Measurement Of Total Antioxidant Capacity Research Articles

Antidepressant potential of β-caryophyllene in maternal separation-induced depression-like in mice: A focus on oxidative stress and nitrite levels

BackgroundMajor depressive disorder is prevalent across different societies, affecting individuals from various cultural and socioeconomic backgrounds. Dysregulation of the nitric oxide (NO) pathway and increased oxidative stress have been implicated as contributing factors. PurposeThis study aimed to explore the antidepressant potential of β-caryophyllene in a mouse model subjected to maternal separation stress, with a focus on its effects on oxidative stress and nitrite levels. Study DesignThe research involved 40 male mice, which were divided into five groups. MethodsThe control group received 1 ml/kg of normal saline, while the maternal separation (MS) groups were administered normal saline in conjunction with β-caryophyllene at doses of 10, 20, and 50 mg/kg. Various behavioral tests, including the open field test (OFT), forced swimming test (FST), and splash test, were employed to assess the impact of β-caryophyllene. Additionally, measurements of total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels in the hippocampus were conducted. ResultsThe findings demonstrated that maternal separation stress induced depressive-like behaviors in mice, as evidenced by increased immobility time in the FST and decreased grooming behavior in the splash test. Furthermore, MS was associated with elevated MDA and nitrite levels and reduced TAC in the hippocampus. However, administration of β-caryophyllene increased grooming activity in the splash test and decreased immobility time in the FST. Additionally, β-caryophyllene exhibited antioxidant properties, lowering MDA and nitrite levels while enhancing TAC in the hippocampus. ConclusionThese results suggest that β-caryophyllene may possess antidepressant-like effects in mice subjected to maternal separation, likely due to its antioxidant actions in the hippocampus.

Relation of Total Antioxidant Capacity to Clinical Severity of COVID-19 Infection in Paediatric Patients

Abstract Objectives The pathogenesis of COVID-19 infection is still not well clarified. In this regard oxidative stress and its relation to disease severity is one of the topics that need to be investigated. Aim This study was carried out to investigate the relationship between the oxidant stress and antioxidant system represented by total antioxidant capacity and clinical severity of COVID19 infection in pediatric age group. Methods The current cross-sectional study included 45 patients with COVID 19 PCR-proven infection admitted at the Children’s Hospital, Faculty of Medicine, Ain Shams University compared to 45 healthy age and sex matched control group. Detailed medical history, thorough examination and recording of all infection related laboratory parameters were done for each enrolled case. Measurement of total antioxidant capacity (TAC) in the serum of all studied patients and controls was done by ELISA. Results TAC levels were considerably lower in pediatric patients (median 24u/l, IQR 9-37u/l) compared to healthy individuals (median 90u/l, IQR 77-100u/l, p < 0.001) and the levels were statistically lower in severe cases compared to those with mild disease (p = 0.008). In this regard, 100% of controls showed normal TAC while only 31.1% from cases exhibited normal TAC levels and 68.9% of cases had low TAC levels. There was strong statistical significance between PICU admission and low TAC levels (p = 0.035). Additionally, the TAC showed negative correlation with the initial CRP of patients (r= -0.433, p = 0.003). There was also a significant inverse correlation between TAC and time needed for viral clearance (r=- 0.418, p = 0.004) as well as a significant positive correlation between body mass index z-score and TAC levels (r = 0.423, p value 0.004). Conclusion Total antioxidant capacity could serve as a novel prognostic marker of COVID -19 infection severity in pediatric patients.

Colorimetric Sensing of Antioxidant Capacity via Auric Acid Reduction Coupled to ABTS Oxidation.

