Estudo da ação psicofarmacológica de Herissantia crispa (L.) Brizicky (Malvaceae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Herissantia crispa (L.) Brizicky popularly know as malvaísco is a plant which belongs to the Malvaceae family. There arent many reports about H. crispa, however, steroids, flavonoids and glycosidic flavonoids with pharmacological activity have been isolated from this species. Other species of Malvaceae have been used in traditional medicine and many studies have shown activities such as anti-inflammatory, antinociceptive, diuretic and others. The aim of this work was to evaluate a possible psychopharmacological activity of H. crispa ethanolic crude extract (EEHc) performing a central nervous system (CNS) investigation in mice. Initially, behavioral pharmacological screening was performed to assess the possible effect of EEHc on the nervous system. Some behavioral changes were observed similar to that of CNS depressant drugs in treated mice. No death was observed 72 hours after treatment with EEHc, nor toxic signs on the highest dose (2000 mg/Kg, i.p.). Therefore we established the doses 500 or 800 mg/kg to perform the pharmacological tests. None of the two doses reduced the time of permanence of mice on a rota-rod revolving bar. On the open-field test, both doses of EEHc significantly reduced ambulation, rearing and defecation, suggesting a profile that resembles hypnotic-sedative drugs. The EEHc treatment did not affect grooming. There were no differences between the control group and the EEHc treated groups when mice were tested for differences in anxiety-related behavior on the elevated plus maze or electroshock- induced tonic convulsions triggered by auricular shock, suggesting that EEHc does not have anxiolytic or anticonvulsant effects. Both doses of EEHc significantly increased the duration of sleeping time induced by sodium thiopental but failed to increase the latency of thiopental-induced hypnosis. Regarding the antinociceptive tests, EEHc significantly reduced acetic acid-induced abdominal writhes in a non dose-dependent manner. EEHc at 500 mg/kg also significantly reduced the hot-plate latency time only 60 minutes after treatment. In the formalin test, EEHc at 500 mg/kg was only able to reduce licking paw time in the first phase of the test. EEHc at the dose of 800 mg/kg reduced licking paw time the first and second phases. These results support the evidence of a central antinociceptive action. In order to confirm the central antinociceptive activity of EEHc, mice were treated with naloxona, an opioid antagonist, and them submitted to formalin test. Since the effect of the EEHc was not reverted by naloxone is excluded the participation of the opioid system in the mechanism of this activity. Therefore, an results suggest that EEHc presented evidences a sedativehypnotic drug profile with central non-opioid antinociceptive activity.

ASSUNTO(S)

psicofarmacologia atividade antinociceptiva herisantia crispa herissantia crispa farmacologia antinociceptivite activity psychopharmacology

ACESSO AO ARTIGO

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