Plasma antioxidant capacity in dogs with naturally occurring heart diseases

Perilla Seed Oil Enhances Cognitive Function and Mental Health in Healthy Elderly Japanese Individuals by Enhancing the Biological Antioxidant Potential

Oxidative stress plays an important role in age-associated cognitive decline. We recently reported that dietary intake of perilla seed oil (PO), a rich source of α-linolenic acid (LNA, C18:3, ω-3), helps in maintaining good mental health in adults. This study aimed to investigate the impacts of dietary PO intake on cognitive functions and mental health in healthy, elderly Japanese individuals. Seventy-five healthy volunteers aged 64–84 years were randomly divided into two groups: a control group and a PO-administered group. At baseline and at 12 months of intervention, cognitive function, mental health condition, fatty acid profile of the red blood cell plasma membranes (RBC-PM), and serum biochemical parameters were evaluated. Results showed that serum biological antioxidant potential and LNA levels in the RBC-PM at 12 months after the trial were significantly higher in the PO group compared to the control group. Further, both the cognitive function measures, as evaluated by the Frontal Assessment Battery test and the apathy scores, tended to be improved after 12 months in the PO group. Our results demonstrate that dietary PO intake enhances the antioxidant potential and prevents the age-related cognitive and mental decline in healthy elderly individuals by enhancing the blood LNA levels.

Serum Total Antioxidant Capacity and Enzymatic Defence of Dogs with Chronic Heart Failure and Atrial Fibrillation: A Preliminary Study

Introduction

Atrial fibrillation may potentially contribute to oxidative stress to a greater extent than chronic heart failure. The aim of the study was to compare the serum total antioxidant capacity and enzymatic antioxidant defence of dogs with chronic heart failure and atrial fibrillation with those of subjects with chronic heart failure and sinus rhythm and healthy controls.

Material and Methods

A total of 33 dogs were divided into three groups: dogs with chronic heart failure and atrial fibrillation (CHF + AF; n = 12), chronic heart failure and sinus rhythm (CHF + SR; n = 9), and healthy controls (n = 12). Serum total antioxidant capacity (TAC), serum CuZn-superoxide dismutase (SOD) and catalase, and plasma glutathione peroxidase (GPx) activity were determined.

Results

SOD activity and serum TAC were significantly lower in the study groups than in control animals. Catalase activity was significantly higher and plasma GPx activity significantly lower in dogs with CHF + AF compared with the CHF + SR and control dogs.

Conclusion

The results suggest that chronic heart failure in dogs significantly impacts the serum TAC and the antioxidant enzymatic defence, while plasma GPx activity is markedly lower in dogs with chronic heart failure and atrial fibrillation. The role of that imbalance needs further investigation.

Antioxidant defence and oxidative stress markers in cats with asymptomatic and symptomatic hypertrophic cardiomyopathy: a pilot study

Background

Hypertrophic cardiomyopathy is the most common cardiovascular cause of death in cats. Although the majority of cats remain asymptomatic, some may develop signs of chronic heart failure due to diastolic failure, arterial thromboembolism (ATE) or sudden cardiac death. Therefore, it is crucial to identify individuals that are in high risk of developing cardiac complications before the onset of life-threatening signs. Oxidative stress is the imbalance between the production and neutralisation of reactive oxygen species. Uncontrolled reactive oxygen species overproduction leads to protein and lipid peroxidation and damages the DNA strands, injuring the cells and leading to their death. The aim of the study was to evaluate the oxidative state in cats with hypertrophic cardiomyopathy and healthy controls.

Results

In total, 30 cats divided into three groups were assessed: animals with clinically evident hypertrophic cardiomyopathy (HCM; n = 8), subclinical hypertrophic cardiomyopathy (SUB-HCM; n = 11) and healthy controls (n = 11). The activity of superoxide dismutase was statistically significantly lower in animals with symptomatic and asymptomatic hypertrophic cardiomyopathy (HCM 0.99 ± 0.35 U/mL; SUB-HCM 1.39 ± 0.4 U/mL) compared to healthy cats (2.07 ± 0.76 U/mL, p < 0.01). The activity of catalase was significantly lower in the SUB-HCM group (19.4 ± 4.2 nmol/min/mL) compared to the HCM (23.6 ± 5.9 nmol/min/mL) and the control (30 ± 7.5 nmol/min/mL, p < 0.01) group. The activity of glutathione peroxidase was 4196 ± 353 nmol/min/mL in the HCM group, 4331 ± 451 nmol/min/mL in the SUB-HCM group and 4037 ± 341 nmol/min/mL in the control group and did not differ significantly between groups. The total antioxidant capacity of plasma was 602 ± 65.5 copper reducing equivalents (CRE) in the HCM group, 605.9 ± 39.9 CRE in the SUB-HCM group and 629 ± 77.5 CRE in the healthy cats and did not differ significantly between the groups.

