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1.
J Ethnopharmacol ; 142(3): 620-6, 2012 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-22609154

RESUMEN

AIM OF THE STUDY: To evaluate the antidiarrhoeal properties of Alstonia congensis leaves claimed to be effective for the treatment of diarrhoea by traditional healers during our ethnopharmacological investigation conducted in Kinshasa, Democratic Republic of Congo. MATERIALS AND METHODS: The aqueous extract (decoction), and the 80% hot methanol extract (Soxhlet extraction) were obtained. This last extract was fractionated. The antidiarrhoeal activity was evaluated using castor oil and magnesium sulphate-induced diarrhoea in animals. The potential antibacterial activity of all samples was also assessed in vitro. RESULTS: At all oral doses of 100 and 200 mg/kg body weight, all A. congensis samples showed significant and dose-dependent antidiarrhoeal activity in treated Wistar rats characterised by significant increase of onset time and decrease of all other diarrhoeal parameters at various degrees compared to untreated groups in both models. At the highest oral dose of 200 mg/kg bodyweight, the 80% hot methanol and aqueous extracts produced 79.8 ± 2.1% and 78.6 ± 0.5%, and 75.0 ± 2.1% and 71.4 ± 2.1% inhibition of defecation and diarrhoea respectively against castor oil-induced diarrhoea, and 75.0 ± 1.2% and 73.3±1.2% inhibition of diarrhoea respectively against magnesium sulphate-induced diarrhoea. The 80% hot methanol and aqueous detannified extracts showed low activity (42-47% inhibition of defecation and/or diarrhoea in both tests) suggesting that tannins may be responsible for the observed activity. At the same oral doses, the total alkaloid extract, the chloroform soluble fraction rich in alkaloids, the 80% methanol and the alkaline aqueous soluble subfractions produced more than 50% inhibition of defecation and/or diarrhoea in both tests. From the antibacterial testing in vitro, results indicated that all A. congensis samples exhibited an antibacterial activity mainly against bacteria implicated in diarrhoea with MIC and MBC values in the range of 15.6-500 µg/ml. The most active samples were the aqueous (decoction) and the 80% hot methanol dried extracts, the chloroform subfraction rich in alkaloids and the total alkaloid extract (MIC: 15.7-125 µg/ml, MBC: 31.2-250 µg/ml). Proteus varibilis was found to be the most resistant microorganism. CONCLUSION: These reported results can partly support and justify the traditional use of extracts from Alstonia congensis leaves for the treatment of diarrhoea in tradittional medicine.


Asunto(s)
Alstonia , Antibacterianos/uso terapéutico , Antidiarreicos/uso terapéutico , Diarrea/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/uso terapéutico , Animales , Antibacterianos/farmacología , Antidiarreicos/farmacología , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Aceite de Ricino , Diarrea/inducido químicamente , Sulfato de Magnesio , Metanol/química , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/farmacología , Hojas de la Planta/química , Ratas , Ratas Wistar , Solventes/química
2.
J Ethnopharmacol ; 127(2): 215-20, 2010 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-19951738

RESUMEN

AIM: The study was aimed to evaluate the in vitro antispasmodic activity of Morinda morindoides leaves aqueous extract, its soluble fractions and isolated compounds to provide the pharmacological basis for its use for the treatment of constipation and diarrhoea in traditional medicine. METHODS: The antispasmodic activity of each sample was evaluated on acetylcholine (ACh) and the depolarized KCl solution induced contractions on guinea-pig isolated ileum suspended in Tyrode's solution. RESULTS: At a test concentration of 40mug/ml in organ bath, the aqueous extract and its petroleum ether soluble fraction showed a spasmogenic effect on both agonists. The diethylether, ethyl acetate, n-butanol and residual aqueous phase soluble fractions from the partition of the aqueous extract exhibited spasmolytic activity producing 47-100% inhibition of contractions induced by both agonists with IC(50) values ranged from 6 to 15 microg/ml according to the case. In addition, the n-butanol and residual aqueous phase soluble fractions showed an inhibitory effect of 75 and 66% respectively on low high [K(+)] (25 mM) and 65 and 60% respectively on high [K+] (80 mM). Crude flavonoids showed spasmolytic on both agonists while crude saponins only showed spasmolytic activity on ACh and displayed spasmogenic effect on KCl. Quercetin, quercitrin and rutin exhibited significant antispasmodic effect with IC(50) values <0.1 microg/ml. Epoxygaertneroside and gaertneroside showed good antispasmodic activity on both agonists (4

