Oxidative stress in horses refers to an imbalance between the production of reactive oxygen species (ROS) and the ability of the horse's body to detoxify these reactive intermediates or repair the resulting damage. It can occur as a result of various physiological and environmental factors, such as exercise, illness, or exposure to toxins. Oxidative stress can lead to cellular damage, affecting lipids, proteins, and DNA. In horses, it is studied in the context of its potential impact on performance, health, and disease progression. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, effects, and management of oxidative stress in equine health.
Rifkind JM, Lauer LD, Chiang SC, Li NC.Oxidation studies of hemoglobin by Cu(II) indicate that for horse hemoglobin, up to a Cu(II)/heme molar ratio of 0.5, all of the Cu(II) added is used to rapidly oxidize the heme. On the other hand, most of the Cu(II) added to human hemoglobin at low Cu(II)/heme molar ratios is unable to oxidize the heme. Only at Cu(II)/heme molar ratios greater than 0.5 does the amount of oxidation per added Cu(II) approach that of horse hemoglobin. At the same time, binding studies indicate that human hemoglobin has an additional binding site involving one copper for every two hemes, which has a higher copper...
Sidhu GS, Brown MA, Johnson AR.Factors contributing to the initiation of lipid oxidation in cow's and mare's milk containing high levels of polyunsaturated fatty acids were studied. Addition of H2O2 just after milking, in slight excess of the stoichiometric amounts required to destroy ascorbic acid, delayed the development of oxidized flavours in cow's milk high in linoleic acid. Hydrogen peroxide treatment followed by the addition of alpha-or gamma-tocopherols prevented lipid oxidation in cow's milk even when 0.1 mg Cu/l milk was added. When used separately in the presence of Cu these treatments were ineffective as was but...
Harvey JW, Kaneko JJ.Partially purified haemoglobin solutions of man, horse, car and dog were oxidized with ascorbate, acetylphenylhydrazine, nitrite, and H2O2 at 25 degrees C and with ascorbate and acetylphenylhydrazine at 37 degrees C. Haemoglobins of the carnivores were more easily oxidized with ascorbate, nitrite, and H2O2 than equine and human haemoglobins. Feline haemoglobin, in general, appeared more susceptible to oxidation, particularly oxidative denaturation, than those of the other species. In addition, results of the incubations at 37 degrees C suggest that feline haemoglobin B might be more susceptibl...
Harvey JW, Kaneko JJ.Glutathione reductase (GR) was studied in erythrocytes of horses, cats, dogs, and man. Glutathione reductase activity was measured in hemolysates with and without preincubation of hemolysates with flavinadenine dinucleotide. The percentage saturation of GR apoenzyme with cofactor (flavin-adenine dinucleotide) was lower in cats and dogs than in horses or man. The greatest amount of inactive apoenzyme was in feline erythrocytes. Total GR activity listed in order by species is cat greater than man greater than dog greater than horse. Kinetic constants for oxidized glutathione and reduced nicotina...
Folin M, Gennari G, Jori G.The irradiation of horse and sperm-whale Fe” or Fez’ myoglobins with visible light
showed that axial ligands that render the heme diamagnetic (e.g. 02, CO or CN-) endow the
hemoproteins with a marked photosensitivity. In contrast, high-spin myoglobins are unaffected by
visible light. These findings appear to be of general validity for all hemo-proteins and are in agreement
with the involvment of the triplet state of the heme as the reactive intermediate. In all cases, the overall
photoprocess occurs within a very narrow spatial range, leading to specific modification of these
photoox...
Rifkind JM.The reduced glutathione in the erythrocyte was found to inhibit the autoxidation of purified horse hemoglobin. It was observed that much higher concentrations of oxidized glutathione also stabilize hemoglobin. The stabilization by oxidized glutathione most likely involves the formation of a mixed disulfide with the reactive β-93 sulfhydryl groups on the hemoglobin. A similar effect is also observed with N-ethyl- maleimide and HgCl2 which also react with the sulfhydryl groups. The apparent stabilization by reduced glutathione is partially due to the reduction of ferrihemoglobin formed by autox...
