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1.
Rev. logop. foniatr. audiol. (Ed. impr.) ; 26(4): 215-230, oct.-dic. 2006. tab
Artigo em Espanhol | IBECS | ID: ibc-76380

RESUMO

El objetivo de este artículo es comparar el habla del modelo adulto del español hablado en la ciudad de Lima (Perú) con el habla de niños limeños monolingües, cuyas edades varían de 2,6 años a 5 años y que no presentan aparentes limitaciones articulatorias, auditivas o intelectuales. En particular, esta investigación se centra en el estudio de qué rasgos fonológicos muestran divergencias cuando se comparan ambos tipos de producciones, así como determinar hasta qué edad dichas divergencias subsisten en el habla de los niños. Uno de los principales resultados de este estudio es la identificación del momento en que se produce una disminución significativa en las divergencias observadas entre el habla del modelo adulto del español de Lima y el habla de los niños. Este momento ocurre entre los 2,6 años y 3,6 años. Estos resultados son de gran importancia para los terapeutas del lenguaje que trabajan con niños en edades preescolares. Además de corroborar que el sistema fonológico se va adquiriendo de manera progresiva, este estudio brinda un punto de referencia que ayudará a detectar y tratar a tiempo a niños que potencialmente podrían presentar retrasos simples del habla o trastornos específicos del lenguaje(AU)


This article compares the adult speech production of the Spanish spoken in Lima (Peru) to the speech of monolingual children from the same city, between the ages of two and a half and five. No of the subjects present any articulatory, auditory or mental disability. In particular, this article focuses on which phonological features show divergences when adult and child speech are compared. It also discusses the age until which those divergences remain in the speech of children. The main result is the identification that between the ages of two and a half and three and a half, a significant decrease of the divergences occurs. The results are of great importance for language therapists who work with preschoolers. In addition to corroborating that the phonological system is progressively acquired, this provides a point of reference that will help language therapists detect and give early treatment to children who may show minor phonological disorders or specific language impairments(AU)


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Transtornos da Articulação/diagnóstico , Distúrbios da Fala/diagnóstico , Audiometria da Fala , Testes de Articulação da Fala , Testes de Discriminação da Fala , Percepção da Fala
2.
Phytother Res ; 16 Suppl 1: S71-2, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11933144

RESUMO

The insecticidal activity of the leaves of Pothomorphe peltata (Piperaceae) was evaluated on Aedes aegypti larvae. The active methanol extract was subjected to a bioactivity-directed fractionation, monitored by the larvicidal assay, and led to the isolation of a catechol derivative, 4-nerolidylcatechol. This compound was quite potent against Aedes aegypti larvae (LC(50) = 9.1 microg/mL).


Assuntos
Aedes/efeitos dos fármacos , Catecóis/farmacologia , Inseticidas/farmacologia , Piperaceae , Extratos Vegetais/farmacologia , Animais , Larva/efeitos dos fármacos , Dose Letal Mediana , Folhas de Planta
3.
Pharmazie ; 56(7): 573-7, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11487978

RESUMO

The in vitro antioxidant and free radical scavenging properties in bark extracts of South American tree Copaifera reticulata Ducke. (Caesalpinaceae) were studied using different bioassays. Lipid peroxidation was assessed by means of the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenate. All the extracts tested were effective in this method. The highest activity was observed in the aqueous extract, showing an IC50 of 30 micrograms/ml. DNA sugar damage induced by Fe (II) salts was also used to determine the capacity of the samples to suppress hydroxyl radical-mediated degradation of DNA. Although all the extracts tested were effective in reducing oxidation of DNA, the highest activity was observed in the methanol extract, showing an IC50 of 2 micrograms/ml. Bioassay-guided fractionation of a total methanol extract monitored by luminol-enhanced chemiluminescence, together with structural elucidation using 13C NMR and FABMS, led to the identification of profisetinidin type tannins in a semi-pure fraction. The fraction containing the active compounds also reduced the production of TBARS in rat liver homogenates (IC50 = 530 micrograms/ml) and DNA damage (IC50 = 1 microgram/ml), suggesting that profisetinidins could be responsible for the free radical scavenging and antioxidant activities observed in the extracts.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Plantas Medicinais/química , Taninos/química , Taninos/farmacologia , Animais , Brasil , Dano ao DNA , Radicais Livres , Técnicas In Vitro , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Espectroscopia de Ressonância Magnética , Ratos , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
4.
Pharmazie ; 55(8): 612-4, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10989841

