Suppressive Effect of Bortezomib on LPS-Induced Inflammatory Responses in Horses

Oral Administration of Meloxicam and Flunixin Meglumine Have Similar Analgesic Effects After Lipopolysaccharide-Induced Inflammatory Response in Thoroughbred Horses

Flunixin meglumine (FM), a nonselective cyclooxygenase (COX) inhibitor, is most frequently selected for the treatment of equine systemic inflammatory response syndrome (SIRS)/endotoxemia. However, FM has considerable adverse effects on gastrointestinal function. The aims of this study were to compare the effect of meloxicam (MX), a COX-2 selective inhibitor commonly used in equine clinical practice, with FM, and to investigate the potential for clinical application in horses with SIRS/endotoxemia. Fifteen horses were divided into three groups of five and orally administered MX (0.6 mg/kg), FM (1.1 mg/kg), or saline as placebo at 30 minutes after LPS challenge. Clinical parameters, including behavioral pain scores, were recorded and blood for clinical pathological data was collected at various times from 60 minutes before to 420 minutes after LPS infusion. The pain score were significantly lower in both the MX and FM groups than in the placebo group, with no significant difference between them. Body temperature was significantly lower in the MX and FM groups than in the placebo group. Heart rates and respiratory rates, hoof wall surface temperature, and leukocyte counts changed similarly between the MX and FM groups. TNF-α and cortisol were lower in the FM group than in the MX group. The results suggest that MX suppresses the inflammatory response after LPS infusion and has an analgesic effect similar to that of FM. Given the adverse effects of nonselective COX inhibitors, clinical application of MX may be beneficial in horses with SIRS/endotoxemia.

Comparative Anti-inflammatory Effects of Insulin and Flunixin on Acute-Phase Responses and Cardiovascular Biomarkers During Inflammatory Phase in Miniature Donkeys

The objective of this study was to comparatively evaluate the anti-inflammatory effects of intravenous administration of insulin (in different doses) and flunixin on physiological variables, acute-phase responses, and cardiovascular biomarkers during inflammatory phase which was induced by Escherichia coli lipopolysaccharide (LPS) serotype O55:B5 in miniature donkeys. A total of twenty-four clinically healthy male adult miniature donkeys aged 5 ± 1 year and weighing 120 ± 10 kg were studied. The animals were assigned randomly to four experimental groups (three treatment and one positive control groups). Six hours after induction of inflammatory phase (by 20 ng kg^-1 LPS), donkeys in groups Insln 1.5, Insln 3, and Flnx received insulin at 1.5 IU kg^-1, insulin at 3 IU kg^-1, and flunixin at 2.2 mg kg^-1, respectively. Animals in the positive control group were assigned to receive LPS without any anti-inflammatory drugs. We have shown that serum concentrations of cardiovascular, acute-phase proteins and cytokines were increased during inflammatory phase in miniature donkeys. Our results revealed that insulin at 3 IU kg^-1 as well as flunixin at 2.2 mg kg^-1 can improve almost all of the physiological variables and hematobiochemical variables (including serum concentrations of tumor necrosis factor-alpha, interferon-gamma, haptoglobin, serum amyloid A, cardiac troponin I, hemocysteine, white blood cell, and packed cell volume) after 24 hours. Unlike insulin at 1.5 IU kg^-1, insulin at 3 IU kg^-1 may be considered useful for inflammatory conditions in miniature donkeys.

Oral Administration of Meloxicam Suppresses Low-Dose Endotoxin Challenge-Induced Pain in Thoroughbred Horses

Nonsteroidal anti-inflammatory drugs such as flunixin meglumine have been used to treat signs of systemic inflammatory conditions, but it is also known to have the side effect to small intestine mucosa. It may be considered to be due to inhibition of both cyclooxygenase (COX)-1 and COX-2. On the other hand, meloxicam is widely used in equine clinical practice and an effective nonsteroidal anti-inflammatory drug with the preferential inhibitory effect on COX-2. However, it has not yet been evaluated in equine systemic inflammation. The aim of this study was to evaluate the effect of meloxicam administered 60 minutes prior lipopolysaccharide (LPS)-induced inflammatory response in five Thoroughbred horses using a crossover test. Clinical parameters including body temperature, heart rate, respiratory rate, behavioral pain score, and hoof wall surface temperature were recorded, and plasma tumor necrosis factor-alpha, cortisol, and leukocyte counts were measured at various times before and after LPS infusion for 420 minutes. At time points 60, 90 (P < .01), 120, and 180 (P < .05) minutes, pain scores were significantly lower in meloxicam-treated horses. There was no significant difference in other parameters. In the present study, we revealed the analgesic effect of meloxicam using an equine low-dose endotoxin model.