Asunto(s)
Morinda , Parasimpatolíticos/farmacología , Extractos Vegetales/farmacología , Hojas de la Planta , Animales , Relación Dosis-Respuesta a Droga , Femenino , Cobayas , Íleon/efectos de los fármacos , Íleon/fisiología , Masculino , Parasimpatolíticos/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Rubiaceae
3.
Talanta ; 76(2): 462-8, 2008 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-18585307

RESUMEN

A new method was developed and validated for the quantification of strictosamide in the extract of the stem bark of Nauclea pobeguinii. This plant belongs to the Rubiaceae family and is widely used in the African traditional medicine against malaria and malaria-like symptoms. Alkaloids are suspected to be responsible for the antimalarial activity. One of these alkaloids is strictosamide, already reported to be the major constituent in the root bark of this plant. Because strictosamide was not commercially available another alkaloid, ajmalicine HCl, with comparable properties was used as a secondary standard. The samples of the dried 80% ethanol extract from the stem bark of N. pobeguinii were purified on C(18) solid phase extraction cartridges and analysed using HPLC-UV. The strictosamide used for the validation of the correction factor for response was isolated and purified by means of preparative HPLC and TLC. Although the relative standard deviation (R.S.D.) of 2.6% was still acceptable, the response factor was determined for every analysis based on the ratio of the peak area of strictosamide compared to the peak area of ajmalicine HCl in a concentration of 0.01 mg/ml. The precision of the method according to the time and the concentration, had a R.S.D. value of 2.2% and 2.6%, respectively. The recovery of the method was 92.2% (R.S.D. of 9.4%) which was acceptable. The method has been proven to be suitable for the determination of alkaloids in the extract of the stem bark of N. pobeguinii, according to the ICH guidelines on the validation of analytical methods.


Asunto(s)
Alcaloides/análisis , Cromatografía Líquida de Alta Presión/métodos , Medicina Tradicional Africana , Rubiaceae/química , Antimaláricos/análisis , Cromatografía Líquida de Alta Presión/normas , Corteza de la Planta/química , Extractos Vegetales/análisis , Reproducibilidad de los Resultados
4.
J Ethnopharmacol ; 115(3): 409-15, 2008 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-18068320

RESUMEN

AIM OF THE STUDY: To evaluate in vitro the antiprotozoal and cytotoxic activities of 80% methanol extract from 45 medicinal plants collected in Sankuru (Democratic Republic of Congo) against Trypanosoma brucei brucei, Trypanosoma cruzi and the chloroquine-sensitive Ghanaian strain of Plasmodium falciparum, and MRC-5 cell lines respectively. MATERIAL AND METHODS: Different extracts were obtained by maceration of each plant part used with 80% methanol for 24h. The mixture was filtered and evaporated in vacuo to give corresponding dried extract. The activity against Trypanosoma brucei brucei and Trypanosoma cruzi were performed in 96 well tissue plates each containing 10 microl aqueous plant extract dilutions (100 to 0.01 microg/ml) with 10 microl of the parasite suspension cultured in Hirumi medium supplemented with 10% foetal calf serum, a solution of 2% penicillin/streptomycin (2% P/S) After 4 days incubation with Almar blueâ solution, fluorescence was measured at 500 nm emission and 530 nm excitation and results expressed as percentage reduction in parasite compared to control wells. The antiplasmodial activity of was assessed in vitro against the chloroquine-sensitive Ghanaian strain of Plasmodium falciparum cultured in RPMI-1640 medium by the lactate deshydrogenase assay in the presence of plant extracts (50 to 0.01 microg/ml). Cell-lines MRC-5 were cultured in MEM medium supplemented with 20mM l-glutamine, 16.5mM NaHCO(3), 5% foetal calf serum and 2% P/S solution. After 4h incubation, cell proliferation/viability was spectrophotomecally assessed at 540 nm after addition of MTT. In each assay, the IC50 value for each sample was derived by the drug concentration-response curves. RESULTS: The extracts from Alcornea cordifolia leaves, Momordica charantia whole plant, Omphalocarpum glomerata, root bark and Piptadia africanum stem bark showed good antiprotozoal activity against Trypanosoma brucei brucei with IC50 values from 0.7 to 7 microg/ml. Only Piptadenia africanum extract showed a pronounced antiprotozoal activity against Trypanosoma cruzi (IC50=4.0+/-06 microg/ml). The extracts from Alchornea cordifolia, Polyathia swaveleons stem bark, Sapium cornutum stem bark and Triclisia giletii stem bark exhibited a pronounced antiplasmodial activity against P. falciparum Ghanaian strain with IC50 values ranging from 0.5 to 3.0 microg/ml. Piptadenia africanum extract was the most cytotoxic sample (CC50=0.25 microg/ml) with poor selectivity against all selected protozoa (SI<10) while other active extracts did not show a significant cytotoxic effect against MCR-5 cell-lines with good selectivity according to the case. CONCLUSION: These active plant extracts are selected for extensive studies leading to the isolation of active constituents.


