Anxiolytic-like actions of leaves of Casimiroa edulis (Rutaceae) in male Wistar rats

Natural Products: Ray of Hope for Anxiety Disorders

Background:

Anxiety, a familiar form of psychiatric disorder, influences numerous persons throughout the world. These psychological disorders frequently need an enduring regime of recommended medicines and impose huge costs on human societies. For the last few decenniums, discovery in the field of natural neurophysiology garnered a lot of recognition because of its least side effects.

Objective:

Many people find it helpful to discover an effective herbal remedy for anxiety with fewer detrimental repercussions. The purpose of the present article is to report medicinal plant species used as anti-anxiety agents, which in turn, are helpful to develop new anti-anxiety herbal formulations.

Method:

An unlimited, semantic electronic and manual exploration of PubMed, Cumulative Index of Nursing and Allied Health Literature, ISI, Google Scholar, Elsevier's abstract and citation database, and the database libraries was carried using keywords such as medicinal plants, herbal drugs, traditional medicine, and anxiety for recognizing natural medications in the management of anxiety disorders.

Results:

Literary review collected the information of potential anti-anxiety plants. Data support the effectiveness of some popular herbal remedies by indicating high-quality scientific studies and support several clinically efficacious natural plants as anxiolytics.

Conclusion:

Evidence-based studies indicate that natural plant treatment is an efficient way to manage anxiety disorders; the benefits outweigh the risks.

Ethnomedicine and neuropsychopharmacology in Mesoamerica

ETHNOPHARMACOLOGICAL RELEVANCE

The burden of disease caused by mental and neurological disorders is increasing globally, to a disproportionate degree in Latin America. In contrast to the many psychoactive plants with a use history in Mesoamerican cultures, the translation to the wider population of knowledge around numerous botanicals used contemporarily by indigenous Mesoamerican societies to treat psychological and neurological disorders did not receive the same attention.

MATERIAL AND METHODS

We used the previously published Mesoamerican Medicinal Plant Database to extract species and associated botanical drugs used as treatments for illnesses associated with the nervous system by Mesoamerican cultures in Belize, Guatemala, and Mexico. With the critical use of published pharmacological literature, the cross-culturally most salient genera are systematically reviewed.

RESULTS

From 2188 plant taxa contained in the database 1324 are used as treatments for illnesses associated with the nervous system. The ethnomedical data was critically confronted with the available biomedical literature for the 58 cross-culturally most salient genera. For a considerable proportion of the frequently used taxa, preclinical data are available, mostly validating ethnomedicinal uses.

CONCLUSION

This quantitative approach facilitates the prioritization of taxa for future pre-clinical, clinical and treatment outcome studies and gives patients, practitioners, and legislators a fundamental framework of evidence, on which to base decisions regarding phytomedicines.

Status analysis of herbal drug therapies in epilepsy: advancements in the use of medicinal plants with anti-inflammatory properties

BACKGROUND

Use of plants and plant products in health care has shown exponential increase in past two decades.

INTRODUCTION

In-spite of the availability of well-established pharmacotherapy for epilepsy, a large no of population still explores alternative treatments due to refractory seizures, adverse effects of drugs, chronic treatment, inaccessibility of standard therapies in rural areas and the social stigma attached to the disease. Various studies on medicinal plants showed the protective effect of herbals in animal models of epilepsy.

METHOD

In the present review, a status analysis of the traditional use of various medicinal plants in epilepsy with a special focus on plats having anti-inflammatory potential is recorded.

RESULT AND CONCLUSION

The shortcomings of research on medicinal plants which needs to be explored further in order to tackle the growing need of safer and effective drugs for epilepsy are discussed. Overall, there is a huge scope of herbal drugs in CNS disorders especially epilepsy, either as an adjunct by reducing the dose and thus side effects of standard anti-epileptic drugs or as standalone agent . Although, there is still an urgent need of well planned randomized controlled clinical trials to validate their efficacy and safety.

