EVALUATION OF PEQUI ON MECHANICAL AND THERMAL HYPERALGESIA INDUCED BY INFLAMMATION

Resumo

Introduction: Caryocar brasiliense, popularly known as "pequi", is a native plant of the Brazilian cerrado (savanna) biome esteemed for its use in the local cuisine and because of its economic importance, especially among the low-income population1,2,3. Medicinal properties are also attributed to this plant, such as antinociceptive and anti-inflammatory effects3,4,5. Unfortunately, there are few studies related to this plant, and it is difficult to recognize and prove all its therapeutic potential3,5. The aim of this study was to evaluate the antinociceptive action of C. brasiliense on mechanical and thermal hyperalgesia induced by inflammation. Material and Methods: The oil obteined of fruts of C. brasiliense was tested in adult male Swiss mice, which were divided into three groups: the negative control group (0,9% saline solution), the C. brasiliense treated group (oil 300mg/kg), treated by oral route, and the positive control group (dexamethasone 1mg/kg s.c.). After 1 hour, the animals received intraplantar injection of carrageenan (300?g). Mechanical hiperalgesia (Von Frey test) and the Cold allodynia (Acetone test) were analyzed 3 and 4 hours after intraplantar injection of carrageenan6,7. The experimental procedures executed in this study were in accordance with the Ethical Principals in Animal Research and approved by the Committee for Ethics in Animal Experimentation at the UFGD (Protocol number 17/2015). Results: In the third hour of the experiment, Dexamethasone reversed 87% of mechanical hyperalgesia in relation to the negative control group (P<0.05). During the fourth hour, it was observed that C. brasiliense reversed 97% of mechanical hyperalgesia (P<0.001), while Dexamethasone reversed 84% (P<0.01). Additionally, during the third and fourth hours, Dexamethasone reversed 49% (P<0.01) and 47% (P<0.05), respectively, of Cold allodynia, compared to the negative control group. Discussion and Conclusion: C. brasiliense oil was effective in reversing mechanical hyperalgesia, proving its use as an alternative therapy for this purpose. However, its effects on termal hyperalgesia (Cold allodynia) were not statistically significant. Further studies will be necessary to determine the medicinal properties of C. brasilienses, especially those related to its anti-inflammatory effects.