Echinodorus grandiflorus (Cham y Schlech) Mich

Nota de alcance

DIVERSIDAD GENÉTICA Y MEJORAMIENTO DE PLANTAS MEDICINALES= Medicinal plants and improvement of medicinal herbs
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The karyotypes of five Brazilian species of Echinodorus; E. bolivianus, E. grandiflorus, E. longipetalus, E. macrophyllus and E. tenellus (Alismataceae); were studied using C-banding, CMA3/DAPI banding and fluorescence in situ hybridization with a 45S rDNA probe. There were few differences in the G-C rich regions of the five species, but marked differences were seen in the no. and position of C-bands, A-T rich regions and 45S rDNA sites. Overall, these characteristics were species-specific, with the exception of E. bolivianus and E. tenellus, which were highly similar in all of the karyotypic characteristics studied.

Nota de alcance

ÚLTIMOS AVANCES EN LA QUÍMICA Y ACTIVIDADES BACTERIOLÓGICAS EN LAS PLANTAS MEDICINALES= Medicinal plants, last advances on chemistry and bacteria activities on the medicinal herbs

1) The antihypertensive action of a crude ethanolic ext. (EEEG) from leaves of Echinodorus grandiflorus (Alismataceae) was investigated in spontaneously hypertensive rats.  The i.p. injection of increasing doses of EEEG (300-1000 mg/kg) elicited dose-dependent redns. in mean arterial pressure (MAP) that were paralleled by redns. of cardiac output and systemic vascular resistance, reaching the max. of 23±5%, 13±3% and 18±4%, resp. (n = 5, P < 0.05).  Comparable redns. of MAP were obtained upon i.v. administration of EEEG (3-100 mg/kg), reaching the max. decrease of 51±6% (n = 7; P < 0.001).  The blockade of nitric oxide synthesis significantly reduced the hypotension induced by i.v. administration of EEEG.  Moreover, the pre-treatment of the animals with a selective antagonist of cholinergic muscarinic receptors or of platelet-activating factor (PAF) receptors partially blunted the cardiovascular effects of EEEG.  The i.v. pre-treatment with the selective B2 bradykinin receptor antagonist HOE 140 or with indomethacin, an inhibitor of the enzyme cyclooxygenase, did not prevent the hypotensive effects induced by EEEG.  Finally, the chronic oral treatment with EEEG presented a significant antihypertensive effect that was comparable to that of ref. antihypertensive drugs currently used to treat arterial hypertension.  It is concluded that EEEG elicits significant acute antihypertensive effects through the release of nitric oxide and the stimulation of cholinergic muscarinic and PAF receptors.  Moreover, our results suggest that EEEG may be appropriate to chronic oral treatment of arterial hypertension.

2) A new clerodane deriv., (-)-16-hydroxycleroda-3,13-dien-16,15-olide-18-oic acid, (4aalpha,6alpha,8aalpha)1-carboxy-5(S)-[2(2,5-dihydro-5-hydroxy-2-oxo-4-furanyl)ethyl]-5,6,8a-trimethyl-3,4,4a,5,6,8a-trimethyl-3,4,4a,5,6,7,8,8a-octahydro-naphthalene was isolated as a minor component of the polar fractions of the leaves of E. gradiflorus.  The structure was detd. by spectroscopy (IR, MS, 1D and 2D 1H and 13C NMR).  The abs. configuration was detd. by a hemisynthesis using (+)-hardwickiic acid Me ester, from com. copaiba oil, as starting material.

