Determination Of Total Antioxidant Capacity Research Articles

Nanoencapsulation of quinoa oil enhanced the antioxidant potential and inhibited digestive enzymes

Quinoa oil is rich in unsaturated fatty acids and vitamin E, but its instability limits its application in food, pharmaceutical, and cosmetic products. Nanoencapsulation emerges as a promising strategy to promote water dispersibility, preserve and enhance functional properties, and increase the bioavailability of bioactive compounds. This study encapsulated quinoa oil through O/W emulsification, using porcine gelatin (OG) and isolated whey protein (OWG) as encapsulating agents. The particles were characterized by different physical and chemical methods and evaluated in vitro for cytotoxicity using Chinese hamster ovary (CHO) cells, human hepatocarcinoma cells (HepG2) and epithelial cells, and bioactive potential through the determination of Total Antioxidant Capacity (CAT) (acidic and neutral media) and iron chelation, and inhibition of digestive enzymes (α-amylase and amyloglucosidase). OG and OWG particles presented smooth surfaces, with an average size between 161 ± 7 and 264 ± 6 nm, with a polydispersity index of 0.11 ± 0.03 and 0.130 ± 0.04, encapsulation efficiency of 74 ± 1.47 % and 83 ± 2.92 %, and water dispersibility >70 %, respectively. Free and nanoencapsulated quinoa oil did not show cytotoxic effects (cell viability >70 %). Nanoencapsulation promoted the enhancement of the antioxidant activity of quinoa oil in the range of 50–63 % in a neutral medium and 96–153 % in an acidic medium than free oil (p < 0.05). OG and OWG also enhanced the inhibition of the enzymes α-amylase (by 5–7 %) and amyloglucosidase (6–9 times more) than free oil (p < 0.05). The results showed that nanoencapsulation increased the potential for quinoa oil application, enabling the development of innovative products.

Heavy atom-induced quenching of fluorescent organosilicon nanoparticles for iodide sensing and total antioxidant capacity assessment.

We present a novel approach for iodide sensing based on the heavy-atom effect to quench the green fluorescent emission of organosilicon nanoparticles (OSiNPs). The fluorescence of OSiNPs was significantly quenched (up to 97.4% quenching efficiency) in the presence of iodide ions (I-) through oxidation by hydrogen peroxide. Therefore, OSiNPs can serve as a fluorescent probe to detect I- with high selectivity and sensitivity. The highly selective response is attributed to the hydrophilic surface enabling good dispersion in aqueous solutions and the lipophilic core allowing the generated liposoluble I2 to approach and quench the fluorescence of OSiNPs. The linear working range for I- was from 0 to 50 μM, with a detection limit of 0.1 μM. We successfully applied this nanosensor to determine iodine content in edible salt. Furthermore, the fluorescent OSiNPs can be utilized for the determination of total antioxidant capacity (TAC). Antioxidants reduce I2 to I-, and the extent of quenching by the remaining I2 on the OSiNPs indicates the TAC level. The responses to ascorbic acid, pyrogallic acid, and glutathione were investigated, and the detection limit for ascorbic acid was as low as 0.03 μM. It was applied to the determination of TAC in ascorbic acid tablets and fruit juices, indicating the potential application of the OSiNP-based I2 sensing technique in the field of food analysis.

Direct and Sensitive Electrochemical Determination of Total Antioxidant Capacity in Foods Using Nanochannel-Based Enrichment of Redox Probes.

Simple and sensitive determination of total antioxidant capacity (TAC) in food samples is highly desirable. In this work, an electrochemical platform was established based on a silica nanochannel film (SNF)-modified electrode, facilitating fast and highly sensitive analysis of TAC in colored food samples. SNF was grown on low-cost and readily available tin indium oxide (ITO) electrode. Fe3+-phenanthroline complex-Fe(III)(phen)3 was applied as the probe, and underwent chemical reduction to form Fe2+-phenanthroline complex-Fe(II)(phen)3 in the presence of antioxidants. Utilizing an oxidative voltage of +1 V, chronoamperometry was employed to measure the current generated by the electrochemical oxidation of Fe(II)(phen)3, allowing for the assessment of antioxidants. As the negatively charged SNF displayed remarkable enrichment towards positively charged Fe(II)(phen)3, the sensitivity of detection can be significantly improved. When Trolox was employed as the standard antioxidant, the electrochemical sensor demonstrated a linear detection range from 0.01 μM to 1 μM and from 1 μM to 1000 μM, with a limit of detection (LOD) of 3.9 nM. The detection performance is better that that of the conventional colorimetric method with a linear de range from 1 μM to 40 μM. Owing to the anti-interfering ability of nanochannels, direct determination of TAC in colored samples including coffee, tea, and edible oils was realized.