RESUMO

Symmetrical bis-1-aminmoethylnaphtalenes, a group of compounds that demonstrated cytotoxicity towards human tumor cell lines, showed human topoisomerase I poisoning activity. The compounds tested were: N,N'-bis-1-naphthylmethyl-1,6-hexanediamine (1a), N,N'-bis-1-naphthylmethyl-1,8-octanediamine (1b), N,N'-bis-1-naphthylmethyl-1,12-dodecanediamine (1c), N,N'-bis-1-naphthylmethyl-4,4-bipiperidine (2) and N-(1-naphthylmethyl)-N'-dimethyl-1,3-diaminepropane dichlorhydrate (3). All showed human topoisomerase I inhibition by producing protein-linked DNA breaks. The most active were 1a, 1b, 1c with a percentage stimulation of DNA cleavage of 75, 84 and 70% at 100 micrograms/ml, respectively. Compounds 2 and 3 were moderately active as poisons of topoisomerase I activity, the former showing 58% stimulation of DNA cleavage at 100 micrograms/ml and the latter a 24% stimulation. The correlation observed between topoisomerase I poisoning and in vitro cytotoxic activity suggests that this could be a possible mechanism for the cytotoxicity observed in tumor cell lines.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Naftalenos/farmacologia , Inibidores da Topoisomerase I , Dano ao DNA , DNA Super-Helicoidal/efeitos dos fármacos , Humanos , Relação Estrutura-Atividade , Células Tumorais Cultivadas
5.
J Ethnopharmacol ; 72(1-2): 185-9, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10967471

RESUMO

The insecticidal activity of 11 extracts from nine South American medicinal plants has been studied using the Aedes aegypti larvicidal assay. Eight of the 11 plant extracts studied showed toxicity against the A. aegypti larvae (LC(50)<500 microg/ml). The dichloromethane extracts of Abuta grandifolia and Minthostachys setosa demonstrated high larvicidal activity, the most active being the dichloromethane extract of A. grandifolia, with an LC(50)=2.6 microg/ml (LC(100)= 8.1 microg/ml), indicating an activity 2-fold higher than beta-asarone, a natural botanical insecticide used as a positive control (LC(100)=16 microg/ml). On the other hand, the dichloromethane extract of M. setosa was quite potent against A. aegypti larvae showing an LC(50)=9.2 microg/ml (LC(100)=25.2 microg/ml). The results obtained suggest that the extracts of A. grandifolia and M. setosa are promising as larvicides against A. aegypti larvae and could be useful in the search for new larvicidal natural compounds.


Assuntos
Aedes , Inseticidas/isolamento & purificação , Plantas Tóxicas/química , Derivados de Alilbenzenos , Animais , Anisóis/toxicidade , Inseticidas/toxicidade , Larva , Dose Letal Mediana , Cloreto de Metileno , Extratos Vegetais/toxicidade , Solventes , América do Sul
6.
J Ethnopharmacol ; 71(1-2): 145-51, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10904157

