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Biomedical subjects

E Deharo

Publications and source records attributed to E Deharo.

At least 19 recordsLinked to original sources
PubMed2006

Quassia amara L. (Simaroubaceae) leaf tea: effect of the growing stage and desiccation status on the antimalarial activity of a traditional preparation.

In French Guiana, Quassia amara L. (Simaroubaceae) leaf tea is a well-known widely used traditional antimalarial remedy. Impact of the vegetal sampling condition on in vivo and in vitro antimalarial activity was assessed. Traditional infusions were prepared with juvenile or mature leaves, both either fresh or dried. Results showed that growing stage and freshness of vegetal material exert a striking effect on antimalarial activity, both in vitro and in vivo. By far, leaf tea made from fresh juvenile (FJ) Quassia amara leaves was the most active. In vitro, active component (simalikalactone D) concentration correlates biological activities, although unexplained subtle variations were observed. In vivo, tea made with dried juvenile (DJ) leaves displays a peculiar behavior, meaning that some components may help simalikalactone D delivery or may be active in vivo only, therefore enhancing the expected curative effect of the traditional preparation.

Animals↗
PubMed2006

From Tonic-cups to Bitter-cups: Kwasi bita beker from Suriname Determination, past and present use of an ancient galenic artefact.

In the main markets of Paramaribo (Suriname), many stands offer what is locally called "Bitter-cups", or "Kwasi bita beker", small footed-cups, roughly carved from a whitish wood. The use of these cups is strictly medicinal and it seems to be restricted to Suriname, as they are not found in neighbouring countries (Guyana, French Guiana). The aim of this study was to identify the botanical origin of Bitter-cups still in use in the Saramaka traditional medicine (as information from field people was controversial), and document the ethnopharmacology of this original galenical artefact. Microscopic and high performance liquid chromatography (HPLC) analyses were carried out on Bitter-cup, and anatomical criteria (marginal parenchyma band, size of intervessel and vessel-ray pits, rays width and rays composition, vessels clustering, frequency and size of parenchyma pits) together with HPLC profiles of the macerates showed that the wood cup was similar to Quassia amara L. (Simaroubaceae) wood. Ethnopharmacological investigation indicates that the use of these cups is simply due to the pharmacological properties attributed to "bitters", and is strongly linked to tradition and cultural attitudes. This study also emphasizes the long lasting use of these cups, now restricted to Suriname only, with almost no variation over one century.

Chromatography, High Pressure Liquid↗
PubMed2006

Simalikalactone D is responsible for the antimalarial properties of an Amazonian traditional remedy made with Quassia amara L. (Simaroubaceae).

French Guiana (North-East Amazonia) records high malaria incidence rates. The traditional antimalarial remedy most widespread there is a simple tea made out from Quassia amara L. leaves (Simaroubaceae). This herbal tea displays an excellent antimalarial activity both in vitro and in vivo. A known quassinoid, simalikalactone D (SkD), was identified as the active compound, with an IC(50) value of 10nM against FcB1 Plasmodium falciparum chloroquine resistant strain in vitro. Lastly, it inhibits 50% of Plasmodium yoelii yoelii rodent malaria parasite at 3.7 mg/kg/day in vivo by oral route. These findings confirm the traditional use of this herbal tea.

Animals↗
PubMed2006

Antimalarial activity of some Colombian medicinal plants.