In this study, a simple and sensitive colorimetric assay has been developed for total antioxidant capacity measurement. The assay is based on the absorption measurement of the bluish-green oxidized product (ABTS·+) formed as a result of the oxidation reaction of the chromogenic reagent ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) with gold(III). However, in the presence of antioxidants, the ABTS oxidation process is effectively suppressed due to the reduction of gold(III) ions to the zerovalent state forming gold nanoparticles (AuNPs). Relatively lighter colors and a significant decrease in absorbance are observed depending on the total antioxidant capacity. Taking advantage of this situation, qualitative and quantitative total antioxidant capacity (TAC) measurements, with the naked eye and UV-vis spectroscopy, respectively, could be successfully performed. The assay is named "auric reducing antioxidant capacity" (AuRAC) because the gold(III) ion-reducing ability of antioxidants is measured. The AuRAC assay was applied to dietary polyphenols, vitamin C, thiol-type antioxidants, and their synthetic mixtures. Trolox equivalent antioxidant capacity (TEAC) values obtained with the AuRAC assay were found to be compatible with those of the reference CUPRAC (cupric reducing antioxidant capacity) assay. The AuRAC assay was validated through linearity, additivity, precision, and recovery, demonstrating that the assay is reliable and robust. Compared to the simple TAC assays in the literature based on AuNP formation with subsequent surface plasmon resonance (SPR) absorbance measurement, this indirect assay has a smoother linear range starting from lower antioxidant concentrations. This method displays much higher molar absorption coefficients for antioxidant compounds than other conventional single electron transfer (SET) assays because 3-e- reduction of trivalent gold (i.e., Au(III) → Au(0)) produces three chromophore cation radicals (ABTS·+) of the assay reagent. The sensor has been successfully applied to complex matrices, such as tea infusions and pharmaceutical samples. The AuRAC assay stands out with its high molar absorptivity connected to enhanced sensitivity as well as its potential to convert into a paper-based colorimetric sensor.

Evaluating oxidative stress biomarkers in oncology nurses exposed to antineoplastic drugs: A cross-sectional study

PurposeAntineoplastic drugs (ADs) are widely used in cancer treatment. Nurses in chemotherapy centers are exposed to these drugs during preparation. They can affect healthy cells, leading to teratogenic and mutagenic effects, as well as oxidative stress. This study aimed to evaluate oxidative stress biomarkers in the nurses exposed to these drugs. MethodThis study was conducted on 30 nurses exposed to ADs and 30 nurses with no exposure to these drugs as non-exposed group. Oxidative stress biomarkers were measured in the blood serum samples of both groups, including malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), total antioxidant capacity (TAC), and blood thiol groups. ResultsConsidering the possibility of confounding effect of nutritional supplement consumption, the effect of this factor was adjusted in the analysis. A significant difference was observed for CAT, SOD, thiol, and TAC biomarkers between two groups (P < 0.05). However, the difference in MDA and GPx biomarkers between two groups was not statistically significant. ConclusionsThe findings of the present study showed that supplement consumption has a significant effect on the biomarker of total antioxidant capacity. Thus, total antioxidant capacity measurement is advised as the best biomarker for tracking oxidative status in nurses exposed to ADs due to its capacity to measure all antioxidants in the body, except the thiol group, and its lower cost when compared to other biomarkers. Furthermore, it can be claimed that the consumption of nutritional supplements has a greater effect on the non-enzymatic biomarkers of oxidative stress than on enzymatic antioxidant system.

Umbelliprenin via increase in the MECP2 and attenuation of oxidative stress mitigates the autistic-like behaviors in mouse model of maternal separation stress.

Introduction: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition. Maternal separation (MS) stress is an early-life stress factor associated with behaviors resembling Autism. Both MECP2 and oxidative stress are implicated in the pathophysiology of Autism. Umbelliprenin (UMB) is a coumarin compound with various pharmacological properties. Our study aimed to investigate the potential effects of UMB in mitigating autistic-like behaviors in a mouse model subjected to MS stress, focusing on probable alterations in MECP2 gene expression in the hippocampus. Methods: MS paradigm was performed, and mice were treated with saline or UMB. Behavioral tests consisting of the three-chamber test (evaluating social interaction), shuttle box (assessing passive avoidance memory), elevated plus-maze (measuring anxiety-like behaviors), and marble-burying test (evaluating repetitive behaviors) were conducted. Gene expression of MECP2 and measurements of total antioxidant capacity (TAC), nitrite level, and malondialdehyde (MDA) level were assessed in the hippocampus. Results: The findings demonstrated that MS-induced behaviors resembling Autism, accompanied by decreased MECP2 gene expression, elevated nitrite, MDA levels, and reduced TAC in the hippocampus. UMB mitigated these autistic-like behaviors induced by MS and attenuated the adverse effects of MS on oxidative stress and MECP2 gene expression in the hippocampus. Conclusion: In conclusion, UMB likely attenuated autistic-like behaviors caused by MS stress, probably, through the reduction of oxidative stress and an increase in MECP2 gene expression.

