Antinociceptive activity of aqueous extract and isolated compounds of Lithrea molleoides.

ETHNOPHARMACOLOGICAL RELEVANCE: Lithrea molleoides (Vell.) Engl. (Anacardiaceae) is a medicinal plant commonly used in traditional medicine in South America. AIM OF THE STUDY: In the present study, the in vivo antinociceptive effect of L. molleoides' aqueous extract and its isolated compounds has been investigated. MATERIALS AND METHODS: Antinociceptive activity was evaluated through writhing, formalin and hot plate tests in mice. The phytochemical analysis was performed. RESULTS: The extract produced significant inhibition on nociception induced by acetic acid (ED50: 8.7 mg/kg, i.p.) and formalin (ED50: 7.7 mg/kg, i.p.) administered intraperitoneally and also orally. Yohimbine diminished the activity of the extract in the acetic acid test meanwhile haloperidol enhanced its effect. Two majority compounds, shikimic and vanillic acid were active in chemical nociceptive models used in this work, producing the highest inhibition of the writhing response at a dose of 30 mg/kg i.p. (55.4% and 57.1%, respectively) meanwhile at 100 mg/kg p.o. produced a slight response (23.3% and 23.9%, respectively). CONCLUSIONS: These results suggest that L. molleoides' aqueous extract produced antinociception possibly related to the presence of shikimic and vanillic acid. The adrenergic and dopaminergic systems seem to be involved in the mechanism of antinociception of the extract.

Insights in the knowledge of two Argentine medicinal species of the genus Hybanthus (Violaceae) / Contribución al estudio de dos especies medicinales argentinas del género Hybanthus (Violaceae)

A differential morphoanatomical study was performed in two Argentine species: Hybanthus parviflorus and Hybanthus bigibbosus. Fresh material fixed in acetoalcoholic formalin and material from herbarium were employed. Paradermal and longitudinal sections of stems and transversal sections of leaves were prepared and stained with aqueous alcoholic safranin. The hydrochloric fluoroglucyn test was performed. Known and novel characters (distribution of vascular bundles of the primary stem and type and relative length of cover hairs and cuticular ornamentation of the adaxial epidermis, respectively) prove to be of value for the recognition of these species.Furthermore, the intestinal propulsor activity, related to the popular uses of these species was also assessed. Infusions of the whole plant, their roots and the 50 percent EtOH extracts of the aerial parts of H. parviflorus and H. bigibbosus were tested by the activated charcoal method. The extracts of H. parviflorus proved to have a significant activity which would allow validating its popular use.

Se encaró el estudio morfoanatómico diferencial de dos especies argentinas: Hybanthus parviflorus e Hybanthus bigibbosus. Se trabajó con material fresco fijado en formalina aceto-alcohólica y de herbario. Se realizaron preparados paradermales y cortes longitudinales y transversales de tallos y transversales de hoja empleando safranina alcohólico-acuosa y el test de floroglucina clorhídrica. Caracteres conocidos (distribución de haces vasculares en tallo primario) y novedosos (tipología y longitud relativa de tricomas tectores; ornamentación cuticular de la epidermis adaxial) poseen valor diferencial para el reconocimiento de estas especies.Asimismo se determinó la actividad de propulsión intestinal de ambas especies, relacionada con su uso popular. Se ensayaron las infusiones de la raíz y de las partes aéreas y el extracto EtOH 50 por ciento de las partes aéreas de H. parviflorus e H. bigibbosus, empleando el método del carbón activado. Los extractos de H. parviflorus presentaron una actividad significativa que permitiría validar su uso popular.

Psychopharmacological effects of Artemisia copa aqueous extract in mice.

OBJECTIVE: To evaluate the aqueous extract from aerial parts of Artemisia copa Phil. (Asteraceae) administered orallyfor its psychopharmacological activities in several experimental models. METHODS: The extract was administered p.o. in Swiss albino mice and tested on pentobarbital-induced hypnosis, locomotor activity, exploration in the hole-board, anxiolytic like profile evaluated in the marble-burying test and anticonvulsant activity on convulsions induced by pentylenetetrazol. RESULTS: Artemisia copa at doses up to 1.5 g/kg produced a dose-dependent sleep induction and potentiation of sub-hypnotic and hypnotic doses of pentobarbital. The extract also produced a dose-dependent increase and decrease in the spontaneous motor activity (0.5-1.5 g/kg, respectively), no disruption or a decrease on exploratory (hole-board) behavioral profiles (0.5-1.5 g/kg respectively) and a dose-related anxiolytic-like activity as indicated by increases in the percentage of marbles they left uncovered in the marble-burying test at doses (0.5 g/kg) that do not disrupt the motor activity. In addition, the extract (1.5 g/kg) produced a significant increase in the latency time and a decrease in the duration of seizures and mortality induced by PTZ 75 mg/kg in mice. CONCLUSION: These results suggest that the aqueous extract of Artemisia copa may contain sedative principles with potential anxiolytic and anticonvulsant activities.

Evaluation of antinociceptive, antinflammatory activities and phytochemical analysis of aerial parts of Urtica urens L.

The antinociceptive and antiinflammatory activities of the ethanol extract of the aerial part of Urtica urens were determined by experimental animal models. U. urens extract was found to possess significant antinociceptive activity in chemically induced mouse pain models (ED50 39.3 mg/kg: 17.2-74.5 mg/kg) in the writhing test and 62.8% inhibition of the licking time in the late phase of the formalin test at a dose of 500 mg/kg p.o. and antiinflammatory activity on carrageenan-induced rat hind paw edema (41.5% inhibition at a dose of 300 mg/kg i.p.). The extract displayed activity neither in the thermal model of pain nor in the topical inflammation model. The major component of the extract was determined as chlorogenic acid (670 mg/1000 g dry weight) and could be partly responsible for this activity.

Neuropharmacological activity of Eupatorium buniifolium aqueous extract in mice.

The aim of this study was to evaluate the neuropharmacological profile of the Eupatorium buniifolium aqueous extract (EB) in mice. EB at doses up to 1.5 g/kg p.o. of the lyophilized material produced a dose dependent sleep induction and potentiation of sub-hypnotic and hypnotic doses of pentobarbital, respectively. However, EB neither modified the spontaneous motor activity nor produced a myorelaxant effect. Moreover, EB 1.5 g/kg in a nose-poke habituation task, produced a disruption of the normal patterns of habituation, and in a step-down inhibitory avoidance task, induced an amnesic effect similar to diazepam. These results suggest that the activity of EB may be a CNS-depressant.