RESUMO

Eight crude extracts from seven Argentine plants with cancer-related ethnobotanical uses have been subjected to a bioscreening study to detect cytotoxic activity. The plants studied were: Aristolochia triangularis, Baccharis grisebachii, Bolax gummifera, Eupatorium hecatanthum, Erythrina crista-galli, Pterocaulon polystachium and Salpichroa origanifolia. Crown gall tumour inhibition, DNA interaction and cytotoxicity towards KB cells were assayed using the potato disc, the DNA-methyl green (DNA-MG) and the KB cells cytotoxicity bioassays respectively. The results obtained indicate that A. triangularis (ED50=47 microg/ml), B. gummifera (ED50=32 microg/ml) and E. hecatanthum (ED50=35 microg/ml) contained cytotoxic compounds against KB cells. All of the plants studied inhibited the growth of crown gall tumours, showing correlation between the experimental data and the uses reported for these plants. Moreover, the results obtained for the extracts of E. hecatanthum and P. polystachium indicate the presence of compounds that interact with DNA (48 and 22% of absorbance decrease, respectively). The results obtained suggest that cytotoxicity could play an important role in the activities claimed for the plants under study.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , DNA/efeitos dos fármacos , Plantas Medicinais/química , Argentina , Etnobotânica , Humanos , Células KB , Verde de Metila , Extratos Vegetais/farmacologia , Corantes de Rosanilina , Solanum tuberosum
7.
Planta Med ; 66(8): 720-3, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11199128

RESUMO

The bioactivity-guided fractionation of an active chloroform extract of Conyza albida led to the isolation of three alkenynes, deca-4,6-diyn-2-(Z)-enoic methyl ester (1), deca-4,6-diyn-2-(Z)-enoic ethyl ester (2) and deca-2,4-diene-4-hydroxy-6-yn-1,4-olide (3), and the terpenoid spathulenol (4), as the active toxic metabolites in the Artemia sp. lethality test. When tested in the KB cell cytotoxicity assay, compounds 1-4 demonstrated IC50 values of 52.2, 38.4, 117.9, and 83.8 microM, respectively. All compounds studied were inactive in the DNA methyl green and DNA strand scission assays, while compounds 3 and 4 showed moderate activity as inhibitors of human topoisomerase I. Compound 2 is reported here for the first time.


Assuntos
Asteraceae/química , Humanos , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Análise Espectral
8.
Fitoterapia ; 71(5): 556-8, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11449506

RESUMO

The methanol extract of Pothomorphe peltata leaves, orally administered at the dose of 20 mg/kg (equivalent to 2.50 g dry plant/kg) body weight, exhibited a significant anti-inflammatory activity, comparable with phenylbutazone (80 mg/kg, p.o.), against adjuvant-carrageenan-induced edema in rats.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Edema/prevenção & controle , Magnoliopsida , Plantas Medicinais , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/uso terapêutico , Carragenina , Edema/induzido quimicamente , Feminino , Humanos , Masculino , Fenilbutazona/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Folhas de Planta , Ratos , Ratos Wistar
9.
Farmaco ; 54(8): 517-23, 1999 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-10510848

RESUMO

A series of diarylsemicarbazones was synthesized and tested against human neoplastic cell lines. The more active members have a l-naphthyl ring at the carbamidic nitrogen, and chloro, dimethylamino or nitro group substituents at the benzylidene moiety. None of these showed affinity to DNA. One of the more active compounds was tested as a topoisomerase I inhibitor and showed a potent effect. SAR studies demonstrated linear correlation between lypophilicity and activity on the most sensitive lines and a definite conformational shape for antineoplastic action.


Assuntos
Antineoplásicos/síntese química , Compostos Azo/síntese química , Inibidores Enzimáticos/síntese química , Inibidores da Topoisomerase I , Antineoplásicos/farmacologia , Compostos Azo/farmacologia , DNA/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Eletroquímica , Inibidores Enzimáticos/farmacologia , Humanos , Relação Estrutura-Atividade , Células Tumorais Cultivadas
10.
Planta Med ; 65(4): 376-8, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10364848