Asunto(s)
Antineoplásicos/farmacología , Antiprotozoarios/farmacología , Extractos Vegetales/farmacología , Animales , Antineoplásicos/aislamiento & purificación , Antiprotozoarios/aislamiento & purificación , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , República Democrática del Congo , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Concentración 50 Inhibidora , Medicina Tradicional Africana , Ratones , Pruebas de Sensibilidad Parasitaria , Plantas Medicinales , Plasmodium falciparum/efectos de los fármacos , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma cruzi/efectos de los fármacos
5.
J Ethnopharmacol ; 114(1): 44-53, 2007 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-17825510

RESUMEN

A total of 418 healers have been interviewed in Guinea, a coastal country of West Africa, ranging between 7 degrees 30 and 12 degrees 30 of northern latitude and 8 degrees and 15 degrees of western longitude. Plant species used by the local inhabitants to treat infectious diseases were identified using ethnobotanical, ethnographic and taxonomic methods. During these investigations, 218 plants were registered, of which the following were the most frequently used: Erythrina senegalensis, Bridelia ferruginea, Crossopteryx febrifuga, Ximenia americana, Annona senegalensis, Cochlospermum tinctorium, Cochlospermum planchonii, Lantana camara, Costus afer, Psidium guajava, Terminalia glaucescens, Uapaca somon and Swartzia madagascariensis. Most plants, and especially the leaves, were essentially used as a decoction. In order to assess antibacterial activity, 190 recipes were prepared and biologically tested, among which six showed activity (minimal inhibitory concentration<125 microg/ml) against Bacillus cereus, Mycobacterium fortuitum, Staphylococcus aureus, or Candida albicans, i.e., Entada africana, Chlorophora regia, Erythrina senegalensis, Harrisonia abyssinica, Uvaria tomentosa, and a mixture of six plants consisting of Swartzia madagascariensis, Isoberlinia doka, Annona senegalensis, Gardenia ternifolia, Terminalia glaucescens and Erythrina senegalensis.


Asunto(s)
Antibacterianos/farmacología , Medicina Tradicional Africana , Extractos Vegetales/farmacología , Plantas Medicinales/química , Adulto , Anciano , Antibacterianos/aislamiento & purificación , Recolección de Datos , Femenino , Guinea , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Extractos Vegetales/aislamiento & purificación , Estructuras de las Plantas
6.
Curr Med Chem ; 14(4): 417-30, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17305543

RESUMEN

Over the last decade, much research has focused on the potential health benefits of antioxidants and indeed many synthetic and natural compounds have been evaluated for their antioxidant profile. However, in several studies only a limited number of assays, often poorly validated, are used and the techniques available frequently lack specificity. These limitations may incorrectly influence the results. This review will therefore focus on several pitfalls that may emerge in vitro and in vivo antioxidant research. First, different in vitro techniques to determine antioxidant potential are discussed, including radical scavenging assays and fingerprinting methods. As a rule, a panel of different assays is indispensable to characterize and establish in vitro antioxidant activity. Furthermore, as problems of absorption, distribution, metabolism and excretion are only accounted for by in vivo studies, the need for in vivo antioxidant research is pointed out. Several methods to characterize the in vivo activity of antioxidants, including major drawbacks and pitfalls of some assays, have been discussed. The availability of both a representative "oxidative stress" animal model and a battery of well-validated assays to assess the broad diversity of oxidative damage and antioxidative defence parameters, are crucial for antioxidant research in vivo.


