BACKGROUND: Oxidative stress reflects an imbalance between the reactive oxygen species (ROS) and a biological system's ability to readily detoxify the oxidative agents. Disturbances in the normal redox state of cells can cause toxic effects through production of peroxides and free radicals that damage all components of the cell, including proteins, lipids, and DNA. ObjectiveS: The purpose of this study was to evaluate the oxidative status in calves within 3 days of birth. Methods: Twenty calves from Zagros dairy farm were selected. Blood samples were collected from the jugular vein at 0 (before administration of colostrum), 24, 48 and 72 hours after birth for measurement of serum levels of TBARS, Superoxide dismutase and catalase. Results: The results indicated higher levels of serum malondialdehyde concentration at birth that subsequently decreased at 24 and 48 hours after birth (p<0.05). There were lower levels of serum concentration of catalase at birth that followed by increasing in it at 24 and 48 hours after birth (p<0.05). Also, the concentration of superoxide dismutase was lower at the birth that subsequently increased at 24 hours after birth (p<0.05). Conclusions: Based on this study, it seems that antioxidant capacity of calves has been increased within 3 days of birth. Improvement of oxidative status in calves could be due to gradual increasing of their antioxidative capacity and also beneficial effects of colostrum.

This study was aimed to assess the effect of fenugreek-insulin-glimepiride interaction on oxidative stress in streptozotocin-induced diabetic rats. A total of 56 male Sprague-Dawley rats were randomly divided into 7 groups (n=8); group 1: served as Sham, group 2: Diabetic control, groups 3, 4 and 5: served as individual treatment group, groups 6 and 7: treated with combination of insulin-fenugreek and glimepiride-fenugreek, respectively. Serum creatinine levels of the rats were estimated at 4th and 8th weeks during treatment. Thiobarbituric Acid Reactive Substances (TBARS), Glutathione (GSH) and protein carbonyls were estimated in the kidney homogenate, and relative kidney weights were measured at the end of the experiment. Present study indicated that the levels of TBARS and protein carbonyls significantly increased in group 2 and decreased in groups 3 to 7. On the other hand, groups 6 and 7 showed significantly lowered values compared to the individual treatment groups. The concentration of GSH was significantly decreased in group 2 and significantly increased in groups 3 to 7, and group 7 showed significantly higher concentration among all the treated groups. The serum creatinine concentration in group 2 was significantly higher and all treatment groups (3 to 7) showed significantly lowered values at 4th and 8th wks after treatment. The individual treatment groups (3, 4 and 5), antagonised the significant alteration in the antioxidant parameters, and their combination was revealed synergism by improving the oxidative status in diabetic rats. [J Adv Vet Anim Res 2015; 2(3.000): 353-356]

Multicomponent nutraceuticals are becoming increasingly popular treatments or adjunctive therapies for osteoarthritis in veterinary medicine despite lack of evidence of efficacy for many products. The objective of this study was to evaluate the anti-inflammatory and antioxidant activities of a commercially available C-phycocyanin-based nutraceutical and select constituent ingredients in an in-vitro model of canine osteoarthritis. Normal canine articular chondrocytes were used in an in-vitro model of osteoarthritis. Inflammatory conditions were induced using interleukin-1β. The nutraceutical preparation as a whole, its individual constituents, as well as carprofen were evaluated at concentrations of 0 to 250 μg/mL for reduction of the following inflammatory mediators and indicators of catabolism of the extracellular matrix: prostaglandin E2 (PGE2), tumor necrosis factor-α (TFN-α), interleukin-6 (IL-6), metalloproteinase-3 (MMP-3), nitric oxide, and sulfated glycosaminoglycans (sGAGs). Validated, commercially available assay kits were used for quantitation of inflammatory mediators. The antioxidant capacities, as well as cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and lipoxygenase (LOX) inhibitory activities of the whole nutraceutical preparation and select constituents, were also assessed using validated commercially available assay kits. The antioxidant capacity of the nutraceutical and constituents was concentration-dependent. The nutraceutical and constituents appear to display anti-inflammatory activity primarily through the inhibition of COX-2. The nutraceutical displayed similar strength to carprofen in reducing TNF-α, IL-6, MMP-3, nitric oxide, and sGAGs at select concentration ranges. The C-phycocyanin (CPC)-based nutraceutical and constituents may be able to mediate 3 primary pathogenic mechanisms of osteoarthritis: inflammation, chondral degeneration, and oxidative stress in vitro. The nutraceutical may be clinically useful in veterinary medicine and its efficacy should be further investigated in vivo.