Srivastava SK, Beutler E.1. Erythrocytes from normal and glucose 6-phosphate dehydrogenase-deficient humans were subjected to hydrogen peroxide diffusion to oxidize the GSH. Studies were carried out in the presence and absence of chromate to inhibit glutathione reductase and with or without the addition of glucose. 2. The GSH content of erythrocytes from other species was oxidized by subjecting them to hydrogen peroxide diffusion in the presence of chromate and glucose. 3. Chromate (1.3mm) inhibited glutathione reductase by about 80%, whereas glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokin...
The objective of this study was to enhance the in vitro sperm quality and in vivo fertility of frozen-thawed equine semen by the addition of l-carnitine (LC) to post-thawed semen. Different concentrations of LC were added to thawed samples to obtain four treatments control and 0.5, 1 and 2 mM LC. In the in vitro experiments, sperm motility and kinematics, membrane integrity and intracellular calcium ion concentration ([Ca ] ) were investigated, and the antioxidant bioactivity of LC was assessed by measuring hydrogen peroxide and nitrite concentrations (NO ). The fertility rate was assessed v...
Vaughn SA, Norton NA, Hurley DJ, Hart KA.Reactive oxygen species (ROS) are the end-products of physiologic functions in health. Oxidative stress occurs when endogenous antioxidants are insufficient to neutralize ROS in the system. As a result, ROS can damage DNA, RNA, proteins, lipids, and cell organelles. To obtain accurate measurements of plasma oxidative stress, levels of both oxidants and antioxidants must be measured. This study validates a commercially available, semi-quantitative, photometric analytical system that measures systemic determinants of reactive oxygen metabolites (dROM) and plasma antioxidant capacity (PAC) in sto...
Dąbrowska I, Grzędzicka J, Niedzielska A, Witkowska-Piłaszewicz O.Green coffee extract is currently of great interest to researchers due to its high concentration of chlorogenic acid (CGA) and its potential health benefits. CGA constitutes 6 to 10% of the dry weight of the extract and, due to its anti-inflammatory properties, is a promising natural supplement and agent with therapeutic applications. The purpose of our study was to discover the effects of CGA on peripheral blood mononuclear cell proliferation, and the production of pro- and anti-inflammatory cytokines as well as reactive oxidative species (ROS) in horses during exercise. According to the find...
Lee HJ, Kim D, Do K, Yang CB, Jeon SW, Jang A.Sarcopenia, the age-related muscle atrophy, is a serious concern as it is associated with frailty, reduced physical functions, and increased mortality risk. Protein supplementation is essential for preserving muscle mass, and horse meat can be an excellent source of proteins. Since sarcopenia occurs under conditions of oxidative stress, this study aimed to investigate the potential anti-muscle atrophy effect of horse meat hydrolysate using C2C12 cells. A horse meat hydrolysate less than 3 kDa (A4<3kDa) significantly increased the viability of C2C12 myoblasts against HO-induced cytotoxicity....
Kruse CJ, Dieu M, Renaud B, François AC, Stern D, Demazy C, Burteau S, Boemer F, Art T, Renard P, Votion DM.Equine atypical myopathy (AM) is a severe environmental intoxication linked to the ingestion of protoxins contained in seeds and seedlings of the sycamore maple (Acer pseudoplatanus) in Europe. The toxic metabolites cause a frequently fatal rhabdomyolysis syndrome in grazing horses. Since these toxic metabolites can also be present in cograzing horses, it is still unclear as to why, in a similar environmental context, some horses show signs of AM, whereas others remain clinically healthy. Label-free proteomic analyses on the serum of 26 diseased AM, 23 cograzers, and 11 control horses were per...
Interlandi C, Tabbì M, Di Pietro S, D'Angelo F, Costa GL, Arfuso F, Giudice E, Licata P, Macrì D, Crupi R, Gugliandolo E.The aim of this study was to evaluate the effect of oral cannabidiol (CBD) administration in addition to a conventional analgesic protocol on the clinical signs of 20 horses with mild joint osteoarthritis. The horses were randomly assigned to either the control group (C group) or the cannabidiol group (CBD group). Both groups were treated with phenylbutazone for 5 days. The CBD group received 0.03 mg/kg cannabidiol in hemp oil orally once daily for 14 days in addition to phenylbutazone treatment. All subjects were monitored for clinical parameters, oxidative status and blood counts. Pain...
