different experimental approaches available allow the determination of TAC using, as a reference, diverse compounds with recognized antioxidant capacities such as Trolox, ascorbic acid, gallic acid, or melatonin. A new portable device, named BRS (BQC redox system), is now commercially available that, through an electrochemical approach, allows the determination of TAC in a simple, fast, reproducible, and robust way. In this chapter, using this portable device, a comparative analysis of the TAC is assayed in different red, citrus, and Solanaceae fruits, several Allium species, and organs of different plant species, including Arabidopsis thaliana. The obtained results demonstrate the versatility of the BRS portable device.

Dietary Supplementation with Bupleuri Radix Reduces Oxidative Stress Occurring during Growth by Regulating Rumen Microbes and Metabolites.

Oxidative stress (OS) in ruminants is closely associated with disease; thus, improving antioxidant capacity is an important strategy for maintaining host health. Bupleuri Radix (BR) could significantly improve host health and stress levels. However, the clear antioxidant mechanism of the function of BR remains unknown. In the current study, LC-MS metabolomics combined with 16S rRNA gene sequencing was employed to explore the effects of BR on rumen microbiota and metabolites in Shanbei Fine-Wool Sheep (SFWS), and Spearman correlation analyses of rumen microbiota, metabolites, and OS were performed to investigate the mechanism of antioxidant function of BR. Our results indicated that as SFWS grows, levels of OS and antioxidant capacity increase dramatically, but providing BR to SFWS enhances antioxidant capacity while decreasing OS. Rumen microbiota and OS are strongly correlated, with total antioxidant capacity (T-AOC) showing a significant negative correlation with Succiniclasticum and a positive correlation with Ruminococcus. Importantly, the Chao1 index was significantly negatively correlated with malondialdehyde (MDA) and positively correlated with superoxide dismutase (SOD) and T-AOC. Two biomarkers connected to the antioxidant effects of BR, 5,6-DHET and LPA (a-25:0/0:0), were screened according to the results of metabolomics and Spearman analysis of rumen contents, and a significant relationship between the concentration of rumen metabolites and OS was found. Five metabolic pathways, including glycerolipid, glutathione, nucleotide, D-amino acid, and inositol phosphate metabolism, may have a role in OS. The integrated results indicate that rumen microbiota and metabolites are strongly related to OS and that BR is responsible for reducing OS and improving antioxidant capacity in post-weaned SFWS. These findings provide new strategies to reduce OS occurring during SFWS growth.

Exploring New Horizons for Wine Grapes: Modulating Functional Effects by Varying Harvest Timing and Solar Exposure.

Grenache (GN) and Cabernet Sauvignon (CS) are two traditional red grape varieties widely cultivated in the Mediterranean area and both late-ripening cultivars, which makes them less sensitive to global warming conditions and more stable to harvest timing. Although different studies have evaluated the final antioxidant properties of grapes and pomaces, few studies have explored the effect of sun exposure and harvest on the nutritional and antioxidant properties of these products. This study investigates the control of sunlight and ripening as tools to tailor nutritional and antioxidant properties of grape juices (GJ) and their byproducts (pomace GP). The compositional analysis showed no significant (p ≥ 0.05) differences associated to either harvesting timing or exposure to sunlight for either of the two studied varieties. However, differences (p ≤ 0.05) were observed between varieties of protein and total dietary fibre (TDF). CS protein content ranged from 0.52 to 3.88 (g 100 g-1) in GJ and from 1.0 to 1.32 (g 100 g-1) in GP; meanwhile, GN had higher protein values in GJ (from 2.11 to 4.77 g 100 g-1) and GP (from 5.11 to 6.75 g 100 g-1). The opposite behaviour was observed in TDF; CS grape had higher values for juice (from 11.43 to 19.53 g 100 g-1) and pomace (from 42.20 to 65.80 g 100 g-1) than GN (from 11.43 to 17.22 g 100 g-1 in juice and from 25.90 to 54.0 g 100 g-1 in pomace). The total phenolic content (TP) in GP was 100 times higher than in the juices and showed a much less pronounced evolution compared to the GJ during the harvesting time. GN TP values ranged from 5835 to 8772 mg GAE 100 g-1; meanwhile, CS values ranged from 7637 to 9040 mg GAE 100 g-1. A significant (p ≤ 0.05) correlation between the TP total antioxidant capacity (TAC) results was observed, regardless of variety, harvesting time, and sunlight exposure. These findings show how the control of different factors can contribute to obtain modified grape-derived products from conventional varieties beyond the wine market.