Antioxidant Effects of Methanolic Extract of Quercus infectoria as a Supplement against Oxidative Stress Induced by Sub-acute Exposure to Arsenic; An in vivo Study

Background: Exposure to arsenic through drinking water is a global health problem that causes multisystem toxicity, mainly by inducing oxidative stress and impairing cellular energy. Objective: We aimed to evaluate the effect of Quercus infectoria gall extract (Qi) against oxidative stress induced by sub acute exposure to arsenic. Methods: The plant galls were extracted with methanol and were used for the determination of total phenolic content using Folin-Cio calteu reagent. Male Wistar rats were randomly divided into 8 groups of 6 animals and treated for 30 days. Negative and positive control groups received, respectively, normal saline and sodium arsenite (5.5 mg/kg) by gavage. Treatment groups received three doses of Qi (200, 400, and 600 mg/kg/day) by intraperitoneal injection 2 h. after oral administration of normal saline or sodium arsenite (5.5 mg/kg) (As-Qi). After 30 days, all animals were anesthetized with ketamine/xylasine and 2 mL of blood was taken for measurement of total antioxidant capacity (TAC) using ferric reducing antioxidant power (FRAP), lipid peroxidation (measurement of malondialdehyde (MDA)) and protein carbonylation of plasma. Results: Total phenolic content of the plant was determined to be 5.78 ± 0.23 mg gallic acid equivalent/g dried extract. The results of pharmacological studies indicated that in arsenic treated animals, a significant decrease in TAC, increase in lipid peroxidation and protein carbonylation happens compared to control group. Co-administration of Qi (600 mg/kg) with arsenic significantly increased TAC compared with arsenic group (0.245 ± 0.007 versus 0.183 ± 0.027 for arsenic) (p &lt; 0.05), while the serum MDA level (1.880 ± 0.499 versus 2.795 ± 0.112 for arsenic) and protein carbonylation were decreased in this group compared with arsenic treated animals (0.128 ± 0.007 versus 0.159 ± 0.009 for arsenic) (p &lt;0.01). In non-treated arsenic animals (NTAS), all three doses of Qi improved oxidative stress markers. Conclusion: Arsenic disrupt cellular antioxidant defense through overproduction of reactive oxygen species (ROS) and the Qi galls are able to revert some of these oxidant activities of arsenic. Previous studies have reported antioxidants in the plant and the present work can conclude that antioxidant effect of Qi is useful against happened oxidative stress in arsenic treated animals.

Study The Lung-Protective Effects of Riboflavin and Cyanocobalamin Against Lung Toxicity-Induced by Cyclophosphamide in Rats

Cyclophosphamide (CP) is a cytotoxic alkylating agent it's used associated with different side effects including lung toxicity. Vitamin B2 and vitamin B12 have lung-protective effects. This study was designed to evaluate lung-protective effects of both vitamins against lung toxicity induced by cyclophosphamide. seventy healthy adult albino male and female rats divided into seven groups each group containing ten rats were used in the present study and treated for seven days. On day eight rats were sacrificed and serum was obtained for glutathione and total antioxidant capacity measurement and lung extracted for immunohistochemical study; both vitamins significantly (P&lt;0.05) increased glutathione and total antioxidant capacity in comparison with group two and improve immunohistochemical changes in comparison with the group treated by cyclophosphamide only

The Relationship between Oxidative Status and Radioiodine Treatment Qualification among Papillary Thyroid Cancer Patients.

