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See detailAntiplasmodial and cytotoxic activities of Rwandan medicinal plants used in the treatment of malaria.
Muganga, R.; Angenot, Luc ULg; Tits, Monique ULg et al

in Journal of Ethnopharmacology (2010), 128

AIM OF THE STUDY: In our study, methanol, dichloromethane and aqueous extracts of 13 Rwandan medicinal plants used in the treatment of malaria were tested for in vitro antiplasmodial activity. MATERIALS ... [more ▼]

AIM OF THE STUDY: In our study, methanol, dichloromethane and aqueous extracts of 13 Rwandan medicinal plants used in the treatment of malaria were tested for in vitro antiplasmodial activity. MATERIALS AND METHODS: The growth inhibition of chloroquine-sensitive Plasmodium falciparum strain (3D7) was evaluated using the measurement of lactate dehydrogenase activity. The active extracts were also tested against the chloroquine-resistant Plasmodium falciparum strain (W2) and for cytotoxicity assay using human normal foetal lung fibroblasts (WI-38). RESULTS: The majority of the plants tested showed an antiplasmodial activity and the best results were observed with dichloromethane leaf and flower extracts of Tithonia diversifolia, leaf extract of Microglossa pyrifolia and root extract of Rumex abyssinicus, methanol leaf extract of Fuerstia africana, root bark extracts of Zanthoxylum chalybeum and methanol bark extract of Terminalia mollis. Those extracts were active (IC(50)<15mug/ml) on both chloroquine-sensitive and resistant strains of Plasmodium falciparum. Zanthoxylum chalybeum, Solanecio mannii and Terminalia mollis presented the best selectivity index. CONCLUSIONS: The traditional use of most of the plant evaluated was confirmed by the antiplasmodial test. This study revealed for the first time the antiplasmodial activity of two plants: Terminalia mollis and Rumex abyssinicus. [less ▲]

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See detailIsostrychnopentamine, an Indolomonoterpenic Alkaloid from Strychnos usambarensis, with Potential Antitumor Activity against Apoptosis-Resistant Cancer Cells
Balde, El-Hadj Saidou; Mégalizzi, Véronique; Angenot, Luc ULg et al

in International Journal of Oncology (2010), 36

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See detailSpectroscopic studies and molecular modeling for understanding the interactions between cholesterol and cyclodextrins
Castagne, Delphine ULg; Dive, Georges ULg; Evrard, Brigitte ULg et al

in Journal of Pharmacy & Pharmaceutical Sciences : A Publication of the Canadian Society for Pharmaceutical Sciences (2010), 13(2), 362-377

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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 detailMetabolomic investigation of the ethnopharmacological use of Artemisia afra with NMR Spectroscopy and Multivariate Data Analysis.
Liu, N. Q.; Cao, Martine ULg; Frederich, Michel ULg et al

in Journal of Ethnopharmacology (2010), 128

Ethnopharmacological relevance: Artemisia afra has been used as an infusion to treat malaria throughout the southern parts of Africa, in much the same way as the antimalarial plant Artemisia annua in ... [more ▼]

Ethnopharmacological relevance: Artemisia afra has been used as an infusion to treat malaria throughout the southern parts of Africa, in much the same way as the antimalarial plant Artemisia annua in China. The antiplasmodial activity of purified components from an apolar fraction of A. afra has been shown in the past. No data on the efficacy of the tea infusion prepared from A. afra are however available. OBJECTIVE: To investigate the antiplasmodial activity of various extracts of A. afra including an ethnopharmacological prepared sample. To identify polar metabolites in A. afra and A. annua and by using multivariate data analysis investigate the metabolic differences between these species. Materials and methods: The antiplasmodial activity of A. afra and A. annua extracts were tested for activity against Plasmodiam falciparum 3D7 (chloroquine-sensitive strain) with chloroquine, quinine and artemisinin as positive controls. Hydrophilic metabolites in A. afra and A. annua were identified directly from the crude extracts through 1D- and 2D-NMR spectra. The NMR spectra were also used to differentiate between the two species using principal component analysis (PCA) for quality control purposes. RESULTS: The apolar fractions of both A. afra and A. annua showed activity against P. falciparum while activity was only found in the tea infusion of A. annua. Metabolomic studies using 1D- and 2D-NMR spectroscopy identified 24 semi-polar components in A. afra including three new phenylpropanoids for this species: caffeic acid, chlorogenic acid and 3,5-dicaffeoyl quinic acid. PCA analysis conducted on the samples yielded good separation between the polar extracts of A. afra and A. annua. CONCLUSION: These findings shows that there are no in vitro activity in the tea infusion of A. afra and lists the identified metabolites causing the metabolic differences between A. afra and A. annua for quality control purposes. [less ▲]