Antimalarial activity of 10 vegetal extracts (9 ethanolic extracts and 1 crude alkaloid extract), obtained from eight species traditionally used in Colombia to treat malaria symptoms, was evaluated in culture using Plasmodium falciparum chloroquine resistant (FcB2) strain and in vivo on rodent malaria Plasmodium berghei. The activity on ferriprotoporphyrin biomineralization inhibition test (FBIT) was also assessed. Against Plasmodium falciparum, eight extracts displayed good activity Abuta grandifolia (Mart.) Sandwith (Menispermaceae) leaves, Acacia farnesiana (L.) Willd. (Mimosaceae) leaves, Acnistus arborescens (L.) Schltdl. (Solanaceae) aerial part, Croton leptostachyus Kunth (Euphorbiaceae) aerial part, Piper cumanense Kunth (Piperaceae) fruits and leaves, Piper holtonii C. DC. (Piperaceae) aerial part and Xylopia aromatica (Lam.) Mart. (Annonaceae) bark with IC(50) values ranging from <1 to 2.1 microg/ml, while in the in vivo model only Abuta grandifolia alkaloid crude extract exhibits activity, inhibiting 66% of the parasite growth at 250 mg/kg/day. In the FBIT model, five extracts were active (Abuta grandifolia, Croton leptostachyus, Piper cumanense fruit and leaves and Xylopia aromatica).

Animals↗
PubMed2005

Antimalarial remedies in French Guiana: a knowledge attitudes and practices study.

A "knowledge attitudes and practices" study about malaria treatments was undertaken in French Guiana, along with an ethnopharmacological study. One hundred and seventeen people from five different groups and nationalities (Creole, Palikur, Galibi, Brazilian, and European) answered the questionnaire. The results were analysed using univariate and multivariate statistical analysis. First, we evaluated the overall knowledge about malaria from the interviewed people. According to bio-medical concepts, we noticed that they have a good knowledge of this illness. Secondly, we studied the treatment used by sick people during their last malaria attack. We demonstrated that, although bio-medical treatment is available in this area, people use both modern drugs and traditional remedies. Finally, preventive attitudes have been examined. One-third of the interviewed people drink regularly some herbal remedy to prevent febrile illnesses and malaria, thus displaying a strong concern about this disease. The ethnopharmacological study highlighted the frequent use of traditional remedies, along with their mode of preparation and administration. A total of 34 different species (both from flora and fauna) have been registered as antimalarial. Twenty-seven are used for curative purposes, 20 as preventive and 13 of them are used for both purposes. Quassia amara (Simaroubaceae) whose antimalarial activity has already been demonstrated was the species most frequently used as antimalarial for curative and preventive purposes.

Adult↗
PubMed2005

Evaluation of French Guiana traditional antimalarial remedies.

In order to evaluate the antimalarial potential of traditional remedies used in French Guiana, 35 remedies were prepared in their traditional form and screened for blood schizonticidal activity in vitro on Plasmodium falciparum chloroquine re4sistant strain (W2). Some of these extracts were screened in vivo against Plasmodium yoelii rodent malaria. Ferriprotoporphyrin inhibition test was also performed. Four remedies, widely used among the population as preventives, were able to inhibit more than 50% of the parasite growth in vivo at around 100 mg/kg: Irlbachia alata (Gentiananceae), Picrolemma pseudocoffea (Simaroubaceae), Quassia amara (Simaroubaceae), Tinospora crispa (Menispermaceae) and Zanthoxylum rhoifolium (Rutaceae). Five remedies displayed an IC50 in vitro < 10 microg/ml: Picrolemma pseudocoffea, Pseudoxandra cuspidata (Annonaceae) and Quassia amara leaves and stem, together with a multi-ingredient recipe. Two remedies were more active than a Cinchona preparation on the ferriprotoporphyrin inhibition test: Picrolemma pseudocoffea and Quassia amara. We also showed that a traditional preventive remedy, made from Geissospermum argenteum bark macerated in rum, was able to impair the intrahepatic cycle of the parasite. For the first time, traditional remedies from French Guiana have been directly tested on malarial pharmacological assays and some have been shown to be active.

Administration, Oral↗
PubMed2005

A new rhabdiasid nematode, Chabirenia cayennensis n. g., n. sp., parasitic in the glands of the buccal mucosa of a South American saurian.