Total oxidative status (TOS), total antioxidant capacity (TAC), tumor protein 53 (p53), nuclear factor kappa B (NF-κB), forkhead box protein O1 (FOXO), and sirtuin 1 (SIRT1) play crucial roles in oxidative homeostasis and the progression of papillary thyroid cancer (PTC), as previously demonstrated in the literature. Therefore, profiling these markers among PTC patients may be useful in determining their eligibility for radioiodine (RAI) treatment. Since treatment indications are based on multiple and dynamic recommendations, additional criteria for adjuvant RAI therapy are still needed. In our study, we evaluated the TOS, TAC, and serum concentrations of p53, NF-κB, FOXO, and SIRT1 to analyze the relationship between oxidative status and qualification for RAI treatment. For the purpose of this study, we enrolled 60 patients with PTC allocated for RAI treatment as the study group and 25 very low-risk PTC patients not allocated for RAI treatment as a reference group. The serum TOS and SIRT1 concentrations were significantly higher in the study group compared to the reference group (both p < 0.001), whereas the TAC and p53, NK-κB, and FOXO concentrations were significantly lower (all p < 0.05). We also demonstrated the diagnostic utility of TAC (AUC = 0.987), FOXO (AUC = 0.648), TOS (AUC = 0.664), SIRT1 (AUC = 0.709), p53 (AUC = 0.664), and NF-κB (AUC = 0.651) measurements as indications for RAI treatment based on American Thyroid Association recommendations. Our study revealed that oxidative status-related markers may become additional criteria for RAI treatment in PTC patients.

Semiconducting Polymer Nanoparticles-Manganese Based Chemiluminescent Platform for Determining Total Antioxidant Capacity in Diabetic Mice.

The total antioxidant capacity (TAC) is a key indicator of the body's resistance to oxidative stress injury in diabetic patients. The measurement of TAC is important for effectively evaluating the redox state to prevent and control the occurrence of diabetes complications. However, there is a lack of a simple, convenient, and reliable method to detect the total antioxidant capacity in diabetes. Herein, we design a novel chemiluminescent platform based on semiconducting polymer nanoparticles-manganese (SPNs-MnVII) to detect the total antioxidant capacity of urine in diabetic mice. We synthesize semiconducting polymer nanoparticles with four different structures and discover the ability of MnVII to produce singlet oxygen (1O2) that is employed to excite thiophene-based SPNs (PFODBT) to emit near-infrared chemiluminescence. Notably, the chemiluminescent intensity has a good linear relationship with the concentration of MnVII (detection limit: 2.8 μM). Because antioxidants (e.g., glutathione or ascorbic acid) can react with MnVII, such a chemiluminescent tool of SPNs (PFODBT)-MnVII can detect the glutathione or ascorbic acid with a larger responsive range. Furthermore, the total antioxidant capacity of urine from mice is evaluated via SPNs (PFODBT)-MnVII, and there are statistically significant differences between diabetic and healthy mice. Thus, this new chemiluminescent platform of SPNs (PFODBT)-MnVII is convenient, efficient, and sensitive, which is promising for monitoring antioxidant therapy of diabetes.

Nanozyme-enabled sensing strategies for determining the total antioxidant capacity of food samples

Gold doped copper hexacyanoferrate (Au@Cu-HCF) nanozyme-based colorimetric sensing strategies were exploited to measure total antioxidant capacity (TAC) of some plant-derived food samples. The new developed Au@Cu-HCF nanozyme replaces natural enzymes to catalyze a redox reaction, and antioxidants can compete with substrates in the interaction with OH, leading to an antioxidant concentration-dependent color change. Depending on the Au@Cu-HCF-based ABTS colorimetric strategy, a smartphone-based sensor was devised using smartphone’s camera as a “smart detector”. The proposed sensor was successfully utilized to measure the TAC of lotus root (4.61 mM), citrus juice (6.35 mM), and lemon beverage (1.00 mM) with standard deviations of 0.16 mM, 0.16 mM, and 0.06 mM, respectively. These results all agree well with the commercial kit (4.55 mM for lotus root, 6.27 mM for citrus juice and 1.11 mM for lemon beverage), indicating this sensor has good practical applications in the TAC measurement of food samples.

