Quantitative determination of pentacyclic triterpenic acids in Amazonian species Eugenia punicifolia DC by ATR-FTIR.

Leaf extracts from Eugenia punicifolia are rich in pentacyclic triterpenic acids (PTAs), especially barbinervic acid (BA), which is an important biomarker of the species. Dichloromethane extracts of E. punicifolia leaf samples harvested in Amazonian summer and winter seasons were analysed by infrared spectroscopy using ATR-FTIR technique aiming to evaluate barbinervic acid (BA) and its PTAs equivalent contents. A validated HPLC-DAD quantification method was also performed to compare the relationship between BA and PTAs contents in E. punicifolia extracts with ATR-FTIR technique. The use of ATR-FTIR allowed a rapid, efficient and environment-friendly quantification method for total PTAs equivalent content, showing a significant statistical difference (p< 0.05) in the production of these metabolites (38.66 µg/mL, summer; 13.62 µg/mL, winter). A mathematical correction factor between the HPLC-DAD and ATR-FTIR quantification methods was established.

In vitro and in silico studies for barbinervic acid, a triterpene isolated from Eugenia punicifolia that inhibits vasopressor tone.

We investigated the role of triterpene barbinervic acid from Eugenia punicifolia dichloromethane extract in vasopressor responses. Renal arteries were cannulated and perfused with Krebs-Hepes solution. Changes in aorta isometric tension were recorded and transferred to a data acquisition system. Cumulative curves were constructed based on the maximum effect of agonists. Barbinervic acid reduced the renal tonus induced by NA in a NO-dependent manner (IC50 = 30 µM). Triterpene (70 µM) also induced rapid and transient relaxation in aorta that had been precontracted with K+ (53.2 ± 0.05%) or phenylephrine (36.7 ± 0.05%). In silico data revealed two possible active sites for interactions between barbinervic acid and NO synthase. Barbinervic acid showed a vasodilator effect and could potentially be used as a template for developing new molecules for the treatment of cardiovascular disease.

Clinical trials on drug repositioning for COVID-19 treatment.

The World Health Organization (WHO) was informed on December 2019 about a coronavirus pneumonia outbreak in Wuhan, Hubei province (China). Subsequently, on March 12, 2020, 125,048 cases and 4,614 deaths were reported. Coronavirus is an enveloped RNA virus, from the genus Betacoronavirus, that is distributed in birds, humans, and other mammals. WHO has named the novel coronavirus disease as COVID-19. More than 80 clinical trials have been launched to test coronavirus treatment, including some drug repurposing or repositioning for COVID-19. Hence, we performed a search in March 2020 of the clinicaltrials.gov database. The eligibility criteria for the retrieved studies were: contain a clinicaltrials.gov base identifier number; describe the number of participants and the period for the study; describe the participants' clinical conditions; and utilize interventions with medicines already studied or approved for any other disease in patients infected with the novel coronavirus SARS-CoV-2 (2019-nCoV). It is essential to emphasize that this article only captured trials listed in the clinicaltrials.gov database. We identified 24 clinical trials, involving more than 20 medicines, such as human immunoglobulin, interferons, chloroquine, hydroxychloroquine, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, methylprednisolone, bevacizumab, and traditional Chinese medicines (TCM). Although drug repurposing has some limitations, repositioning clinical trials may represent an attractive strategy because they facilitate the discovery of new classes of medicines; they have lower costs and take less time to reach the market; and there are existing pharmaceutical supply chains for formulation and distribution.