Development of silver nanoparticle-chitosan composite film for determination of total antioxidant capacity of some fruit juices and plant extracts

In this study, a silver nanoparticle-chitosan (AgNPCh) composite film was developed for the determination of antioxidant capacity of polyphenolic compounds. The optimum conditions of solid nanosensor based on chitosan-based polymeric membranes containing AgNPs such as content of the composite film, pH and incubation time were idendified. The sensor measurement is based on the fact that the addition of polyphenols to the sample solution increases the absorption of Ag(0) NPs, which exhibit a characteristic plasmon absorption band at a wavelength of 423 nm and the developed method exhibits a linear variation versus the concentrations standard polyphenolic compounds. The method was applied to the apple, peach, cherry, grape and pomegranate juices and rosemary, marjoram and sage plant extracts. This sensor may be an alternative to conventional spectroscopic methods to design portable, low-cost, simple and easy-to-use field analyses without the need for special equipment for the determination of antioxidant capacity of polyphenolic compounds.

Conductive polymer-based modified electrode for total antioxidant capacity determination

A poly(3,4-ethylenedioxythiophene)-modified glassy carbon electrode (PEDOTvx/GCE) was prepared by electropolymerization at different scan rates (v) from a monomer EDOT solution by co-doping with an organic dopant (sodium dodecyl sulphate, SDS) and an inorganic compound (LiClO4). The PEDOTv10/GCE modified electrode, which exhibited the highest surface area, was investigated by cyclic voltammetry (CV) at different scan rates or pHs of electrolyte solution, and by differential pulse voltammetry (DPV). The electrochemical and electroanalytical parameters were expressed using caffeic acid, a reference substance. The new modified electrode was used to estimate the antioxidant activity (AA) in different varieties of wines (white, rose, and red). For all types of wines, a good correlation between AA results obtained by electrochemical and spectrophotometrically FRAP assay was obtained.

Ultrathin porous PdCu metallenezymes as oxidase mimics for colorimetric analysis.

Ultrathin porous and highly curved two-dimensional PdCu alloy metalleneare shown to be highly efficient oxidase mimics. Serving as intrinsic oxidase mimic, the ultrathin porous structure of the PdCu metallenezymes could effectively utilize all the Pd atoms of the metallenezymes during catalytic reactions. By using the oxidation capability of 3,3'5,5'-tetramethylbenzidine as distinctive chromogenic substrate, the PdCu metallenezymes was used as oxidase-like mimics for determination of total antioxidant capacity (TAC) of vitamin C containing real products including fresh orange juice, commercial beverages, Vitamin C tablets and dermo-cosmetic products. AAP was hydrolyzed using ALP to generate AA and the corresponding ALP activity was successfully detected in the0-100 U/L rangewith a lowest detection limit of 0.9 U/L. This study demonstrates the significant catalytic performance and oxidase-like activity of PdCu metallene nanozyme providing astrategy to develop a TAC assay for the assessment of antioxidant food quality as well as oxidative stress in skin and health care products.

The performance of hypochlorous acid modified Ag nanoparticle-based assay in the determination of total antioxidant capacity of Boswellia Serrata and Aronia

In this study, the SNPAC method was developed by using hypochlorous (ClO−) at pH 9.3. Polyvinylpyrrolidone (PVP) was used as a stabilizer. The existence of HOCl enables to formation stronger and more stable yellow emission which gives sensitivity. As a result, lower LOD and LOQ values were achieved by the AgNP–HOCl method. The obtaining lower values was attributed to the reoxidation of silver atoms with ClO− ions in the presence of PVP. The newly modified method was applied to the total antioxidant capacity (TAC) measurement of Boswellia Serrata, Aronia Melanocarpa tea, and juice. The results were compared with the results obtained by application of CUPRAC (Cupric ion Reducing Antioxidant Capacity) and FRAP (Ferric Reducing Antioxidant Power) assays. The TAC values of Boswellia Serrata, Aronia Melanocarpa tea, and juice were found as 6.18, 137.98, and 12.08 mmol TEAC/kg, respectively.