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See detailMolecular biology, phytochemistry and bioactivity of three endemic Aloe species from Mauritius and Reunion Islands.
Ranghoo-Sanmukhiya, M.; Govinden-Soulange, J.; Lavergne, C. et al

in Phytochemical Analysis [=PCA] (2010)

Introduction - Aloe tormentorii, A. purpurea and A. macra are used as multipurpose folk medicines in Reunion and Mauritius Islands and are mistaken for the introduced Aloe vera.Objective - To compare the ... [more ▼]

Introduction - Aloe tormentorii, A. purpurea and A. macra are used as multipurpose folk medicines in Reunion and Mauritius Islands and are mistaken for the introduced Aloe vera.Objective - To compare the phytochemical, antimicrobial and DNA profiles of Aloe endemic to Mauritius and Reunion with the profiles of A. vera.Methodology - Leaf extracts of these Aloe species were analysed using standard phytochemical screening techniques, TLC and by HPLC. These extracts were also assayed for antimicrobial activity using microdilution techniques. Genetic diversity was studied using RAPD markers.Results - Phytochemical and antimicrobial assays and RAPD analysis showed that Mascarene Aloe species were very different from A. vera.Conclusion - This study is the first report highlighting the differences between Aloe sp.p from Mascarene and Aloe vera at the metabolic and genomic level. Copyright (c) 2010 John Wiley & Sons, Ltd. [less ▲]

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See detailIn vitro and in vivo antimalarial and cytotoxic activity of five plants used in Congolese traditional medicine.
Lusakibanza, M.; Mesia, G.; Tona, G. et al

in Journal of Ethnopharmacology (2010), 129

AIM OF THE STUDY: The in vitro antiplasmodial activity and cytotoxicity of methanolic and dichloromethane extracts from five Congolese plants were evaluated. The plants were selected following an ... [more ▼]

AIM OF THE STUDY: The in vitro antiplasmodial activity and cytotoxicity of methanolic and dichloromethane extracts from five Congolese plants were evaluated. The plants were selected following an ethnobotanical survey conducted in D.R. Congo and focusing on plants used traditionally to treat malaria. The in vivo antimalarial activity of aqueous and methanolic extracts active in vitro was also determined in mice infected by Plasmodium berghei berghei. MATERIALS AND METHODS: The growth inhibition of Plasmodium falciparum strains was evaluated using the measurement of lactate dehydrogenase activity. The extracts (aqueous, CH(3)OH, EtOH and CH(2)Cl(2)) were prepared by maceration and tested in vitro against the 3D7 (chloroquine sensitive) and W2 (chloroquine resistant) strains of Plasmodium falciparum and against the human normal fetal lung fibroblasts WI-38 to determine the selectivity index. Some extracts were also used at the dose of 300mg/kg to evaluate their activity in mice infected since 4 days by Plasmodium berghei. RESULTS: Two plants presented a very high activity (IC(50)<3mug/ml). These plants were Strychnos icaja roots bark (MeOH and CH(2)Cl(2)) and Physalis angulata leaves (MeOH and CH(2)Cl(2)). One plant (Anisopappus chinensis whole plant, MeOH and CH(2)Cl(2)) presented a high activity (IC50<15mug/ml). The extracts of Anisopappus chinensis and Physalis angulata showed also a good inhibition of parasitemia in vivo. Flavonoids, phenolic acids and terpenes were identified in these plants by a general phytochemical screening method. CONCLUSION: Three plants showed a very interesting antiplasmodial activity (Anisopappus chinensis, Physalis angulata and Strychnos icaja) and one of them showed a good selectivity index (>10, Anisopappus chinensis). Anisopappus chinensis and Physalis angulata were also active in vivo. [less ▲]

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See detailA la découverte de médicaments d'origine naturelle pour lutter contre le paludisme
Frederich, Michel ULg

Scientific conference (2009, October 08)

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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 detailMétabolomique - Identification de métabolites (biomarqueurs) par RMN 2D et LC-NMR
Frederich, Michel ULg

Conference (2009, January 28)