En diciembre de 2019 fue informado a la Organización Mundial de la Salud (OMS) un brote de neumonía por coronavirus en Wuhan, provincia de Hubei, China. Al 12 de marzo de 2020, se habían notificado 125 048 casos y 4 614 muertes. El coronavirus es un virus ARN envuelto del género Betacoronavirus distribuido en aves, seres humanos y otros mamíferos. La OMS ha denominado a la nueva enfermedad por coronavirus COVID-19. Se han puesto en marcha más de 80 ensayos clínicos para evaluar un tratamiento para el coronavirus, que incluyen algunos ensayos de reposicionamiento de medicamentos para la COVID-19. En marzo de 2020 se llevó a cabo una búsqueda de los ensayos clínicos registrados en la base de datos clinicaltrials.gov. Los criterios de elegibilidad para los estudios recuperados fueron tener un número de identificación de la base de datos clinicaltrials.gov; describir el número de participantes y el período del estudio; describir las condiciones clínicas de los participantes; y emplear intervenciones con medicamentos ya estudiados o aprobados para cualquier otra enfermedad en pacientes infectados con el nuevo coronavirus SARS-CoV-2 (2019-nCoV). Es esencial destacar que este artículo solo recoge los ensayos que figuran en la base de datos clinicaltrials. gov. Se identificaron 24 ensayos clínicos relacionados con más de 20 medicamentos, como inmunoglobulina humana, interferones, cloroquina, hidroxicloroquina, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, metilprednisolona, bevacizumab y medicina tradicional china. Aunque el reposicionamiento de medicamentos tiene algunas limitaciones, el reposicionamiento de los ensayos clínicos puede representar una estrategia atractiva porque facilita el descubrimiento de nuevas clases de medicamentos; estos tienen costos más bajos y tardan menos en llegar al mercado; y existen cadenas de suministro farmacéutico que apoyan la formulación y la distribución.

A Organização Mundial da Saúde (OMS) foi informada, em dezembro de 2019, sobre um surto de pneumonia por coronavírus em Wuhan, província de Hubei (China). Posteriormente, em 12 de março de 2020, 125 048 casos e 4 614 mortes haviam sido registrados. O coronavírus é um vírus RNA envelopado do gênero Betacoronavírus, distribuído em aves e em humanos e outros mamíferos. A OMS designou a nova doença por coronavírus como COVID-19. Mais de 80 ensaios clínicos foram iniciados para testar tratamentos para o coronavírus, incluindo alguns de reposicionamento de medicamentos para o COVID-19. Assim, em março de 2020 realizou-se uma busca na base de dados clinicaltrials.gov. Os critérios de elegibilidade para os estudos recuperados foram: conter o número identificador da base de dados clinicaltrials.gov; descrever o número de participantes e o período do estudo; descrever as condições clínicas dos participantes; e utilizar intervenções para tratamento de doentes infectados com o novo coronavírus SARS-CoV-2 (2019-nCoV) com medicamentos já estudados ou aprovados para qualquer outra doença. É essencial salientar que este artigo apenas capturou ensaios listados na base de dados clinicaltrials.gov. Foram identificados 24 ensaios clínicos envolvendo mais de 20 medicamentos, tais como imunoglobulina humana, interferons, cloroquina, hidroxicloroquina, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, metilprednisolona, bevacizumabe e medicamentos chineses tradicionais. Embora o reposicionamento de medicamentos tenha algumas limitações, os ensaios clínicos de reposicionamento podem representar uma estratégia atraente, porque facilitam a descoberta de novas classes de medicamentos, têm custos mais baixos, levam menos tempo para chegar ao mercado e se beneficiam de cadeias de fornecimento farmacêutico já existentes para formulação e distribuição.

Clinical trials on drug repositioning for COVID-19 treatment

[ABSTRACT]. The World Health Organization (WHO) was informed on December 2019 about a coronavirus pneumonia outbreak in Wuhan, Hubei province (China). Subsequently, on March 12, 2020, 125,048 cases and 4,614 deaths were reported. Coronavirus is an enveloped RNA virus, from the genus Betacoronavirus, that is distributed in birds, humans, and other mammals. WHO has named the novel coronavirus disease as COVID-19. More than 80 clinical trials have been launched to test coronavirus treatment, including some drug repurposing or repositioning for COVID-19. Hence, we performed a search in March 2020 of the clinicaltrials.gov database. The eligibility criteria for the retrieved studies were: contain a clinicaltrials.gov base identifier number; describe the number of participants and the period for the study; describe the participants' clinical conditions; and utilize interventions with medicines already studied or approved for any other disease in patients infected with the novel coronavirus SARS-CoV-2 (2019-nCoV). It is essential to emphasize that this article only captured trials listed in the clinicaltrials.gov database. We identified 24 clinical trials, involving more than 20 medicines, such as human immunoglobulin, interferons, chloroquine, hydroxychloroquine, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, methylprednisolone, bevacizumab, and traditional Chinese medicines (TCM). Although drug repurposing has some limitations, repositioning clinical trials may represent an attractive strategy because they facilitate the discovery of new classes of medicines; they have lower costs and take less time to reach the market; and there are existing pharmaceutical supply chains for formulation and distribution.

