References of "Jansen, Olivia"
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See detailStrychnobaillonine, an Unsymmetrical Bisindole Alkaloid with an Unprecedented Skeleton from Strychnos icaja Baill. Roots
Tchinda Tiabou, Alembert ULg; Jansen, Olivia ULg; Nyemb, Jean-Noel et al

in Journal of Natural Products (2014), 77

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See detailIs artemisinin the only antiplasmodial compound in the Artemisia annua tea infusion? An in vitro study.
Mouton, Julia; Jansen, Olivia ULg; Frederich, Michel ULg et al

in Planta Medica (2013), 79(6), 468-70

In our ongoing investigation into Artemisia annua for the treatment of malaria, we decided to study the possibility that synergism might enhance the efficacy of artemisinin. Our main objective was to test ... [more ▼]

In our ongoing investigation into Artemisia annua for the treatment of malaria, we decided to study the possibility that synergism might enhance the efficacy of artemisinin. Our main objective was to test tea infusions and nonpolar extracts prepared from different A. annua varieties against Plasmodium falciparum in vitro in order to determine if synergism will increase the effectiveness of artemisinin in the samples as compared to pure artemisinin. We found that the IC50 of artemisinin in the tea and nonpolar extracts was not significantly different to the IC50 of pure artemisinin. We could show that the year and country of harvest or storage conditions did not have any influence on the activity and that it narrowly followed the concentration of artemisinin in all the extracts. In conclusion, based on these in vitro results, artemisinin seems to be the only active antiplasmodial compound in A. annua. [less ▲]

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See detailAnti-plasmodial activity of Dicoma tomentosa (Asteraceae) and identification of urospermal A-15- O-acetate as the main active compound.
Jansen, Olivia ULg; Tits, Monique ULg; Angenot, Luc ULg et al

in Malaria Journal (2012), 11(1), 2891-9

ABSTRACT: BACKGROUND: Natural products could play an important role in the challenge to discover new anti-malarial drugs. In a previous study, Dicoma tomentosa (Asteraceae) was selected for its promising ... [more ▼]

ABSTRACT: BACKGROUND: Natural products could play an important role in the challenge to discover new anti-malarial drugs. In a previous study, Dicoma tomentosa (Asteraceae) was selected for its promising anti-plasmodial activity after a preliminary screening of several plants traditionally used in Burkina Faso to treat malaria. The aim of the present study was to further investigate the antiplasmodial properties of this plant and to isolate the active anti-plasmodial compounds. METHODS: Eight crude extracts obtained from D. tomentosa whole plant were tested in vitro against two Plasmodium falciparum strains (3D7 and W2) using the p-LDH assay (colorimetric method). The Peters' four-days suppressive test model (Plasmodium berghei-infected mice) was used to evaluate the in vivo anti-plasmodial activity. An in vitro bioguided fractionation was undertaken on a dichloromethane extract, using preparative HPLC and TLC techniques. The identity of the pure compound was assessed using UV, MS and NMR spectroscopic analysis. In vitro cytotoxicity against WI38 human fibroblasts (WST-1 assay) and haemolytic activity were also evaluated for extracts and pure compounds in order to check selectivity. RESULTS: The best in vitro anti-plasmodial results were obtained with the dichloromethane, diethylether, ethylacetate and methanol extracts, which exhibited a high activity (IC50 [less than or equal to] 5 mug/ml). Hot water and hydroethanolic extracts also showed a good activity (IC50 [less than or equal to] 15 mug/ml), which confirmed the traditional use and the promising anti-malarial potential of the plant. The activity was also confirmed in vivo for all tested extracts. However, most of the active extracts also exhibited cytotoxic activity, but no extract was found to display any haemolytic activity. The bioguided fractionation process allowed to isolate and identify a sesquiterpene lactone (urospermal A-15-O-acetate) as the major anti-plasmodial compound of the plant (IC50 < 1 mug/ml against both 3D7 and W2 strains). This was also found to be the main cytotoxic compound (SI =3.3). While this melampolide has already been described in the plant, this paper is the first report on the biological properties of this compound. CONCLUSIONS: The present study highlighted the very promising anti-plasmodial activity of D. tomentosa and enabled to identify its main active compound, urospermal A-15-O-acetate. The high antiplasmodial activity of this compound merits further study about its anti-plasmodial mechanism of action. The active extracts of D. tomentosa, as well as urospermal A 15-Oacetate, displayed only a moderate selectivity, and further studies are needed to assess the safety of the use of the plant by the local population. [less ▲]