The Confrontation between Ethnopharmacology and Pharmacological Tests of Medicinal Plants Associated with Mental and Neurological Disorders

For neurological disorders, pharmacological tests have shown promising results in the reduction of side effects when using plants with known therapeutic effects in the treatment of some types of dementia. Therefore, the goals of this study are to gather data about the major medicinal plants used in the nervous system as described in ethnopharmacological surveys from South America and Brazil and to compare this data with the results from pharmacological tests on the active principles of those same plants found in the scientific literature. After collecting the data about each plant, their respective popular indication was compared with the results found through pharmacological tests. The discrepancy rate between the effects observed by ethnopharmacological and pharmacological methods in this study is greater than 50%. In conclusion, despite the importance of ethnopharmacological data, it is important to make comparisons with pharmacological tests for the same plants, since the pharmacological studies, although few, have shown a high rate of discrepancy in the results.

Mexican medicinal plants with anxiolytic or antidepressant activity: Focus on preclinical research

ETHNOPHARMACOLOGICAL RELEVANCE

Anxiety and depression are considered the most prevalent psychiatric disorders worldwide. In Mexico, the use of medicinal plants to alleviate the symptoms associated with these psychiatric disorders is increasing. However, there is little scientific evidence that validates the efficacy of these plants. This evidence needs to be critically revised, and further studied to provided scientific support for their use.

AIM OF THE STUDY

To identify the plants that are used in Mexico for the treatment of disorders related to anxiety and depression, and to review the current preclinical and when available, clinical information of these plants.

METHODS

We searched in scientific databases (Pubmed, Web of Science, Scopus and other web sources such as "Biblioteca digital de la medicina tradicional Mexicana" ) for Mexican plants used for the treatment of anxiety and depression that have been analyzed in preclinical studies. Additional information was obtained from published books. For this review, we also consider those plants used in Mexican traditional medicine for the treatment of "nervios," "susto" or "espanto;" common terms that describe symptoms related to anxiety and depression disorders.

RESULTS

The bibliographic search identified 49 plants used in Mexican traditional medicine for the treatment of disorders related to anxiety and depression. From all these plants, 59% were analyzed in preclinical research, and only 8% were tested in clinical studies; only a few of these studies tried to elucidate their mechanism of action. In general, it is proposed that the plant extracts interact with the GABAergic system. However, only part of these studies attempted to analyze other neurotransmitter systems. Finally, in some cases, drug-herbal interactions were reported.

CONCLUSIONS

There is a large number of Mexican medicinal plants used as a treatment for anxiety and depression disorders. Although some of these plants have been studied in preclinical research, in most cases these studies are preliminary, and the understanding of the mechanism of action is inconclusive. The need for systematic studies in preclinical and clinical research is evident, and efforts should be done to fulfill these research. Finally, it is important also to study possible drug-herbal interactions to establish specific recommendations for people that use these plants as anxiolytic or antidepressant treatments either alone or in combination with another type of medicine.

Concordance and incongruence in preclinical anxiety models: Systematic review and meta-analyses

Rodent defense behavior assays have been widely used as preclinical models of anxiety to study possibly therapeutic anxiety-reducing interventions. However, some proposed anxiety-modulating factors - genes, drugs and stressors - have had discordant effects across different studies. To reconcile the effect sizes of purported anxiety factors, we conducted systematic review and meta-analyses of the literature on ten anxiety-linked interventions, as examined in the elevated plus maze, open field and light-dark box assays. Diazepam, 5-HT1A receptor gene knockout and overexpression, SERT gene knockout and overexpression, pain, restraint, social isolation, corticotropin-releasing hormone and Crhr1 were selected for review. Eight interventions had statistically significant effects on rodent anxiety, while Htr1a overexpression and Crh knockout did not. Evidence for publication bias was found in the diazepam, Htt knockout, and social isolation literatures. The Htr1a and Crhr1 results indicate a disconnect between preclinical science and clinical research. Furthermore, the meta-analytic data confirmed that genetic SERT anxiety effects were paradoxical in the context of the clinical use of SERT inhibitors to reduce anxiety.