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See detailA la découverte de médicaments d'origine naturelle pour lutter contre le paludisme
Frederich, Michel ULg

Scientific conference (2009, January 27)

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See detailAntimalarial compounds isolated from plants used in traditional medicine.
Bero, Joanne; Frederich, Michel ULg; Quetin-Leclercq, Joelle

in Journal of Pharmacy & Pharmacology (2009), 61(11), 1401-33

OBJECTIVES: This review covers the compounds with antiplasmodial activity isolated from plants published from 2005 to the end of 2008, organized according to their phytochemical classes. Details are given ... [more ▼]

OBJECTIVES: This review covers the compounds with antiplasmodial activity isolated from plants published from 2005 to the end of 2008, organized according to their phytochemical classes. Details are given for substances with IC50 values < or = 11 microm. KEY FINDINGS: Malaria is a major parasitic disease in many tropical and subtropical regions and is responsible for more than 1 million deaths each year in Africa. The rapid spread of resistance encourages the search for new active compounds. Nature and particularly plants used in traditional medicine are a potential source of new antimalarial drugs as they contain molecules with a great variety of structures and pharmacological activities. SUMMARY: A large number of antimalarial compounds with a wide variety of structures have been isolated from plants and can play a role in the development of new antimalarial drugs. Ethnopharmacological approaches appear to be a promising way to find plant metabolites that could be used as templates for designing new derivatives with improved properties. [less ▲]

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See detailThiaminylated adenine nucleotides — chemical synthesis, structural characterization and natural occurrence
Frederich, Michel ULg; Delvaux, David ULg; Gigliobianco, Tiziana ULg et al

in FEBS Journal (2009), 276(12), 32563268

Thiamine and its three phosphorylated derivatives (mono-, di- and triphosphate) occur naturally in most cells. Recently, we reported the presence of a fourth thiamine derivative, adenosine thiamine ... [more ▼]

Thiamine and its three phosphorylated derivatives (mono-, di- and triphosphate) occur naturally in most cells. Recently, we reported the presence of a fourth thiamine derivative, adenosine thiamine triphosphate (AThTP), produced in E. coli in response to carbon starvation. Here, we show that the chemical synthesis of AThTP leads to another new compound, adenosine thiamine diphosphate (thiaminylated ADP, AThDP), as a side product. The structure of both compounds was confirmed by mass spectrometry and 1H-, 13C- and 31P-NMR and some of their chemical properties were determined. Our results show an upfield shifting of the C-2 proton of the thiazolium ring in adenosine thiamine derivatives compared to the conventional thiamine phosphate derivatives. This modification of the electronic environment of the C-2 proton might be explained by a through-space interaction with the adenosine moiety, suggesting an U-shaped folding of adenosine thiamine derivatives. Such a structure where the C-2 proton is embedded in a closed conformation can be located using molecular modeling as an energy minimum. In E. coli, AThTP may account for 15% of total thiamine under energy stress. It is less abundant in eukaryotic organisms, but is consistently found in mammalian tissues and in some cell lines. Using a HPLC method, we show for the first time that AThDP may also occur in small amounts in E. coli and in vertebrate liver. The discovery of two natural thiamine adenine compounds further highlights the complexity and diversity of thiamine biochemistry, which is not restricted to the cofactor role of thiamine diphosphate. [less ▲]

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See detailIn vitro antiplasmodial activity of plants used in Benin in traditional medicine to treat malaria
Bero, Joanne; Ganfon, Habib; Jonville, Marie ULg et al

in Journal of Ethnopharmacology (2009), 122

Aim of the study: The aim of the studywas to evaluate the in vitro antiplasmodial activity of crude extracts of 12 plant species traditionally used in Benin for the treatment of malaria in order to ... [more ▼]