Asunto(s)
Antioxidantes/uso terapéutico , Investigación Biomédica , Evaluación Preclínica de Medicamentos/métodos , Animales , Antioxidantes/farmacocinética , Antioxidantes/farmacología , Humanos , Estrés Oxidativo/efectos de los fármacos
7.
J Ethnopharmacol ; 107(1): 83-90, 2006 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-16603327

RESUMEN

An aqueous decotion (dried extract), an 80% MeOH extract from Morinda morindoides leaves, and 10 flavonoids and 4 iridoids isolated from the 80% MeOH extract were evaluated in vitro for their potential antiamoebic activity and their cytotoxic effect against MT-4 cells. Results indicated that the aqueous decoction and the 80% MeOH extract exhibited an interesting antiamoebic activity with IC(50) values of 3.1 +/- 1.7 and 1.7 +/- 0.6 microg/ml, respectively. Apigenin-7-O-glucoside and luteolin-7-O-glucoside exhibited a moderate antiamoebic activity with IC(50) values of 22.3 +/- 3.2 and 37.4 +/- 2.7 microg/ml, respectively. Kaempferol (IC(50) = 10.3 +/- 2.3 microg/ml), apigenin (IC(50) = 12.7 +/- 4.3 microg/ml), and luteolin (IC(50) = 17.8 +/- 4.3 microg/ml) showed a more pronounced activity than their corresponding glycosides. All tested iridoids displayed a very good activity with IC(50) values less than 10 microg/ml. The most active iridoids were epoxygaertneroside (IC(50) = 1.3 +/- 0.4 microg/ml) and methoxygaertneroside (IC(50) = 2.3. +/- 0.7), followed by gaertneroside and gaertneric acid with IC(50) values of 4.3 +/- 1.8 and 7.1 +/- 1.4 microg/ml, respectively. Except quercetin and quercetin-7,4'-dimethylether which have shown a cytotoxic effect with IC(50) ranging from 14 to 22 microg/ml. No correlation could be deduced between the observed antiamoebic and cytotoxic activity of these tested samples. A structure-activity relationship for isolated compounds is discussed. These findings support the medicinal report for the traditional use of Morinda morindoides leaves for the treatment of amoebiasis.


Asunto(s)
Amebicidas/farmacología , Entamoeba histolytica/efectos de los fármacos , Morinda/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Animales
8.
Ann Trop Med Parasitol ; 99(4): 345-57, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15949182

RESUMEN

The antimalarial activities of crude extracts and 17 fractions from the partition of 80%-methanolic extracts of three plants (the stem bark of Croton mubango, the stem bark of Nauclea pobeguinii and the leaves of Pyrenacantha staudtii) used as antimalarial remedies in the Democratic Republic of Congo were studied both in vitro (against Plasmodium falciparum) and in mice infected with Pl. berghei berghei. The toxic effects of dried aqueous extracts of the plants were also investigated, in uninfected mice. The most active crude extracts in vitro, with median inhibitory concentrations (IC(50)) of <1 microg/ml, were found to be the methanolic and dichloromethane extracts of C. mubango, and the dichloromethane extracts of N. pobeguinii and Py. staudtii. The aqueous extract with the most antimalarial activity in vitro was that of C. mubango (IC(50) = 3.2 microg/ml), followed by that of N. probeguinii (IC(50) = 5.3 microg/ml) and then that of Py. staudii (IC(50) = 15.2 microg/ml). Results from the in-vivo tests of antimalarial activity showed that, at a daily oral dose of 200 mg/kg, all the dichloromethane extracts, the petroleum-ether, chloroformic, ethyl-acetate and residual water-soluble fractions from C. mubango, and the chloroformic, ethyl-acetate and n-butanolic fractions from Py. staudtii produced >80% chemosuppression of the parasitaemias by day 4. The aqueous extracts of C. mubango and N. probeguinii produced a slightly lower but still significant inhibition of parasitaemia (60%-80%) whereas that of Py. staudtii only suppressed the day-4 parasitaemias by 37%. The dried aqueous extract of the stem bark of C. mubango showed some signs of toxicity in mice, with median lethal doses (LD(50)) of 350 mg/kg in the female mice and 900 mg/kg in the male. The extract significantly increased the serum concentrations of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) in mice of both sexes, but had no effect on the blood levels of creatinine or urea. No significant toxic effect was observed for the dried aqueous extracts of N. pobeguinii and Py. staudtii (LD(50) >5 g/kg). Neither of these extracts affected the serum concentrations of GPT or the blood concentrations of creatinine and urea, although the N. pobeguinii extract did increase the serum concentration of GOT.