Association between dietary antioxidant capacity and type 2 diabetes mellitus in Chinese adults: a population-based cross-sectional study.

BACKGROUND: Higher intakes of dietary antioxidants have been linked to a lower type 2 diabetes mellitus (T2DM) risk. However, few studies have comprehensively examined the overall dietary antioxidant capacity, assessed by dietary antioxidant quality scores (DAQS) and dietary total antioxidant capacity (DTAC), related to T2DM risk, especially in populations consuming relatively monotonous diets. This study aimed to evaluate the associations of DAQS, DTAC, and T2DM among rural Chinese adults. METHODS: Data from 12,467 participants from the Natural Population Cohort of Northwest China: Ningxia Project was analyzed. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. DAQS were calculated based on vitamins A, C, and E, zinc (Zn), and selenium (Se) intake. DTAC was estimated using the ferric-reducing ability of plasma assay. Logistic regression models were used to evaluate the associations of DAQS and DTAC with T2DM risk. Restricted cubic splines were used to assess potential non-linear relationships between DTAC and T2DM. RESULTS: T2DM was observed in 1,238 (9.9%) participants. After adjusting for confounders, compared to the lowest tertiles (T1) of DAQS, the odds ratios (ORs) for T2DM were 1.03 (95% CI 0.82-1.30) in T2 and 0.85 (95% CI 0.68-1.06) in T3 (P = 0.010). Compared to T1, the ORs for T2DM in the highest T3 were 0.78 (95% CI 0.67-0.91, P-trend = 0.008) for vitamin A, 1.34 (95% CI 1.15-1.56, P-trend < 0.001) for vitamin E, 0.83 (95% CI 0.71-0.97, P-trend = 0.007) for Se, and 0.86 (95% CI 0.74-1.01, P-trend = 0.033) for Zn. Compared to the lowest quartile(Q1) of DTAC, the OR in the highest Q4 was 0.96 (95% CI 0.80-1.17, P-trend = 0.024) for T2DM. A non-linear relationship was observed between DATC and T2DM. CONCLUSION: Higher DAQS and DATC were associated with a lower T2DM risk, suggesting that consuming antioxidant-rich foods may reduce the T2DM risk.

Efficacy of a dietary supplement derived from five edible plants on telomere length in Thai adults: A randomized, double-blind, placebo-controlled trial.

Mylife/Mylife100® is a dietary supplement consisting of black sesame seed, guava fruit, mangosteen aril, pennywort leaves, and soy protein. These edible plants contain multiple high-potential bioactive compounds exerting various vital biological functions including antioxidants which contribute to delaying the rate of telomere shortening. Telomere length is associated with cellular aging and age-related diseases. This study aimed to assess the efficacy of Mylife/Mylife100® on telomere length through a randomized, double-blind placebo-controlled trial. The trial assessed the alteration of leukocyte telomere length after 32 adults aged 50-65 years received either Mylife/Mylife100® or placebo (five capsules/day) for 8-week supplementation. The results demonstrated a significant increase in mean telomere length from baseline (6313 bp) to the 8-week supplementation period (6655 bp; p < 0.05) in the group receiving the product, whereas no significant change was observed in the placebo group. Additionally, the product group exhibited a significant improvement in plasma total antioxidant capacity levels compared to the placebo group (mean change, +35 vs -38; p = 0.006). This study also showed a significant correlation between telomere length and % CD4 + T cells (r = +0.325; p = 0.00003), % CD8 + T cells (r = +0.156; p = 0.048), and visceral fat (r = - 0.349; p = 0.000006). The findings suggest that consuming this dietary supplement (Mylife/Mylife100®) for 8 weeks has a positive effect on cellular aging by lengthening telomeres possible through their antioxidant capacities. Oxidative stress and cellular aging are underlying predisease mechanisms that might be alleviated by supplementing with this product.

Impact of seed priming with Selenium nanoparticles on germination and seedlings growth of tomato.