RESUMO

Bioactivity-guided fractionation of the leaf methanolic extract of P. peltata (Piperaceae), using the brine shrimp lethality test, led to the isolation of catechol derivative 4-nerolidylcatechol (4-NC). The methanolic extract was active against crown gall tumour in potato discs, showing a 22% crown gall tumour inhibition (SD = 4%), while 4-NC was cytotoxic against KB tumour cells growth (EC50 = 1.3 micrograms/ml). No interaction with DNA could be observed when tested using the methyl green-DNA (MG-DNA) bioassay. An inhibition in the activity of topoisomerase I using agarose gel electrophoresis was detected in the presence of the purified compound (IC50 = 20 micrograms/ml), suggesting that this could be a possible mechanism for the cytotoxicity observed in KB cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Catecóis/farmacologia , Inibidores Enzimáticos/farmacologia , Plantas/química , Inibidores da Topoisomerase I , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células Tumorais Cultivadas
11.
J Ethnopharmacol ; 67(1): 69-77, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10616962

RESUMO

The in vitro antioxidant and free radical scavenging properties of bark extracts of Anadenanthera macrocarpa Brenan (Fabaceae), Astronium urundeuva Engl. (Anacardiaceae), Mimosa verrucosa Benth. (Fabaceae) and Sideroxylon obtusifolium T.D. Penn. (Sapotaceae), four trees used as anti-inflammatory agents in the Brazilian state of Bahia, were studied using different bioassays. The total reactive antioxidant potential (TRAP) of the aqueous and methanolic extracts was determined by monitoring the intensity of luminol-enhanced chemiluminescence (CL), using 2,2'-azo-bis(2-amidinopropane) as a peroxyl radical source. All the extracts studied were active in this method. The highest activity, measured as equivalents of Trolox concentration, was observed in the methanolic extract of A. macrocarpa (TRAP = 3028 +/- 95 microM). Lipid peroxidation was assessed by means of the production of thiobarbituric acid reactive substances (TBARS) and hydroperoxide-initiated CL in rat liver homogenates. As in the case of luminol-enhanced CL, all the extracts tested were effective in reducing the production of TBARS. The highest activity was observed in the aqueous extract of A. macrocarpa (IC50 = 54 microg/ml). Extracts of A. macrocarpa and S. obtusifolium also reduced hydroperoxide-initiated CL, the methanolic extract of the former being the most active, showing an IC50 = 2.0 microg/ml. DNA-sugar damage induced by Fe(II) salts was also used to determine the capacity of the extracts to suppress hydroxyl radical-mediated degradation of DNA. All extracts tested were highly effective in reducing oxidation of DNA. The highest activity was observed in the methanolic extract of A. urundeuva, showing an IC50 = 37 microg/ml. The results obtained suggest that the antioxidant activity described could play an important role in the anti-inflammatory activity claimed for the plants under study.


Assuntos
Antioxidantes/química , Sequestradores de Radicais Livres/química , Medicina Tradicional , Extratos Vegetais/química , Plantas Medicinais , Árvores , Animais , Antioxidantes/farmacologia , Bioensaio , Brasil , Dano ao DNA/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Medições Luminescentes , Masculino , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar
12.
Braz. j. med. biol. res ; 31(9): 1163-70, sept. 1998.
Artigo em Inglês | LILACS | ID: lil-222965

RESUMO

Achyrocline satureioides (Lam.) DC. (Compositae) is a medicinal herb used in Argentina, Uruguay, Brazil and Paraguay for its choleretic, antispasmodic and hepatoprotective properties. The presence of the flavonoid quercetin and its derivatives, and of different phenolic acids such as caffeic, chlorogenic and isochlorogenic acids in the aerial parts of this plant has led us to study the antioxidant activity of its extracts using different bioassays. The inhibition of luminol-enhanced chemiluminescence by the aqueous and methanolic extracts was used to show that their total reactive antioxidant potential index (TRAP; in µM Trolox equivalents) was 91.0 ñ 15.4 and 128.1 ñ 20.1 µM, respectively, while the total antioxidant reactivity index (TAR) was calculated to be 1537 ñ 148 and 1910 ñ 171 µM. Only the methanolic extract was capable of reducing iron (II)-dependent DNA damage. Lipid peroxidation was assessed by two different methods. The aqueous extract reduced hydroperoxide-initiated chemiluminescence in rat liver homogenates at all concentrations in a dose-dependent manner, with a calculated IC50 = 225 µg/ml, while the methanolic extract was only effective at higher concentrations (100 and 1000 µg/ml). Both aqueous and methanolic extracts were capable of reducing the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates, with an IC50 >1000 µg/ml. The results obtained suggest that the extracts of A. satureioides possess significant free radical scavenging and antioxidant activity in vitro, a fact that should encourage future in vivo studies