3) We investigated the vascular effects of a crude aqueous extract (AEEG) of Echinodorus grandiflorus (Alismataceae) using the in vitro experimental models of the rabbit isolated aorta and perfused kidney.  Echinodorus grandiflorus, a native semi-aquatic plant widely distributed in Brazil, has been extensively used in Brazilian folk medicine for the treatment of high blood pressure and inflammatory diseases.  The bolus injection of AEEG (0.1-10 mg) into the rabbit renal circulation pre-contracted with norepinephrine induced marked and dose-dependent vasodilator responses (maximum of 37+/-4%; n=6; P<0.001), which was similar to that induced by injection of 10 mmol acetylcholine (41+/-3%).  Moreover, AEEG elicited a significant and concentration-dependent relaxation in the endothelium-intact, but not endothelium-denuded aortic rings, reaching the maximum of 81+/-5% (n=7, P<0.001).  Inhibition of the nitric oxide-cGMP pathway with L-NAME (100 microM) or Methylene Blue (20 microM) reduced maximum relaxation induced by AEEG from 81+/-5% to 46+/-3 and 45+/-3%, respectively (n=7, P<0.001).  A similar reduction was obtained with the incubation of the aortic rings with the selective PAF receptor antagonist WEB 2086 (10 microM) (from 81+/-5% to 55+/-3%; n=7; P<0.01).  Conversely, blockade of muscarinic receptors with atropine (10 microM) did not affect the vasodilator effects of AEEG, while inhibition of the enzyme cyclooxigenase not only did not block, but rather potentiated vasodilation induced by AEEG (n=7, P<0.001).  Finally, blockade of Ca(2+)- and ATP-activated K(+) channels using the specific blockers charydbotoxin (100 nM) and glibenclamide (3 microM), respectively, did not modify aortic relaxation induced by AEEG.  We conclude that water-soluble extracts from leaves of Echinodorus grandiflorus elicit an endothelium-dependent, nitric oxide and PAF receptor-mediated vasodilation in rabbit aortic rings, which does not appear to involve the generation of vasodilating prostaglandins or the activation of K(+) channels.This potent vasodilator effect of the extracts was confirmed in the isolated rabbit renal circulation.

Nota de alcance

PARTE UTILIZADA=Used part:
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Hojas. 

ACCIÓN FARMACOLÓGICA= Pharmacological action: Antirreumático, antineurálgico y en enfermedades del hígado. 

COMPOSICIÓN QUÍMICA= Adverse effects and pharmacology: O presente trabalho visou estudar a influência da aplicação do ácido naftalenoacético (NAA) e ethephon (ET) nos teores de fenóis totais, flavonóides e taninos em função da sazonalidade em plantas de Echinodorus grandiflorus (Cham. & Schldl.) Micheli – chapéu de couro. Objetivou-se também a análie dos perfis dos n-alcanos da cera epicuticular das folhas da planta e a influência dos reguladores vegetais em aspectos da fenologia. 

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Origen: Especie originaria de America Austral

Usos etnomédicos y modo de empleo:
La infusión de la hoja fresca se toma en Brasil como antirreumática, diurética, depurativa, en problemas renales y afecciones del tracto urinario. Externamente se usa en el tratamieno de erupciones cutánea y para eliminar las manchas de la piel. En Paraguay se la usa como antihipertensivo.

Nota bibliográfica

1) GONZALEZ, Matías; LOMBARDO, Atilio; VALLARINO, Aida. Plantas de la medicina vulgar del Uruguay. Montevideo : Talleres Gráficos, 1937, p.50.

2) COSTA, J. Y.; FORNI-MARTINS, E. R.; Vanzela, A. L. L. Karyotype characterization of five Brazilian species of Echinodorus (Alismataceae) with chromosomal banding and 45S rDNA FISH.N. Plant Systematics and Evolution . 2006, vol.257, nº1-2, p.119-127.
 
3) LESSA, Marcos Adriano; ARAUJO, Claudia Valeria; KAPLAN, Maria Auxiliadora; PIMENTA, Daniel; FIGUEIREDO, Maria Raquel; TIBIRICA, Eduardo. Antihypertensive effects of crude extracts from leaves of Echinodorus grandiflorus. Fundamental & Clinical Pharmacology . 2008, vol.22, nº2, p.161-168.
 
4) COSTA, Marta; TANKA, Clara M. A.; IMAMURA, Paulo M.; MARSAIOLI, Anita J. Isolation and synthesis of a new clerodane from Echinodorus grandiflorus. Phytochemistry . 1999, vol.50, nº1, p.117-122.
 
5) TIBIRICA,  Eduardo; ALMEIDA, Andressa; CAILLLEAUX, Solange; PIMENTA,  Daniel; KAPLAN,  Maria Auxiliadora; LESSA, Marcos Adriano; FIGUEIREDO, Maria Raquel. Pharmacological mechanisms involved in the vasodilator effects of extracts from Echinodorus grandiflorus. Journal of ethnopharmacology. 2007, vol.111 , nº 1, p.50-5.   

6) Gupta, Mahabir P.; Santana, Ana Isabel; Espinosa, Alex/ Plantas medicinales de Panamá. sd: sd. - p. sd.

Echinodorus grandiflorus (Cham y Schlech) Mich
Término aceptado: 26-Jul-2007