Topic:Antioxidants
Antioxidants in horses refer to a group of molecules that help protect cells from oxidative stress caused by reactive oxygen species (ROS). These compounds can be naturally occurring within the horse's body or obtained through diet. Antioxidants play a role in maintaining cellular integrity and supporting overall health by neutralizing free radicals. Common antioxidants relevant to equine health include vitamin E, vitamin C, and glutathione. Their presence and activity in the body are influenced by factors such as diet, exercise, and environmental conditions. This page compiles peer-reviewed research studies and scholarly articles that explore the sources, mechanisms, and potential impacts of antioxidants on equine physiology and well-being.
[Antioxidant properties of proteins after freezing-thawing]. Experimental data are presented which were obtained under comparative evaluation of influence of different freezing-thawing conditions on antioxidant properties of isolated proteins: human serum albumin, cytochrome c from the horse heart and glucose oxidase from Aspergillus niger. The observed protein antioxidant activity alterations are assumed to be a result of protein conformational changes. The character of freezing-thawing influence on the protein antioxidant activity depends on the molecular structure and cooling conditions.
DNA hypomethylation and oxidative stress-mediated increase in genomic instability in equine sarcoid-derived fibroblasts. It is widely accepted that equine sarcoid disease, the most common skin associated neoplasm in equids, is induced by bovine papillomavirus (BPV-1). Although BPV-1 DNA has been found in almost all examined sarcoids so far, its detailed impact on the horse's host cell metabolism is largely unknown. We used equine fibroblast cell lines originating from sarcoid biopsies to study BPV-1-associated changes on DNA methylation status and oxidative stress parameters. Sarcoid-derived fibroblasts manifested increased proliferation in vitro, transcriptional rDNA activity (NORs expression) and DNA hypometh...
Effect of potential therapeutic agents in reducing oxidative stress in pulmonary tissues of recurrent airway obstruction-affected and clinically healthy horses. To determine and compare the reactive oxygen and nitrogen species (ROS and RNS) in pulmonary tissues of horses affected with recurrent airway obstruction (RAO) and clinically healthy horses, and to evaluate the effectiveness of potential therapeutic agents in reducing ROS and RNS in the tissues of these horses. Objective: We hypothesised that RAO-affected horses would have high levels of reactive species and that the test agents would reduce them. The objectives were as follows: 1) to determine the level of ROS and RNS in pulmonary tissues (bronchial and arterial rings) of RAO-affected and cli...
Antioxidant effect of different vitamins on methemoglobin production: An in vitro study. Nitrite intoxication occurs frequently in ruminants and equines. The most common treatment of this disorder is administration of 1% methylene blue, although the use of some antioxidant agents e.g. vitamins and complementary treatment may also be useful. The aim of this study was to evaluate the in vitro antioxidative effects of some vitamins on methemoglobinemia induced by sodium nitrite. For this purpose the blood sample of a healthy dairy cattle was pre-incubated with three different concentrations (5, 10, 20 mmol L(-1)) of each vitamin (E, C, B1, A and a combination of vitamin E and vitamin...
Evidence of oxidative injury of the spinal cord in 2 horses with equine degenerative myeloencephalopathy. The cervical spinal cords of 2 horses with equine degenerative myeloencephalopathy (EDM) were evaluated for evidence of oxidative damage to the central nervous system (CNS) using immunohistochemical staining for 3-nitrotyrosine (3-NT) and 4-hydroxynonenol (4-HNE). Neurons of the CNS from horses with EDM had positive immunohistochemical staining, whereas control samples did not, thus supporting the theory that oxidative damage is a potential underlying factor in horses with EDM. In addition, serum vitamin E concentration was low in both EDM-affected horses, and vitamin E concentration was also ...
The influence of road transport on the activities of glutathione reductase, glutathione peroxidase, and glutathione-S-transferase in equine erythrocytes. Transport of horses may have significant impact on serum biochemical and hematologic analytes and resistance to infection. Objective: The aim of our study was to assess the influence of transport stress on selected enzymatic antioxidants in equine blood. Methods: The study was conducted on a group of 60 horses of different breeds and ranging in age from 4 to 10 years. Venous blood was collected immediately before loading horses onto trailers for 8 hours of transport (I), immediately after unloading them from the trailer (II), and after subsequent stall rest for 24 hours (III). Hemolysates of b...
Consequences of butylated hydroxytoluene in the freezing extender on post-thaw characteristics of stallion spermatozoa in vitro. Ejaculates from six pure Spanish stallions were split, and one subsample frozen in a commercial extender supplemented with the lipid soluble antioxidant butylated hydroxytoluene (BHT), while the other subsample served as control. After at least 4 weeks of storage, samples were thawed and post-thaw sperm quality analysed: sperm motility and kinematics using a CASA system, membrane and acrosome integrity and mitochondrial membrane potential using flow cytometry. The outcome of cryopreservation varied significantly among stallions. However, the supplementation with 1 mm BHT had no significant eff...