A Smartphone-Based Chemosensor to Evaluate Antioxidants in Agri-Food Matrices by In Situ AuNP Formation.

In recent years, there has been a continuously growing interest in antioxidants by both customers and food industry. The beneficial health effects of antioxidants led to their widespread use in fortified functional foods, as dietary supplements and as preservatives. A variety of analytical methods are available to evaluate the total antioxidant capacity (TAC) of food extracts and beverages. However, most of them are expensive, time-consuming, and require laboratory instrumentation. Therefore, simple, cheap, and fast portable sensors for point-of-need measurement of antioxidants in food samples are needed. Here, we describe a smartphone-based chemosensor for on-site assessment of TAC of aqueous matrices, relying on the antioxidant-induced formation of gold nanoparticles. The reaction takes place in ready-to-use analytical cartridges containing an hydrogel reaction medium preloaded with Au(III) and is monitored by using the smartphone’s CMOS camera. An analytical device including an LED-based lighting system was developed to ensure uniform and reproducible illumination of the analytical cartridge. The chemosensor permitted rapid TAC measurements of aqueous samples, including teas, herbal infusions, beverages, and extra virgin olive oil extracts, providing results that correlated with those of the reference methods for TAC assessment, e.g., oxygen radical absorbance capacity (ORAC).

Kapasitas Total Antioksidan Ekstrak Metanol Biji Kakao (Theobroma cacao. L) Dengan Metode Spektrofotometri Uv-Vis

Antioxidant compounds is one of compounds are needed by the body to reduce free radicals. The ability of antioxidants to reduce free radicals is called antioxidant capacity. The purpose of this study was to provide information on the total antioxidant capacity of the methanol extract of cocoa beans with the DPPH (2,2-Diphenyl-1-Picrylhydrazyl) method using spectrophotometer uv-vis. The crude extract obtained was extracted using methanol solvent by maceration method. The results of the phytochemical screening test on the methanol extract of cocoa beans showed the presence of flavonoids and tannins. The total antioxidant capacity test of cocoa bean extract used the standard equivalent value of gallic acid which has been shown to have a strong antioxidant ability to reduce DPPH free radicals at a wavelength of 517 nm. The results of the measurement of total antioxidant capacity in the variation of treatment, namely sun-dried cocoa beans and oven cocoa beans were 27.730 and 42.454 mg/mL GAEAC. Based on the results of this study, it was found that the ethanol extract of oven cocoa beans had the greatest total antioxidant capacity, namely 42.454 mg/mL GAEAC.

Definition of the total antioxidant capacity and vitamin D levels in professional athletes who play football in Giresunspor

Objective: A sufficient amount of vitamin D levels; while protein synthesis, muscle strength, jumping height, speed, exercise capacity, and physical performance increase; stress fractures cause a decrease in the rates of injury, fall, muscle relaxation, muscle pain, and weakness. Serum 25-hydroxy vitamin D (25(OH)D) levels are very important for maintaining and improving optimal performance in football players. The formation of free radicals and oxidative stress during exercise is known to affect optimal performance and recovery period after exercise. The aim of the study was to determine serum 25(OH)D and total antioxidant capacity of professional football players. Methods: The study group consists of 56 professional football players (26 players from the first team, 30 players from the academy team) playing in Giresunspor Football Club. The control group consisted of 30 volunteer healthy male subjects. The SPSS 21 package program was used to calculate and interpret the survey data applied face to face to the study group. In addition, the body composition of the players was determined by the InBody 230 device which works with the principle of bioelectric impedance analysis (BIA). Serum 25(OH)D levels of the football players were compared with reference values (≥30 ng / mL). Serum 25(OH)D levels were determined by immunoassay method on the Roche Cobas e411 branded test analyzer. Serum total antioxidant capacity was compared with 30 healthy volunteers in the control group. Total antioxidant capacity measurements were studied with the ready-to-use kit. The method previously described for the kit has been applied to Architect c8000 clinical chemistry autoanalyzer.Results: As a result of the study, mean serum 25(OH)D levels of the players were determined as 31.68 ng / mL. The mean serum antioxidant capacity of the participants was found to be 1.97 mmol Trolox Equiv/L. The mean serum antioxidant capacity of the control group was 1.94 mmol Trolox Equiv/L.Conclusion: Mean serum 25(OH)D levels of the players were within the reference range (≥30 ng/mL).There is an increase in metabolic rate during training, which leads to a rapid release of free radicals. Despite this thought, there was no significant difference in serum total antioxidant capacity between the study and control groups.