Poor germination and seedlings growth can lead to significant economic losses for farmers, therefore, sustainable agricultural strategies to improve germination and early growth of crops are urgently needed. The objective of this work was to evaluate selenium nanoparticles (Se NPs) as nanopriming agents for tomato (Solanum lycopersicum) seeds germinated without stress conditions in both trays and Petri dishes. Germination quality, seedlings growth, synergism-antagonism of Se with other elements, and fate of Se NPs, were determined as function of different Se NPs concentrations (1, 10 and 50 ppm). Results indicated that the germination rate in Petri dishes improved with 10 ppm, while germination trays presented the best results at 1 ppm, increasing by 10 and 32.5%, respectively. Therefore, seedlings growth was measured only in germination trays. Proline content decreased up to 22.19% with 10 ppm, while for same treatment, the total antioxidant capacity (TAC) and total chlorophyll content increased up to 38.97% and 21.28%, respectively. Antagonisms between Se with Mg, K, Mn, Zn, Fe, Cu and Mo in the seed were confirmed. In the case of seedlings, the N content decreased as the Se content increased. Transmission Electron Microscopy (TEM) imaging confirmed that Se NPs surrounded the plastids of the seed cells. By this finding, it can be inferred that Se NPs can reach the embryo, which is supported by the antagonism of Se with important nutrients involved in embryogenesis, such as K, Mg and Fe, and resulted in a better germination quality. Moreover, the positive effect of Se NPs on total chlorophyll and TAC, and the negative correlation with proline content with Se content in the seed, can be explained by Se NPs interactions with proplastids and other organelles within the cells, resulting with the highest length and fresh weight when seeds were exposed to 1 ppm.

Efficacy of a Novel Intracanal Medicament on Total Antioxidant Status in Patients With Apical Periodontitis: A Randomized Controlled Clinical Trial.

Introduction Successful endodontic treatment relies upon the microbial debridement of the root canal system. This can be achieved to a great extent by using intracanal medicaments, which inhibit the microbes growing in the root canal. Evaluating the capacity of oxidants in the saliva is a crucial parameter for assessing the antioxidant capacity of any individual, which decreases in inflammatory conditions. An effective intracanal medicament can increase the total antioxidant capacity of saliva, which comes down because of inflammatory conditions. Aim To evaluate the effect of two intracanal medicaments on the antioxidant capacity of saliva. Materials and methods In a randomized prospective clinical trial, 42 patients with a mean age of 18-70 years were selected based on exclusion and inclusion criteria, and the baseline value of the total antioxidant capacity of saliva was recorded. The patients were categorized into two groups as per the block randomization method (Group I: calcium hydroxide (Maarc, New Delhi, India) intracanal medicament; Group II: Hekla lava (SBL Pvt. Ltd., Germany) intracanal medicament). Access opening, working length determination, and cleaning and shaping were conducted using hand K-files and ProTaper Gold rotary files. Intracanal medicaments were placed according to the groups assigned, and temporary restoration was placed. The patients were recalled after seven days. If the tooth was asymptomatic, obturation was completed, and a saliva sample was collected to assess the total antioxidant capacity. Results The total antioxidant capacity of saliva was increased after using intracanal medicaments and endodontic therapy, and there was a statistically significant difference before and after using both the medicaments (p=0.0005; i.e., calcium hydroxide and Hekla lava. When both medicaments were compared, there was no significant difference in the antioxidant capacity of saliva among medicaments (p=0.384). Conclusion The total antioxidant capacity of saliva was increased after using both the intracanal medicaments. Hence, Hekla lava can be potentially used as an alternative intracanal medicament.

The association between dietary total antioxidant capacity and hearing loss: results from the Tehran employees Cohort Study.

BACKGROUND: Despite numerous studies that have explored the association between individual antioxidants or specific combinations and the risk of hearing loss, there is lack of information regarding the relationship between dietary total antioxidant capacity (dTAC) and hearing loss. The conflicting results on this association further highlight the need for more research in this area. This study aims to investigate the association between overall dietary antioxidant intake and the risk of hearing loss among Iranian adults. METHODS: This cross-sectional study recruited 3443 adult participants aged between 19 and 67 years (with an average age of 41.4 years ± 8.8) who were employed at Tehran University of Medical Sciences in Iran. Participants underwent dietary assessment using a validated Food Frequency Questionnaire (FFQ). The hearing status of each participant was evaluated by a licensed audiologist in a soundproof room, using diagnostic audiometry that adhered to American National Standards specifications and followed standard audiometric clinical procedures. The dietary total antioxidant capacity (dTAC) was calculated using the Ferric Reducing-Antioxidant Power (FRAP) values. RESULTS: 43.6% of male participants had hearing loss, while 26.8% among female participants. After accounting for various confounding factors, no significant association was observed between higher levels of dTAC and reduced odds of hearing loss in the overall population. However, among men under the age of 40, higher levels of dTAC were associated with decreased odds of hearing loss, even after adjusting for several covariates (OR: 0.56, 95% CI: 0.31-1.02, Ptrend = 0.02). This relationship was not evident in men over 40 years of age or among women. CONCLUSION: The study found an inverse relationship between higher antioxidant intake in the diet and lower odds of hearing loss, specifically among men who were 40 years old or younger. However, this relationship was not observed in the overall population or among women. Additional prospective studies are necessary to validate these results.