Oxidant-antioxidant imbalance in horses infected with equine infectious anaemia virus. This study assesses the impact of equine infectious anaemia virus (EIAV) infection on the oxidant/antioxidant equilibrium of horses. Blood samples from 96 Romanian horses aged 1-25 years, were divided into different groups according to their EIAV-infection status, age, and time post-seroconversion. The effect of infection on oxidative stress was estimated by measuring enzymatic antioxidants (superoxide dismutase [SOD], glutathione peroxidase [GPx] and catalase), non-enzymatic antioxidants (uric acid and carotenoids), and lipid peroxidation (malondialdehyde [MDA]). Infection modified the oxidan...
Training-induced modifications of circadian rhythmicity of peroxidative parameters in horses. The aim of this study was to evaluate the daily rhythms of peroxidative parameters in untrained and trained horses. Blood samples were collected every 4 h for a 48-h period for the determination of reactive oxygen metabolites test (d-ROMs), antioxidant barrier (Oxy-ads), thiol antioxidant barrier (SHp) and lipid peroxidation (LPO). Two-way anova showed a significant effect of time of day on all parameters studied, except on LPO. Higher values of Oxy-ads and SHp were observed in trained horses during both days of monitoring (p < 0.01). All studied parameters, except for LPO, showed rob...
Oral supplementation with superoxide dismutase in Standardbred trotters in training: a double-blind placebo-controlled study. Intense physical exercise produces an excess of reactive oxygen species which can disturb the antioxidant/oxidant balance of the horse in training. Several classes of antioxidant dietary compounds have been suggested to provide health benefits and there is evidence that consumption of these products leads to a reduction in the expression of various pro-inflammatory and/or oxidative stress biomarkers. The recent development of a new galenic system allows the oral delivery of the antioxidant enzyme: superoxide dismutase (SOD). This has been developed from a specific melon variety with a particul...
Oxidative stress and antioxidant status in intensely exercising horses administered nutraceutical extracts. Many nutraceuticals are used as equine supplements without their efficacy having been scientifically tested. Black tea, cranberries, orange peel and ginger are a few of those nutraceuticals that warrant further study. Objective: To test the effects of single doses of black tea, cranberry, orange peel and ginger extract on markers of oxidative stress and antioxidant status following exercise in horses. Methods: In Study 1, 9 mature, healthy but unfit Standardbred mares were administered 2 l of a control (water), orange peel extract (30 g extract) or decaffeinated black tea extract (28 g extract...
Modulatory activities of Agelanthus dodoneifolius (Loranthaceae) extracts on stimulated equine neutrophils and myeloperoxidase activity. Agelanthus dodoneifolius DC Danser (Loranthaceae) is used for the treatment of various diseases including asthma. The aqueous and hydroalcoholic extracts have been reported to have anti-inflammatory, spasmolytic and bronchorelaxant activities. The present study investigates the effects of the aqueous decoction and the diethyl ether, ethyl acetate and butanolic fractions of Agelanthus dodoneifolius DC Danser (Loranthaceae) on reactive oxygen species (ROS) production and myeloperoxidase (MPO) release by phorbol 12-myristate 13-acetate (PMA)-stimulated equine neutrophils and on purified equine MP...
Melatonin reduces lipid peroxidation and apoptotic-like changes in stallion spermatozoa. Lipid peroxidation (LPO) has been claimed as a major factor involved in stallion damage during storage or cryopreservation. Because melatonin is a well-known potent antioxidant, the aim of the present study was to investigate the effect of melatonin during in vitro incubation. Furthermore, we investigated the presence of specific melatonin receptors (MT1 and MT2) using specific polyclonal antibodies and western blotting. Stallion spermatozoa were incubated up to 3 hr at 37°C in the presence of different concentrations of melatonin (0, 50 pm, 100 pm, 200 pm, or 1 μm). At the beginning and at ...
Acute kidney injury mediated by oxidative stress in Egyptian horses with exertional rhabdomyolysis. The present study was carried out to evaluate the role of oxidative stress in the pathophysiologic process of acute renal failure associated with exertional rhabdomyolysis (ER) in Egyptian horses. ER was tentatively diagnosed in 31 Baladi horses based on case history, physical examination findings and confirmed by elevation of plasma creatine kinase (CK) and urine myoglobin concentrations. According to severity of the condition, the diseased horses were categorized into two main groups; the first group included 18 horses with minimal clinical signs and plasma CK <60 000 IU/L; whereas, the seco...
