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See detailAntiplasmodial activity of alkaloids from various Strychnos species
Frederich, Michel ULg; Jacquier, M. J.; Thepenier, P. et al

in Journal of Natural Products (2002), 65(10), 1381-1386

The in vitro antiplasmodial activities of 69 alkaloids from various Strychnos species were evaluated against chloroquine-resistant and chloroquine-sensitive lines of Plasmodium falciparum. The compounds ... [more ▼]

The in vitro antiplasmodial activities of 69 alkaloids from various Strychnos species were evaluated against chloroquine-resistant and chloroquine-sensitive lines of Plasmodium falciparum. The compounds, comprising mainly indolomonoterpenoid alkaloids, exhibited a wide range of biological potencies in the antiplasmodial assays. The most active alkaloids were also tested for cytotoxicity against HCT-116 colon cancer cells to determine their antiplasmodial selectivity. As a result of these studies, structure-activity relationships for these alkaloids have begun to emerge. Alkaloids presenting four types of bisindole skeleton exhibited potent and selective activities against Plasmodium. They were sungucine-type (IC(50) values ranging from 80 nM to 10 microM), longicaudatine-type (IC(50) values ranging from 0.5 to 10 microM), matopensine-type (IC(50) values ranging from 150 nM to 10 microM), and usambarine-type alkaloids. Within the last structural type, isostrychnopentamine (49) and ochrolifuanine A (46) were found to be active against chloroquine-sensitive and -resistant strains (IC(50) values of 100-150 and 100-500 nM, respectively), and dihydrousambarensine (51) exhibited a 30-fold higher activity against the chloroquine-resistant strain (IC(50) = 32 nM) than against the chloroquine-sensitive one. [less ▲]

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See detailAntiplasmodial activity of Heinsia crinita (Rubiaceae) and identification of new iridoids.
Tshisekedi Tshibangu, P.; Mutwale Kapepula, P.; Kabongo Kapinga, M. J. et al

in Journal of Ethnopharmacology (2017), 196

ETHNOPHARMACOLOGICAL RELEVANCE: Heinsia crinita is used in traditional medicine for the treatment of febrile illness and erectile dysfunction. Its stem bark powder is found in some peripheral markets in ... [more ▼]

ETHNOPHARMACOLOGICAL RELEVANCE: Heinsia crinita is used in traditional medicine for the treatment of febrile illness and erectile dysfunction. Its stem bark powder is found in some peripheral markets in the Democratic Republic of the Congo (DRC) as a remedy against malaria. Investigations were conducted on crude extracts of leaves, fruits and stem barks in view to validate their use and to determine which plant part possesses the best antiplasmodial properties. MATERIALS AND METHODS: Different plant parts were extracted with methanol, ethanol and dichloromethane. Based on the preliminary assays, the dichloromethane extract of the stem bark was subjected to fractionation using preparative HPLC system and column chromatography. This step led to the isolation of two new iridoids which had their structures elucidated by NMR, UV, MS and FT-IR spectroscopic techniques. Extracts and pure compounds were tested in vitro against the 3D7 strain of Plasmodium falciparum. The inhibition of the parasite growth was evaluated in vitro by colorimetric method (p-LDH assay) and their cytotoxicity evaluated in vitro against the human non-cancer fibroblast cell line (WI38) through WST1 assay. The in vivo antiplasmodial activity was assessed by the inhibition of Plasmodium berghei growth in infected mice treated with the ethanol extract of H. crinita stem bark at the concentrations of 200 and 300mg/Kg/day per os, using a protocol based on the 4-d suppressive test of Peters and compared to a non-treated negative control group of mice (growth =100%). Finally the antioxidant activity of the same extract was evaluated using ABTS, DPPH and cell-based assays. RESULTS: A moderate in vitro antiplasmodial activity was observed for the dichloromethane extract of the stem bark of H. crinita (IC50 =29.2+/-1.39microg/mL) and for the two new iridoids, lamalbide 6, 7, 8- triacetate (IC50 =16.39+/-0.43microg/mL) as well as for its aglycone lamiridosin 6, 7, 8-triacetate (IC50 =0.44.56+/-1.12microg/mL). The ethanolic stem bark extract (200 and 300mg/kg/day, oral route) showed a moderate in vivo antimalarial activity in Plasmodium berghei-infected mice with 27.84+/-2.75% and 48.54+/-3.76% of inhibition of the parasite growth, respectively (p<0.01).). This extract displayed high cellular antioxidant activity using dichlorofluorescein-diacetate (DCFDA) on HL-60 monocytes. These crude extracts and pure compounds tested at the higher concentration of 100microg/mL did not show any cytotoxicity against WI38 cells. CONCLUSIONS: The results showed that H. crinita extracts possess antimalarial activity and contain some unusual iridoids with moderate antiplasmodial activity, therefore justifying to some extent its traditional use by the local population in DRC for this purpose. This is the first report of the isolation and antiplasmodial activity of these two new iridoids. [less ▲]

