ABSTRACT
Anacardium occidentale Linn. (Anacardiaceae) is a plant largely used in Africa for the treatment of different diseases. In Côte d'Ivoire it's commonly used for the treatment of hypertension. The present study was carried out in order to assess the effects of Anacardium occidentale extract (ANOE) on cardiovascular parameters in animal models. A mercury manometer kymograph of Ludwig was used to measure the blood pressure of normotensive rabbits in control conditions (normal physiological solution) and under the influence of ANOE. The contractile activity of an isolated rat heart was also measured in control conditions and under the influence of ANOE in different physiological media using a modified Langendhorff (1895) apparatus. The aqueous Anacardium occidentale (ANOE) bark extract applied intravenously in different doses (12, 40, 90, and 167 mg/kg b.w.), produced a significant dose-dependent decrease in blood pressure of previously normotensive rabbits (up to 89% vs control). Atropine (1 mg/ml) pre-treatment failed to reverse the hypotensive effects elicited by the extract. ANOE applied to isolated rat heart preparations in different concentrations (0.01, 0.1, 1.0, and 10 µg/ml) induced negative inotropic and chronotropic effects. Atropine pre-treatment of heart preparations (0.1 µg/ml) failed to reverse the negative effects induced by ANOE. The extract's action on heart contractile activity studied in modified culture media further confirmed its cardio-inhibitory effects. ANOE induced strong hypotensive and cardio-inhibitory effects in animal models.
Subject(s)
Anacardium , Blood Pressure/drug effects , Heart Rate/drug effects , Hypotension/chemically induced , Myocardial Contraction/drug effects , Plant Extracts , Animals , Depression, Chemical , Dose-Response Relationship, Drug , Hypotension/physiopathology , Injections, Intravenous , Lethal Dose 50 , Models, Animal , Plant Bark , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Extracts/toxicity , Plant Stems , Rabbits , Rats , Rats, WistarABSTRACT
The aim of this study was to examine the psychopharmacological effects of antidepressants on post-ischemic rats. Global transient cerebral ischemia was performing with the four-vessels occlusion method. Locomotor activity, neurological scores and activity during the 20 min forced swimming test (FST) session were comparatively evaluated in sham-operated and ischemic animals. Three doses of four antidepressants or saline were then intraperitoneally administered 23.5, 5 and 1h before the 5 min FST session, and 0.5h before the elevated plus-maze (EPM). Histological quantification of neuronal loss was performed at the end of the experiments. Results show that before treatment, ischemic animals present significantly greater spontaneous motor activity, a neurological score and an immobility time in the 20 min FST lower than sham-operated animals. After treatment, compared to the saline group, we show an antidepressant-like activity in the FST with all the molecules, except with the fluvoxamine, and an anxiolytic-like effect in the EPM, with at least one dose of each compounds. The observed effect is very similar according to whether or not the animals were ischemic, with a tendency to react more important for ischemic animals versus sham-operated. This difference is significant in the FST for the immobility time and in the EPM for the ratio of distance, of time, of number of entrances and non-protected head dips with the 45 mg dose of milnacipran. These results demonstrate that even though global transient cerebral ischemia induces important cerebral lesions, it modifies little the effects of the different antidepressants, whatever their primary pharmacological target, with a particular effectiveness with the dual serotonin and norepinephrine reuptake inhibitor milnacipran.
Subject(s)
Antidepressive Agents/pharmacology , Brain Ischemia/complications , Depressive Disorder/prevention & control , Exploratory Behavior/drug effects , Immobility Response, Tonic/drug effects , Motor Activity/drug effects , Analysis of Variance , Animals , Anxiety Disorders/etiology , Anxiety Disorders/prevention & control , Behavior, Animal/drug effects , Behavior, Animal/physiology , Brain Ischemia/pathology , Brain Ischemia/psychology , Cyclopropanes/pharmacology , Depressive Disorder/etiology , Desipramine/pharmacology , Disease Models, Animal , Dose-Response Relationship, Drug , Exploratory Behavior/physiology , Fluvoxamine/pharmacology , Hippocampus/pathology , Imipramine/pharmacology , Immobility Response, Tonic/physiology , Male , Milnacipran , Motor Activity/physiology , Rats , Rats, WistarABSTRACT
We used two validated psychopharmacological methods, the forced swimming test (FST 20 min and 5 min) and the elevated plus-maze (EPM), to quantify depression-like and anxiety-like behavior induced by transient global cerebral ischemia in the rat. We also validated use of these methods for the study of antidepressant (imipramine) and anti-anxiety drugs (diazepam). Twelve days after surgery to provoke transient global ischemia, spontaneous motor activity was 40% higher in ischemic rats than in sham-operated controls. Duration of immobility during the FST 20 min and 5 min was 28 and 30% shorter, respectively, than in controls. Treatment with imipramine (3 x 30 mg/kg i.p.) induced a significantly shorter duration of immobility during the FST 5 min, but with no difference between ischemia and control rats. The EPM demonstrated that ischemia did not induce any change in the six behavior parameters measured. Diazepam (1.5 mg/kg i.p.) induced significant anxiolytic effects which were similar in ischemic and sham-operated animals. Both tests failed to demonstrate perturbed performance but conversely, these findings did disclose the sensitivity of ischemia-exposed rats to the action of imipramine and diazepam, demonstrating the usefulness of these tests as psychopharmocological tools for evaluating the effect of psychotropics in the ischemic rat.