Disturbance of oxidant/antioxidant equilibrium in horses naturally infected with Trypanosoma evansi. Oxidant/antioxidant equilibrium disturbance has already been reported in trypanosome infections by several authors. The present study was aimed to explore the possible oxidant/antioxidant disturbance in surra of naturally infected horses before and after treatment. Fifteen naturally infected horses were chosen to analyse erythrocytic indices, platelet counts, lipid peroxides (LPO), nitric oxide (NO), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) while six healthy animals acted as control. There was a highly significant (P<0.001) reduction in red blood cell (RBC) c...
Effect of dietary antioxidant supplementation on fresh semen quality in stallion. In this study, the effect of dietary supplementation of organic selenium, vitamin E, and zinc on raw semen characteristics was evaluated. Ten stallions with normal fertility were divided into two groups: a control group (CG), in which standard diet was provided, and a treated group (TG), in which the standard diet was supplemented with 1500 mg of α-tocopherol acetate, 360 mg of zinc, and 2.5 mg of organic selenium on a daily basis. Semen parameters on fresh semen were evaluated three times in all stallions before antioxidant supplementation (T0) and 30 (T1), 60 (T2), and 90 (T3) d after suppl...
Effect of sod (superoxide dismutase) protein supplementation in semen extenders on motility, viability, acrosome status and ERK (extracellular signal-regulated kinase) protein phosphorylation of chilled stallion spermatozoa. New studies are underway to find new methods for supporting longer storage of cooled stallion semen. It is known that high concentrations of reactive oxygen species (ROS) cause sperm pathology. The metalloprotein superoxide dismutase (SOD) is responsible for H(2)O(2) and O(2) production, by dismutation of superoxide radicals. The aim of this study is to assess the quality of chilled stallion semen processed with extenders containing SOD at different concentrations as antioxidant additives. A total of 80 ejaculates collected from 5 standardbred stallions was divided into 5 aliquots treated as: ...
Redox status of equine seminal plasma reflects the pattern and magnitude of DNA damage in sperm cells. Antioxidant status of seminal plasma from 23 stallions was evaluated. We found a negative correlation between total antioxidant capacity (ABTS(•+) decolorization assay) and thiol content of seminal plasma, and sperm DNA damage (8-oxoG immunostaining, TUNEL reaction, comet assay). Low seminal redox status was the strongest correlated with 8-oxoG level which may indicate that seminal total antioxidant capacity influences mainly the formation of single strand DNA breaks in sperm cells. Since inter-individual differences in seminal antioxidant status were reported, we postulated that the redox s...
The influence of vitamin E on immune function and response to vaccination in older horses. Horses have an increased susceptibility to infection because of a decline in immune function with advancing age. Vitamin E has been found to play a key role in normal immune system function. The purpose of the study was to examine the effect of vitamin E supplementation on immune function and response to vaccination in older horses. Predominantly older horses (18.9 +/- 1.3 yr, range 7 to 26 yr; 523 +/- 38 kg of BW) were supplemented orally once daily for 16 wk with either all-rac-alpha-tocopheryl acetate (15 IU/kg of BW; n = 8) or a placebo (n = 8). One horse from each group was removed from t...
In vivo administration of acepromazine or promethazine to horse decreases the reactive oxygen species production response of subsequently isolated neutrophils to stimulation with phorbol myristate acetate. The previous experiments have shown that some phenothiazines have antioxidant and anti-inflammatory properties in vitro. In this study the inhibition of the production of reactive oxygen species (ROS) by neutrophils was studied in two groups of horses, which received a dose of 0.1 mg/kg of either acepromazine or promethazine intravenously. Blood samples were collected before (T0) and 0.5, 1, 3 and 5 h after drug administration. The chemiluminescence (CML) response of neutrophils was measured ex vivo in the presence of luminol for a period of 10 min and the maximum CML value (peak value) record...
Comparison of the antioxidant effects of synovial fluid from equine metacarpophalangeal joints with those of hyaluronic acid and chondroitin sulfate. To evaluate the antioxidant effects of synovial fluid (SF) pooled from metacarpophalangeal joints of healthy horses and horses with various pathological conditions, and to compare then with the antioxidant effects of hyaluronic acid (HA) and chondroitin sulfate (CS). Methods: SF from 1 metacarpophalangeal joint was obtained from 42 horses immediately after humane slaughter. Samples were classified into 3 groups on the basis of origin: healthy joints or joints with chronically damaged cartilage or vascularly congested synovial membranes as detected via macroscopic evaluation. Methods: Antioxida...