Highly efficient carbon supported Co–Ir nanozyme for the determination of total antioxidant capacity in foods

Nanozyme–based colorimetric assays have aroused extensive attention in biosensing due to quick response, low cost and simplicity. However, their practical applications are limited by the unsatisfactory stability and catalytic activity of nanozymes in complex detection environments. Herein, using the one–pot chemical vapor deposition method, we successfully prepare a highly efficient and stable carbon supported Co–Ir nanozyme (termed as Co–Ir/C nanozyme) for the determination of total antioxidant capacity (TAC) in food samples. The Co–Ir/C nanozyme shows excellent durability under extensive pH ranges, high temperature and high salt concentration due to the protection of carbon supporter. It can be recycled by simple magnetic separation, and its catalytic activity remains stable after long–term operation and storage. Taking full advantage of the superior peroxidase–like activity of Co–Ir/C nanozyme, it is used for colorimetric detection of ascorbic acid (or known as vitamin C), an important vitamin to adjust body's normal physiological function, with results showing higher sensitivity (detection limit of 0.27 μM) than most of the recently published works. Moreover, the determination of TAC in vitamin C tablets and fruits are further achieved, which are in good agreement with those of commercial colorimetric test kits. This study helps guide the rational preparation of versatile and highly stable nanozymes, and develops a robust TAC determination platform for future food quality monitoring.

Synergistic effect of silver nanoclusters and graphene oxide on visible light-driven oxidase-like activity: Construction of a sustainable nanozyme for total antioxidant capacity detection

The high cost and low reusability of natural enzymes greatly limit their application in biosensing. In this work, a sustainable nanozyme with light-driven oxidase-like activity was fabricated by integrating protein-capped silver nanoclusters (AgNCs) with graphene oxide (GO) through multiple non-covalent interactions. The prepared AgNCs/GO nanozyme could effectively catalyze the oxidation of various chromogenic substrates by activating dissolved O2 to reactive oxygen species under visible light irradiation. Moreover, the oxidase-like activity of AgNCs/GO could be well controlled by switching on and off the visible light source. Compared with natural peroxidase and most of other oxidase-mimicking nanozymes, AgNCs/GO possessed improved catalytic activity owing to the synergistic effect between AgNCs and GO. More importantly, AgNCs/GO showed outstanding stability against precipitation, pH (2.0–8.0), temperature (10–80 °C), and storage and could be reused at least 6 cycles without obvious loss in catalytic activity. On this basis, AgNCs/GO nanozyme was used to develop a colorimetric assay for the determination of total antioxidant capacity in human serum, which had the merits of high sensitivity, low cost, and good safety. This work holds a promising prospect in developing sustainable nanozymes for biosensing and clinical diagnosis.

Platinum-Nickel Nanoparticles with Enhanced Oxidase-like Activity for Total Antioxidant Capacity Bioassay.

While great progress in nanozyme-enabled analytical chemistry has been made, most current nanozyme-based biosensing platforms are based on peroxidase-like nanozymes. However, peroxidase-like nanozymes with multienzymatic activities can influence the detection sensitivity and accuracy, while the use of unstable hydrogen peroxide (H2O2) in a peroxidase-like catalytic reaction may result in the reproducibility challenge of sensing signals. We envision that constructing biosensing systems by using oxidase-like nanozymes can address these limitations. Herein, we reported that platinum-nickel nanoparticles (Pt-Ni NPs) with Pt-rich shells and Ni-rich cores possessed high oxidase-like catalytic efficiency, exhibiting a 2.18-fold higher maximal reaction velocity (vmax) than initial pure Pt NPs. The oxidase-like Pt-Ni NPs were applied to develop a colorimetric assay for the determination of total antioxidant capacity (TAC). The antioxidant levels of four bioactive small molecules, two antioxidant nanomaterials, and three cells were successfully measured. Our work not only provides new insights for preparing highly active oxidase-like nanozymes but also manifests their applications for TAC analysis.