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See detailAntiplasmodial activity of Mezoneuron benthamianum leaves and identification of its active constituents
Jansen, Olivia ULg; Tchinda, Alembert T.; Loua, Jean et al

in Journal of Ethnopharmacology (2017), 203(March), 20--26

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See detailAntiplasmodial Alkaloids from the Stem Bark of Strychnos malacoclados.
Tchinda Tiabou, Alembert ULg; Ngono, A. R.; Tamze, V. et al

in Planta Medica (2012), 78

From the stem bark of STRYCHNOS MALACOCLADOS, one new bisindole alkaloid, 3-hydroxylongicaudatine Y ( 1), was isolated along with the known alkaloids vomicine ( 2), bisnordihydrotoxiferine ( 3), divarine ... [more ▼]

From the stem bark of STRYCHNOS MALACOCLADOS, one new bisindole alkaloid, 3-hydroxylongicaudatine Y ( 1), was isolated along with the known alkaloids vomicine ( 2), bisnordihydrotoxiferine ( 3), divarine ( 4), longicaudatine ( 5), longicaudatine Y ( 6), and longicaudatine F ( 7). All the compounds were tested for their antimalarial activity against the chloroquine-sensitive 3D7 and -resistant W2 strains of PLASMODIUM FALCIPARUM. Longicaudatine was the most active compound with IC (50) values of 0.682 and 0.573 microM, respectively. The activity of compounds 1, 3, 4, 6, and 7 against the two strains ranged from 1.191 to 6.220 microM and 0.573 to 21.848 microM, respectively. Vomicine ( 2), the only monomer isolated, was inactive. The alkaloids of the longicaudatine-type ( 1, 5- 7) were more active than those of the caracurine-type ( 3- 4). The presence of the ether bridge in the molecule seems to increase the antiplasmodial activity. Compounds 1, 5, and 7 were tested against the WI-38 human fibroblast cell line. Longicaudatine was the most cytotoxic compound with an IC (50) of 2.721 microM. Longicaudatine F was 40-46 times more active against the two strains of P. FALCIPARUM than against the human fibroblasts and was thus considered as the more selective alkaloid. The structures of the compounds were determined based on the analysis of their spectral data. [less ▲]

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See detailAntiplasmodial and antitrypanosomal activity of Triclisia sacleuxii (Pierre) Diels
Murebwayire, Sangabo; Frederich, Michel ULg; Hannaert, V. et al

in Phytomedicine : International Journal of Phytotherapy and Phytopharmacology (2008), 15(9), 728-733

The antiplasmodial and antitrypanosomal activities of Triclisia sacleuxii (Pierre) Diels were investigated on three Plasmodium falciparum strains [FcB1, 3D7 (chloroquine – sensitive) and W2 (chloroquine – ... [more ▼]

The antiplasmodial and antitrypanosomal activities of Triclisia sacleuxii (Pierre) Diels were investigated on three Plasmodium falciparum strains [FcB1, 3D7 (chloroquine – sensitive) and W2 (chloroquine – resistant) strains] and on Trypanosoma brucei Tbsf 221. Roots, stems and leaves ethanolic extracts as well as crude tertiary and quaternary alkaloids fractions were considered. Whereas the ethanolic extracts and quaternary crude alkaloids fractions exhibited no significant activity, the roots and stems tertiary alkaloid fractions revealed interesting growth inhibition against the Plasmodium FcB1 and Trypanosoma Tbsf 221 strains. The IC50 were 1.04 and 0.89 g/ml (roots), 2.50 and 0.91 g/ml (stems), respectively. The leaves tertiary alkaloids fraction also showed a promising antitrypanosomal activity (IC50 : 1.85 g/ml). Phytochemical analysis of the roots tertiary alkaloids fraction yielded four major compounds, phaeanthine, N-methylapateline, 1,2-dehydroapateline and 1,2-dehydrotelobine, which were identified on the basis of their spectroscopic data. The four compounds displayed (in vitro) antitrypanosomal activity with IC50 of 2.68, 1.19, 1.06 and 1.11 µM, respectively. They also demonstrated antiplasmodial activity on Plasmodium falciparum 3D7, with IC50 of 1.72, 0.93, 1.39 and 12.4 µM respectively and on the chloroquine – resistant W2 with IC50 of 0.35, 1.10, 1.63, 1.52 µM. [less ▲]

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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 detailAntiplasmodial and cytotoxic alkaloids from Strychnos species
Frederich, Michel ULg

Conference (2003, March 14)