Development of a green synthesized silver nanoparticle-based antioxidant capacity method using carob extract

The measurement of total antioxidant capacity (TAC) indicating the cooperative action of all antioxidants in a complex sample is an important analytical challenge. A novel green silver nanoparticle-based antioxidant capacity (GSNP-AC) method using carob extract was designed for TAC measurement. Green synthesis of nanoparticles has various advantages such as environmentally friendliness, reliability, sustainability and fast production. In the presence of silver seeds formed with carob extract, Ag+ is reduced to spherical silver nanoparticles (SNPs) with antioxidants, resulting in enlarged particles with a symmetric surface plasmon resonance (SPR) absorption band at 434 nm. The SPR of SNPs allowed quantification of antioxidants (i.e., increase in SPR absorbance being correlated to antioxidant concentration), and the GSNP-AC method gave a linear response over a wide concentration range of antioxidants. The molar absorptivity and LOD for trolox were 11700 L mol−1 cm−1 and 0.31 µM, respectively. The proposed method was validated in terms of concentration-dependent linear response, additivity of absorbances, precision and accuracy. The results obtained with the proposed method for standard antioxidants, synthetic mixtures and real sample extracts were correlated with those of the traditional CUPRAC method. This green synthesized silver nanoparticle-based TAC method showed simple, rapid, cost-effective, and eco-friendly superiorities over similar other nanoparticle-based assays.

Gene Expression, Immunological and Oxidative Indices of Aflatoxicated Broiler Chickens Supplemented with Alpha-Lipoic Acid

This work aimed to investigate experimentally the effect of lipoic acid as super-antioxidant on the balance between immune and antioxidant status of birds fed aflatoxicated diet as well as histological alterations of immune organs including spleen, thymus, bursa of fabricious and liver. One hundred and twenty-one-day old chicks, fed basal diet till 8th day of age then divided into 4 groups (30 birds/group), each group subdivided into 3 replicates (10 birds/replicate). Group 1: aflatoxicated chickens (125 µg/kg diet). Group 2: aflatoxicated lipoic treated (300 mg/kg diet), Group 3: lipoic treated. Group 4: non-treated (control). The blood samples were collected at 14th day post aflatoxicosis and at the end of experiment, then the serum was separated for HI and different biochemical tests. At the end of experiment, four birds from each group were sacrificed and immune organs (thymus, spleen, bursa of fabricious and liver) were collected for histopathology. Livers were also collected for measurement of apoptotic gene expression Caspase (Cystinyle Aspartate Protease), MDA (Malano-Di-Aldehyde) and TAC (Total Antioxidant Capacity). The results showed the addition of lipoic acid into the aflatoxicated broiler ration improved the antibody titer against Newcastle Disease Virus NDV, hepatic apoptotic gene expression, TAC, and the level of different biochemical parameters (protein profile, lipid profile, bilirubin, total calcium and alkaline phosphatase). It was alleviated the toxic effect of aflatoxin on the histological structure of liver, and immune organs. Therefore, lipoic acid could be implicated as a dependent approach in the control of aflatoxicosis in broiler chickens. Keywords: Aflatoxin, broiler chickens, histopathology, immunity, lipoic acid.

