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1.
Heliyon ; 7(2): e06173, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33659733

RESUMO

Medicinal plants are essential aspects of readily available primary healthcare remedies. Phytochemical constituents of medicinal plants cover a broad variety of chemical fields to explore medicines. This review highlights selected empirical data on traditional uses, phytochemistry, and pharmacological properties of Taunggyi medicinal plants, Andrographis paniculata, Physalis peruviana, and Cassia fistula. Historically, these plants have been used for many infections and diseases in Taunggyi. More than 361 chemical compounds have been isolated and identified from the selected plants. Some of the chemical constituents have substantial pharmacological properties. It is clear that these herbs have significant potential for useful natural supplements in many contemporary diseases. Thus, the aim of this review compiles an ethnobotanical survey and documentation of medicinal plants in Taunggyi (Myanmar). This review will also inspire Myanmar researcher's to further investigate the potential of these plants in their future work into new compound and new drugs.

2.
Curr Med Chem ; 24(17): 1874-1891, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28578650

RESUMO

Snakes are fascinating creatures and have been residents of this planet well before ancient humans dwelled the earth. Venomous snakes have been a figure of fear, and cause notable mortality throughout the world. The venom constitutes families of proteins and peptides with various isoforms that make it a cocktail of diverse molecules. These biomolecules are responsible for the disturbance in fundamental physiological systems of the envenomed victim, leading to morbidity which can lead to death if left untreated. Researchers have turned these life-threatening toxins into life-saving therapeutics via technological advancements. Since the development of captopril, the first drug that was derived from bradykininpotentiating peptide of Bothrops jararaca, to the disintegrins that have potent activity against certain types of cancers, snake venom components have shown great potential for the development of lead compounds for new drugs. There is a continuous development of new drugs from snake venom for coagulopathy and hemostasis to anti-cancer agents. In this review, we have focused on different snake venom proteins / peptides derived drugs that are in clinical use or in developmental stages till to date. Also, some commonly used snake venom derived diagnostic tools along with the recent updates in this exciting field are discussed.


Assuntos
Venenos de Serpentes/química , Animais , Anticoagulantes/química , Anticoagulantes/metabolismo , Anticoagulantes/uso terapêutico , Batroxobina/química , Batroxobina/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Captopril/química , Captopril/uso terapêutico , Peptídeos/metabolismo , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Venenos de Serpentes/metabolismo , Serpentes/metabolismo , Trombose/tratamento farmacológico , Trombose/patologia , Tirofibana , Toxinas Biológicas/metabolismo , Toxinas Biológicas/farmacologia , Toxinas Biológicas/uso terapêutico , Tirosina/análogos & derivados , Tirosina/química , Tirosina/uso terapêutico
3.
Eur J Med Chem ; 74: 314-23, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24486414

RESUMO

Thiourea derivatives (1-38) were synthesized and evaluated for their urease inhibition potential. The synthetic compounds showed a varying degree of in vitro urease inhibition with IC50 values 5.53 ± 0.02-91.50 ± 0.08 µM, most of which are superior to the standard thiourea (IC50 = 21.00 ± 0.11 µM). In order to ensure the mode of inhibition of these compounds, the kinetic study of the most active compounds has been carried out. Most of these inhibitors were found to be mixed-type of inhibitors, except compounds 13 and 30 which were competitive, while compound 19 was identified as non-competitive inhibitor with Ki values between 8.6 and 19.29 µM.


Assuntos
Inibidores Enzimáticos/farmacologia , Tioureia/farmacologia , Urease/antagonistas & inibidores , Inibidores Enzimáticos/farmacocinética , Técnicas In Vitro , Concentração Inibidora 50 , Tioureia/farmacocinética
4.
Bioorg Med Chem ; 20(4): 1521-6, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-22264761

RESUMO

6-Nitrobenzimidazole derivatives (1-30) synthesized and their phosphodiesterase inhibitory activities determined. Out of thirty tested compounds, ten showed a varying degrees of phosphodiesterase inhibition with IC(50) values between 1.5±0.043 and 294.0±16.7 µM. Compounds 30 (IC(50)=1.5±0.043 µM), 1 (IC(50)=2.4±0.049 µM), 11 (IC(50)=5.7±0.113 µM), 13 (IC(50)=6.4±0.148 µM), 14 (IC(50)=10.5±0.51 µM), 9 (IC(50)=11.49±0.08 µM), 3 (IC(50)=63.1±1.48 µM), 10 (IC(50)=120.0±4.47 µM), and 6 (IC(50)=153.2±5.6 µM) showed excellent phosphodiesterase inhibitory activity, much superior to the standard EDTA (IC(50)=274±0.007 µM), and thus are potential molecules for the development of a new class of phosphodiesterase inhibitors. A structure-activity relationship is evaluated. All compounds are characterized by spectroscopic parameters.