[RESUMEN]. En diciembre de 2019 fue informado a la Organización Mundial de la Salud (OMS) un brote de neumonía por coronavirus en Wuhan, provincia de Hubei, China. Al 12 de marzo de 2020, se habían notificado 125 048 casos y 4 614 muertes. El coronavirus es un virus ARN envuelto del género Betacoronavirus distribuido en aves, seres humanos y otros mamíferos. La OMS ha denominado a la nueva enfermedad por coronavirus COVID- 19. Se han puesto en marcha más de 80 ensayos clínicos para evaluar un tratamiento para el coronavirus, que incluyen algunos ensayos de reposicionamiento de medicamentos para la COVID-19. En marzo de 2020 se llevó a cabo una búsqueda de los ensayos clínicos registrados en la base de datos clinicaltrials.gov. Los criterios de elegibilidad para los estudios recuperados fueron tener un número de identificación de la base de datos clinicaltrials.gov; describir el número de participantes y el período del estudio; describir las condiciones clínicas de los participantes; y emplear intervenciones con medicamentos ya estudiados o aprobados para cualquier otra enfermedad en pacientes infectados con el nuevo coronavirus SARS-CoV-2 (2019-nCoV). Es esencial destacar que este artículo solo recoge los ensayos que figuran en la base de datos clinicaltrials. gov. Se identificaron 24 ensayos clínicos relacionados con más de 20 medicamentos, como inmunoglobulina humana, interferones, cloroquina, hidroxicloroquina, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, metilprednisolona, bevacizumab y medicina tradicional china. Aunque el reposicionamiento de medicamentos tiene algunas limitaciones, el reposicionamiento de los ensayos clínicos puede representar una estrategia atractiva porque facilita el descubrimiento de nuevas clases de medicamentos; estos tienen costos más bajos y tardan menos en llegar al mercado; y existen cadenas de suministro farmacéutico que apoyan la formulación y la distribución.

[RESUMO]. A Organização Mundial da Saúde (OMS) foi informada, em dezembro de 2019, sobre um surto de pneumonia por coronavírus em Wuhan, província de Hubei (China). Posteriormente, em 12 de março de 2020, 125 048 casos e 4 614 mortes haviam sido registrados. O coronavírus é um vírus RNA envelopado do gênero Betacoronavírus, distribuído em aves e em humanos e outros mamíferos. A OMS designou a nova doença por coronavírus como COVID-19. Mais de 80 ensaios clínicos foram iniciados para testar tratamentos para o coronavírus, incluindo alguns de reposicionamento de medicamentos para o COVID-19. Assim, em março de 2020 realizou-se uma busca na base de dados clinicaltrials.gov. Os critérios de elegibilidade para os estudos recuperados foram: conter o número identificador da base de dados clinicaltrials.gov; descrever o número de participantes e o período do estudo; descrever as condições clínicas dos participantes; e utilizar intervenções para tratamento de doentes infectados com o novo coronavírus SARS-CoV-2 (2019-nCoV) com medicamentos já estudados ou aprovados para qualquer outra doença. É essencial salientar que este artigo apenas capturou ensaios listados na base de dados clinicaltrials.gov. Foram identificados 24 ensaios clínicos envolvendo mais de 20 medicamentos, tais como imunoglobulina humana, interferons, cloroquina, hidroxicloroquina, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, metilprednisolona, bevacizumabe e medicamentos chineses tradicionais. Embora o reposicionamento de medicamentos tenha algumas limitações, os ensaios clínicos de reposicionamento podem representar uma estratégia atraente, porque facilitam a descoberta de novas classes de medicamentos, têm custos mais baixos, levam menos tempo para chegar ao mercado e se beneficiam de cadeias de fornecimento farmacêutico já existentes para formulação e distribuição.