A comparison of clinical, hepatic and immunological effects of three different parenteral lipid emulsions in children

Objectives: Lipid emulsions are not only considered as a source of energy, but also as a regulatory substance for key metabolic functions in different diseases. The aim of the present study was to compare clinical, biochemical and immunological effects of olive oil, soybean oil and omega-3 fatty acid which are administrated to the children in parenteral nutrition products. Methods: Patients who were admitted to pediatric intensive care unit and had parenteral nutrition for 7 days are included in the study. The patients were randomised into 3 groups based on the admission order, including 10 patients in each group. The children in Group O were fed by a lipid emulsion based on olive oil; the children in Group S were fed by a soybean based lipid emulsion and the children in group F were fed by soybean based lipid emulsion with omega-3 based solution. Analysis were made on the first and the seventh day. Laboratory parameters as well as hemogram, biochemical analysis, immunoglobulins, lymphocyte subgroup panel and cytokine levels were evaluated just before parenteral nutrition (day 0, basal value) and at day 7 of parenteral nutrition. Clinical monitoring parameters included body weight, and circumference of the mid-upper arm. Results: Thirty children were enrolled into the study. Total cholesterol and triglyceride levels significantly increased in Group O whereas triglyceride level significantly increased in Group S. Hemogram, liver function tests, cytokine levels, lymphocyte sub-group distribution, immunoglobulin levels and total antioxidant capacity measurements were not different. Conclusions: Three lipid emulsions which are used for parenteral nutrition treatment in intensive care unit patients are clinically and biochemically useful.

Relative Deficiency in Albumin Methionine Content is Associated With Decreased Antioxidant Capacity of Equine Plasma

Relative to other species, horses seem particularly susceptible to oxidative stress. Plasma albumin plays an important role in preventing oxidative damage, in part due to its methionine (MET) content. Equine albumin is highly unusual in that it contains no MET residues. Whether or not this causes deficient antioxidant capacity in equine plasma relative to that of other species has not yet been explored. The objective of this study was to compare the redox status of equine (no MET) to that of bovine (moderate amount of MET) plasma. Plasma was collected from healthy, nonpregnant Quarter Horse mares (n = 10) and adult, healthy, nonpregnant, dried Holstein cows (n = 15). Measures of total antioxidant capacity and oxidative stress were assessed for each plasma sample using multiple commercially available assays: total antioxidant capacity, thiol detection, thiobarbituric acid reactive substances, and advanced oxidation protein products. Plasma from horses had significantly (P < .05) lower thiol content and thiobarbituric and reactive substances and higher advanced oxidation protein products than plasma from cattle. A difference in total antioxidant capacity was not observed; however, our study was underpowered to establish a meaningful comparison. Based on these findings, the lack of MET in equine albumin appears to translate to a lower antioxidant capacity of equine plasma. Our findings are consistent with previous reports in other species that identify MET as having an important role in the antioxidant capacity of albumin. Our results also highlight the complex system of antioxidant defenses in plasma that counteract the harmful effects of oxidants.

Determinación de la capacidad antioxidante total de alimentos y plasma humano por fotoquimioluminiscencia: Correlación con ensayos fluorométricos (ORAC) y espectrofotométricos (FRAP)