Chabirenia cayennensis n. g., n. sp. (Nematoda: Rhabdiasidae) is described from the teiid lizard Ameiva ameiva. A total of 139 worms were recovered, all females, from the mucous glands of the buccal cavity. The worm has a free-living phase in a homogonic life-cycle. Infective larvae are enclosed in a sheath with chequered ornamentation and composed of two exuviae. The new genus is distinct from the five known genera of the family, Pneumonema Johnston, 1916, Acanthorhabdias Pereira, 1927, Entomelas Travassos, 1930, Rhabdias Stiles and Hassall, 1905 and Neoentomelas Hasagawa, 1989, in the following characters: helical habitus, longitudinal cuticular crests, very tiny buccal cavity without thick walls and three oesophageal onchia. Several characters of this new rhabdiasid suggest the Strongylida.

Animals↗
PubMed2004

A search for natural bioactive compounds in Bolivia through a multidisciplinary approach. Part VI. Evaluation of the antimalarial activity of plants used by Isoceño-Guaraní Indians.

Seventy-seven plant extracts (corresponding to 62 different species) traditionally used by the Isoceño-Guaraní, a native community living in the Bolivian Chaco, were screened for antimalarial activity in vitro on Plasmodium falciparum chloroquine sensitive strain (F32), and on ferriprotoporphyrin (FP) IX biocrystallisation inhibition test (FBIT). Among these extracts, seven displayed strong in vitro antimalarial activity, and 25 were active in the FBIT test. Positive results on both tests were recorded for six extracts: Argemone subfusiformis aerial part, Aspidosperma quebracho-blanco bark, Castela coccinea leaves and bark, Solanum argentinum leaves and Vallesia glabra bark. Results are discussed in relation with Isoceño-Guaraní traditional medicine. Further studies to be undertaken in relation with these results are also highlighted.

Animals↗
PubMed2004

In vitro immunomodulatory activity of plants used by the Tacana ethnic group in Bolivia.

One hundred and seventy-eight ethanolic plant extracts from the pharmacopoeia of the Tacana, an ethnic group from Bolivia, were screened for immunomodulatory activity using complement cascade inhibition and ADP-induced platelet aggregation inhibition assays. Six impaired both complement pathways (classical and alternative): stem bark from Astronium urundeuvea (Anacardiaceae), Cochlospermum vitifolium (Cochlospermaceae), Terminalia amazonica (Combretaceae), Triplaris americana (Polygonaceae), Uncaria tomentosa (Rubiaceae) and Euterpe precatoria (Arecaceae) roots. Inhibition of complement cascade was independent of essential ion complexation, and was not due to direct hemolytic activity on target red blood cells. For A. urundeuvea, C. vitifolium, and T. amazonica, anti-inflammatory activity relied on cyclo-oxygenase inhibition. Four of these species (A. urundeuva, T. americana, U. tomentosa and E. precatoria) are used traditionally to treat inflammatory processes.

Bolivia↗
PubMed2002

A non-radiolabelled ferriprotoporphyrin IX biomineralisation inhibition test for the high throughput screening of antimalarial compounds.

Intraerythrocytic malaria parasites produce large amounts of toxic ferriprotoporphyrin IX (FP) during their digestion of host cell haemoglobin. The inhibition of biomineralisation of FP to haemozoin (or beta-haematin) by antimalarial drugs underlies their mode of action. We have developed an in vitro microassay for testing the inhibition of biomineralisation by drugs. It is based on the detection by optical density measurement of solubilised beta-haematin remaining after contact with drugs. The assay uses a 192-microM haemin chloride solution in dimethyl sulfoxide, 96-well filtration microplates as well as normal microplates; it lasts 18-24h and requires a spectrophotometer. We determined by this assay the IC(50) of chloroquine phosphate (28microM) and quinine base (324microM) and showed that unlike previous methods it is insensitive to inorganic anions. We also determined the activity of synthetic dyes and plant extract to determinate the interference of coloured compounds on the accuracy of the test. We found that methylene blue, thionine (IC(50) 38 and 87microM, respectively), and an extract of plants that contains quinoline derivatives, inhibited the biomineralisation of FP regardless of their intrinsic colour.

