Orally administered phenylbutazone causes oxidative stress in the equine gastric mucosa

J Vet Pharmacol Ther. 2015 Jun;38(3):257-64. doi: 10.1111/jvp.12168. Epub 2014 Oct 7.


Phenylbutazone (PBZ) is widely used in equine medicine, and its side effects on the gastrointestinal tract are well known. The inhibition of prostaglandins and the oxidative stress induced by nonsteroidal anti-inflammatory drugs (NSAIDs) are described as mechanisms of gastric mucosal injury in humans. In horses, only the secondary effect of changes in cyclooxygenases is related to gastric mucosal injury. The objective of this study was to evaluate the effect of PBZ on certain antioxidative/oxidative parameters of the gastric mucosa. The concentrations of antioxidants and oxidants (superoxide dismutase, SOD; catalase, CAT; nitric oxide, NO; total glutathione, GSH; myeloperoxidase, MPO; and malondialdehyde, MDA), PGE2 levels, and the ulcerative lesions score were assessed. The results demonstrated decreased levels of antioxidant variables, increased levels of oxidant variables, and alterations in the prostaglandin E2 (PGE2 ), myeloperoxidase (MPO), and glutathione (GSH) levels. In conclusion, PBZ induces oxidative stress in the gastric glandular mucosa of horses by changing the antioxidant-oxidant balance of this surface, which might be regarded as another mechanism of injury in the horse stomach.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / administration & dosage
  • Anti-Inflammatory Agents, Non-Steroidal / adverse effects*
  • Catalase / analysis
  • Dinoprostone / analysis
  • Female
  • Gastric Mucosa / chemistry
  • Gastric Mucosa / drug effects*
  • Gastric Mucosa / metabolism
  • Gastroscopy / veterinary
  • Glutathione / analysis
  • Horse Diseases / chemically induced
  • Horses
  • Male
  • Malondialdehyde / analysis
  • Nitric Oxide / analysis
  • Oxidative Stress / drug effects*
  • Peroxidase / analysis
  • Phenylbutazone / administration & dosage
  • Phenylbutazone / adverse effects*
  • Stomach Ulcer / chemically induced
  • Superoxide Dismutase / analysis


  • Anti-Inflammatory Agents, Non-Steroidal
  • Nitric Oxide
  • Malondialdehyde
  • Catalase
  • Peroxidase
  • Superoxide Dismutase
  • Glutathione
  • Phenylbutazone
  • Dinoprostone