Asunto(s)
Antimaláricos/uso terapéutico , Malaria/tratamiento farmacológico , Fitoterapia/métodos , Animales , Aspartato Aminotransferasas/sangre , Creatinina/sangre , Croton/química , Femenino , Masculino , Ratones , Fitoterapia/efectos adversos , Extractos Vegetales/efectos adversos , Extractos Vegetales/química , Extractos Vegetales/uso terapéutico , Plasmodium berghei/efectos de los fármacos , Plasmodium falciparum/efectos de los fármacos , Rubiaceae/química , Pruebas de Toxicidad Aguda/métodos , Urea/sangre
9.
Fitoterapia ; 75(7-8): 771-3, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15567262

RESUMEN

The isolation, (1)H-NMR and revised (13)C-NMR assignments of syringaresinol-beta-D-glucoside from Cressa cretica are reported.


Asunto(s)
Convolvulaceae , Medicamentos Herbarios Chinos/química , Glucósidos/química , Lignanos/química , Fitoterapia , Egipto , Humanos , Espectroscopía de Resonancia Magnética , Medicina Tradicional , Estructuras de las Plantas
10.
J Ethnopharmacol ; 95(2-3): 399-404, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15507366

RESUMEN

The ethanolic extracts from fresh apical stems of Phyllanthus niruri L. (Euphorbiaceae) cultured on Murashige and Skoog (MS) medium supplemented with IBA/BAP/Coco nucifera L. milk for 1, 2, 4 and 6 months were phytochemically and biologically investigated and compared with intact plant part and whole plant extracts. Results from the in vitro antiplasmodial testing indicated that the EtOH extract of a 1-month-old callus culture (IC(50) = 16.3 +/- 2.5 microg/ml) exhibited a higher activity than the ethanolic extracts of the fresh apical stem (IC(50) = 18.2 +/- 2.4 microg/ml) and callus cultures of 2-, 4- and 6-months-old (25 microg/ml < IC(50) < 40 microg/ml). These activities were however lower than that displayed by the ethanolic extract of the whole plant (IC(50) < 3 microg/ml). The EtOH extract of 1-month-old callus culture (the most active) was fractionated with solvents of different polarities. Its CH(2)Cl(2) fraction rich in terpenic constituents (IC(50) = 9.2 +/- 3.4 microg/ml) exhibited a higher antiplasmodial activity than its isoamylic alcohol fraction obtained at pH 2-3 (IC(50) = 25.6 +/- 2.3 microg/ml) rich in flavonoids. The activity of these two fractions was lower than that displayed by the same fractions from the whole plant (2 microg/ml < IC(50) < 3 microg/ml). Alkaloidic fractions from the whole plant and 1-month-old callus culture of fresh apical stem were considered as inactive (IC(50) > 100 microg/ml).


Asunto(s)
Antimaláricos/farmacología , Phyllanthus , Plasmodium falciparum/efectos de los fármacos , Animales , Antimaláricos/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Tallos de la Planta , Plasmodium falciparum/fisiología
11.
J Ethnopharmacol ; 93(1): 27-32, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15182900

RESUMEN

The in vitro antiplasmodial activity of seven EtOH extracts and twenty fractions from the partition of the initial ethanolic extracts from seven African medicinal plants used in the Democratic Republic of Congo (DR Congo) for the treatment of malaria was evaluated. The most active EtOH extracts (IC50 < 3 microg/ml) were those from Cassia occidentalis leaves, Euphorbia hirta whole plant, Garcinia kola stem bark and Phyllanthus niruri whole plant. Their respective petroleum ether soluble fractions also exhibited an antiplasmodial activity with IC50 < 3 microg/ml. EtOH extracts from Vernonia amygdalina leaves (5 < IC50 < 10 microg/ml), Tetracera poggei leaves (10 < IC50 < 50 microg/ml) and Morinda morindoides leaves (50 < IC50 < 100 microg/ml) were less active, but their petroleum ether fractions exhibited a pronounced antiplasmodial activity (IC50 < 3 microg/ml). The same observation could also be made for the petroleum ether fraction from Cassia occidentalis, Euphorbia hirta, Garcinia kola and Phyllanthus niruri. Isoamyl alcohol fractions from Euphorbia hirta, Phyllanthus niruri and Vernonia amygdalina showed IC50) values less than 3 microg/ml, and from Cassia occidentalis, Garcinia kola, Morinda morindoides and Tetracera poggei between 10 and 50 microg/ml. The observed antiplasmodial activity may be related to the presence of terpenes, steroids, coumarins, flavonoids, phenolic acids, lignans, xanthones and anthraquinones.