Conclusions

Activities of superoxide dismutase and catalase differed in cats with hypertrophic cardiomyopathy, however the activity of the latter was only significantly lower in asymptomatic stage of the disease. The potentially beneficial effect of antioxidative substances on the disease progression in the asymptomatic and symptomatic stage of this disease should also be examined.

Changes in the blood redox balance during a simulated duathlon race and its relationship with athletic performance

The duathlon is an endurance multisport event that consists of sequential running, cycling, and further running. Imbalance in the redox homeostasis is associated with fatigued status and underperformance in various sports; however, there are no corresponding reports regarding the duathlon. The purpose of this study was to examine the changes in the blood redox balance during a simulated duathlon race and to determine the relationship between performance and the redox balance. Eight male triathletes participated in a simulated race, consisting of a 5-km run, 30 km cycling, and a further 5-km run, with 5 min rest between two parts to collect the blood samples. The serum levels of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) were measured and BAP/d-ROMs ratio and oxidative stress index (OSI) were calculated. The d-ROMs levels after the first Run were significantly increased compared with the levels observed before the race. Moreover, BAP levels increased significantly over the race. The BAP/d-ROMs ratio also gradually increased through the race, while the OSI was gradually decreased. In addition, a significant relationship was observed only between d-ROMs levels after the first Run and the first Run performance. These results suggest that the redox balance shifts toward reduction (antioxidation) during the duathlon race and increased oxidant potential levels are negatively correlated with performance in the early stages of the race.

Acute phase proteins and antioxidant responses in queens with pyometra

Acute phase proteins (APP) and biomarkers of oxidative status have proved to be clinically useful biomarkers of pyometra in different species. Despite pyometra is considered one of the most important feline reproductive diseases, information about the APP response and the oxidative status in queens with pyometra is lacking. This study aimed to evaluate the APP and the antioxidant responses at diagnosis and in the post-operative period in feline pyometra. Serum concentrations of serum amyloid A (SAA), haptoglobin (Hp), albumin, total serum thiols (Thiol) and total antioxidant capacity determined by different assays, including trolox equivalent antioxidant capacity (TEAC) assessed by two different methodologies (TEAC1 and TEAC2), ferric reducing ability of plasma (FRAP), and cupric reducing antioxidant capacity (CUPRAC), were determined in 23 queens with pyometra at diagnosis and in 13 healthy control queens submitted to elective ovariohysterectomy. The APP and antioxidants were also evaluated in 11 queens of the pyometra group at days two and 10 after surgery. At diagnosis, queens with pyometra had serum concentrations of SAA, Hp, and FRAP significantly higher (P < 0.001, P < 0.001 and P < 0.05, respectively), and of albumin, Thiol, CUPRAC and TEAC2 significantly lower (P < 0.001, P < 0.001, P < 0.001 and P < 0.01, respectively) than controls. Moreover, concentrations of APP and antioxidants were significantly different (with a tendency to return to physiologic levels) at day 10 after surgery than before surgery. Significant associations were found between APP and antioxidants. According to these results, an APP response and the development of oxidative stress were detected in queens with pyometra. In addition, APP and antioxidants tended to return to physiologic values after surgery in the queens that recovered from the disease. Therefore, our results suggest that APP and selected antioxidants, such as Thiol and CUPRAC, could be potentially useful biomarkers in diagnosis and assessment of the post-operative period in feline pyometra.

Memory Training Program Decreases the Circulating Level of Cortisol and Pro-inflammatory Cytokines in Healthy Older Adults

Aging cognitive decline has been associated to impairment of the Hypothalamus Pituitary Adrenals (HPA) axis activity and a higher level of the systemic inflammation. However, little is known about the molecules driving this process at peripheral level. In addition, the cognitive function is to some extent modifiable with Memory Training (MT) programs, even among older adults and beyond. The study aims to evaluate whether MT could contribute to ameliorate cognitive performance and modulate the HPA axis activity as well the low level inflammation in the aging phenotype. Whether the phosphatase WIP-1, a negative regulator for inflammation, is involved in this process was also investigated. We recruited 31 young adults (19-28, years of age) and 62 older adults aged over 60. Thirty-two older adults were submitted to 6-months of MT program (EG), and 28 older adults were no treated and used as Control Group (CG). Global cognitive functioning (MMSE score), verbal and visual memory, and attention were assessed at baseline (T0) and after 6-months (T1). At the same time, plasmatic level of Cortisol (C), IL-1β, IL-18, IL-6, and the expression of WIP-1 mRNA and protein in ex vivo Peripheral Blood Mononuclear Cells were analyzed in young adults at T0, as well in older adults at T0 and T1. Together, the results suggest that MT improves the global cognitive functionality, verbal and visual memory, as well as the level of attention. At the same time we observed a decrease of the plasmatic level of C, of the cytokines, and an increase of the expression of mRNA and protein of WIP-1. The analysis of correlations highlighted that the level of the mRNA of WIP-1 was positively associated to the MMSE score, and negatively to the C and cytokine levels. In conclusion, we purpose the MT as tool that could help support successful aging through the improving of memory, attention and global cognitive function performance. Furthermore, this approach could participate to maintain lower the peripheral levels of the C and pro-inflammatory cytokines. The WIP-1 as a potential new target of the pathophysiology of aging is theorized.