Enhancing Spatial Memory: Anxiolytic and Antidepressant Effects of Tapinanthus dodoneifolius (DC) Danser in Mice

We evaluated the anxiolytic and antidepressant effects of the aqueous extract of the bark of Tapinanthus dodoneifolius (TAE) (Danser) (25, 50, and 100 mg/kg), using open field, elevated plus maze, and forced swimming tests. Effect of TAE was compared to standard drugs diazepam (2 mg/kg) and imipramine (10 mg/kg). Additionally, the same doses of TAE were evaluated on rat's memory using Y-maze task. Results showed a significant (P < 0.05; 100 mg/kg) increase in the percentage of open arm entry and the time spent in the open arms in the elevated plus maze, suggesting an anxiolytic activity of the extract. In a dose-dependant manner, TAE at 25 mg/kg significantly (P < 0.05) decreased the number of lines crossed and the rearing behavior in the open field test, suggesting its possible sedative activity. In the forced swimming test, the immobility time of the animal was significantly reduced (P < 0.05) by TAE (100 mg/kg), compared to control, and this effect was quite comparable to that of imipramine. In the Y-maze paradigm, TAE at 50 mg/kg caused a significant increase in the spontaneous alternations but with a significant decrease in exploratory behavioral pattern. Taking these results together, TAE improved the spatial memory and showed anxiolytic, antidepressant, and sedative activities. The present results support the anxiolytic and antidepressant activities of TAE and, to our knowledge, for the first time, demonstrate its enhancing effect on memory.

Plant-based medicines for anxiety disorders, Part 1: a review of preclinical studies

Research in the area of herbal psychopharmacology has revealed a variety of promising medicines that may provide benefit in the treatment of general anxiety and specific anxiety disorders. However, a comprehensive review of plant-based anxiolytics has been absent to date. This article (part 1) reviews herbal medicines for which only preclinical investigations for anxiolytic activity have been performed. In part 2, we review herbal medicines for which there have been clinical investigations for anxiolytic activity. An open-ended, language-restricted (English) search of MEDLINE (PubMed), CINAHL, Scopus and the Cochrane Library databases was conducted (up to 28 October 2012) using specific search criteria to identify herbal medicines that have been investigated for anxiolytic activity. This search of the literature revealed 1,525 papers, from which 53 herbal medicines were included in the full review (having at least one study using the whole plant extract). Of these plants, 21 had human clinical trial evidence (reviewed in part 2), with another 32 having solely preclinical studies (reviewed here in part 1). Preclinical evidence of anxiolytic activity (without human clinical trials) was found for Albizia julibrissin, Sonchus oleraceus, Uncaria rhynchophylla, Stachys lavandulifolia, Cecropia glazioui, Magnolia spp., Eschscholzia californica, Erythrina spp., Annona spp., Rubus brasiliensis, Apocynum venetum, Nauclea latifolia, Equisetum arvense, Tilia spp., Securidaca longepedunculata, Achillea millefolium, Leea indica, Juncus effusus, Coriandrum sativum, Eurycoma longifolia, Turnera diffusa, Euphorbia hirta, Justicia spp., Crocus sativus, Aloysia polystachya, Albies pindrow, Casimiroa edulis, Davilla rugosa, Gastrodia elata, Sphaerathus indicus, Zizyphus jujuba and Panax ginseng. Common mechanisms of action for the majority of botanicals reviewed primarily involve GABA, either via direct receptor binding or ionic channel or cell membrane modulation; GABA transaminase or glutamic acid decarboxylase inhibition; a range of monoaminergic effects; and potential cannabinoid receptor modulation. Future research should focus on conducting human clinical trials on the plants reviewed with promising anxiolytic activity.