Aim of the study: The aim of the studywas to evaluate the in vitro antiplasmodial activity of crude extracts of 12 plant species traditionally used in Benin for the treatment of malaria in order to validate their use. Materials and methods: For each species, dichloromethane, methanol and total aqueous extracts were tested. The antiplasmodial activity of extracts was evaluated using the measurement of the plasmodial lactate dehydrogenase activity on chloroquine-sensitive (3D7) and resistant (W2) strains of Plasmodium falciparum. The selectivity of the different extractswas evaluated using the MTT test on J774 macrophagelike murine cells and WI38 human normal fibroblasts. Results: The best growth inhibition of both strains of Plasmodium falciparum was observed with the dichloromethane extracts of Acanthospermum hispidum DC. (Asteraceae) (IC50 =7.5 g/ml on 3D7 and 4.8 g/ml on W2), Keetia leucantha (K. Krause) Bridson (syn. Plectronia leucantha Krause) (Rubiaceae) leaves and twigs (IC50 = 13.8 and 11.3 g/ml on 3D7 and IC50 = 26.5 and 15.8 g/ml on W2, respectively), Carpolobia lutea G.Don. (Polygalaceae) (IC50 = 19.4 g/ml on 3D7 and 8.1 g/ml on W2) and Strychnos spinosa Lam. (Loganiaceae) leaves (IC50 = 15.6 g/ml on 3D7 and 8.9 g/ml on W2). All these extracts had a low cytotoxicity. Conclusion: Our study gives some justifications for the traditional uses of some investigated plants. [less ▲]

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See detailIn Vitro Anticancer Potential of Tree Extracts from the Walloon Region Forest.
Frederich, Michel ULg; Marcowycz, Aline; Cieckiewicz, Ewa ULg et al

in Planta Medica (2009), 75(15), 1634-1637

Forty-eight extracts from 16 common Belgian trees from the Walloon Region forest were evaluated for IN VITRO growth inhibitory activity against the human LoVo colon cancer, PC3 prostate cancer, and U373 ... [more ▼]

Forty-eight extracts from 16 common Belgian trees from the Walloon Region forest were evaluated for IN VITRO growth inhibitory activity against the human LoVo colon cancer, PC3 prostate cancer, and U373 glioblastoma cell lines. Our study was performed with the aim of selecting plant candidates in order to later isolate new anticancer compounds from an easily affordable tree material. Extracts from ALNUS GLUTINOSA (stem bark), CARPINUS BETULUS (leaves and stem bark), CASTANEA SATIVA (stem bark), FAGUS SYLVATICA (leaves), ILEX AQUIFOLIUM (leaves), LARIX DECIDUA (leaves), QUERCUS PETRAEA (stem bark), and QUERCUS ROBUR (leaves) showed for the first time potent IN VITRO growth inhibitory activity and could become easily affordable sources of potential new anticancer agents. Root extracts from ROBINIA PSEUDOACACIA, already known for containing cytotoxic lectins, also showed interesting activity. [less ▲]

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See detailTriclisia sacleuxii (Pierre) Diels (Menispermaceae), a potential source of acetylcholinesterase inhibitors.
Murebwayire, Sengabo; Ingkaninan, Kornkanok; Changwijit, Kanokwan et al

in Journal of Pharmacy & Pharmacology (2009), 61(1), 103-7

OBJECTIVES: To search for compounds possibly useful for the treatment of Alzheimer's disease. METHODS: Alkaloid fractions from the roots, stems and leaves of Triclisia sacleuxii (Menispermaceae) and pure ... [more ▼]

OBJECTIVES: To search for compounds possibly useful for the treatment of Alzheimer's disease. METHODS: Alkaloid fractions from the roots, stems and leaves of Triclisia sacleuxii (Menispermaceae) and pure bisbenzylisoquinoline alkaloids isolated from the roots (phaeanthine, N-methylapateline, 1,2-dehydroapateline and gasabiimine) were assessed for acetylcholinesterase inhibitory activity. KEY FINDINGS: All extracts and compounds tested inhibited acetylcholinesterase to varying degrees; the leaf tertiary alkaloid fractions and the root quaternary alkaloid fractions exhibited the strongest inhibitory potential (90% at 0.1 mg/ml). The leaf tertiary alkaloid fraction was selected for further analysis (the quaternary alkaloids, which are too polar for absorption and brain distribution, were presumed to be clinically uninteresting). TLC bioautography using Ellman's reagent allowed the detection of acetylcholinesterase inhibitors and the isolation of the major active constituent, which was identified as lindoldhamine, a one-bridged bisbenzylisoquinoline alkaloid. Lindoldhamine displayed high acetylcholinesterase inhibitory activity with a 50% inhibition concentration in the micromolar range. CONCLUSIONS: All T. sacleuxii alkaloid fractions tested exhibited anti-acetylcholinesterase activity; isolated bisbenzylisoquinoline alkaloids showed weak-to-high inhibition depending on their structural features. Structure modification could provide interesting derivatives with enhanced anti-acetylcholinesterase activity. [less ▲]

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