Serum antioxidant capacity and oxidative damage in clinical and subclinical canine ehrlichiosis

The objective of this study was to evaluate and compare the antioxidant response and the products of oxidative damage analysed by various assays in clinical and subclinical canine monocytic ehrlichiosis (CME). For this purpose, four assays to measure the total serum antioxidant capacity (TAC), such as the cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of plasma (FRAP), trolox equivalent antioxidant capacity (TEAC) using acidic medium (TEAC_A), and the TEAC using the horseradish peroxidase (TEAC_H) were used. In addition, the serum thiol concentrations were analysed. Reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), and ferrous oxidation-xylenol orange (FOX) were measured to determine the concentrations of free radical and the products of oxidative damage as result of the disease. All antioxidant markers were significantly lower in the dogs on clinical ehrlichiosis when compared with healthy dogs; however only the CUPRAC, FRAP and thiol were significantly lower in subclinical CME compared with healthy dogs. TBARS and FOX showed no significant differences between dogs with CME and healthy dogs; however, a significant increased ROS concentration was observed in dogs with clinical and subclinical CME when compared with healthy dogs. Results showed that in CME there is a state of oxidative stress with significant changes in markers of antioxidant defence and in concentrations of free radicals. However, the detection of these changes would depend of the assay used.

Plasma coenzyme Q10 concentration, antioxidant status, and serum N-terminal pro-brain natriuretic peptide concentration in dogs with various cardiovascular diseases and the effect of cardiac treatment on measured variables

OBJECTIVE To determine the plasma total antioxidant capacity, erythrocyte superoxide dismutase activity, whole blood glutathione peroxidase activity, and plasma coenzyme Q₁₀ (CoQ₁₀) concentration in dogs with various stages of cardiovascular diseases and in healthy dogs; assess the influence of cardiac treatment on the levels of antioxidant variables, plasma CoQ₁₀ concentration, and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, and determine any correlation between the disease severity (NT-proBNP concentration) and antioxidant variables or CoQ₁₀ concentration. ANIMALS 43 dogs with various types and stages of cardiovascular diseases (congenital and acquired) and 29 healthy dogs. PROCEDURES Blood samples were collected from all dogs for spectrophotometric assessment of antioxidant variables. Plasma CoQ₁₀ concentration was determined with a high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry method. Serum NT-proBNP concentration was measured with an ELISA. RESULTS Values for antioxidant variables did not differ among groups of dogs with cardiovascular diseases, regardless of disease stage or treatment. Plasma CoQ₁₀ concentration was significantly increased in treated dogs with congestive heart failure (CHF), compared with untreated patients. However, plasma CoQ₁₀ concentration did not differ among heart failure classes. A significant, negative correlation between serum NT-proBNP and plasma CoQ₁₀ concentrations was identified in treated CHF-affected dogs, suggesting that low plasma CoQ₁₀ concentration may be associated with increased severity of CHF. CONCLUSIONS AND CLINICAL RELEVANCE The antioxidant variables evaluated were not altered in dogs with CHF, regardless of cardiac disease stage or treatment. Further investigation into the possible effects of CoQ₁₀ supplementation in dogs with advanced stages of CHF is warranted.

Analytical validation of an automated assay for ferric-reducing ability of plasma in dog serum

We performed analytical validation of an automated ferric-reducing ability of plasma (FRAP) assay in the serum of dogs. Intra- and interassay precision, accuracy, detection limit, and effects of hemolysis and lipemia were evaluated. Intra- and interassay coefficients of variation were <1% and <13%, respectively. The assay showed a high correlation with a FRAP assay described previously, and results were linear when serial sample dilutions were tested. The detection limit was lower than the values observed in sera from healthy dogs; decreased serum FRAP was found in dogs with leishmaniosis. Lipemia and hemolysis caused a significant increase in the results of the assay.