The aqueous crude extract of Montanoa frutescens produces anxiolytic-like effects similarly to diazepam in Wistar rats: involvement of GABAA receptor

ETHNOPHARMACOLOGICAL RELEVANCE

Cihuapatli is the Nahuatl name assigned to some medicinal plants grouped in the genus Montanoa, where Montanoa frutescens (Family: Asteraceae, Tribe: Heliantheae) is included. The crude extract from these plants has been used for centuries in the Mexican traditional medicine as a remedy for reproductive impairments and mood disorders. Experimental studies have systematically corroborated the traditional use of cihuapatli on reproductive impairments and sexual motivation, however, the effect on mood and "nervous" disorders, remains to be explored.

MATERIALS AND METHODS

The anxiolytic-like effect of aqueous crude extract of M. frutescens (25, 50 and 75 mg/kg) was investigated in male Wistar rats evaluated in the elevated plus-maze and compared with several doses of diazepam (1, 2 and 4 mg/kg) as a reference anxiolytic drug. Picrotoxin (1 mg/kg), a noncompetitive antagonist of the GABA(A) receptor, was used in experimental procedures to evaluate if this receptor could be involved in the anxiolytic-like effects produced by M. frutescens. To discard hypoactivity, hyperactivity, or no changes associated with treatments, which could interfere with the behavioral activity in the elevated plus-maze, rats were subjected to the open field test.

RESULTS

M. frutescens at 50 mg/kg showed anxiolytic-like activity similarly to 2 mg/kg of diazepam, without disrupts in general motor activity. The anxiolytic-like effect of M. frutescens detected in the elevated plus-maze was blocked by picrotoxin, indicating that GABA(A) receptors are involved in the modulation of this effect.

CONCLUSIONS

The results corroborate the use of M. frutescens in folk Mexican ethnomedicine as a potential anxiolytic agent and suggest that this effect is mediated by the GABA(A) receptors. Additionally, some sedative effects with high doses of M. frutescens were detected in the present study.

The anxiolytic-like effect of an essential oil derived from Spiranthera odoratissima A. St. Hil. leaves and its major component, β-caryophyllene, in male mice

Spiranthera odoratissima A. St. Hil. (manacá) is used in folk medicine to treat renal and hepatic diseases, stomachache, headaches and rheumatism. A central nervous system (CNS) depressant effect of the hexane fraction from the ethanolic extract of this plant has been described. β-caryophyllene, the main component of this essential oil, is a sesquiterpene compound with anti-inflammatory properties that has been found in essential oils derived from several medicinal plants. This work is aimed to evaluate the pharmacological activity of the essential oil obtained from S. odoratissima leaves (EO) and its major component on the murine CNS; we aimed to evaluate a possible anxiolytic-like effect and the underlying mechanisms involved. In an open field test, EO (500 mg/kg) and β-caryophyllene (50, 100 and 200 mg/kg) increased the crossing frequency (P<0.05) and, EO (250 and 500 mg/kg) and β-caryophyllene (200 mg/kg) increased the time spent in the center (P<0.05) without altering total crossings of the open field. EO and β-caryophyllene did not alter the number of falls in the rota-rod test (P>0.05). In the pentobarbital-induced sleep test, EO (500 mg/kg) and β-caryophyllene (200 and 400 mg/kg) decreased the latency to sleep (P<0.05), and EO (125, 250 and 500 mg/kg) (P<0.001) and β-caryophyllene (200 and 400 mg/kg) (P<0.05 and P<0.001) increased the sleep time. In anxiety tests, EO (500 mg/kg) and β-caryophyllene (100 and 200 mg/kg) increased head-dipping behavior (P<0.05) in the hole-board test, entries (P<0.05) into and time spent (P<0.05) on the open arms of the elevated plus maze (EPM), and number of transitions (P<0.05) and time spent in the light compartment (P<0.05) of a light-dark box (LDB). We further investigated the mechanism of action underlying the anxiolytic-like effect of EO and β-caryophyllene by pre-treating animals with antagonists of benzodiazepine (flumazenil) and 5-HT(1A) (NAN-190) receptors prior to evaluation using EPM and LDB. The anxiolytic-like effects of EO were significantly reduced by pre-treatment with NAN-190 (P<0.05) but not flumazenil (P>0.05). The anxiolytic-like effects of β-caryophyllene were not blocked by either NAN-190 or flumazenil (P>0.05). In conclusion, these results suggest that the essential oil derived from S. odoratissima produces an anxiolytic-like effect without altering motor performance and that this effect is mediated by 5-HT(1A) but not via benzodiazepine receptors. In addition, the major component, β-caryophyllene, also has an anxiolytic-like effect that may contribute to the effects of EO, but this effect does not seem to be mediated via 5-HT(1A) or benzodiazepine receptors.