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See detailAntiplasmodial anthraquinones and hemisynthetic derivatives from the leaves of Tectona grandis (Verbenaceae)
Kopa, T.K.; Tchinda Tiabou, Alembert ULg; Tala, M.F. et al

in Phytochemistry Letters (2014), 8

Chemical investigation of the methanol extract of the leaves of Tectona grandis led to the isolation of one new anthraquinone derivative, grandiquinone A (3-acetoxy-8-hydroxy-2-methylanthraquinone) (1 ... [more ▼]

Chemical investigation of the methanol extract of the leaves of Tectona grandis led to the isolation of one new anthraquinone derivative, grandiquinone A (3-acetoxy-8-hydroxy-2-methylanthraquinone) (1), along with nine known compounds: 5,8-dihydroxy-2-methylanthraquinone (2), hydroxysesamone (3), 3-hydroxy-2-methylanthraquinone (4), quinizarine (5), betulinic acid (6), ursolic acid (7), tectograndone (8), corosolic acid (9) and sitosterol 3-O-β-d-glucopyranoside (10). Compounds 2 and 3 were isolated for the first time from the leaves of this plant, while 5 has never been reported from the genus Tectona. Hydroxysesamone (3) and tectograndone (8) were subjected to cyclisation and acetylation reactions to afford two hemisynthetic derivatives, 6,9-dihydroxy-2,2-(dimethyldihydropyrano)-3,4-dihydro-2H-benzo[g]chromene-5,10-dione (11) and acetyltectograndone (12) respectively, which are reported here for the first time. The ethyl acetate-soluble portion, some of the isolated compounds and hemisynthetic derivatives were evaluated for their antiplasmodial activity against the multidrug-resistant Dd2 strain of Plasmodium falciparum. Compound 3 showed a prominent activity, while 2, 8, 9, 11 and 12 showed significant in vitro anti-malarial activity. Compound 1 was weakly active in this test. The structures of the compounds were elucidated by spectroscopic methods and comparison of the data with the literature. [less ▲]

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See detailAntiplasmodial, anti-inflammatory and cytotoxic activities of various plant extracts from the Mascarene Archipelago.
Jonville, Marie ULg; Kodja, H.; Strasberg, D. et al

in Journal of Ethnopharmacology (2011), 136

AIM OF THE STUDY: Antiplasmodial activity, inhibition of nitric oxide (NO) overproduction, and anti-proliferative activity were investigated in vitro to evaluate the bioactive potential of the traditional ... [more ▼]

AIM OF THE STUDY: Antiplasmodial activity, inhibition of nitric oxide (NO) overproduction, and anti-proliferative activity were investigated in vitro to evaluate the bioactive potential of the traditional pharmacopoeia of the Mascarene Archipelago, which is known for its biodiversity and for the richness of its endemic flora. MATERIALS AND METHODS: A total of 45 methanol (MeOH) and dichloromethane (DCM) extracts were prepared from 19 plant species collected on Reunion and Mauritius Islands. Ninety-six-well microplate assays were performed on chloroquine sensitive Plasmodium falciparum 3D7 strain, on LPS-stimulated Raw 264.7 murine macrophages and on A-549, DLD-1 and WS1 human cells. Activity was evaluated through spectrophotometric methods. RESULTS: Activity was attributed to plant extracts expressing IC(50)<50mug/ml for antiplasmodial response, IC(50)<100mug/ml for cytotoxicity, and IC(50)<130mug/ml for anti-inflammatory reaction. The majority of the extracts tested (69%) exhibited potency in at least one of these three types of activity. This is the first report describing promising antiplasmodial activity (IC(50)<15mug/ml) for Psiadia dentata DCM extract and Terminalia bentzoe MeOH bark extract. NO inhibition assay revealed seven interesting plants, described for the first time as anti-inflammatory: Aphloia theiformis, Buddleja salviifolia, Eupatorium riparium, Hiptage benghalensis, Psiadia arguta, Psiadia dentata, and Scutia commersonii. Finally, anti-proliferative activity was observed for two endemic species, Geniostoma borbonicum and Nuxia verticillata. CONCLUSION: Using the criterion of endemism as part of the criteria for traditional medicinal use raises the chances of finding original active principles. In our case, 86% of the endemic plants tested displayed pharmacological interest. [less ▲]

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See detailAntiplatelet Activity of Clopidogrel in Coronary Artery Bypass Graft Surgery Patients
David, Jean-Louis ULg; Limet, Raymond ULg

in Thrombosis and Haemostasis (1999), 82(5), 1417-21

Clopidogrel is a recently introduced platelet ADP receptor antagonist, belonging to the thienopyridine derivatives, like its analogue ticlopidine. Its potential advantage is to be safer than ticlopidine ... [more ▼]