Bujok J, Pavľak A, Walski T, Zigo F, Trochanowska-Pauk N, Bohara R, Miśta D.Combat training of police horses, involving physical activity in the presence of environmental stressors, poses a risk of oxidative stress. This study compared the oxidative imbalance after combat training in horses in the regular police service and in horses that had just been schooled. Blood collection was performed immediately after training and after 16 h rest. The activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and total antioxidant status (TAS) were determined as the markers of enzymatic antioxidant defence. At the same time, lipid peroxidation (TBAR...
Giers J, Bartel A, Kirsch K, Müller SF, Horstmann S, Gehlen H.After submaximal exercise, blood values of eventing horses show physiological reactions. This prospective longitudinal study investigated blood parameters in 20 elite eventing horses before and after two-four-star cross-country rides. Using a mixed model adjusting for plasma volume shift, we assessed exercise-dependent parameters and compared blood values with reference ranges for healthy horses at rest. Following exercise, cortisol, triiodothyronine (T3) and thyroxine (T4) showed short-term increases, and superoxide-dismutase showed a small short-term increase. Hepatic values showed short-ter...
Muñoz-Prieto A, Llamas-Amor E, Contreras-Aguilar MD, Ayala I, Martín Cuervo M, Cerón JJ, Hansen S.Ammonia (NH3) and bicarbonate (HCO3) have been related to gastric ulcers in humans. Ammonia is considered a possible cause of gastric ulcers, whereas bicarbonate has a protective function. The presence of ulcers in the stomach of horses is defined as Equine Gastric Ulcer Syndrome (EGUS), which is a frequent disease in this species, and it has been associated with changes in saliva composition, such as in analytes related to inflammation, immune system and oxidative stress. The objectives of this study were (1) to perform an analytical validation of two automated spectrophotometric assays, one ...
Catalán J, Yánez-Ortiz I, Torres-Garrido M, Ribas-Maynou J, Llavanera M, Barranco I, Yeste M, Miró J.Cryopreservation is a stressful process for sperm, as it is associated with an increased production of reactive oxygen species (ROS). Elevated ROS levels, which create an imbalance with antioxidant capacity, may result in membrane lipid peroxidation (LPO), protein damage and DNA fragmentation. This study aimed to determine whether the membrane LPO and DNA fragmentation of frozen-thawed horse sperm relies upon antioxidant activity, including enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and paraoxonase type 1 (PON1)); non-enzymatic antioxidant capacity (Trolo...
Whitfield-Cargile CM, Chung HC, Coleman MC, Cohen ND, Chamoun-Emanuelli AM, Ivanov I, Goldsby JS, Davidson LA, Gaynanova I, Ni Y, Chapkin RS.The equine gastrointestinal (GI) microbiome has been described in the context of various diseases. The observed changes, however, have not been linked to host function and therefore it remains unclear how specific changes in the microbiome alter cellular and molecular pathways within the GI tract. Further, non-invasive techniques to examine the host gene expression profile of the GI mucosa have been described in horses but not evaluated in response to interventions. Therefore, the objectives of our study were to (1) profile gene expression and metabolomic changes in an equine model of non-ster...
Zhang X, Geng A, Cao D, Dugarjaviin M. Horses are susceptible to oxidative stress during strenuous endurance exercise, leading to muscle fatigue and damage. Mulberry leaf flavonoids (MLFs) possess significant antioxidant properties. However, the antioxidant efficacy of MLFs can be influenced by the extraction process, and their impact on HO-induced oxidative stress in equine skeletal muscle satellite cells (ESMCs) remains unexplored. Our study employed three extraction methods to obtain MLFs: ultrasound-assisted extraction (CEP), purification with AB-8 macroporous resin (RP), and n-butanol extraction (NB-EP). We assessed the prot...
Meissner JM, Chmielińska A, Ofri R, Cisło-Sankowska A, Marycz K.Corneal ulcers, characterized by severe inflammation of the cornea, can lead to serious, debilitating complications and may be vision-threatening for horses. In this study, we aimed to investigate the role of endoplasmic reticulum (ER) stress in corneal stem progenitor cell (CSSC) dysfunction and explore the potential of equine adipose-derived stromal stem cell (ASC)-derived extracellular vesicles (EVs) to improve corneal wound healing. We showed that CSSCs expressed high levels of CD44, CD45, and CD90 surface markers, indicating their stemness. Supplementation of the ER-stress-inducer tunicam...