Determination of total antioxidant capacity in patients with bladder cancer and its correlation with the results of pathology

Introduction: The accumulative consequence of all antioxidants that exist in the blood and body fluids is called total antioxidant capacity (TAOC). The major objective of this investigation is to determine the correlation between TAOC and pathology results in patients with non-muscle invasive bladder cancer (NMIBC). Materials and Methods: Based on the cross-sectional method, 35 patients with NMIBC and 35 controls (healthy characters) were studied. Biochemical and haematological variables were achieved and noted for each individual. Two blood samples (n = 5 ml) from each patient were obtained and analysed using Trolox standard immunoassay kit. Three groups were made according to the pathology results. The significance level was set at P ≤ 0.05. Results: There were not any significant differences (P = 0.12) between the mean age of patients and controls (60.7 vs. 59.5 years old) correspondingly. The mean value of TAOC (μmol/L) was significantly (P = 0.005) lower in patients when compared to controls (24.5 μmol/L vs. 94 μmol/L), respectively. In patients with NMIBC, sodium, magnesium, calcium, albumin, MCH, MCHC, VHCO3, haemoglobin, haematocrit and lymph were lower than the normal range. Blood sugar, creatinine, prothrombin time and white blood cells were higher than the normal range. The mean TAOC was as follows: papillary cell carcinoma (26.3 μmol/L), radical cystectomy (19 μmol/L) and high-grade bladder cancer (15.9 μmol/L). Conclusion: As deregulation of reactive oxygen species and antioxidant defence is two important components, in this study, there was high variation in TAOC according to pathology results. Combing individual TAOC and pathology results might be able to contribute to the advanced management of NMIBC. Further studies in this direction seem to be advantageous.

Carbon nanotubes regulated by oxidizing functional groups as peroxidase mimics for total antioxidant capacity determination

With the rapid development of nanozymes research, many carbon nanotubes (CNTs) and their derivatives have been reported as mimics of peroxidases. Despite this, their low peroxidase-like activity severely limited their ability to be applied. In this study, multi-walled CNTs were mixed with oxidizing agents to produce oxygenated carbon nanotubes (O-CNTs) that are rich in oxidizing functional groups. After the simple and green oxidation treatment, the CNTs' peroxidase-like activity was significantly improved. Intriguingly, the degree of oxidation affected the content of oxygen-containing functional groups, which gave O-CNTs different peroxidase-like functions. Since O-CNTs-7 (0.5 g CNTs treated with 3.5 g NaClO3) exhibited the best peroxidase-like activity, its steady-state dynamics and catalytic mechanism were analyzed. It is found that that hydroxyl radical may be the key oxygen active species in the reaction process. Furthermore, on the basis that ascorbic acid can inhibit the oxidation reaction of TMB, O-CNTs-7 was successfully applied to assay the total antioxidant capacity of fresh juice, beverages, and vitamin C tablets. It not only demonstrated how simple oxidation treatments can enhance the peroxidase-like activity of carbon-based nanozymes, but also demonstrated how these nanozymes can be applied to the design of biosensors with colorimetric analysis.

Antioxidant and Anti-Inflammatory Effects of Thyme (Thymus vulgaris L.) Essential Oils Prepared at Different Plant Phenophases on Pseudomonas aeruginosa LPS-Activated THP-1 Macrophages.