Multifunctional bimetallic MOF with oxygen vacancy synthesized by microplasma for rapid total antioxidant capacity assessment in agricultural products.

The assessment of total antioxidant capacity (TAC) is crucial for evaluating overall antioxidant potential, predicting the risk of chronic diseases, guiding dietary and nutritional interventions, and studying the effectiveness of antioxidants. However, achieving rapid TAC assessment with high sensitivity and stability remains a challenge. In this study, Ce/Fe-MOF with abundant oxygen vacancies was synthesized using microplasma for TAC determination. The microplasma synthesis method was rapid (30 min) and cost-effective. The presence of oxygen vacancies and the collaboration between iron and cerium in Ce/Fe-MOF not only enhanced the catalyst's efficiency but also conferred multiple enzyme-like properties: peroxidase-like, oxidase-like, and superoxide dismutase mimetic activities. Consequently, a simple colorimetric assay was established for TAC determination in vegetables and fruits, featuring a short analysis time of 15 min, a good linear range of 5-60 µM, a low detection limit of 1.3 µM and a good recovery of 91 %-107 %. This method holds promise for rapid TAC assessment in agricultural products.

Iridium nanoparticles supported on polyaniline nanotubes for peroxidase mimicking towards total antioxidant capacity assay of fruits and vegetables.

In this study, a straightforward approach is presented for the first time to anchor Ir nanoparticles on the surface of uniform polyaniline (PANi) nanotubes (NTs), which can be used as an efficient peroxidase (POD)-like catalyst. The morphology and chemical structure of the PANi-Ir nanocomposite are characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffractometer (XRD), Raman and X-ray photoelectron spectroscopy (XPS) measurements. Owing to the strong interaction between Ir nanoparticles and PANi, a remarkable catalytic enhancement is achieved compared to the bare Ir black catalyst and individual PANi NTs, dominating withan electron transfer mechanism. Furthermore, an efficient colorimetric sensor for ascorbic acid (AA) is developed with a low detection limit of 1.0 µM (S/N = 3), and a total antioxidant capacity (TAC) sensing platform is also constructed for the rigorous detection and analysis of fruits and vegetables.

Evaluation of serum placenta-specific gene 8 protein, total antioxidant capacity, interleukin-10, interleukin-17A, interleukin-21 and interleukin-33 levels in Turkish women with gestational diabetes mellitus.

PURPOSE: Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance that begins or is diagnosed during pregnancy. Our study aimed to establish a correlation between proinflammatory and anti-inflammatory response in order to be able to develop treatment strategies and determine early diagnosis biomarkers in the sera of cases diagnosed with GDM. Moreover, we aimed to investigate interleukin (IL), placenta-specific gene 8 protein (PLAC8) and total antioxidant capacity (TAC) in patients with GDM. METHODS: A total of 121 patients were included in the study. These were divided into four patient groups: pregnant and diagnosed with DM (P-GDM, n=30); pregnant and not diagnosed with DM (P-NGDM, n=32); non-pregnant diagnosed with DM (NP-DM, n=29) and non-pregnant and not diagnosed with DM (NPNDM, n=30). IL-10, IL-17A, IL-21, IL-33, PLAC8 and TAC determinations from patients were evaluated by ELISA (Enzyme-Linked ImmunoSorbent Assay) method. RESULTS: IL-10 and IL-33 concentrations were found to be significantly higher in P-GDM and NP-DM patient groups compared to P-NGDM and NP-NDM groups (p<0.001). The PLAC8 level in the P-GDM patient group (20.38±5.37) was determined to be significantly higher than in the P-NGDM patient group (3.41±2.17, p<0.001). TAC in the P-NGDM and NP-NDM groups (12.42±2.31 vs. 12.96±3.78, p<0.001) was determined to be significantly higher than in the P-GDM and NP-DM groups (4.8±0.52 vs. 2.21±0.71, p<0.001). DISCUSSION: The fact that the importance of PLAC8 level and TAC in the diagnosis and follow-up of GDM in pregnancy is demonstrated for the first time in this study shows that it is unique.