Clopidogrel is a recently introduced platelet ADP receptor antagonist, belonging to the thienopyridine derivatives, like its analogue ticlopidine. Its potential advantage is to be safer than ticlopidine. At 75 mg/od clopidogrel significantly inhibits platelet aggregation in ambulatory patients with symptomatic atherosclerotic disease and it prevents the recurrence of ischemic events more efficiently than aspirin. Its adequate dose in more acute situations remained to be determined. Therefore, sixty two patients with coronary artery disease were randomly assigned in four groups treated, within 24 h after coronary artery bypass graft, by clopidogrel 50 mg/od, 75 mg/od or 100 mg/od or by ticlopidine 250 mg/bid which was considered as the reference. The tolerance of clopidogrel was fairly good during the whole period of the study. Bleeding time and ex-vivo platelet aggregation induced by ADP 2 microM and 5 microM were performed at day -1, +9 and +28 after surgery. Like ticlopidine, the three dose levels of clopidogrel significantly inhibited ex-vivo platelet activity and prolonged the bleeding time at day 28. However, unlike ticlopidine, the inhibitory effects of clopidogrel were not significant at day 9, especially with 75 mg/od, a dose which was found to significantly protect patients in a chronic situation. Hence, although the clinical outcome for patients included in this limited study was the same in the four groups, these results suggest that the dose regime of clopidogrel should be more extensively investigated during the early period following coronary artery bypass graft, facing an overproduction of young and hyperreactive platelets. By analogy, the dose regime should be also investigated in other situations with an acute risk of arterial thrombotic occlusion. [less ▲]

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See detailAntiplatelet therapy in the perioperative period.
Engelen, S.; Sinaeve, P.; Van Damme, Hendrik ULg et al

in Acta Anaesthesiologica Belgica (2010), 61

antiplatelet drugs are the cornerstone treatment in the secondary prevention of arterial thrombosis. Until recently, their intake was interrupted in the perioperative period because of fear for bleeding ... [more ▼]

antiplatelet drugs are the cornerstone treatment in the secondary prevention of arterial thrombosis. Until recently, their intake was interrupted in the perioperative period because of fear for bleeding, but new insights have challenged this old habit. in patients at high risk for atherothrombotic events who need to undergo surgery or an invasive procedure, the risk for bleeding complications because of a treatment with low-dose acetylsalicylic acid (lD aSa) needs to be balanced against the risk of atherothrombotic events after treatment discontinuation. for patients at high risk of atherothrombotic complications recent guidelines do no longer advocate to interrupt lD aSa routinely. However, the likelihood of bleeding versus atherothrombotic complications should be considered on a case-by-case basis. when continued perioperatively, the bleeding risk associated with thienopyridines (ticlopidine, clopidogrel and prasugrel) is higher than that of lD aSa. it is recommended to stop their intake 1 week before the surgical intervention, except in patients with (recent) coronary stenting [less ▲]

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See detailAntipodean Dialogue in the Novels of David Malouf
Delrez, Marc ULg

Conference (1988)

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See detailAntipodean Dialogue: Randolph Stow and David Malouf
Delrez, Marc ULg

in Davis, Geoffrey V.; Maes-Jelinek, Hena (Eds.) Crisis and Creativity in the New Literatures in English (1990)

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See detailAntiproliferative and genotoxic effects of Mikania glomerata (Asteraceae)
Dalla Nora, G; Pastori, T; Laughinghouse IV, Haywood ULg et al

in Biocell : Official Journal of the Sociedades Latinoamericanas de Microscopia Electronica ... Et. Al (2010), 34(3), 95-101

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See detailAntiproliferative effect of the arboreal and medicinal species Luehea divaricata on the Allium cepa cell cycle
Frescura, VDS; Laughinghouse IV, Haywood ULg; Tedesco, SB

in Caryologia : Giornale di Citologia, Citosistematica, e Citogenetica (2012), 65(1), 27-33

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See detailAntiproton and Antilambda Annihilations on Several Nucleons
Cugnon, Joseph ULg; Vandermeulen, Jacques

in Physical Review. C : Nuclear Physics (1989), 39

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See detailAntiproton Annihilation Inside Nuclei
Cugnon, Joseph ULg; Cahay, M.; jasselette, Pierre et al

in Physics Letters B (1982), 115

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See detailAntiproton Annihilation on Nuclei
Cugnon, Joseph ULg

in Bunce, G.M. (Ed.) Proceedings of the Third International Conference on the Intersections Between Nuclei and Particles (1988)

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See detailAntiproton-Nucleus Annihilation
Cugnon, Joseph ULg

in Richard, Jean-Marc; Aslanidès, E.; Boccara, N. (Eds.) The Elementary Structure of Matter (1988)

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See detailAntiproton-Nucleus Interaction
Cugnon, Joseph ULg; Vandermeulen, Jacques

in Annales de Physique Fr. (1989), 14

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