Thyme (Thymus vulgaris L.) essential oil (TEO) is widely used as an alternative therapy especially for infections of the upper respiratory tract. TEO possesses antiviral, antibacterial, and antifungal properties. The emerging antibiotic resistance of bacterial strains, including Pseudomonas aeruginosa, has prompted the urge to find alternative treatments. In the present study, we examined the anti-inflammatory and antioxidant effects of thymol, the main compound of TEO, and two TEOs prepared at the beginning and at the end of the flowering period that may make these oils promising candidates as complementary or alternative therapies against P. aeruginosa infections. The activity measurements of the antioxidant enzymes peroxidase (PX), catalase (CAT), and superoxide dismutase (SOD) as well as the determination of total antioxidant capacity of P. aeruginosa-activated THP-1 cells revealed that thymol and both TEOs increased CAT and SOD activity as well as the antioxidant capacity of the THP-1 cells. The measurements of the proinflammatory cytokine mRNA expression and secreted protein level of LPS-activated THP-1 cells showed that from the two TEOs, only TEO prepared at the beginning of the flowering period acted as a potent inhibitor of the synthesis of IL-6, IL-8, IL-β, and TNF-α. Our results suggest that not only thymol, but also the synergism or the antagonistic effects of the additional compounds of the essential oils are responsible for the anti-inflammatory activity of TEOs.

Coactivity of Mast Cells and Stem Cells on Angiogenesis and Antioxidants' Potentials at Inflammation, Proliferation, and Tissue Remodeling Phases of Wound.

Background Reactive oxygen species cause serious damage to the physiological function of tissues. Determination of total antioxidant capacity of skin tissue is one of the determinants of damaged tissue function. Mast cells (MCs) are one of the groups of cells that are invited to the site of injury. The healing process begins with the rapid release of various types of MCs' intermediate factors at the site of injury. Bone marrow mesenchymal stem cell (BMMSC) production and secretion have been shown to regenerate the skin. The aim of this research was to evaluate the wound-healing and antioxidant effects of BMMSCs per MCs. Methods Fifty-four albino Wistar male rats were divided into three groups: (1) nonsurgery, (2) surgery, and (3) surgery + BMMSCs. Groups 2 and 3 were operated with a 3 × 8 cm flap and in group 3, cell injections (7 × 10 9 cell injection at the time of surgery) were performed. After days 4, 7, and 15, percentage of the surviving tissue, histological characteristics, superoxide dismutase (SOD) activity, and amount of malondialdehyde (MDA) were measured in the groups. For results, Graph Pad Prism 8 software was used, and data were analyzed and compared by analysis of variance and Tukey test. Results BMMSCs' application decreased the amount of MDA, increased SOD activity and survival rate of the flaps, and improved the histological characteristics. Conclusion This study revealed the protective effects BMMSCs alongside MCs against oxidative stress on the survival of the flaps. However, for clinical use, more research is needed to determine its benefits.

A novel flow injection amperometric method for sensitive determination of total antioxidant capacity at cupric-neocuproine complex modified MWCNT glassy carbon electrode

A novel flow injection amperometric method for sensitive determination of total antioxidant capacity at cupric-neocuproine complex modified MWCNT glassy carbon electrode

Study of interaction between cationic surfactant (CTAB) and ascorbic acid/ascorbic acids derivatives by tensiometric and spectroscopic methods

The interactions between the cationic surfactant-cetyltrimethylammonium bromide (CTAB) and ascorbic acid and its derivatives in an aqueous media were investigated by using tensiometric and spectroscopic methods. On the basis of the surface tension isotherms, the values of the critical micelle concentration were determined also the adsorption parameters (the Gibbs free energy of adsorption, the surface excess at the saturated interface, the minimum molecular area in the adsorption layer at the saturated interface) were calculated using the Szyszkowski equation. The charged pseudophase model was adopted for define the Gibbs free energy of micellization. The infrared analysis (FTIR) contributed to the estimation of the possibility of the existence of interactions prevailing in the analyzed systems. The effect of CTAB-ascorbic acid/ascorbic acid derivatives interactions on their antioxidant activity was analyzed. Sets of ascorbic acid, 3-O-ethyl ascorbic acid and ascorbyl glucoside solutions differing in CTAB concentration were prepared. For the total antioxidant capacity determination, the Ferric Reducing Antioxidant Power (FRAP) assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH•) assay were used. The results obtained for CTAB - ascorbic acid/ascorbic acid derivatives systems were compared with the ones obtained for pure antioxidants.