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See detailEvaluation of 13 selected medicinal plants from Burkina Faso for their antiplasmodial properties.
Jansen, Olivia ULg; Angenot, Luc ULg; Tits, Monique ULg et al

in Journal of Ethnopharmacology (2010), 130

AIM OF THE STUDY: The aim of this study was to evaluate the antiplasmodial properties of 13 plants used against malaria in traditional medicine in Burkina Faso. MATERIALS AND METHODS: In vitro ... [more ▼]

AIM OF THE STUDY: The aim of this study was to evaluate the antiplasmodial properties of 13 plants used against malaria in traditional medicine in Burkina Faso. MATERIALS AND METHODS: In vitro antiplasmodial activity of dichloromethane, methanol and aqueous crude extracts obtained from vegetal samples collected in Burkina Faso was first evaluated on the Plasmodium falciparum 3D7 chloroquine-sensitive strain using a colorimetric method. RESULTS: Thirteen extracts obtained from 8 different species were found to exhibit antiplasmodial activity (IC(50)<50mug/ml). Five species demonstrated a moderate activity (15mug/ml<IC(50)<50mug/ml): Boswellia dalzielii (leaves), Waltheria indica (roots and aerial parts), Bergia suffruticosa (whole plant), Vitellaria paradoxa (bark) and Jatropha gossypiifolia (leaves). The best results were obtained with extracts from the Dicoma tomentosa whole plant, from Psorospermum senegalense leaves and from Gardenia sokotensis leaves. These extracts found to display promising antiplasmodial activity, with IC(50) values ranging from 7.0 to 14.0mug/ml. The most active plant extracts were then tested for in vitro activity on the Plasmodium falciparum W2 chloroquine-resistant strain and also for in vitro cytotoxicity on normal human fibroblasts (WI-38) in order to determine the selectivity index. CONCLUSIONS: Dicoma tomentosa (Asteraceae) and Psorospermum senegalense (Clusiaceae) appeared to be the best candidates for further investigation of their antiplasmodial properties, reported for the first time by this study. [less ▲]

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See detailEvaluation des potentialités antiplasmodiales de plantes utilisées en médecine traditionnelle au Burkina Faso
Jansen, Olivia ULg; Nikiéma, Jean-Baptiste; Angenot, Luc ULg et al

Conference (2009, October 07)

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See detailAntisickling properties of divanilloylquinic acids isolated from Fagara zanthoxyloides Lam. (Rutaceae).
Ouattara, Badiore; Jansen, Olivia ULg; Angenot, Luc ULg et al

in Phytomedicine : International Journal of Phytotherapy and Phytopharmacology (2009), 16(2-3), 125-129

Fagara zanthoxyloides Lam. (syn. Zanthoxylum zanthoxyloides) (Rutaceae) is the most cited Fagara species for the treatment and the prevention of sickle cell disease crisis. Sickle cell anemia (SCA) is a ... [more ▼]

Fagara zanthoxyloides Lam. (syn. Zanthoxylum zanthoxyloides) (Rutaceae) is the most cited Fagara species for the treatment and the prevention of sickle cell disease crisis. Sickle cell anemia (SCA) is a public health problem in many countries particularly in Africa. The present study was designed to evaluate the antisickling properties of three isomeric divanilloylquinic acids (3,4-O-divanilloylquinic acid or burkinabin A; 3,5-O-divanilloylquinic acid or burkinabin B and 4,5-O-divanilloylquinic acid or burkinabin C) identified previously by LC/MS/NMR analysis in the root bark of F. zanthoxyloides [Ouattara et al., 2004. LC/MS/NMR analysis of isomeric divanilloylquinic acids from the root bark of Fagara zanthoxyloides Lam. Phytochemistry 65, 1145-1151]. The three isomers showed interesting antisickling properties which increased from burkinabins A to C. [less ▲]

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See detailEthnopharmacologie et paludisme au Burkina Faso : sélection de 13 espèces à potentialités antiplasmodiales méconnues
Jansen, Olivia ULg; Frederich, Michel ULg; Tits, Monique ULg et al

in Ethnopharmacologia (2008), 41

Dans la recherche de nouvelles substances actives contre les Plasmodium, les flores non explorées du Sud constituent une source potentielle privilégiée de nouveaux médicaments antipaludéens. Dans ce ... [more ▼]

