Study of the Psychopharmacologic Effect of Hydroxydihydrocarvone in Mice

Abstract

SUMMARY Essential oils are natural products composed of several chemical constituents including monoterpenes with central pharmacological activity. Hydroxydihydrocarvone (HC) is a synthetic intermediate obtained from (-)-carvone hydration. Owing to the chemical and structural likeness to other monoterpenes with psychopharmacologic activity, this work was aimed at investigating the possible behavioral effects in mice after treatment with HC. The Letal Dose 50% (LD50) was established allowing the use of doses in subsequent tests. Some behavioral alterations were observed in the pharmacological screening, redirecting the study to the evaluation of a central depressant activity. These results were better characterized in the spontaneous locomotor activity test, where HC (50, 100 e 200 mg/kg) decreased the ambulation. In the pentobarbital-induced sleeping time test, HC (100 e 200 mg/kg) increased the sleeping time of the animals, showing a central activity. In the pentilenotetrazol-induced seizures test, HC was unable to inhibit or increase the latency of clonic seizures. In the antipsychotic activity evaluation, HC did not induce catalepsy in mice. In the evaluation of the antinociceptive activity, the decrease in the number of abdominal writhings after administration of acetic acid indicated an antinociceptive activity of (25, 50, 100 e 200 mg/kg) HC. In the tail immersion test, the time of response to the thermoceptive stimulus was greater in HC (200 mg/kg) treated animals. In the formalin test, HC (50, 100 e 200 mg/kg) was effective on both phases of the test, showing a central antinociceptive activity. In an attempt of evaluating HC action mechanism, the mice were pretreated with naloxone, an opioid antagonist. No HC blocking effect was observed. Therefore, HC presents an antinociceptive action in the central nervous system and which seems to be unrelated to the opioid system. DESCRIPTORS Hydroxydihydrocarvone. Essential oils. Antinociceptive activity. Monoterpene. Grade: Master's Dissertacion. Presentation date: July 10th 2006. Supervising Professor: Reinaldo Nóbrega de Almeida. Curso: Programa de Pós-Graduação em Farmacologia da Universidade Federal da Paraíba – João Pessoa – Paraíba – Brasil.