Asunto(s)
Antimaláricos/farmacología , Plantas Medicinales , Plasmodium falciparum/efectos de los fármacos , Animales , Antimaláricos/aislamiento & purificación , República Democrática del Congo , Humanos , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Estructuras de las Plantas , Plasmodium falciparum/fisiología
12.
J Pharm Pharmacol ; 56(3): 381-7, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15025864

RESUMEN

In traditional medicine Gossypium barbadense L. is used against hypertension. Looking for a scientific basis for this use, the blood-pressure-lowering effect of the decoction of the leaves was confirmed. Fraction II (frII) of the crude extract of G. barbadense showed a dose-dependent hypotensive effect in anaesthetized rats. In hexamethonium-treated rats, the blood-pressure-lowering effect of frII was almost abolished. A small decrease of the blood-pressure-lowering effect was followed by an increase in the blood pressure. Phentolamine antagonized the increase in blood pressure in hexamethoniumtreated rats. High doses of atropine (4 mg/rat) suppressed both depressor and heart effects. In-vitro experiments revealed that atropine did not antagonize the contraction of the ileum of the rat. Tripelennamine in a concentration of 100 microg could not influence the contraction either, whereas 300 microg did. In the guinea-pig ileum 10 microg tripelennamine did not reduce the contraction significantly. In the mechanism of action of frII, acetylcholine receptors could be involved, but not histaminergic or adrenergic receptors. Although it is still not known which compound(s) in G. barbadense is (are) the active substance(s), the results obtained may explain the use of this plant in traditional medicine in Suriname.


Asunto(s)
Gossypium , Hipotensión/inducido químicamente , Plantas Medicinales , Animales , Atropina/farmacología , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Cobayas , Hexametonio/farmacología , Íleon/efectos de los fármacos , Inyecciones Intraperitoneales , Medicina Tradicional , Contracción Muscular , Fenoxibenzamina/administración & dosificación , Extractos Vegetales/antagonistas & inhibidores , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Hojas de la Planta/química , Propranolol/administración & dosificación , Ratas , Ratas Wistar , Suriname , Agua
13.
Phytomedicine ; 9(1): 56-61, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11924765

RESUMEN

Forty-two ethanolic extracts of thirty-six Rwandan medicinal plants were investigated for their influence on complement-mediated hemolysis. The plants were selected on the base of their ethnomedicinal use in infections and autoimmune diseases. Eight plant extracts showed an inhibitory activity against the classical pathway of the complement system and ten plant extracts against the alternative pathway. Three plant extracts exhibited an interesting activity against both pathways, i.e. Aspilia pluriseta, Coleus kilimandschari, and Macaranga kilimandscharica (leaves and stem). Further study indicated that the complement inhibitory activity was not caused by chelation of bivalent cations or by direct action on the target erythrocytes.


Asunto(s)
Activación de Complemento , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Medicina Tradicional Africana , Fitoterapia , Extractos Vegetales/farmacología , Humanos , Concentración 50 Inhibidora , Estructuras de las Plantas , Rwanda
14.
Phytomedicine ; 9(1): 62-8, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11924766

RESUMEN

Selected plants used in Rwandan traditional medicine for the treatment of infections and/or rheumatoid diseases were investigated for antiviral activity in vitro against human immunodeficiency virus type-1 (HIV-1). Of the 38 tested 80% ethanolic extracts, belonging to plants of 21 different families only the extracts from the leaves of Aspilia pluriseta (Asteraceae) and Rumex bequaertii (Polygonaceae) had interesting selectivity indices (SI = ratio of the 50% cytotoxic concentration to the 50% effective antiviral concentration) higher than 1. Further fractionation of the initially antivirally inactive ethanolic extract of Tithonia diversifolia, however, led to an aqueous fraction with a high anti-HIV-1 activity (SI > 461), indicating that the cytotoxicity of some plant components may mask the antiviral properties of the active plant substances in total plant extracts.