Clinical trials on drug repositioning for COVID-19 treatment / Ensayos clínicos de reposicionamiento de medicamentos para el tratamiento de la COVID-19 / Ensaios clínicos de reposicionamento de medicamentos para o tratamento do COVID-19

ABSTRACT The World Health Organization (WHO) was informed on December 2019 about a coronavirus pneumonia outbreak in Wuhan, Hubei province (China). Subsequently, on March 12, 2020, 125,048 cases and 4,614 deaths were reported. Coronavirus is an enveloped RNA virus, from the genus Betacoronavirus, that is distributed in birds, humans, and other mammals. WHO has named the novel coronavirus disease as COVID-19. More than 80 clinical trials have been launched to test coronavirus treatment, including some drug repurposing or repositioning for COVID-19. Hence, we performed a search in March 2020 of the clinicaltrials.gov database. The eligibility criteria for the retrieved studies were: contain a clinicaltrials.gov base identifier number; describe the number of participants and the period for the study; describe the participants' clinical conditions; and utilize interventions with medicines already studied or approved for any other disease in patients infected with the novel coronavirus SARS-CoV-2 (2019-nCoV). It is essential to emphasize that this article only captured trials listed in the clinicaltrials.gov database. We identified 24 clinical trials, involving more than 20 medicines, such as human immunoglobulin, interferons, chloroquine, hydroxychloroquine, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, methylprednisolone, bevacizumab, and traditional Chinese medicines (TCM). Although drug repurposing has some limitations, repositioning clinical trials may represent an attractive strategy because they facilitate the discovery of new classes of medicines; they have lower costs and take less time to reach the market; and there are existing pharmaceutical supply chains for formulation and distribution.(AU)

RESUMEN En diciembre de 2019 fue informado a la Organización Mundial de la Salud (OMS) un brote de neumonía por coronavirus en Wuhan, provincia de Hubei, China. Al 12 de marzo de 2020, se habían notificado 125 048 casos y 4 614 muertes. El coronavirus es un virus ARN envuelto del género Betacoronavirus distribuido en aves, seres humanos y otros mamíferos. La OMS ha denominado a la nueva enfermedad por coronavirus COVID-19. Se han puesto en marcha más de 80 ensayos clínicos para evaluar un tratamiento para el coronavirus, que incluyen algunos ensayos de reposicionamiento de medicamentos para la COVID-19. En marzo de 2020 se llevó a cabo una búsqueda de los ensayos clínicos registrados en la base de datos clinicaltrials.gov. Los criterios de elegibilidad para los estudios recuperados fueron tener un número de identificación de la base de datos clinicaltrials.gov; describir el número de participantes y el período del estudio; describir las condiciones clínicas de los participantes; y emplear intervenciones con medicamentos ya estudiados o aprobados para cualquier otra enfermedad en pacientes infectados con el nuevo coronavirus SARS-CoV-2 (2019-nCoV). Es esencial destacar que este artículo solo recoge los ensayos que figuran en la base de datos clinicaltrials. gov. Se identificaron 24 ensayos clínicos relacionados con más de 20 medicamentos, como inmunoglobulina humana, interferones, cloroquina, hidroxicloroquina, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, metilprednisolona, bevacizumab y medicina tradicional china. Aunque el reposicionamiento de medicamentos tiene algunas limitaciones, el reposicionamiento de los ensayos clínicos puede representar una estrategia atractiva porque facilita el descubrimiento de nuevas clases de medicamentos; estos tienen costos más bajos y tardan menos en llegar al mercado; y existen cadenas de suministro farmacéutico que apoyan la formulación y la distribución.(AU)