Animals↗
PubMed2001

Anti-Trypanosoma activity of some natural stilbenoids and synthetic related heterocyclic compounds.

We report the anti-Chagasic activity of the natural dihydrostilbenoid isonotholaenic acid and several simple derivatives, as well as that of some representative compounds of related synthetic series, with basic structures of benzalphthalides, dihydrostilbamides, isoindoles, phthalazin-1-ones, imidazo[2,1-a]isoindoles and pyrimido[2,1-a]isoindoles. The evaluation was performed in vitro on cultures of epimastigote and trypomastigote forms of Trypanosoma cruzi. Some of the tested compounds resulted to be as potent as benznidazole (epimastigotes), and others were shown to be more active than gentian violet (trypomastigotes), used as reference drugs.

Animals↗
PubMed2001

Leishmanicidal activity of some stilbenoids and related heterocyclic compounds.

We have evaluated the leishmanicidal activity of some natural and semisynthetic dihydrostilbenoids and several compounds of other series of dihydrostilbamides, isoindoles, phthalazinones, imidazoisoindoles and pyrimidoisoindoles. The evaluation was performed in vitro, on cultures of cutaneous, mucocutaneous and visceral strains of Leishmania spp. The most potent and selective compounds of these series were the dihydrostilbene piperidides.

Animals↗
PubMed2001

A search for natural bioactive compounds in Bolivia through a multidisciplinary approach. Part V. Evaluation of the antimalarial activity of plants used by the Tacana Indians.

One hundred and twenty-five extracts of 122 different plant species traditionally used by the Tacana, a native community living in lowland forest at the base of the last foothills of the Cordillera Oriental of the Bolivian Andes, were screened for antimalarial activity in vitro on Plasmodium falciparum chloroquine resistant (D2) and sensitive strains (F32), and were evaluated in vivo on rodent malaria Plasmodium berghei. Five ethanolic stembark extracts showed marked activity either in vitro or in vivo, and only one of them, Bowdichia virgilioides being traditionally used against malaria, was active in vitro (IC50=1 microg/ml on both strains) and in vivo (51% at 100 mg/kg). Other active extracts were from Caesalpinia pluviosa bark displaying activity in vitro against chloroquine resistant strain (IC50 8.3 microg/ml), traditionally used against dysentery; two Lauraceae bark extracts, Nectandra aff. hihua and Licaria canella respectively used for construction purposes and against stomach ache, both displaying activity in vitro against P. falciparum sensible and resistant strains (IC50 around 4 microg/ml); finally, the bark of a strongly aromatic Burseraceae, Protium glabrescens exuding an anti-inflammatory and analgesic resin, was active in vivo only (61% at 100 mg/kg). Results are discussed in relation with Tacana traditional medicine.

Animals↗
PubMed2001

Antiprotozoal activities of Colombian plants.

In our search for therapeutical alternatives for antiprotozoal chemotherapy, we collected a selection of 44 plants from western Colombia upon ethnopharmacological and chemotaxonomic considerations. Polar and apolar extracts of these species were examined for antimalarial activity using in vitro tests with two clones of Plasmodium falciparum. Leishmanicidal and trypanocidal activity were determined in vitro using promastigote and amastigote forms of several strains of Leishmania sp. and epimastigotes of Trypanosoma cruzi. Among the selected plants, the 15 following species showed good or very good antiprotozoal activity in vitro: Aspidosperma megalocarpon, Campnosperma panamense, Conobea scoparioides, Guarea polymera, Guarea guidonia, Guatteria amplifolia, Huberodendron patinoi, Hygrophila guianensis, Jacaranda caucana, Marila laxiflora, Otoba novogranatensis, Otoba parviflora, Protium amplium, Swinglea glutinosa and Tabernaemontana obliqua. Cytotoxicity was assessed in U-937 cells and the ratio of cytotoxicity to antiprotozoal activity was determined for the active extracts. Ten extracts from eight species showed selectivity indexes > or = 10. Among the extracts that showed leishmanicidal activity, the methylene chloride extract of leaves from C. scoparioides showed a selectivity index in the same range that the one of the Glucantime control. Several of the active leishmanicidal plants are traditionally used against leishmaniasis by the population of the concerned area.