Rho kinase activation and ROS production contributes to the cooling enhanced contraction in cutaneous equine digital veins. A decrease in environmental temperature can directly affect the contractility of cutaneous vasculature, mediated in part by alpha(2)-adrenoceptors. Most of the cellular mechanisms underlying the cooling-enhanced contractility to alpha(2)-adrenoceptor agonists have been reported in cutaneous arteries but little information is available on cutaneous veins. To investigate the cellular mechanisms associated with the cooling-enhanced contraction to UK-14304 (alpha(2)-adrenoceptor agonist), isolated equine digital veins (EDVs) were studied at 30 degrees C and 22 degrees C. The effects of inhibitors ...
Antioxidant capacity and oxidative damage determination in synovial fluid of chronically damaged equine metacarpophalangeal joint. In order to determine oxidative stress in equine joints with degenerative processes, we analyzed synovial fluid (SF) antioxidant capacity and the concentration of oxidative damage biomarkers in healthy and chronically damaged metacarpophalangeal joints. SF samples were collected from joints of thirty 2-5 year-old crossbreed male equine, macroscopically classified at post mortem inspection and later histologically confirmed. The antioxidant capacity was determined measuring uric acid and the concentration of sulfhydryl groups and the total radical trapping antioxidant potential (TRAP). The oxid...
Metabolic and hematological profiles in mature horses supplemented with different selenium sources and doses. This study was conducted to determine the effects of dietary Se source and dose on metabolic and hematological profiles, and their relationships with oxidative status in horses. Twenty-five mature horses were blocked by BW and randomly allocated to 1 of 5 dietary treatments: negative control (CTRL: 0.085 mg of Se/kg of DM), 3 different dietary concentrations of organic Se provided by Se yeast (SY02, SY03, and SY04 containing 0.2, 0.3, and 0.4 mg of total Se/kg of DM, respectively), and 1 positive control provided by sodium selenite (SS03 containing 0.3 mg of total Se/kg of DM). Horses were fed...
Whole blood selenium concentrations in endurance horses. Exercise causes an increase in the production of reactive oxygen species, which can result in oxidant/antioxidant disequilibrium. Deficiency of antioxidants can further alter this balance in favor of pro-oxidation. Selenium (Se) is one of many antioxidant catalysts, as a component of the glutathione peroxidase enzymes. Soils and forages vary widely in Se concentration and a deficient diet can lead to sub-clinical or clinical deficiency in horses. Endurance horses are prone to oxidative stress during long periods of aerobic exercise and their performance could be affected by Se status. This stu...
alpha-Lipoic acid modulates thiol antioxidant defenses and attenuates exercise-induced oxidative stress in standardbred trotters. Several micronutrient supplementation strategies are used to cope with oxidative stress, although their benefits have recently been questioned. The aim of the present study was to examine the effects of DL-alpha-lipoic acid (LA) in response to acute exercise and during recovery in horses. Six standardbred trotters were tested on the treadmill before and after 5-week LA supplementation (25 mg/kg body weight/day). According to electron paramagnetic resonance measurements, strenuous aerobic exercise increased significantly free radical formation in the gluteus medius muscle, which was prevented b...
Effect of a tart cherry juice blend on exercise-induced muscle damage in horses. To evaluate whether administering a tart cherry juice blend (TCJB) prior to exercise would reduce skeletal and cardiac muscle damage by decreasing the inflammatory and oxidative stress response to exercise in horses. Methods: 6 horses. Methods: Horses were randomly allocated into 2 groups in a crossover study with a 2-week washout period and orally administered either TCJB or a placebo solution (1.42 L, twice daily) in a double-masked protocol for 2 weeks prior to a stepwise incremental exercise protocol. Horses were tested for serum activities of creatine kinase and aspartate aminotransferase...
alpha-Lipoic acid supplementation enhances heat shock protein production and decreases post exercise lactic acid concentrations in exercised standardbred trotters. Heat shock protein (HSP) expression is an adaptive mechanism against the disruption of cell homeostasis during exercise. Several antioxidant supplementation strategies have been used to enhance tissue protection. In this study, we examined the effects of a redox modulator, alpha-lipoic acid (LA) on HSP responses in six standardbred trotters following intense aerobic exercise. DL-LA supplementation (25 mg kg(-1) d(-1)) for five weeks increased the resting levels of HSP90 (1.02+/-0.155 in control and 1.26+/-0.090 after supplementation in arbitrary units) and the recovery levels of inducible HSP7...
Blood glutathione status and activity of glutathione-metabolizing antioxidant enzymes in erythrocytes of young trotters in basic training. The aim of this study was to evaluate response of blood glutathione status and activity of glutathione-metabolizing antioxidant enzymes in erythrocytes of young trotters in basic training. Nine untrained trotters (aged 16-20 months) were exposed to a 4-month training program based on exercises at low-to-moderate intensity. The conditioning consisted of breaking the horses and running them on distances varying from 4 to 40 km a week. The workloads were increased on a 3-week basis. Exercise intensity was monitored by measuring heart rate and blood lactate. Blood samples were collected at rest, b...