Inhibition of HIV-1 reverse transcriptase associated activities by the hydroalcoholic extract of Casimiroa edulis seeds

The hydroalcoholic extract obtained from the seeds of Casimiroa edulis cultivated in Sardinia (Italy) have been assayed on the two enzymatic-associated activities of the HIV-1 reverse transcriptase (RT), the RNA-dependent DNA polymerase (RDDP) and the ribonuclease H. In biochemical assays, the extract inhibited both activities in a dose-dependent manner, showing a 10-fold more potent inhibition of the HIV-1 RT RDDP activity. Furthermore, the extract was cytotoxic on K562 cell replication.

Anxiolytic and anticonvulsant effects on mice of flavonoids, linalool, and alpha-tocopherol presents in the extract of leaves of Cissus sicyoides L. (Vitaceae)

The aim of the present study is to demonstrate the anxiolytic and anticonvulsant effects of a hydroalcoholic extract obtained from the aerial parts of Cissus sicyoides L. (CS) (Vitaceae) on male and female mice using several behavioral assays. Groups of males and females treated via intraperitoneal (IP) with doses of 300, 600, and 1000 mg/kg of the extract showed significant action in the elevated plus-maze (EPM), time spent in the open arms, and number of entries in the open arms. The board-hole test also showed a significant increase in the time spent in head-dipping and in marble-burying test of the number of marbles buried. The same treatment increased the duration of sleeping time induced by sodium pentobarbital and also showed a significant increase in protection against pentylenotetrazole-induced convulsions. These results indicate an anxiolytic and anticonvulsant-like action from C. sicyoides L. extract on mice, probably due to the action of flavonoid(s), Linalool, and alpha-tocopherol present in the C. sicyoides leaves.

Chemical Composition of the Leaf Essential Oil of Casimiroa Edulis La Llave & Lex. (Rutaceae) from Monteverde, Costa Rica

The leaf essential oil of Casimiroa edulis (Rutaceae), collected from Monteverde, Costa Rica, has been obtained by hydrodistillation and analyzed by GC-MS. The leaf oil was dominated by sesquiterpene hydrocarbons, predominately germacrene D (16-22%) and ( E)-caryophyllene (16-17%), consistent with the traditional use of this plant as a sedative, sleep inducer and hypotensive.

Animal models of anxiety and anxiolytic drug action

Animal models of anxiety attempt to represent some aspect of the etiology, symptomatology, or treatment of human anxiety disorders, in order to facilitate their scientific study. Within this context, animal models of anxiolytic drug action can be viewed as treatment models relevant to the pharmacological control of human anxiety. A major purpose of these models is to identify novel anxiolytic compounds and to study the mechanisms whereby these compounds produce their anxiolytic effects. After a critical analysis of "face," "construct," and "predictive" validity, the biological context in which animal models of anxiety are to be evaluated is specified. We then review the models in terms of their general pharmacological profiles, with particular attention to their sensitivity to 5-HTIA agonists and antidepressant compounds. Although there are important exceptions, most of these models are sensitive to one or perhaps two classes of anxiolytic compounds, limiting their pharmacological generality somewhat, but allowing in depth analysis of individual mechanisms of anxiolytic drug action (e.g., GABAA agonism). We end with a discussion of possible sources of variability between models in response to 5-HTIA agonists and antidepressant drugs.