La determinación de la capacidad antioxidante es útil para valorar la calidad de un alimento, la cantidad de antioxidantes presentes en un sistema, o la biodisponibilidad de compuestos antioxidantes en el cuerpo humano. Los métodos disponibles realizan la determinación del efecto potencial de las sustancias antioxidantes, presentes en los alimentos y en el organismo humano, contra las reacciones de oxidación. El objetivo fue comparar los resultados de la detección de la capacidad antioxidante total (CAT) en muestras de alimentos y plasma humano, mediante la quimioluminiscencia por fotosensibilización (PCL), en contraste con métodos que cuantifican la capacidad de absorbancia del radical de oxígeno (ORAC) y el poder antioxidante reductor del hierro (FRAP). Se obtuvieron extractos hidrosolubles y liposolubles de salvado de arroz estabilizado (SAE) y de harina de Ulva clathrata (HUC). El plasma se obtuvo de muestras de sangre humana (PHU). Se procesaron tres muestras en cada caso. Los resultados se analizaron mediante análisis de varianza de una vía y correlación de Pearson, p &lt; 0.05. La CAT determinada mediante PCL fue: SAE 246.37 ± 5.37, HUC 21.05 ± 0.41 y PHU 90.59 ± 1.17 equivalentes Trolox (ET) μmol /100 g ó 100 mL, p &lt; 0.05; ORAC: SAE 5015.62 ± 12.83, HUC 852.37 ± 3.45 y PHU 2563.31 ± 39.47 ET μmol /100 g ó 100 mL, p &lt; 0.05. FRAP: SAE 519.37 ± 0.04, HUC 52.78 ± 0.01 y PHU 90.26 ± 0.01 equivalentes Fe2+ (EFe2+) µmol /100 g ó 100 mL. Se observaron correlaciones entre PCL y ORAC, r = 0.99; y la PCL y FRAP, r = 0.94, ambas estadísticamente significativas (p &lt; 0.05). La PCL mostró ser un método confiable y alternativo para cuantificar la CAT, que se puede aplicar en estudios de alimentos y de intervenciones en salud.

Dietary total antioxidant capacity (TAC), general and central obesity indices and serum lipids among adults: An updated systematic review and meta-analysis.

Background: In the present meta-analysis, we aimed to summarize the relationship between dietary total antioxidant capacity (TAC), general and central obesity indices and lipid profile in adult population. Methods: The electronic databases of Web of Sciences, PubMed, Scopus and Cochrane library were searched for relevant studies from inception to October 2019. The effect size was indicated as weighted mean difference (WMD) and 95% confidence intervals (CI) by using random effects model. The I2 index and Cochran's Q-test were used for evaluating heterogeneity. Results: From 2,469 studies identified, thirty-four studies (nineteen cross-sectional studies, thirteen cohort studies, two case-control studies) were included in the meta-analysis. According to our results, higher categories of TAC were associated with significantly lower serum triglyceride concentartions (TG; WMD: -7.58; CI: -11.42, -3.75; P<0.001) and waist circumference (WC; WMD: -1.17; 95% CI: -1.47, -0.87; P<0.001); while no significant change in body mass index (BMI; WMD: -0.17; 95% CI: -0.35, 0.01; P=0.12), high density lipoprotein cholesterol (HDL-C; WMD: 0.61; 95% CI:-0.16, 1.40; P=0.12), low density lipoprotein cholesterol (LDL-C; WMD: 1.34; 95% CI: -0.61, 3.30; P=0.17) and total cholesterol (TC; WMD: 1.19; 95% CI: -1.46, 3.855; P=0.37) was reported. Conclusion: Higher dietary TAC was related to reduced prevalence of central obesity, reduced WC and TG concentrations in the current meta-analysis. Moreover, subgroup analysis showed that TAC measurement index, geographical area, dietary assessment tool, health status and gender were potential sources of heterogeneity.

Total antioxidant capacity assessment by a development of an antioxidant assay based on green synthesized MnO2nanosheets

The determination of total antioxidant capacity (TAC) as an integration activity of several antioxidants in samples is a significant parameter in the analysis of biological or food matrices. In this study, MnO2 nanosheets were for the first time employed for TAC measurements. Gum Arabic, a highly branched polysaccharide, was both the reducing and templating agent for the synthesis of MnO2 nanosheets. MnO2 nanosheets are a potent oxidizing agent to oxidize tetramethylbenzidine (TMB) in physiological pH to a blue product. Due to the redox reaction between MnO2 nanosheets and antioxidants, the color intensity of the MnO2 mixture in the presence of antioxidants decreased and the absorbance difference of the resulting suspension was measured at 652 nm. The trolox equivalent antioxidant capacity (TEAC) values of several antioxidant compounds were also measured using the new assay and conventional standard CUPRAC assay (r = 0.989). Under an optimal condition, linear concentration range, detection limit, precision and accuracy of the proposed assay were evaluated for the detection of various antioxidant compounds and represented the reliability and robustness of this assay. This assay was operated in physiological pH and could be applicable in the detection of TAC in the biological samples.