Enhanced biomimetic catalysis via self-cascade photocatalytic hydrogen peroxide production over modified carbon nitride nanozymes for total antioxidant capacity evaluation.

The peroxidase mimics usually requires the addition of exogenous hydrogen peroxide (H2O2), which greatly hinder their practical applications. Herein, through rational co-modification of multiple elements (potassium (K), chlorine (Cl) and iodine (I)), the modified carbon nitride nanomaterials (KCl/KI-CN) could serve as efficient bifunctional catalysts. The multiple elements doping and the incorporation of cyano groups (CN) are deemed to enhance their photocatalytic and peroxidase-like activity, respectively. Based on the photocatalytic function, H2O2 can be produced continuously and steadily via two-electron oxygen reduction over modified carbon nitride under visible light irradiation. Subsequently, the KCl/KI-CN could catalyze the chromogenic substrate by the in-situ produced H2O2. Taking advantage of the bifunctional properties of modified carbon nitride, we for the first time demonstrate a self-cascade catalytic process and apply successfully for the ascorbic acid (AA) detection and versatile total antioxidant capacity (TAC) evaluation. This paper not only prepares an efficiently bifunctional catalyst but also provides a new self-cascade photocatalytic H2O2 production strategy for the peroxidase-like application.

E-cadherin and TAC in GCF accurately discriminate periodontal health and disease.

OBJECTIVE: To investigate the accuracy of gingival crevicular fluid (GCF) E-cadherin and total antioxidant capacity (TAC) to discriminate periodontal health from disease. SUBJECTS AND METHODS: GCF samples were collected from participants with periodontal health (control), gingivitis, and periodontitis (n = 25 each group). The latter group was further subdivided according to stage (S) and grade. Periodontal parameters were recorded then levels of biomarkers were assayed using ELISA and antioxidant status by use of the Total Antioxidant Capacity Assay for E-cadherin and TAC, respectively. RESULTS: All periodontal parameters were significantly higher in periodontally diseased groups than controls. The GCF E-cadherin significantly increased in gingivitis and periodontitis (S2 to S4) cases as compared to controls. Level of this protein in GCF samples from periodontitis S3 was significantly higher than in gingivitis and S2 groups. The GCF-TAC level was significantly higher in controls than in periodontally diseased groups. No significant differences were observed in the levels of these proteins between grade B and C periodontitis. Both molecules could discriminate periodontal health from gingivitis and periodontitis stages and differentiating periodontitis S3 from gingivitis and other periodontitis stages. CONCLUSIONS: Levels of TAC and unbounded E-cadherin in GCF samples exhibited promising diagnostic abilities to differentiate periodontal health and disease.

The effect of mother's age on the neonatal cord serum's oxidative stress index and maternal and neonatal outcomes: a case control study.

BACKGROUND: One of the main challenges of many societies in reducing and ageing of the population is marriage at an advanced age in women and decrease of producing offspring due to the concern of increasing the probability of maternal and neonatal outcomes. The mother's oxidative stress conditions during pregnancy affect mothers and their baby's health. Aging is one of the increasing factors of oxidants in the body. Aim of this study is the compartion total antioxidant capacity (TAC), total oxidants status (TOS), oxidative stress index (OSI) values, and maternal and neonatal outcomes in three groups of mothers with different age ranges from 20 to 29, 30 to 34, and 35 to 45 years old. METHODS: 164 pregnant women were grouped according to age into three groups: 25 to 30 (group I), 30 to 35 (group II), and 35 to 45 years old (group III). The umbilical cord blood samples were taken to the assay TAC, TOS, and OSI (TOS/TAC). The Kolmogorov-Smirnov test was employed to assess the normal distribution of countinus variables. The one-way ANOVA and Kruskal-Wallis test were used to compare anthropometric and biochemical factors between groups. RESULTS: TAC levels decreased non-significantly (438.2 ± 102; 431.7 ± 99.8; and 428.2 ± 100.26 for groups I, II, and III respectively, P value = 0.99), TOS levels increased significantly (23.93 ± 11.7; 25.4 ± 12.3; and 28.2 ± 12.7 for groups I, II, and III respectively, P value = 0.034), and OSI increased non-significantly with increasing maternal age (0.055 ± 0.044; 0.091 ± 0.031; 0.069 ± 0.005, for groups I, II, and III respectively, P value = 0.14). Increasing age did not significantly affects the maternal and infant birth outcomes. CONCLUTION: The results showed that the increasing the age of the mother up to 45 doesn't have a significant effects on the value of OSI and the maternal and infant outcomes.