Assuntos
Animais , Ratos , Antioxidantes/farmacologia , Dano ao DNA/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Desoxirribose/farmacologia , Medições Luminescentes , Extratos Vegetais/química , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico
13.
Braz J Med Biol Res ; 31(9): 1163-70, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9876284

RESUMO

Achyrocline satureioides (Lam.) DC. (Compositae) is a medicinal herb used in Argentina, Uruguay, Brazil and Paraguay for its choleretic, antispasmodic and hepatoprotective properties. The presence of the flavonoid quercetin and its derivatives, and of different phenolic acids such as caffeic, chlorogenic and isochlorogenic acids in the aerial parts of this plant has led us to study the antioxidant activity of its extracts using different bioassays. The inhibition of luminol-enhanced chemiluminescence by the aqueous and methanolic extracts was used to show that their total reactive antioxidant potential index (TRAP; in microM Trolox equivalents) was 91.0 +/- 15.4 and 128.1 +/- 20.1 microM, respectively, while the total antioxidant reactivity index (TAR) was calculated to be 1537 +/- 148 and 1910 +/- 171 microM. Only the methanolic extract was capable of reducing iron (II)-dependent DNA damage. Lipid peroxidation was assessed by two different methods. The aqueous extract reduced hydroperoxide-initiated chemiluminescence in rat liver homogenates at all concentrations in a dose-dependent manner, with a calculated IC50 = 225 micrograms/ml, while the methanolic extract was only effective at higher concentrations (100 and 1000 micrograms/ml). Both aqueous and methanolic extracts were capable of reducing the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates, with an IC50 > 1000 micrograms/ml. The results obtained suggest that the extracts of A. satureioides possess significant free radical scavenging and antioxidant activity in vitro, a fact that should encourage future in vivo studies.


Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Dano ao DNA , Desoxirribose/farmacologia , Extratos Vegetais/química , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico
14.
J Ethnopharmacol ; 56(2): 117-21, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9174972

RESUMO

Aqueous and dichloromethane extracts of Bolax gummifera (Lam.) Sprengel (Apiaceae), a plant of the Falkland Islands used as a treatment of wounds, were studied in order to support the ethnopharmacological information related to the medicinal use of this plant. The antimicrobial, antioxidant and red blood cells membrane stabilizing activities were analyzed. The antimicrobial bioassay was carried out using the test turbidity method (OD 620 nm), the aqueous extract showing an 82% inhibition of Staphylococcus aureus but no activity against Pseudomonas aeruginosa. The dichloromethane extract inhibited both microorganisms: S. aureus in 94% and P. aeruginosa in 32%. No antioxidant activity could be observed using hydroperoxide-initiated chemiluminescence in rat liver homogenates. Investigations into the membrane stabilizing activity of the extracts were carried out using human red blood cells subjected to hypotonic- and heat-induced lyses. The aqueous extract showed an important stabilizing activity of the red blood cell membrane.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Membrana Eritrocítica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/terapia , Animais , Membrana Eritrocítica/patologia , Ilhas Malvinas , Temperatura Alta/efeitos adversos , Humanos , Fígado/efeitos dos fármacos , Fígado/patologia , Medições Luminescentes , Medicina Tradicional , Cloreto de Metileno/química , Testes de Sensibilidade Microbiana , Plantas Medicinais/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos , Ratos Wistar , Staphylococcus aureus/efeitos dos fármacos , Água/química , Infecção dos Ferimentos/prevenção & controle
15.
Braz J Med Biol Res ; 30(1): 85-91, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9222409