Assuntos
Benzimidazóis/síntese química , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/farmacologia , Animais , Benzimidazóis/química , Benzimidazóis/farmacologia , Ativação Enzimática/efeitos dos fármacos , Concentração Inibidora 50 , Estrutura Molecular , Inibidores de Fosfodiesterase/química , Relação Estrutura-Atividade
5.
Asian Pac J Trop Biomed ; 2(9): 727-32, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23570003

RESUMO

OBJECTIVE: To evaluate the antioxidant and antiglycation potential of polyphenols from three spices; alligator pepper, ginger and nutmeg. METHODS: Polyphenol extracts of these spices were subjected to brine-shrimp lethality assay, phytotoxicity test, DPPH and superoxide anion radical scavenging as well as BSA-glucose antiglycation assay. RESULTS: Results obtained showed that polyphenol extract of ginger has the highest antioxidant potential with IC50 0.075 and 0.070 mg/mL for DPPH and superoxide anion radical scavenging assay while alligator pepper displayed highest antiglycation activity with IC50 0.125 mg/mL. However, nutmeg extract exhibited weakest cytotoxic and phytotoxic potential with LD50 4359.70 and 1490 µg/mL respectively. CONCLUSIONS: It can be concluded that the polyphenol extracts of alligator pepper, ginger and nutmeg displayed good antioxidant as well as antiglycation potential and are safe for consumption.


Assuntos
Antioxidantes/farmacologia , Capsicum/química , Gengibre/química , Myristica/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Animais , Antioxidantes/química , Artemia/efeitos dos fármacos , Compostos de Bifenilo/antagonistas & inibidores , Glicosilação/efeitos dos fármacos , Concentração Inibidora 50 , Dose Letal Mediana , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Polifenóis/química , Testes de Toxicidade Aguda
6.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 8): o2122, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22091140

RESUMO

The title compound, C(21)H(28)O(3), is a fungal transformed metabolite of decoxycorticosterone acetate, consisting of four fused rings A, B, C and D. Ring A is nearly planar, with a maximum deviation of 0.010 (3) Šfrom the least-squares plane, while the trans-fused rings B and C adopt chair conformations. The five-membered ring D is in an envelope conformation. The orientation of the side chain is stabilized by an intramolecular O-H⋯O hydrogen bond. In the crystal, adjecent mol-ecules are linked by C-H⋯O hydrogen bonds into extended zigzag chains along the a axis.

7.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 11): o2918, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22219950

RESUMO

The title compond, C(26)H(44)N(2)O, is an steroidal alkaloid isolated from the medicinally important plant Sarcococca saligna. The mol-ecule consists of four fused rings (A-D), having chair, half-chair, chair and envelope conformations, respectively. The dimethyl-amino group is axially oriented on ring A, whereas the (N-methyl-acetamido)-ethyl group is attached equatorially on ring D. The crystal structure is stabilized only by van der Waals forces.

8.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 12): o3066, 2010 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-21589376

RESUMO

The title compound, C(15)H(14)O(5), is a natural product, isolated from Sorbus lanata Syn. Pyrus lanata (D. Don) found in Pakistan. The compound is composed of three spiro-fused rings. The dihedral angle between the mean planes of the benzene rings is 4.81 (13)°. The meth-oxy groups are oriented at dihedral angles of 74.44 (14), 83.0 (2) and 66.3 (2)° with respect to the planes of the benzene rings to which they are attached. The mol-ecule is consolidated by three intra-molecular O-H⋯O and C-H⋯O hydrogen bonds. In the crystal, mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds, forming infinite chains along the b axis.

9.
J Asian Nat Prod Res ; 11(11): 933-9, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20183256

RESUMO

The mechanism of inhibition of the alpha-chymotrypsin enzyme by two lignans of the fused bistetrahydrofuran series, epiexcelsin (1) and 5'-demethoxyepiexcelsin (2), which were isolated from the Commiphora mukul Engl., was investigated. Lineweaver-Burk and Dixon plots and their secondary replots showed that these compounds were noncompetitive inhibitors of the enzyme. K(i) values for 1 and 2 were found to be 22.29 +/- 0.015 and 336.30 +/- 0.053 microM, respectively.