RESUMO A Organização Mundial da Saúde (OMS) foi informada, em dezembro de 2019, sobre um surto de pneumonia por coronavírus em Wuhan, província de Hubei (China). Posteriormente, em 12 de março de 2020, 125 048 casos e 4 614 mortes haviam sido registrados. O coronavírus é um vírus RNA envelopado do gênero Betacoronavírus, distribuído em aves e em humanos e outros mamíferos. A OMS designou a nova doença por coronavírus como COVID-19. Mais de 80 ensaios clínicos foram iniciados para testar tratamentos para o coronavírus, incluindo alguns de reposicionamento de medicamentos para o COVID-19. Assim, em março de 2020 realizou-se uma busca na base de dados clinicaltrials.gov. Os critérios de elegibilidade para os estudos recuperados foram: conter o número identificador da base de dados clinicaltrials.gov; descrever o número de participantes e o período do estudo; descrever as condições clínicas dos participantes; e utilizar intervenções para tratamento de doentes infectados com o novo coronavírus SARS-CoV-2 (2019-nCoV) com medicamentos já estudados ou aprovados para qualquer outra doença. É essencial salientar que este artigo apenas capturou ensaios listados na base de dados clinicaltrials.gov. Foram identificados 24 ensaios clínicos envolvendo mais de 20 medicamentos, tais como imunoglobulina humana, interferons, cloroquina, hidroxicloroquina, arbidol, remdesivir, favipiravir, lopinavir, ritonavir, oseltamivir, metilprednisolona, bevacizumabe e medicamentos chineses tradicionais. Embora o reposicionamento de medicamentos tenha algumas limitações, os ensaios clínicos de reposicionamento podem representar uma estratégia atraente, porque facilitam a descoberta de novas classes de medicamentos, têm custos mais baixos, levam menos tempo para chegar ao mercado e se beneficiam de cadeias de fornecimento farmacêutico já existentes para formulação e distribuição.(AU)

Punica granatum L. Hydrogel for Wound Care Treatment: From Case Study to Phytomedicine Standardization.

The pharmacological activities of many Punica granatum L. components suggest a wide range of clinical applications for the prevention and treatment of diseases where chronic inflammation is believed to play an essential etiologic role. The current work reports a case study analyzing the effect produced by a magistral formulation of ethanolic extracts of Punica granatum peels on a non-healing chronic ulcer. The complete closure of the chronic ulcer that was initially not responsive to standard medical care was observed. A 2% (w/w) P. granatum peels ethanolic extract hydrogel-based formulation (PGHF) was standardized and subjected to physicochemical studies to establish the quality control parameters using, among others, assessment criteria such as optimum appearance, pH range, viscosity and hydrogel disintegration. The stability and quantitative chromatographic data was assessed in storage for six months under two temperature regimes. An efficient HPLC-DAD method was established distinguishing the biomarkers punicalin and punicalagin simultaneously in a single 8 min run. PGHF presented suitable sensorial and physicochemical performance, showing that punicalagin was not significantly affected by storage (p > 0.05). Formulations containing extracts with not less than 0.49% (w/w) total punicalagin might find good use in wound healing therapy.

Implant of polymer containing pentacyclic triterpenes from Eugenia punicifolia inhibits inflammation and activates skeletal muscle remodeling.

Sustained chronic inflammation induces activation of genes involved in cellular proliferation and apoptosis, thereby causing skeletal muscle degeneration. To investigate in vitro effects of isolated pentacyclic triterpenes from Eugenia punicifolia (Ep-CM) upon signaling pathways involved in the regulation of skeletal muscle cell line proliferation, and in vivo muscular tissue remodeling. C2C12 cells were seeded on eight-well plates and [(3)H]-thymidine incorporation, TUNEL assays, mitochondria viability, zymography for matrix metalloproteases (MMPs), Western blot analysis for MAPKinase signaling pathway, NFκB activation and HMGB1 production subsequently determined under basal conditions and after Ep-CM treatment. A polymer containing Ep-CM was implanted on the volar surface of gastrocnemius muscles subjected to acute injury induced by bupivacaine for local slow and gradual release of bioactive compounds, and mice killed 4 days after surgery. Ep-CM inhibited proliferation of C2C12 myoblast cell line in a dose-dependent manner, confirmed by reduction of [(3)H]-thymidine uptake without affecting cell viability or inducing apoptosis. The cytostatic effect of Ep-CM occurred mainly via inhibition of phosphorylated extracellular signal-regulated kinase (pERK) activation and DNA synthesis, possibly inhibiting the G1 phase of the cell cycle, since Ep-CM increased pAkt and p27(kip1) but reduced Cyclin D1. Ep-CM in vitro treatment increased MMP-9 and MMP-2 activities of C2C12 myoblast cells, but reduced in vivo MMP-9 activity and acute muscular inflammation. Besides cytostatic and anti-inflammatory effects, Ep-CM pentacyclic triterpenes also contributed to degradation of basement membrane components by activating mechanisms of skeletal muscle remodeling in response to local injury.