Dans la recherche de nouvelles substances actives contre les Plasmodium, les flores non explorées du Sud constituent une source potentielle privilégiée de nouveaux médicaments antipaludéens. Dans ce travail, nous avons suivi une démarche ethnopharmacologique afin de répertorier et de sélectionner des végétaux intéressants à étudier en laboratoire pour leurs propriétés antiplasmodiales. Notre travail de recensement des espèces utilisées contre la malaria au Burkina Faso nous a permis de répertorier 72 espèces végétales utilisées seules ou en association dans le traitement traditionnel du paludisme dans ce pays d’Afrique de l’Ouest. Finalement, treize espèces ont été sélectionnées et dix-sept échantillons végétaux ont été récoltés au Burkina Faso pour évaluation de leurs propriétés antiplasmodiales en laboratoire. Les principaux critères de sélection ont été : leur utilisation traditionnelle contre la malaria et le fait que ces plantes n’aient pas (ou peu) été étudiées sur le plan antiplasmodial. Les liens de chimiotaxonomie éventuels avec des plantes déjà connues pour leurs propriétés antiplasmodiales ainsi que les possibilités de valorisation des espèces au niveau local (MTA) ont également été considérés. [less ▲]

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See detailIn vitro antiplasmodial activity of ethnobotanically selected plants from Burkina Faso
Jansen, Olivia ULg; Angenot, Luc ULg; Tits, Monique ULg et al

in Planta Medica (2008), 74(9), 1142-1142

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See detailIn vitro cytotoxicity of some medicinal plants from Georgian amaryllidaceae
Jokhadze, Malkhaz; Eristavi, Lina; Kutchukhidze, Jumber et al

in Phytotherapy Research (2007), 21(7), 622-624

Using an ethnomedical data approach, some Georgian plants, which are used in Georgian traditional medicine for cancer or non-cancer diseases, were collected and evaluated for cytotoxic activity. The ... [more ▼]

Using an ethnomedical data approach, some Georgian plants, which are used in Georgian traditional medicine for cancer or non-cancer diseases, were collected and evaluated for cytotoxic activity. The cytotoxic effect of the methanol extracts of species from the genera Galanthus and Leucojum was evaluated in vitro on three human cell lines (Hela, ephitheloid cervix carcinoma; HCT-116, colon carcinoma; HL-60, acute myeloid leukaemia). Cell type cytotoxic specificity was observed for some extracts. Overall, the HCT-116 cells were much more sensitive to most of the extracts than were the other cell lines. Plants that showed pronounced cytotoxic activity will be further evaluated for the possible isolation of active antitumour compounds. Copyright (C) 2007 John Wiley [less ▲]

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See detailHPLC quantification of alkaloids from Haplophyllum extracts and comparison with their cytotoxic properties
Fiot, Julien; Jansen, Olivia ULg; Akhmedjanova, Valentina et al

in Phytochemical Analysis [=PCA] (2006), 17(5), 365-369

An efficient system for the analysis of total alkaloids extracted from the aerial parts from different species of genus Hoplophyllum (Rutaceac) by HPLC on a reversed-phase column is described. The HIPLC ... [more ▼]

An efficient system for the analysis of total alkaloids extracted from the aerial parts from different species of genus Hoplophyllum (Rutaceac) by HPLC on a reversed-phase column is described. The HIPLC method described was validated for its specificity, linearity and precision using external standards (haplopine, skimmianine and haplamine). The chromatographic conditions allowed the separation of alkaloids and the quantification of haplopine, skimmianine and haplamine in different samples of species of Haplophyllum collected in Uzbekistan. The alkaloidal contents of samples were compared with their in vitro cytotoxic properties against two cancer cell lines (HeLa. and HCT-116). The cytotoxicity of extracts was correlated with the concentration of haplopine, skimmianine or haplamine in aerial parts of species of Haplophyllum. Copyright (c) 2006 John Wiley [less ▲]

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See detailPhytochemical and pharmacological study of roots and leaves of Guiera senegalensis JF Gmel (Combretaceae)
Fiot, Julien; Sanon, Souleymane; Azas, Nadine et al

in Journal of Ethnopharmacology (2006), 106(2), 173-178

The chemical composition of total alkaloids from leaves and roots of Guiera senegalensis was investigated. Three beta-carboline alkaloids were purified: in addition to harman and tetrahydroharman, known ... [more ▼]