Asunto(s)
Fármacos Anti-VIH/farmacología , VIH-1/efectos de los fármacos , Medicina Tradicional Africana , Fitoterapia , Extractos Vegetales/farmacología , Fármacos Anti-VIH/uso terapéutico , Línea Celular/efectos de los fármacos , Infecciones por VIH/tratamiento farmacológico , Humanos , Extractos Vegetales/uso terapéutico , Estructuras de las Plantas , Rwanda
15.
J Ethnopharmacol ; 79(2): 155-63, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11801376

RESUMEN

A total of 45 Rwandan plant extracts, belonging to 37 different plant species out of 21 families, were investigated for their antibacterial, antifungal, and antiviral properties. The plants were selected on the base of their ethnomedicinal use against infections and autoimmune diseases. From all the plant extracts tested, only Clematis hirsuta (leaves) showed a pronounced antifungal activity against Candida albicans and the dermatophytes Trichophyton rubrum, Epidermophyton floccosum, and Microsporum canis. Seven plant extracts showed a high antiviral activity against the DNA-virus Herpes simplex type 1, while five and three plant extracts were highly active against the RNA-viruses Coxsackie and Polio, respectively. Only Macaranga kilimandscharica (leaves) showed an interesting anti-measles activity, whereas Eriosema montanum (leaves) and Entada abyssinica (leaves) were highly active against Semliki forest virus. Some plant extracts showed an antibacterial activity against Gram-positive bacteria and Mycobacterium fortuitum, but none of them were active against the Gram-negative bacteria tested.


Asunto(s)
Antiinfecciosos/farmacología , Antivirales/farmacología , Evaluación Preclínica de Medicamentos/métodos , Medicina Tradicional Africana , Extractos Vegetales/farmacología , Antibacterianos , Antiinfecciosos/uso terapéutico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Antivirales/uso terapéutico , Evaluación Preclínica de Medicamentos/estadística & datos numéricos , Fitoterapia/métodos , Fitoterapia/estadística & datos numéricos , Extractos Vegetales/uso terapéutico , Hojas de la Planta/química , Rwanda
16.
J Ethnopharmacol ; 79(2): 213-20, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11801384

RESUMEN

The chemical composition of essential oils from 15 aromatic medicinal plant species growing in the Democratic Republic of Congo have been studied. More than 15 constituents in an amount higher than 0.1% were identified in each essential oil. 1,8-cineole, alpha and beta-pinene, p-cymene, myrcene, gamma-terpinene, alpha-terpineol and limonene were prevalent constituents in almost more than 10 selected plant species. Results from the antibacterial testing by the diffusion method indicate that all essential oils (5 microl per disc) inhibited the growth of selected bacteria at different extents. The most active antibacterial essential oils were those of the leaves of Eucalyptus camadulensis and Eucalyptus terticornis (12-30 mm zone diameter of inhibition). They showed particularly a most potent inhibition of Pseudomonas aeruginosa growth (15-16 mm), followed by Eucalyptus robusta (12 mm). Essential oils from the leaves of Eucalyptus alba, Eucalyptus citriodora, Eucalyptus deglupta, Eucalyptus globulus, Eucalyptus saligna, Eucalyptus robusta, Aframomum stipulatum, Cymbopogon citratus, Ocimum americanum and that of the seeds of Monodora myristica showed also a good antibacterial activity (10-18 mm). Eucalyptus propinqua, Eucalyptus urophylla and Ocimum gratissimum essential oils were the less active samples against the selected bacteria. No correlation between the amount of major constituents such as 1,8-cineol, alpha-pinene, p-cymene, cryptone or thymol and the antibacterial activity was observed.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Medicina Tradicional Africana , Aceites Volátiles/química , Aceites Volátiles/farmacología , Antibacterianos/uso terapéutico , República Democrática del Congo , Evaluación Preclínica de Medicamentos/métodos , Evaluación Preclínica de Medicamentos/estadística & datos numéricos , Bacterias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/crecimiento & desarrollo , Aceites Volátiles/uso terapéutico , Fitoterapia/métodos , Fitoterapia/estadística & datos numéricos , Semillas/química
17.
Phytother Res ; 15(7): 593-7, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11746840

RESUMEN

Different extracts and fractions of the leaves, fruits and seeds of Zizyphus spina-christi L. grown in Egypt were investigated in vitro for their antiviral, antifungal and antibacterial activities. The flavonoids quercetin, hyperoside, rutin and quercetin-3-O-[beta-xylosyl-(1-2)-alpha-rhamnoside] 4'-O-alpha- rhamnoside) were isolated.