Augmentation of catecholamine release elicited by an Eugenia punicifolia extract in chromaffin cells

Plant extracts of Eugenia punicifolia (Kunth) DC., Myrtaceae, are used in Amazon region of Brazil to treat diarrhea and stomach disturbances, and as hypoglycemic medicine. We have recently shown that an aqueous extract of E. punicifolia augmented cholinergic neurotransmission in a rat phrenic nerve-diaphragm preparation. In this study, we investigated the effects of an E. punicifolia dichloromethane extract (EPEX) in a neuronal model of cholinergic neurotransmission, the bovine adrenal chromaffin cell. EPEX augmented the release of catecholamine triggered by acetylcholine (ACh) pulses but did not enhance ACh-evoked inward currents, which were inhibited by 30 percent. Since EPEX did not cause a blockade of acetylcholinesterase or butyrylcholinesterase, it seems that EPEX is not directly activating the cholinergic system. EPEX also augmented K+-elicited secretion without enhancing the whole-cell inward calcium current. This novel and potent effect of EPEX in enhancing exocytosis might help to identify the active component responsible for augmenting exocytosis. When elucidated, the molecular structure of this active principle could serve as a template to synthesise novel compounds to regulate the exocytotic release of neurotransmitters.

Anti-inflammatory activity of Eugenia punicifolia extract on muscular lesion of mdx dystrophic mice.

Eugenia punicifolia known as "pedra-ume caá" is a shrub largely distributed in the Amazon region popularly used in decoctions or infusions as a natural therapeutic agent, which can interfere on cholinergic nicotinic neurotransmission. This work aimed to investigate a putative anti-inflammatory effect of dichloromethane fraction of E. punicifolia extract (Ep-CM) in the muscular lesion of mdx dystrophic mice, considering that activation of cholinergic mechanisms mitigates inflammation. A polymer containing the Ep-CM was implanted in mdx gastrocnemius muscle before onset of myonecrosis for local slow and gradual release of bioactive compounds and mice sacrificed 7 days or 9 weeks after surgery. Comparing to control muscle, treatment did not alter choline acetyltransferase and acetylcholinesterase enzymatic activities, but decreased metaloproteases-9 and -2 activities and levels of tumor necrosis factor α and NFκB transcription factor. In addition, treatment also reduced levels of bioactive IL-1ß form and cleaved caspase-3, related to early events of cellular death and inflammatory activation and further increased myogenin expression without affecting collagen production which is associated with fibrosis. In vivo treatment of mdx dystrophic mice with Ep-CM caused significant reduction of muscular inflammation and improved skeletal muscle regeneration without inducing fibrosis.

Pharmacological effects of Eugenia punicifolia (Myrtaceae) in cholinergic nicotinic neurotransmission.

The effects of the aqueous crude extract (5%) of Eugenia punicifolia on cholinergic nicotinic neurotransmission were investigated. Actions of aqueous crude extract over the inhibitory effect of the cholinergic nicotinic antagonists gallamine or pancuronium, on contractions induced by electrical stimulation of phrenic nerve of rat diaphragm, were studied. Tissues were mounted as for isotonic contractions and stimulation was delivered at submaximal voltage. Addition of Eugenia punicifolia did not alter the amplitude of twitch contraction. Gallamine (IC(50): 28.8+/-0.51 microM) or pancuronium (IC(50): 3.16+/-0.11 microM) completely inhibited twitch contractions. After the maximum effect of the antagonists was achieved, addition of the aqueous crude extract (0.5-1.0 mL) totally recovered the responses to electrical stimulation. Neostigmine, a reversible acethylcholinesterase inhibitor, partially recovered responses (49.70+/-6.90% at 1 microM). In another series of experiments, previous incubation of the extract (0.5 mL) shifted to the right inhibitory concentration-response curves for the antagonists gallamine (IC(50) before E. punicifolia: 35.8+/-1.61 microM; IC(50), after E. punicifolia: 2.24+/-0.04 mM) and pancuronium (IC(50), before E. punicifolia: 3.55+/-0.13 microM; IC(50), after E. punicifolia: 0.39+/-0.01 mM). Our results show that the aqueous extract of E. punicifolia recovered the action of competitive nicotinic antagonists at the neuromuscular junction. A receptor-mediated mechanism or the possibilities of interactions of the extract with the enzyme acethylcholinesterase, however, remain to be investigated.