Effects of calcium channel blockers on antidepressant action of Alprazolam and Imipramine

Alprazolam is effective as an anxiolytic and in the adjunct treatment of depression. In this study, the effects of calcium channel antagonists on the antidepressant action of alprazolam and imipramine were investigated. A forced swimming maze was used to study behavioral despair in albino mice. Mice were divided into nine groups (n = 7 per group). One group received a single dose of 1% Tween 80; two groups each received a single dose of the antidepressant alone (alprazolam or imipramine); two groups each received a single dose of the calcium channel blocker (nifedipine or verapamil); four groups each received a single dose of the calcium channel blocker followed by a single dose of the antidepressant (with same doses used for either in the previous four groups). Drug administration was performed concurrently on the nine groups. Our data confirmed the antidepressant action of alprazolam and imipramine. Both nifedipine and verapamil produced a significant antidepressant effect (delay the onset of immobility) when administered separately. Verapamil augmented the antidepressant effects of alprazolam and imipramine (additive antidepressant effect). This may be due to the possibility that verapamil might have antidepressant-like effect through different mechanism. Nifedipine and imipramine combined led to a delay in the onset of immobility greater than their single use but less than the sum of their independent administration. This may be due to the fact that nifedipine on its own might act as an antidepressant but blocks one imipramine mechanism that depends on L-type calcium channel activation. Combining nifedipine with alprazolam produced additional antidepressant effects, which indicates that they exert antidepressant effects through different mechanisms.

Zapotin, a Phytochemical Present in a Mexican Fruit, Prevents Colon Carcinogenesis

Zapotin (5,6,2',6'-tetramethoxyflavone), found in the tropical fruit zapote blanco (Casimiroa edulis), is consumed in many parts of the world, including Central America and Asia. Previously, we have demonstrated in vitro chemopreventive activity of extracts derived from the seeds of C. edulis. In the present study, we examined the effects of natural and synthetic zapotin in SW480, SW620, and HT-29 colon cancer cell lines and on the generation of aberrant crypt foci (ACF) using mice. Zapotin treatment (IC50=2.74x10(-7 M)) resulted in a marked suppression of cell proliferation in the HT-29 cells. Cell cycle analysis demonstrated a significant accumulation of cells in the G2-M phase, with a concomitant decrease of cells in the G0-G1 phase, after treatment with zapotin (molecular weight=342.35 g/mol; 1 microM for 18, 24, and 48 h). Zapotin treatment enhanced apoptosis in all of the colon cancer cell lines studied. For the study of ACF, 5-wk-old CF-1 mice were given subcutaneous injections of azoxymethane (AOM; 10 mg/kg body weight, BW) weekly for 2 wk, and zapotin (5 or 10 mg/kg BW; 46 or 92 pmol/kg BW) or vehicle was administered intragastrically 7 days/wk. The mean number of ACF for the control group was 14.0+/-2.3, whereas the mean numbers of ACF in the zapotin-treated groups were 6.2+/-1.7 and 4.6+/-1.4 at doses of 5.0 and 10.0 mg/kg BW, respectively. Loss of hexosaminidase, a lysosomal enzyme active in normal colonic crypts but decreased in up to 95% of ACF, was used as a second biomarker for colon carcinogenesis. Zapotin was found to significantly (P<0.01) prevent loss of hexosaminidase in the colon of AOM-treated mice. The present study is the first to report the potent anticancer activity of zapotin and suggests a role for zapotin both as a chemopreventive and a chemotherapeutic agent against colon cancer.

Cardiotonic and sedative effects of Cecropia pachystachya Mart. (ambay) on isolated rat hearts and conscious mice