RESUMO

Leaves of Pothomorphe peltata (L.) Miq. (Piperaceae) are used locally as anti-inflammatory, antipyretic, hepatoprotective and diuretic infusions and to treat external ulcers and local infections in several parts of the Peruvian, Bolivian and Brazilian Amazon region. The antioxidant activity of different extracts of P. peltata was studied using the hydroperoxide-initiated chemiluminescence assay in liver homogenates, and the methanolic extract was found to have the highest antioxidant activity, with an IC50 = 4 micrograms/ml. Aqueous and dichloromethane extracts did not show antioxidant activity. The extracts were further evaluated using the thiobarbituric acid-reactive substances (TBARS) assay. Finally, an assay of DNA sugar damage induced by Fe (II) salt was used to determine the capacity of the extracts to suppress the oxidative degradation of DNA. All the extracts showed antioxidant activity in the latter two bioassays. The methanolic extract showed the highest activity in reducing oxidative damage to DNA, with an IC50 = 5 micrograms/ml. Since this extract was highly effective in reducing chemiluminescence and DNA damage, and because the latter activity could be due to the presence of compounds that bind to DNA, DNA-binding activity was studied using the DNA-methyl green (DNA-MG) bioassay. A 30% decrease in the initial absorbance of DNA-MG complex was observed in the methanolic extract at 1000 micrograms/ml, suggesting the presence of compounds that bind to genetic material. No DNA-binding activity was observed in the aqueous or dichloromethane extracts.


Assuntos
Antioxidantes/farmacologia , Dano ao DNA/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Ferro , Medições Luminescentes , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/análise
16.
Braz. j. med. biol. res ; 30(1): 85-91, Jan. 1997. tab, graf
Artigo em Inglês | LILACS | ID: lil-187339

RESUMO

Leaves of Pothomorphe peltata (L.) Miq. (Piperaceae) are used locally as anti-inflammatory, antipyretic, hepatoprotective and diuret infusions and to treat external ulcers and local infections in several parts of the Peruvian, Bolivian and Brazilian Amazon region. The antioxidant activity of different extracts of P. peltata was studied using the hydroperoxide-initiated chemiluminescence assay in liver homogenates, and the methanolic extract was found to have the highest antioxidant activity, with an IC50 = 4 mug/ml. Aqueous and dichloromethane extracts did not show antioxidant activity. The extracts were further evaluated using the thiobarbituric acid-reactive substances (TBARS) assay. Finally, an assay of DNA sugar damarge induced by Fe (II) salt was used to determine the capacity of the extracts to suppress the oxidative degradation of DNA. All the extracts showed antioxidant activity in the latter two bioassays. The methanolic extract showed the highest activity in reducing oxidative damage to DNA, with an IC5O = 5 mug/ml. Since this extract was highly effective in reducing chemiluminescence and DNA damage, and because the latter activity could be due to the presence of compounds that bind to DNA, DNA-binding activity was studied using the DNA-methyl green (DNA-MG) bioassay. A 30 per cent decrease in the initial absorbance of DNA-MG complex was observed in the methanolic extract at 1000 mug/ml, suggesting the presence of compounds that bind to genetic material. No DNA-binding activity was observed in the aqueous or dichloromethane extracts.


Assuntos
Ratos , Animais , Antioxidantes/farmacologia , Dano ao DNA/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Medições Luminescentes , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/análise
17.
J Ethnopharmacol ; 58(3): 157-63, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9421251