The chemical composition of total alkaloids from leaves and roots of Guiera senegalensis was investigated. Three beta-carboline alkaloids were purified: in addition to harman and tetrahydroharman, known in roots and leaves. harmalan (dihydroharman) was isolated for the first time from roots of Guiera senegalensis. Guieranone A, a naphthyl butenone, was also purified from leaves and roots. The in vitro antiplasmodial activity and the cytotoxicity of extracts and pure compounds were evaluated. Each total alkaloid extract and beta-carboline alkaloids presented an interesting antiplasmodial activity associated with a low cytotoxicity. Harmalan was less active than harman and tetrahydroharman. Guieranone A showed a strong antiplasmodial activity associated with a high cytotoxicity toward human monocytes. Its cytotoxicity was performed against two cancer cell lines and normal skin fibroblasts in order to study its anticancer potential: guieranone A presented a strong cytotoxicity against each cell strains. Finally, we evaluated the potent synergistic antimalarial interaction between Guiera senegalensis and two plants commonly associated in traditional remedies: Mitragyna inermis and Pavetta crassipes. Three associations evaluated were additive. A synergistic effect was shown between total alkaloids extracted from leaves of Guiera senegalensis and those of Mitragyna inermis. This result justified the traditional use of the plants in combination to treat malaria. (c) 2006 Elsevier Ireland Ltd. All rights reserved. [less ▲]

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See detailScreening of 14 alkaloids isolated from Haplophyllum A. Juss. for their cytotoxic properties
Jansen, Olivia ULg; Akhmedjanova, Valentina; Angenot, Luc ULg et al

in Journal of Ethnopharmacology (2006), 105(1-2), 241-245

Further to a systematic chemotaxonomic study of Uzbek Haplophyllum A. Juss. plants selected on ethnopharmacological data, 14 alkaloids were screened for their cytotoxic properties. As a first selection ... [more ▼]

Further to a systematic chemotaxonomic study of Uzbek Haplophyllum A. Juss. plants selected on ethnopharmacological data, 14 alkaloids were screened for their cytotoxic properties. As a first selection for interesting compounds, each alkaloid was tested against two human cancer cell lines (HeLa and HCT-116), using WST-1 reagent. Of the 14 alkaloids, 5 were cytotoxic when tested against the HeLa line with an IC50 < 100 microM. These five compounds consisted of three furoquinolines: skimmianine; haplopine and gamma-fagarine and two pyranoquinolones: flindersine and haplamine. Only haplamine was active against the HCT-116 line. The cytotoxic properties of these five alkaloids were further investigated against five additional human cancer cell lines. Their structure-activity relationships will be discussed. Of these five pre-selected alkaloids, only haplamine showed significant cytotoxic activity against all the tested cell lines. This is the first report of the cytotoxic activity of haplamine. Finally, this pyranoquinolone alkaloid was tested here against 14 different cancer cell lines and against normal skin fibroblasts. [less ▲]

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See detailLC/MS/NMR analysis of isomeric divanilloylquinic acids from the root bark of Fagara zanthoxyloides Lam
Ouattara, Badiore; Angenot, Luc ULg; Guissou, Pierre et al

in Phytochemistry (2004), 65(8), 1145-1151

Gradient HPLC coupled to DAD/UV, MS/MS and NMR has been applied to the rapid structure determination of three new isomeric divanilloylquinic acids from Fagara zanthoxyloides collected in Burkina Faso: 3,4 ... [more ▼]

Gradient HPLC coupled to DAD/UV, MS/MS and NMR has been applied to the rapid structure determination of three new isomeric divanilloylquinic acids from Fagara zanthoxyloides collected in Burkina Faso: 3,4-O-divanilloylquinic acid, 3,5-O-divanilloylquinic acid and 4,5-O-divanilloylquinic acid. Furthermore these new compounds named burkinabins A-C could play a useful role in sickle cell disease, as the active agents of Fagara zanthoxyloides are said to be unidentified aromatic compounds with carboxylic acid grouping (Adesanya, S.A., Sofowora, A., 1983. Biological standardisation of Zanthoxylum roots for antisickling activity. Planta Med. 48, 27-33). (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

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