OBJECTIVE To determine whether thioredoxin (TRX)-1 can be used as a valid biomarker for oxidative stress in dogs. ANIMALS AND SAMPLES 10 Beagles and Madin-Darby canine kidney cells. PROCEDURES Madin-Darby canine kidney cells were used to verify antigen cross-reactivity between human and canine anti–TRX-antibodies. Dogs were assigned to receive 21% or 100% O2 (5 dogs/group) via an artificial respirator during a 3-hour period of isoflurane anesthesia (starting at 0 hours). Blood and urine samples were collected before (baseline) and at 6, 12, 24, and 48 hours after commencement of inhalation anesthesia. Concentrations of TRX-1 and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in plasma and urine samples were analyzed; urine concentrations were reported as ratios against urine creatinine concentration. RESULTS Canine TRX-1 was recognized by monoclonal human anti-TRX-1 antibodies (clones of adult T-cell leukemia-derived factor [ADF]-11 and ADF21) by western blot analysis. Results of an ELISA indicated that plasma TRX-1 concentration and urine TRX-1-to-creatinine concentration ratio increased rapidly after the 3-hour period of hyperoxia with maximal peaks at 12 and 6 hours, respectively. Urine 8-OHdG-to-creatinine concentration ratio also increased significantly after hyperoxia induction. However, unlike the rapid increase in urine TRX-1-to-creatinine concentration ratio, maximal urine 8-OHdG-to-creatinine concentration ratio was attained at 48 hours after hyperoxia induction. These variables remained unchanged from baseline in the control group. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that human anti-TRX monoclonal antibodies cross-reacted with canine TRX, and plasma TRX-1 concentrations were rapidly increased in dogs following an oxidative stress challenge. Thus, TRX may be a valuable clinical biomarker for detecting oxidative stress more rapidly than 8-OHdG in dogs.

In horses, hyperinsulinemia and insulin resistance (insulin dysregulation) are associated with the development of laminitis. Although obesity is associated with insulin dysregulation, the mechanism of obesity-associated insulin dysregulation remains to be established. We hypothesized that oxidative stress in skeletal muscle is associated with obesity-associated hyperinsulinemia in horses. Thirty-five light breed horses with body condition scores (BCS) of 3/9 to 9/9 were studied, including 7 obese, normoinsulinemic (BCS ≥ 7, resting serum insulin < 30 μIU/mL) and 6 obese, hyperinsulinemic (resting serum insulin ≥ 30 μIU/mL) horses. Markers of oxidative stress (oxidative damage, mitochondrial function, and antioxidant capacity) were evaluated in skeletal muscle biopsies. A Spearman’s rank correlation coefficient was used to determine relationships between markers of oxidative stress and BCS. Furthermore, to assess the role of oxidative stress in obesity-related hyperinsulinemia, markers of antioxidant capacity and oxidative damage were compared among lean, normoinsulinemic (L-NI); obese, normoinsulinemic (O-NI); and obese, hyperinsulinemic (O-HI) horses. Increasing BCS was associated with an increase in gene expression of a mitochondrial protein responsible for mitochondrial biogenesis (estrogen-related receptor alpha, ERRα) and with increased antioxidant enzyme total superoxide dismutase (TotSOD) activity. When groups (L-NI, O-NI, and O-HI) were compared, TotSOD activity was increased and protein carbonyls, a marker of oxidative damage, decreased in the O-HI compared to the L-NI horses. These findings suggest that a protective antioxidant response occurred in the muscle of obese animals and that obesity-associated oxidative damage in skeletal muscle is not central to the pathogenesis of equine hyperinsulinemia.