Assuntos
Quimotripsina/antagonistas & inibidores , Lignanas/isolamento & purificação , Lignanas/farmacocinética , Magnoliaceae/química , Plantas Medicinais/química , Lignanas/química , Matemática , Estrutura Molecular , Paquistão
10.
Pharmazie ; 63(1): 20-2, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18271297

RESUMO

A new method of capillary electrophoresis was developed for the quantitative determination of vasicine and vasicinone from Adhatoda vasica (L.) Nees. The electrophoretic separation was performed using a 47 cm x 50 microm ID (38.5 cm effective length) fused silica capillary. The samples were injected by pressure for 3 s at 50 mbar and the running voltage was 19 kV at the injector end of the capillary. The capillary temperature was maintained at 40 degrees C. The separation of the two alkaloids has been achieved within 11 min with good repeatability. The method was validated in terms of reproducibility, linearity, accuracy and applied for the quantitative determination of vasicine and vasicinone in A. vasica plant samples/extracts. Parameters affecting the resolution such as pH, temperature, organic modifier, buffer concentration and capillary dimensions were reported.


Assuntos
Alcaloides/análise , Broncodilatadores/análise , Justicia, Planta/química , Quinazolinas/análise , Tampões (Química) , Cromatografia Líquida de Alta Pressão , Ciclodextrinas/química , Eletroforese Capilar , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Extratos Vegetais/química , Padrões de Referência , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta
11.
Drug Discov Ther ; 2(5): 286-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22504722

RESUMO

Antioxidant activity of a selection of commonly occurring wild plants growing in Beni-Sueif governorate, Upper Egypt, has been tested. The plants selected are Tamarix nilotica, Ambrosia maritima, Zygophyllum coccenium, Conyza dioscoridis, Chenopodium ambrosioides, and Calotropis procera. The in vitro antioxidant assays used in this study were 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, superoxide anion scavenging activity and iron chelating activity. Extracts prepared from the leaves and flowers of Tamarix nilotica have shown the highest antioxidant activity in the three kinds of assay.

12.
Nat Prod Res ; 21(13): 1178-86, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17987498

RESUMO

In this article, we describe a simple and new method for the synthesis of some N4-substituted isatin-3-thiosemicarbazones based on the reactions of the common intermediate, methyl 2-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)-1-hydrazinecarbodithioate, prepared by condensing isatin with methyl 1-hydrazinecarbodithioate, and the readily available amines in essentially a one-step reaction. The synthesized thiosemicarbazones were fully characterized by their physical, analytical, and spectral (IR, 1H-NMR, EIMS) data.


Assuntos
Isatina/análogos & derivados , Tiossemicarbazonas/síntese química , Isatina/síntese química , Isatina/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Espectrofotometria Infravermelho , Tiossemicarbazonas/química
13.
Afr J Tradit Complement Altern Med ; 4(3): 294-8, 2007 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-20161892

RESUMO

A new glyceryl derivative (Glyceryl-1-hexacosanoate) and a flavone derivative (methyletherapigenin) were isolated from the stem bark extract of Piptadenia africana, a western Cameroonian plant species. Common terpenes like sitosterol, beta-amyrin and eicosane were also isolated. These compounds were identified using physical and spectroscopic methods including mp, IR, (1)H and (13)C-NMR, DEPT, COSY, HMQC, HMBC, EI MS, HREI MS as well as some chemical transformations. The antibacterial activity of the extract, the fractions and the pure compounds is also discussed.

14.
Nat Prod Res ; 20(6): 586-92, 2006 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-16835092

RESUMO

The CH2Cl2/CH3OH (1/1) extract of the dried stem of Drypetes chevalieri Beille afforded two new triterpenoïds named drypechevalin A (11-oxo-beta-amyrin-3beta-ylcaffeate) and drypechevalin B (3,7-dioxo-D:A-friedooleanan-24-al) along with five known compounds: lupeol, lupeone, erythrodiol, putranjivadione, friedelin. Their structures were established on the basis of spectroscopic analysis and chemical evidence.


