RESUMO
CONTEXT: Myrtus communis L. (Myrtaceae), myrtle, is an evergreen shrub with strong antibacterial, anti-inflammatory, antihyperglycemic and antioxidant activities. Also, it is used as a sedative-hypnotic plant in Iranian traditional medicine. OBJECTIVE: This study evaluates the effect of 80% ethanolic extract of M. communis leaves on sleep and anxiety in mice and rats. MATERIALS AND METHODS: Male NMRI mice were subjected to open field, righting reflex, grip strength and pentylentetrazole-induced seizure tests. Male Wistar rats were used to evaluate the alterations in rapid eye movement (REM) and non-REM (NREM) sleep. They were treated with 25-400 mg/kg doses of the extract intraperitoneally. RESULTS: The applied doses (50-200 mg/kg) of M. communis extract increased vertical (ED50 = 40.2 ± 6.6 mg/kg) and vertical and horizontal activity (ED50 = 251 ± 55 mg/kg), while treatment with 200 and 400 mg/kg attenuated muscle tone significantly compared to vehicle treated animals (p < 0.001 for all) in a dose-independent manner. Also, a significant hypnotic and not anticonvulsant effect was observed when animals were treated with 200 mg/kg of the extract (p < 0.01). In this regard, electroencephalography results showed that REM sleep time was decreased (2.4 ± 0.5%), while total and NREM sleep times were increased significantly compared to the control group of mice (82.5 ± 7.6%). DISCUSSION AND CONCLUSION: The data show the anxiolytic and muscle relaxant effect of the extract without anticonvulsant activities. The anxiolytic, myorelaxant and hypnotic effects without effect on seizure threshold are in line with the effect of a alpha 2 GABA receptor agonist.
Assuntos
Ansiolíticos/farmacologia , Comportamento Animal/efeitos dos fármacos , Eletroencefalografia , Etanol/química , Hipnóticos e Sedativos/farmacologia , Fármacos Neuromusculares/farmacologia , Extratos Vegetais/farmacologia , Sono/efeitos dos fármacos , Solventes/química , Animais , Ansiolíticos/isolamento & purificação , Relação Dose-Resposta a Droga , Eletromiografia , Agonistas de Receptores de GABA-A/farmacologia , Hipnóticos e Sedativos/isolamento & purificação , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Força Muscular/efeitos dos fármacos , Myrtus/química , Fármacos Neuromusculares/isolamento & purificação , Fitoterapia , Extratos Vegetais/isolamento & purificação , Folhas de Planta , Plantas Medicinais , Ratos Wistar , Receptores de GABA-A/efeitos dos fármacos , Receptores de GABA-A/metabolismo , Fatores de TempoRESUMO
The search for natural antioxidants, especially of plant origin, has notably increased in recent years. Bunium persicum Boiss. is an economically important medicinal plant growing wild in the dry temperature regions in Iran. In this study, chemical constituents of the essential oil of the seed from Bunium persicum Boiss. have been studied by GC/MS technique. The major components were caryophyllene (27.81%), gamma-terpinene (15.19%), cuminyl acetate (14.67%). Individual antioxidant assays such as, DPPH* scavenging activity and beta-carotene bleaching have been carried out. In DPPH* system, the EC(50) value of essential oil was determined as 0.88 mg/mL. In beta-carotene bleaching antioxidant activity of essential oil (0.45%) was almost equal to BHT at 0.01%. In addition, the antioxidant activity of the essential oil was evaluated in crude soybean oil by monitoring peroxide and thiobarbituric acid values of the oil substrate. The results showed that the Bunium persicum essential oil (BPEO) was able to reduce the oxidation rate of the soybean oil in the accelerated condition at 60 degrees C (oven test). The essential oil at 0.06% showed the same effect of BHA at 0.02%. Hence, BPEO could be used as an additive in food after screening.