Asunto(s)
Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Hongos/efectos de los fármacos , Fitoterapia , Extractos Vegetales/farmacología , Rhamnaceae , Antibacterianos , Antiinfecciosos/química , Antiinfecciosos/uso terapéutico , Frutas , Humanos , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/química , Extractos Vegetales/uso terapéutico , Hojas de la Planta , Semillas , Virus/efectos de los fármacos
18.
Planta Med ; 67(6): 515-9, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11509970

RESUMEN

Thirty-five flavonoids of seven different types, namely isoflavonoids, chalcones, dihydroflavonols, flavanols, flavanones, flavones, and flavonols were investigated for their ability to inhibit ascorbate-induced microsomal lipid peroxidation and their cytotoxicity. For each activity a structure-activity relationship was established. Subsequently, an antioxidant selectivity index, i. e., the maximal non-toxic dose divided by the IC(50) value for lipid peroxidation, was introduced. Kaempferol showed the highest antioxidant selectivity index of all flavonoids tested.


Asunto(s)
Antioxidantes/farmacología , Flavonoides/toxicidad , Peroxidación de Lípido/efectos de los fármacos , Microsomas Hepáticos/efectos de los fármacos , Animales , Células Cultivadas , Fibroblastos/efectos de los fármacos , Flavonoides/antagonistas & inhibidores , Flavonoides/química , Flavonoides/farmacología , Humanos , Concentración 50 Inhibidora , Masculino , Ratas , Ratas Wistar , Piel/efectos de los fármacos , Relación Estructura-Actividad
19.
Fitoterapia ; 72(4): 438-40, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11395274

RESUMEN

A new cycloterpene, 4beta,14-dimethyl-9,19-cyclo-5alpha,9beta-ergost-24(28)-en-3-one (cycloabyssinone) (1), and a known terpene, 3-friedelanone, were isolated from stem bark of Harrisonia abyssinica and identified by spectroscopic methods.


Asunto(s)
Plantas Medicinales , Rosales , Triterpenos/aislamiento & purificación , Humanos , Espectroscopía de Resonancia Magnética , Medicina Tradicional Africana , Fitoterapia , Extractos Vegetales/química , Tallos de la Planta , Triterpenos/química
20.
J Pharm Pharmacol ; 53(5): 757-61, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11370716

RESUMEN

Bridelia ferruginea Benth. (Euphorbiaceae) is a subtropical medicinal plant widely used in traditional African medicine against various diseases, including rheumatic pains. Seven of its constituents (3-O-methylquercetin (1), 3,7,3',4'-tetra-O-methylquercetin (rutisin, 2), myricetin (3), 3',4',5'-tri-O-methylmyricetin (ferrugin, 4), 3,3',4',5'-tetra-O-methylmyricetin (5), quercetin 3-O-glucoside (6), and a biflavanol gallocatechin-[4'-O-7]-epigallocatechin (7)) have been evaluated in-vitro in the xanthine-xanthine oxidase enzymatic system for inhibition of xanthine oxidase and radical scavenging activity. Results indicated that compounds 1, 3, 4 and 6 exhibited, at different levels, xanthine oxidase inhibiting and superoxide scavenging activity at micromolar concentrations, whereas compound 7 showed scavenging activity only. Compounds 2 and 5 were inactive in both cases. Study of the structure-activity relationship demonstrated that for flavonoids the xanthine oxidase inhibitory activity was reduced by methylation of the hydroxyl functionality at C-3 and in rings A and B. These results may partly explain and support the use of B. ferruginea stem bark for the treatment of rheumatic pains in traditional medicine.


Asunto(s)
Depuradores de Radicales Libres/farmacología , Fenoles/farmacología , Xantina Oxidasa/metabolismo , Artritis Reumatoide/tratamiento farmacológico , Humanos , Medicina Tradicional Africana , Fenoles/aislamiento & purificación , Extractos Vegetales , Plantas Medicinales , Xantina Oxidasa/efectos de los fármacos
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