Assuntos
Euphorbiaceae/química , Sesquiterpenos/isolamento & purificação , Ácidos Cafeicos/química , Ácidos Cafeicos/isolamento & purificação , Hidrólise , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Caules de Planta/química , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Infravermelho
15.
Phytomedicine ; 13(4): 255-60, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16492528

RESUMO

Phytochemical investigation of the methanol extract of Vitex negundo afforded eight lignans; negundin A 1, negundin B 2, 6-hydroxy-4-(4-hydroxy-3-methoxy)-3-hydroxymethyl-7-methoxy-3,4-dihydro-2-naphthaledehyde 3, vitrofolal E 4, (+)-lyoniresinol 5, (+)-lyoniresinol-3alpha-O-beta-d-glucoside 6, (+)-(-)-pinoresinol 7, and (+)-diasyringaresinol 8. The structures of these compounds were elucidated unambiguously by spectroscopic methods including 1D and 2D NMR analysis and also by comparing experimental data with literature data. The tyrosinase inhibitory potency of these compounds has been evaluated and attempts to justify their structure-activity relationships have been made in the present work. The compound 5 was found to be the most potent (IC(50)=3.21 microM) while other compounds demonstrated moderate to potent inhibitions. It was found that the substitution of functional group(s) at C-2 and C-3 positions and the presence of the -CH(2)OH group plays a vital role in the potency of the compounds. The compound 5 can act as a potential lead molecule to develop new drugs for the treatment of hyperpigmentation associated with the high production of melanocytes.


Assuntos
Lignina/química , Lignina/farmacologia , Peptídeos/farmacologia , Extratos Vegetais/química , Vitex/química , Concentração Inibidora 50 , Lignina/isolamento & purificação , Espectroscopia de Ressonância Magnética/métodos , Medicina Tradicional , Metanol/química , Peptídeos/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Relação Estrutura-Atividade
16.
Phytother Res ; 20(1): 49-52, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16397921

RESUMO

Syzygium samarangense (Family; Myrtaceae) or 'makopa', as it is commonly known, is native to Malaysia, some islands of Indonesia and to Far East in general. This study was undertaken to rationalize the use of this plant in hypermotility states of the gut. The hexane extract of S. samarangense (Ss.Hex) was found to dose-dependently (10-3000 microg/mL) relax the spontaneously contracting isolated rabbit jejunum. When tested for a possible calcium channel blocking (CCB) activity, the extract (10-1000 microg/mL) relaxed the high K+-induced contractions and also decreased the Ca++ dose-response curves in a dose-dependent manner (30-100 microg/mL), confirming the CCB activity. Four flavonoids isolated from the hexane extract were tested for a possible spasmolytic activity. All flavonoids, identified as: 2'-hydroxy-4',6'-dimethoxy-3'-methylchalcone (SS1), 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (SS2), 2',4'-dihydroxy-6'-methoxy-3'-methylchalcone (SS3) and 7-hydroxy-5-methoxy-6,8-dimethylflavanone (SS4), showed dose-dependent (10-1000 microg/mL) spasmolytic activity with SS2 being the most potent. These results indicate that the presence of compounds with spasmolytic and calcium antagonist activity may be responsible for the medicinal use of the plant in diarrhoea.


Assuntos
Bloqueadores dos Canais de Cálcio/uso terapêutico , Diarreia/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Syzygium/química , Animais , Bloqueadores dos Canais de Cálcio/isolamento & purificação , Bloqueadores dos Canais de Cálcio/farmacologia , Relação Dose-Resposta a Droga , Feminino , Jejuno/efeitos dos fármacos , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta/química , Coelhos
17.
J Enzyme Inhib Med Chem ; 20(1): 41-7, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15895683

RESUMO

A series of variably substituted chalcones were synthesized by condensation of substituted acetophenones with mono-, di- or trisubstituded benzaldehydes. It was observed that some of these compounds have the potential to inhibit acetylcholinesterase, whereas others show activity against butyrylcholinesterase, depending on the substitution pattern at the two aromatic rings of these chalcones. Similarly, lipoxygenase was inhibited by two of these compounds. It has been observed that inhibition of the three enzymes was concentration dependent with the IC50 values ranging from 28.2-134.5 microM against acetylcholinesterase, 16.0-23.1 microM against butyrylcholinesterase and 57.6-71.7 microM against lipoxygenase, respectively.


Assuntos
Acetilcolinesterase/química , Butirilcolinesterase/química , Chalconas/síntese química , Chalconas/farmacologia , Lipoxigenase/química , Acetilcolinesterase/metabolismo , Animais , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/farmacologia , Electrophorus/metabolismo , Cavalos , Concentração Inibidora 50 , Lipoxigenase/metabolismo , Inibidores de Lipoxigenase/síntese química , Inibidores de Lipoxigenase/farmacologia , Estrutura Molecular
18.
J Enzyme Inhib Med Chem ; 19(4): 367-71, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15558955

RESUMO

Dicoumarols 1-10 with substituted phenyl residues at C-11 were synthesized and screened for their urease inhibition effects. All synthesized compounds showed varying degree of urease inhibitory activity ranging from IC50 = 74.30-91.35 microM.