Plasma Total Antioxidant Capacity and Activities of Blood Glutathione Peroxidase and Superoxide Dismutase Determined in Healthy Dogs by Using Commercially Available Kits

Data on the values of selected blood antioxidant parameters, i.e. total antioxidant capacity, glutathione peroxidase, and superoxide dismutase in healthy dogs, are lacking. There are no published accepted standard reference methods for their determination. The aim of this study was to determine the values of plasma total antioxidant capacity and the activities of whole blood glutathione peroxidase and erythrocyte superoxide dismutase in 30 healthy client-owned dogs (19 females, 11 males). The effect of age and sex on the measured antioxidant parameters was also investigated. Antioxidant parameters were determined with an automated biochemical analyser, using the commercially available Randox kits. No significant difference in age, weight, and antioxidant parameters was determined between females and males. A significant positive effect of age (p = 0.002, r2 = 0.284) on superoxide dismutase activity was confirmed. There was no effect of sex on any of the antioxidant parameters measured. However, we observed a tendency of the effect of sex (p = 0.063, r2 = 0.118), as well as age (p = 0.073, r2 = 0.111), on the activity of glutathione peroxidase. Our results are in part comparable with the results of other studies in which the same types of methods and samples were used to determine antioxidant parameters. In conclusion, the sex and age of dogs should be taken into consideration when planning a study on antioxidant status parameters.

Validation of three automated assays for total antioxidant capacity determination in canine serum samples

We performed analytical validation of 3 automated assays of the total antioxidant capacity (TAC) in canine serum and evaluated their use in dogs with inflammatory bowel disease. The assays were based on the generation of a 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical cation (ABTS•⁺) in aqueous media, which produces a blue-green color. The antioxidants present in the sample remove the chromogen in proportion to their concentrations. The assays differed mainly in the way in which this radical was produced. All 3 assays produced acceptable results in the analytical validation. However, only 2 of the assays were capable of detecting significantly different TAC values in healthy and diseased animals.

Changes in serum biomarkers of oxidative stress after treatment for canine leishmaniosis in sick dogs

Canine leishmaniosis (CanL) is a zoonotic disease being endemic in several parts of the world. In this study we investigated the behavior of a panel of biomarkers of oxidative stress in 12 sick dogs naturally infected by CanL before and at days 30 and 180 of a successful therapy with a standard treatment. The assays total oxidant status (TOS), trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), cupric reducing antioxidant capacity (CUPRAC), serum thiol and paraoxonase 1 (PON1) were included in the panel. In addition, correlations between biomarkers of oxidative stress and inflammation (C-reactive protein (CRP) and ferritin) and urinary protein:creatinine ratio (UPC) were calculated. Serum CUPRAC, thiol and PON1 significantly increased after treatment and were negatively correlated with CRP, ferritin and UPC. This study demonstrates that biomarkers of oxidative stress, not previously studied in leishmaniosis such as CUPRAC and thiol, can change after a successful treatment for CanL showing a potential for use in monitoring the treatment of this disease.

Spectrophotometric assays for total antioxidant capacity (TAC) in dog serum: an update

The aim of this review is to study the main spectrophotometric methods used to evaluate total antioxidant capacity (TAC) in serum samples of dogs. Total antioxidant capacity (TAC) is an analyte frequently used to assess the antioxidant status of biological samples and can evaluate the antioxidant response against the free radicals produced in a given disease. Trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), and cupric reducing antioxidant capacity (CUPRAC) are different assays described to determine TAC of a sample. This review explains the basis of each assay and their application in the determination of TAC in dogs, and also provides selected information about reports in humans for comparative purposes. It is concluded that, ideally, various different assays integrated in a panel should be used for TAC evaluation, since depending on the assay performed TAC results can be markedly different.

Analytical performances of d-ROMs test and BAP test in canine plasma. Definition of the normal range in healthy Labrador dogs

An high level of ROS (Reactive Oxygen Species), due to an increased production of oxidant species and/or a decreased efficacy of antioxidant system, can lead to oxidative stress, an emerging health risk factor involved in the aging and in many diseases, including inflammatory, infectious and degenerative disorders, either in humans or in animals. In the last years some assays panels have been developed to globally evaluate the oxidative balance by means of the concomitant assessment of ROS production and antioxidant system capability. In this report, the validation trials of d-ROMs (Reactive Oxygen Metabolites- derived compounds) and BAP (Biological Antioxidant Potential) tests in canine specie are described and also the specific referral ranges are calculated in a Labrador population. The results of linearity, precision and accuracy trials show that both tests exhibit good to excellent analytical performances. The possibility of measuring oxidative stress in vivo with simple, cheap and accurate tests, d-ROMs test and BAP test, provides for the veterinarians a very suitable tool to monitor oxidative stress and to correctly choice of eventual antioxidant supplementations in diseases proven related to oxidative stress in animals and particularly in dogs. Further studies will be useful to confirm this possibility.