Nickel doping of ferrous disulfide nanocubes exhibits enhanced oxidase-like activity for In vitro detection of total antioxidant capacity.

The development of nanomaterials that mimic oxidase-like activities has recently attracted an increasing amount of attention. Obtaining highly active and cost-effective oxidase mimics has posed a significant challenge in this area of research. In this study, we successfully synthesized nickel-doped ferrous disulfide nanocubes (Ni-FeS2) via a facile one-step method. Characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that Ni was predominantly distributed within the surface layer of the Ni-FeS2 nanocubes. The incorporation of nickel in density functional theory (DFT) calculations effectively reduced the d-band center of Fe, resulting in weakened adsorption to intermediates and thereby enhancing its catalytic efficiency. Moreover, we developed a novel approach based on Ni-FeS2 (the Ni-FeS2 method) for detecting reducing substances, which exhibited good sensitivity toward ascorbic acid (AA), glutathione (GSH), and cysteine (Cys). Remarkably, the established Ni-FeS2 method was successfully employed for in vitro assessment of total antioxidant capacity (TAC) in cellular and organ samples, thereby enabling discrimination between normal, senescent, and malignant cells as well as distinguishing among healthy liver tissue, cancerous liver tissue, and metastatic organs.

Non-Thyroidal Illness in Chronic Renal Failure: Triiodothyronine Levels and Modulation of Extra-Cellular Superoxide Dismutase (ec-SOD).

Oxidative stress (OS) is implicated in several chronic diseases. Extra-cellular superoxide dismutase (ec-SOD) catalyses the dismutation of superoxide anions with a protective role in endothelial cells. In chronic kidney disease (CKD), OS and thyroid dysfunction (low fT3 syndrome) are frequently present, but their relationship has not yet been investigated. This cohort study evaluated ec-SOD activity in CKD patients during haemodialysis, divided into "acute haemodialytic patients" (AH, 1-3 months of treatment) and "chronic haemodialytic patients" (CH, treated for a longer period). We also evaluated plasmatic total antioxidant capacity (TAC) and its relationships with thyroid hormones. Two basal samples ("basal 1", obtained 3 days after the last dialysis; and "basal 2", obtained 2 days after the last dialysis) were collected. On the same day of basal 2, a sample was collected 5 and 10 min after the standard heparin dose and at the end of the procedure. The ec-SOD values were significantly higher in CH vs. AH in all determinations. Moreover, the same patients had lower TAC values. When the CH patients were divided into two subgroups according to fT3 levels (normal or low), we found significantly lower ec-SOD values in the group with low fT3 in the basal, 5, and 10 min samples. A significant correlation was also observed between fT3 and ec-SOD in the basal 1 samples. These data, confirming OS and low fT3 syndrome in patients with CKD, suggest that low fT3 concentrations can influence ec-SOD activity and could therefore potentially contribute to endothelial oxidative damage in these patients.

Differences in change of post-operative antioxidant levels between laser-assisted lenticule extraction and femtosecond laser in situ keratomileusis.

To evaluate the change of total antioxidant capacity (TAC) and ascorbic acid (AA) between femtosecond laser in situ keratomileusis (FS-LASIK) and laser-assisted lenticule extraction (LALEX). A prospective non-randomized study was conducted, and 33 and 75 eyes that had undergone FS-LASIK or LALEX surgeries were enrolled, respectively. The tear films near corneal incisions were collected, and the concentrations of TAC and AA were determined. The generalized linear mixed model was adopted to calculate the adjusted odds ratio (aOR) with 95% confidence interval (CI) of TAC and AA between the two groups. The AA reduction was significant 1 month after the LALEX and FS-LASIK procedures (both p < 0.05), and the decrement in AA level was significantly larger in the FS-LASIK group compared to the LALEX group (p = 0.0002). In the subgroup analysis, the LALEX group demonstrated a lower decrement in TAC level in the individuals with dry eye disease (DED) than the FS-LASIK group (p = 0.0424), and the LALEX group demonstrated a significantly lower AA decrement in the participants with high myopia (p = 0.0165) and DED (p = 0.0043). The LALEX surgery causes lesser AA decrement compared to FS-LASIK surgery especially for the patients with DED.