Assuntos
Dicumarol/síntese química , Dicumarol/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Urease/antagonistas & inibidores , Dicumarol/análogos & derivados , Fabaceae/enzimologia , Estrutura Molecular , Urease/química
19.
J Ethnopharmacol ; 91(1): 57-60, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15036468

RESUMO

The chloroform:medianol (1:1) extracts of a number of the plant species belonging to eight families, namely Corydalis solida (L.) Swartz subsp. solida and Glaucium corniculatum (L.) J. H. Rudolph (Papaveraceae), Rhododendron ponticum L. subsp. ponticum and Rhododendron luteum Sweet. (Ericaceae), Buxus sempervirens L. (Buxaceae), Vicia faba L. (Fabaceae), Robinia pseudoacacia L. (Caeselpiniaceae), Tribulus terrestris L. and Zygophyllum fabago L. (Zygophyllaceae), Lycopodium clavatum L. (Lycopodiaceae), Fumaria vaillantii Lois., Fumaria capreolata L., Fumaria kralikii Jordan, Fumaria asepala Boiss., Fumaria densiflora DC., Fumaria flabellata L., Fumaria petteri Reichb. subsp. thuretii (Boiss.) Pugsley, Fumaria macrocarpa Boiss. ex Hausskn., Fumaria cilicica Hauskkn., Fumaria parviflora Lam. and Fumaria judaica Boiss. (Fumariaceae) were screened for their anticholinesterase activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes by in vitro Ellman method at 10 microg/ml and 1 mg/ml concentrations. The extracts did not show any noticeable inhibitory activity against both of the enzymes at 10 microg/ml. The extracts of Rhododendron ponticum subsp. ponticum, Rhododendron luteum, Corydalis solida subsp. solida, Glaucium corniculatum, and Buxus sempervirens showed remarkable inhibitory activity above 50% inhibition rate on AChE at 1 mg/ml. Among them, Rhododendron ponticum subsp. ponticum, Corydalis solida subsp. solida and Buxus sempervirens were the most active extracts against BChE having 95.46 +/- 1.03%, 93.08 +/- 0.97%, and 93.45 +/- 0.88% inhibition rates, respectively. Among the extracts screened, all of the Fumaria extracts displayed highly potent inhibition against both of the enzymes at 1 mg/ml concentration compared to the standard.


Assuntos
Butirilcolinesterase , Inibidores da Colinesterase/farmacologia , Extratos Vegetais/farmacologia , Inibidores da Colinesterase/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Turquia
20.
J Ethnopharmacol ; 90(2-3): 367-74, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15013203

RESUMO

In this report we investigated the effects of the aqueous fraction (AF) isolated from Delphinium denudatum on sustained repetitive firing in cultured neonatal rat hippocampal pyramidal neurons. Blockade of SRF is one of the basic mechanisms of antiepileptic drugs (AED) at the cellular level. The effects of aqueous fraction (0.2-0.6 mg/ml) were compared with the prototype antiepileptic drug, phenytoin (PHT). Using the whole cell current-clamp technique, sustained repetitive firing was elicited in neurons by a depolarizing pulse of 500 ms duration, 0.3 Hz and 0.1-0.6 nA current strength. Similar to phenytoin, aqueous fraction reduced the number of action potentials (AP) per pulse in a concentration-dependent manner until no action potentials were elicited for the remainder of the pulse. There was a corresponding use-dependent reduction in amplitude and Vmax (velocity of upstroke) of action potentials. The Vmax and amplitude of the first action potential was not affected by phenytoin, while aqueous fraction exhibited concentration-dependent reduction. At 0.6 mg/ml aqueous fraction reduced Vmax to 58-63% and amplitude to 16-20% of the control values. The blockade of sustained repetitive firing by aqueous fraction was reversed with hyperpolarization of membrane potential (-65 to -75 mV) while depolarization of membrane potential (-53 to -48 mV) potentiated the block. The results suggest that aqueous fraction blocks sustained repetitive firing in hippocampal neurons in a use-dependent and voltage-dependent manner similar to phenytoin. However, unlike phenytoin, which interacts preferably with the inactive state of the Na+ channel, the compounds present in aqueous fraction apparently also interact with the resting state of the Na+ channels as suggested by dose-dependent reduction of Vmax and amplitude of first AP. We conclude that aqueous fraction contains potent anticonvulsant compounds.


Assuntos
Potenciais de Ação/efeitos dos fármacos , Delphinium , Hipocampo/efeitos dos fármacos , Inibição Neural/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Hipocampo/fisiologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Raízes de Plantas , Ratos , Ratos Sprague-Dawley , Água
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