Study of copaiba oil on behavioral testing in rodent models by inducing neuropathic and inflammatory pain

Abstract

Objective: The Copaiba sp. oil has been known to possess anti-inflammatory, antiulcer, antiviral and others activities. The copaiba oil pharmacological activity was assessed using models of nociception in mice. The involvement of both megakaryocytes and enzyme markers for muscle damage under acute copaiba oil treatment on acetic acid (AA)-induced abdominal constriction was investigated. Materials and Methods: Swiss mice and/or Wistar rats were pretreated orally (2 h) before all experimental procedure with Copaifera officinalis oil or vehicle. The abdominal constriction response was induced by intra-peritoneal injection of AA 0.6% and the number of abdominal constrictions was counted cumulatively over 60 min. Behavioral nociception models, i.e., hot plate and tail-flick test, were also performed. Plasma enzymes (creatine kinase [CK]; aspartate aminotransferases [AST] and alanine aminotransferases; [ALT]) and organs histology were analyzed too. Results: Cop aiba oil administration caused a significant reduction on the AA-induced writhing in the rodents. It also presented significant antinociceptive activity in the behavioral models. Plasma CK levels and megakaryocyte production were significantly augmented in the copaiba oil-pretreated animals when compared with control group. AST and ALT remained unchanged. Conclusion: Our results indicate that copaiba oil may act as an anti-nociceptive agent and induce plasmatic CK increase by a mechanism involving probably the splenic overproduction of megakaryocytes, suggesting this way the participation of immature platelets in the process.