RESUMO

The in vitro antioxidant and cytotoxic activities in different extracts of Baccharis coridifolia DC. (Compositae) were studied using different bioassays. Antioxidant activity was tested using hydroperoxide-initiated chemiluminescence (CL) in rat liver homogenates. The aqueous extract showed antioxidant activity (IC50 = 141 microg/ml), while the dichloromethane and methanol extracts were prooxidant. Activity in the aqueous extract was confirmed by determination of thiobarbituric acid-reactive substances (TBARS), showing an IC50 = 556 microg/ml. On the other hand, studies on the cytotoxic activity demonstrated a 78% crown gall tumour inhibition and an ED50 = 4. 2 microg/ml in KB cells growth for the dichloromethane extract. A 56% decrease in the initial absorbance of DNA-Methyl Green complex could also be observed at 1000 microg/ml, suggesting the presence of compounds that interact with DNA.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Plantas Medicinais/química , Animais , Dano ao DNA , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Peróxido de Hidrogênio/metabolismo , Técnicas In Vitro , Células KB , Fígado/efeitos dos fármacos , Fígado/metabolismo , Medições Luminescentes , Masculino , Oxidantes/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , América do Sul , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
18.
Planta Med ; 63(6): 561-3, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9434614

RESUMO

The total reactive antioxidant potential (TRAP) and total antioxidant reactivity (TAR) of 4-nerolidylcatechol (4-NC) and methanolic extracts of Pothomorphe umbellata and P. peltata were determined by monitoring the intensity of luminol enhanced chemiluminescence by peroxyl radicals derived from thermolysis of 2,2'-azobis(2-amidinopropane). The highest antioxidant potential was measured in the extract of P. umbellata (TRAP = 97.2 microM) while the highest reactivity was observed in the extract of P. peltata (TAR = 5.0 microM), measured as equivalents of Trolox concentration. These results were higher than those obtained for 4-NC (TRAP = 33.6 microM, TAR = 4.9 microM). DNA sugar damage induced by Fe(II) salts was also used to determine the capacity of 4-NC to suppress hydroxyl radical-mediated degradation of DNA. Calculated IC50 values for 4-NC and catechin, used as a standard, were 25 and 17 microM, respectively.


Assuntos
Catecóis/farmacologia , Dano ao DNA , Compostos Ferrosos/toxicidade , Sequestradores de Radicais Livres/farmacologia , Folhas de Planta/química , Catecóis/isolamento & purificação , Sequestradores de Radicais Livres/isolamento & purificação
19.
J Ethnopharmacol ; 52(1): 45-51, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8733119

RESUMO

The Ese'eja is a hunter-fisher-gatherer tribe of Amerindians which occupies the south-eastern part of Perú. Their culture cannot be disassociated from religious beliefs. Disease can be caused by accident, distraction or indolence, or by evil powers. These evil powers come either from the direct action of a harmful shaman or by interactions with the Devil. A description of shamanic practices is given to elucidate the position of health practices in Ese'eja culture, which includes the use of medicinal and ritual plants. Aspects of ayahuasca (Banisteriopsis caapi (Spruce) Morton, Malpighiaceae) ritual in shaman initiation and in healing rituals are presented. Diagnosis and treatment include invocation to the ayahuasca spirit. Plants used as medicine or invoked for healing are presented.


Assuntos
Indígenas Sul-Americanos , Medicina Tradicional , Extratos Vegetais/isolamento & purificação , Plantas Medicinais , Comportamento Ritualístico , Cura Mental , Peru , Extratos Vegetais/metabolismo , Religião e Medicina
20.
J Ethnopharmacol ; 50(2): 91-6, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8866729

RESUMO

Thirty-nine extracts of 13 plants used traditionally as medicinal by the Ese'ejas were studied in order to determine their cytotoxic effect in the brine shrimp. Infusions showed no toxicity. Those plants that tested positive for methanolic and dichloromethane extracts were assayed for DNA-binding activity. Cytotoxicity was not due to the presence of compounds that interact with DNA. Antimicrobial activity of plants used to treat infectious diseases was also performed for the decoctions. These proved to be active against some of the test microrganisms used in the assay.


Assuntos
Bactérias/efeitos dos fármacos , DNA/efeitos dos fármacos , Medicina Tradicional , Extratos Vegetais/farmacologia , Animais , Artemia
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