Functionalized natural melanin nanoparticle mimics natural peroxidase for total antioxidant capacity determination

Natural peroxidase composed of protein and metallic cofactor suffers from deactivation in harsh environment. Learning from the natural structure of active site in peroxidase, in this work, natural melanin nanoparticles from cuttlefish were facilely functionalized with Fe3+ to construct peroxidase-like nanozyme, showing high stability and activity. In the presence of H2O2, Fe-melanin nanoparticles (Fe-NMPs) catalyzes the formation of·OH from H2O2, converting colorless 3,3,5,5-Tetramethylbenzidine (TMB) into blue oxidized TMB (ox-TMB). When the antioxidants were added into the system, ox-TMB will be reduced to colorless TMB, thus allowing the detection of total antioxidant capacity. The results show that the lowest detection limit of AA in Fe-NMPs is 12.61 μM and the detection range is 5–250 µm. The test results for AA were similar to the sample instructions for beverages and fruits, validating the feasibility of using Fe-NMPs for the actual total antioxidant capacity determination. This study provides a broader perspective for fabricating foodborne nanozyme for related applications.

Development and application of a high-throughput method for determination of total antioxidant capacity in suspensions of thiol antioxidants and nanodelivery platforms

Development and application of a high-throughput method for determination of total antioxidant capacity in suspensions of thiol antioxidants and nanodelivery platforms

Some Oxidative Stress Biomarkers among Patients with Prostate Cancer in Sokoto, North Western Nigeria

Globally, prostate cancer (PCa) is the most common malignancy and the second leading cause of cancer-related death in men. It is a significant contributor to the burden of diseases and affects over a million men. This study investigated the levels of malondialdehyde and plasma total antioxidant capacity among patients with prostate cancer in Sokoto. This case-control study was conducted among 28 confirmed prostate cancer patients attending the Urology clinics in Usmanu Danfodiyo University Teaching Hospital and Sokoto Specialist Hospital in North Western Nigeria. Twenty-eight age-matched healthy males were monitored as controls. Determination of Total Antioxidant Capacity (TAC) was determined using Ferric Reducing Antioxidant Power (FRAP) reagent while the Malondialdehyde in serum was determined as a conjugate with Thiobarbituric acid (TBA) acid. Data were collected using a semi-structured interviewer-administered questionnaire. Data were processed using SPSS version 20 and results were reported as Mean ± Standard deviation. The malondialdehyde level was significantly increased (p s evidence of redox imbalance. Subjects in monogamous relationships compared to polygamous, rural dwellers, farmers, individuals of Hausa ethnicity and subjects who reported no family history of the disease were more predisposed to prostate cancer. Further epidemiological studies are needed to determine the predisposing factors and the potential role of these markers in the diagnosis, prognosis and management of prostate cancer patients in Sokoto in particular and Nigeria in general. We recommend that Malondialdehyde and Total Antioxidant Capacity be routinely monitored among patients with prostate cancer patients in the area.

Estimation of Malondialdehyde Levels and Determination of Total Antioxidant Capacity in Serum and Saliva of Patient Affected with Sickle Cell Anemia

Introduction: Hemoglobinopathy is an inherited blood disorder in which an individual has an abnormal form of hemoglobin (variant) or decreased production of hemoglobin. The molecular pathogenesis of sickle cell disease explains the phenomenon well when there is adeficiency of oxygen carriage by the erythrocytes. The horrendous patterns of sickling/unsickling bring about the accumulation of lipid oxidation items and reactive oxygen speciesthat gather inside sickle-shaped red blood cells (RBCs). Aims: To estimate the malondialdehyde levels and determine the total antioxidant capacity in serum and saliva of sickle cell anemic patients. Methods and Material: Fiftysubjects aged 5–40 years were selected for the study. The subjects were divided into two groups. Blood and saliva samples were collected from both groups and were subjected to the phosphomolybdenum method. Absorbance was read spectrophotometrically at 695 nm. SPSS software was used, and statistical analysis was performed using Student's unpaired ttests. Results: Oxidative stress results f an imbalance between reactive oxygen species formation and enzymatic and non-enzymatic antioxidants. Conclusion: Salivary levels of total antioxidant capacity, malondialdehyde, and electrolytes make saliva a potential prognostic and diagnostic medium as there is an alteration of oxidative stress in sickle cell anemia (SCA).