Animals↗
PubMed2001

New Pudicinae (Trichostrongylina, Heligmosomoidea) coparasites of Proechimys longicaudatus (Caviomorpha) from Bolivia. I--Description of Pudica ginsburgi n. sp. and Heligmostrongylus chiarae n. sp.

Two new Pudicinae (Trichostrongylina, Heligmosomoidea, Heligmonellidae) coparasites of Proechimys longicaudatus (Caviomorph rodent) from Bolivia are described: Pudica ginsburgi n. sp. is differentiated from all the other species of the genus by the great length of the spicules and of the vestibule and by a different ratio of the length of the spicules on the length of the body. Heligmostrongylus chiarae n. sp. has very developed rays 4, strongly divergent from rays 5 as occurs in three other species, H. almeidai (Durette-Desset & Tcheprakoff, 1969), a parasite of Trichomys apereoides (= Cercomys cunicularius) from Brazil, H. squamastrongylus (Travassos, 1937), a parasite of Proechimys oris from Brazil and H. proechimysi Durette-Desset, 1970, a parasite of Proechimys semispinosus from Columbia. The specimens from Bolivia are differentiated from the three species by the division of the dorsal ray (anterior half versus posterior half) and by a different ratio of the length of the spicules on the length of the body.

Animals↗
PubMed2000

Aminothiol multidentate chelators against Chagas disease.

Three compounds of an aminothiol family of iron chelators were examined for activity against trypomastigote (human) and epimastigote (vector) forms of Trypanosoma cruzi: tetraethyl and tetramethyl derivatives of ethane-1,2-bis (N-1-amino-3-ethyl butyl-3-thiol) (BAT-TE and BAT-TM) and N',N',N'-tris-(2-methyl-2-mercaptopriopyl)- 1,4,7-triazacyclonane (TAT). BAT-TE at 270 microM completely arrested the growth of trypomastigote forms in mouse blood stored at 4 degrees C for 24 h (IC(50) 67.7+/-7 microM), while BAT-TM arrested growth at 630 microM (IC(50) 158+/-17 microM) and TAT at concentrations >800 microM (IC(50) 415+/-55 microM). In T. cruzi-infected mice, BAT-TE and BAT-TM had no anti-trypanosomal activity in doses up to 200 mg/kg, whether the route of administration was intraperitoneal or oral, and TAT was not tested due to insufficient quantity. TAT had an IC(50) of 52+/-7 microM against the epimastigote forms while BAT-TM and BAT-TE were inhibitory only at concentrations >250 microM. The trypanocidal activity of BAT derivatives in blood stored at 4 degrees C makes these compounds potential candidates for the purpose of clearing donated blood of trypomastigotes.

Animals↗
PubMed2000

Experimental conditions for testing the inhibitory activity of chloroquine on the formation of beta-hematin.

Some antimalarial drugs act by inhibiting the process of ferriprotoporphyrin IX polymerization which protects the parasite against the noxious effect of this product of host cell hemoglobin digestion. As the quest for new drugs with a similar mode of action continues, high-throughput screening methods are needed. We demonstrate herein that such a recently described screening technique (Basilico et al., J. Antimicrob. Chemother. 42, 55-60, 1998) is considerably disturbed by certain ions. Thus, at the assay's pH 2.6, the phosphate ions are responsible for the inhibitory activity of chloroquine phosphate, rather than chloroquine itself. Using a combination of solubility tests and Fourier transform infrared spectrometry we also show that two alternative methods using higher pH's are also prone to salt effects and demonstrate that these can be minimized by extensive washing of the product with DMSO.

Antimalarials↗