Cecropia pachystachya Mart. is popularly called "ambay" and extensively used in herbal medicine of South America for cough and asthma. In Argentina it grows in neotropical rainforest (Ntr C.p.) and in a temperate region (Tp C.p.). In a previous work we showed their hypotensive properties with different potency and toxicity, and now we studied the Tp C.p. effects in isolated heart from rats and central effects of both plants on the open-field test for mice. Tp C.p. produced a positive inotropic effect on isolated rat hearts, which was not affected by 1 microM propranolol, suggesting that it is not due to a beta-adrenergic effect. In contrast, it was prevented by pretreatment with high [K](o) media, which stimulates the Na,K-ATPase pump, suggesting an inhibition of the pump by "ambay", as digital do. In the open-field test, both Ntr C.p. and Tp C.p. similarly decreased the spontaneous locomotion and exploratory behavior of mice at doses between 180 and 600 mg/kg. Ntr C.p. potentiated the effect of 3 mg/kg diazepam to one similar to 10 mg/kg diazepam, but was not antagonized by 0.5 mg/kg flumazenil. Amphetamine at 5 mg/kg prevented the sedative effect of Ntr C.p. Chromatographic analysis showed that both plants have a qualitatively similar fingerprint but quantitatively differed in at least three components. Although the purpose was not to identify them, both plants have at least 10 compounds. Two of them were in higher amount in Tp C.p. than in Ntr C.p., and then, they could be responsible for the cardiovascular toxicity of Tp C.p. In conclusion, the results suggest that ambay has cardiotonic and sedative properties. The sedative effect could be useful in cough treatment. The extract resulted additive to benzodiazepines but it did not bind to the same site on GABA-A receptor, and it was interfered by the dopamine release produced with amphetamine.

The hydroalcoholic extract of Salvia elegans induces anxiolytic- and antidepressant-like effects in rats

Behavioral effects of a hydroalcoholic (60% ethanol) extract from the leaves of Salvia elegans Vahl (Lamiaceae) were studied in male Sprague-Dawley rats. The extract was administered intraperitoneally and its effects on spontaneous motor activity (total motility, locomotion, rearing and grooming behavior) were monitored. Putative anxiolytic and antidepressant properties of Salvia elegans were studied in the elevated plus-maze test (EPM) and in the forced swimming test (FST), respectively. Deleterious effects of Salvia elegans on learning and memory were also studied by using active and passive avoidance paradigms. The results revealed that all doses (3.12, 12.5, 25 and 50 mg/kg) of the extract caused a significant decrease in total motility, locomotion, rearing and grooming behavior. Only the dose of 12.5 mg/kg increased the exploration of the EPM open arms in a similar way to that of diazepam (1 mg/kg). In the FST, all doses of the extract induced a reduction of immobility, in a similar way to that of fluoxetine (10 mg/kg) and imipramine (12.5 mg/kg), along with a significant increase in the time spent in swimming behavior. Acquisition of active avoidance responses was disrupted by pre-treatment with the extract, but retention of a passive avoidance response was not significantly modified. These results suggest that some of the components of the hydroalcoholic extract of Salvia elegans have psychotropic properties, which deserve further investigation.

The anxiolytic-like effects of Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) in mice

The aim of the present work is to demonstrate the putative sedative and anxiolytic-like effects of a hydro-ethanolic extract obtained from the aerial parts of Aloysia polystachya (Verbenaceae) in male mice using several behavioural assays. Groups of male mice orally treated with doses of 1.0, 10.0 and 100.0 mg/kg of the extract did not show any significant alteration of their locomotor activity, body temperature or motor coordination. The same treatment increased the duration of the sleeping time induced by 30.0 mg/kg i.p. of sodium pentobarbital. However, the sleeping time induced by ethyl ether was not modified by the oral administration of the extract, not confirming the putative sedative effect of the plant. The ethanolic extract also significantly increased the percentage of both entries (1.0 and 100.0 mg/kg) and the time spent (10.0 and 100.0 mg/kg) into the open arms of the elevated plus maze (EPM). Nevertheless, the binding of (3)H-flunitrazepam ((3)H-FNZ) to the benzodiazepine binding site (BDZ-bs), in washed crude synaptosomal membranes from rat cerebral cortex, was not affected by the semi-purified components from Aloysia polystachya. These results indicate an anxiolytic-like profile of action for the extract of Aloysia polystachya without sedative side effect, being this activity probably mediated by other mechanism than BDZ-bs modulation at the GABA(A) receptors.