Impact of a 50bp insertion/deletion polymorphism of the superoxide dismutase-1 on oxidative stress status and risk of keratoconus.

Keratoconus (KC) is characterized by the predominant primary ectatic disease, affecting the cornea, necessitating corneal transplants in some cases. While some loci associated with KC risk have been identified, the understanding of the disease remains limited. Superoxide dismutase (SOD) enzymes play a crucial role in countering the reactive oxygen species and providing protection against oxidative stress (OS). Accordingly, the objective of this study was to investigate a potential association of a 50 nucleotide base pairs (bp) insertion/deletion (I/D) within the SOD1 promoter, and the located 1684 bp upstream of the SOD1 ATG, with KC in the Iranian population. Additionally, an assessment was conducted on SOD activity and the total antioxidant capacity (TAC), as determined by the ferric reducing-antioxidant power assay, along with malondialdehyde (MDA) levels. In this case-control study, genomic DNA was extracted from the blood cells of KC (n = 402) and healthy (n = 331) individuals. The genotype of this gene was determined using the PCR technique. Furthermore, the amount of SOD enzyme activity and the MDA and TAC levels were measured in the serum of the study groups. The (I/I) genotype was present in 84.23%, the (I/D) genotype in 15.06%, and the (D/D) genotype in 0.69% of both groups. A statistically significant relationship was seen between different genotypes and TAC, MDA, and SOD1 activity indices (P < 0.05). Individuals with the D/D genotype exhibited a decrease in total antioxidant capacity, an increase in the amount of MDA, and a decrease in SOD1 enzyme activity (P < 0.05). Moreover, the logistic regression analysis of KC development indicated that elevated levels of MDA increased the risk of KC incidence in the patient group compared to the healthy group, while a higher activity of SOD1 and greater values of TAC decreased the KC risk. The removal of the 50 bp fragment reduced SOD1 activity and elevated OS levels, thereby impacting the oxidant-antioxidant balance. This could potentially play a significant role in individuals afflicted by KC.

Neutral pH photoenzymatic activity of Au-doped g-C3N4 nanosheet for colorimetric detection of total antioxidant capacity in food samples.

Total antioxidant capacity (TAC) is vital for food quality evaluation. The emergence of various nanozymes with TMB as substrate offered a new avenue for TAC detection due to simple operation and fast response, but a long-standing challenge is its low activity at physiological pH, which may account for the discrepancy between the measured TAC and the actual antioxidant capacity in vivo. Herein, Au doping was explored to break the pH limitation of g-C3N4 nanosheets (CNNS) photozyme. The catalytic activities of Au@CNNS at pH 4.0 and 7.4 were 14.9- and 6.2-fold higher than that of CNNS at pH 4. The neutral pH photozymatic activity (photosensitized oxidation of TMB, oxidase mimic) of Au@CNNS was explored for sensitivity TAC detection (LOD: 1.0 µM TE), which featured more convenient operations and higher sensitivity over the DPPH assay. The proposed Au@CNNS-based photozymatic colorimetric method was explored for accurate detection of TAC in drinks and juices.

Difunctional AuNPs@PVP with oxidase-like activity for SERRS detection of total antioxidant capacity.

Assessing the total antioxidant capacity (TAC) of foods plays a significant role in dietary guidance and disease risk reduction. Therefore, building a simple, rapid, and sensitive sensing method for detecting TAC possesses broad application prospects. Herein, we constructed a novel nanozyme catalyzed‒surface-enhanced Raman resonance scattering (SERRS) sensing strategy for analysis of TAC based on polyvinylpyrrolidone coated gold nanoparticles (AuNPs@PVP) that was synthesized by one step reduction method. AuNPs@PVP not only served as the SERRS substrate but also possessed high oxidase activity which can catalyze 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by generating hydroxyl radicals (•OH) and superoxide anion free radical (•O2-). According to the inhibiting effect of antioxidants, ascorbic acid (AA) was selected as the representative for TAC detection. The linear range and limit of detection (LOD) were determined to be 10-8‒10-5 M and 0.6 nM, respectively. More importantly, the proposed nanozyme catalyzed‒SERRS strategy has been successfully applied to the detection of TAC in fruit juices, demonstrating promising potential in the field of food supervision and healthcare applications.