References of "Angenot, Luc"
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See detailPotential antimalarial activity of indole alkaloids
Angenot, Luc ULg

Conference (2006, July 06)

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See detailPotential antimalarial activity of indole alkaloids
Angenot, Luc ULg

in 42nd International meeting on medicinal chemistry- Program and abstracts (2006, July)

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See detailAntiprotozoal and cytotoxic triterpenoid saponins from the roots of Cephalaria gigantea
Tabatadze, Nino; Elias, Riad; Delmas, F. et al

Poster (2006, July)

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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 detailValidation of a high-performance thin-layer chromatography/densitometry method for the quantitative determination of glucosamine in a herbal dietary supplement
Esters, Virginie ULg; Angenot, Luc ULg; Brandt, V. et al

in Journal of Chromatography. A (2006), 1112(1-2), 156-164

A quantitative densitometric high-performance thin-layer chromatography (HPTLC) method was developed for the determination of glucosamine in a dietary supplement containing dried extracts of the main ... [more ▼]

A quantitative densitometric high-performance thin-layer chromatography (HPTLC) method was developed for the determination of glucosamine in a dietary supplement containing dried extracts of the main plants traditionally used for rheumatic disorders. The HPTLC method was chosen in order to circumvent the tedious and time-consuming sample preparation steps necessarily performed before using HPLC methods when analysing complex matrixes. Glucosamine was separated from the plant extracts on a silica gel 60 F(254) HPTLC plate using a saturated mixture of 2-propanol-ethyl acetate-ammonia solution (8%) (10:10:10, v/v/v). The plates were developed vertically up to a distance of 80 mm. For visualization, the plate was dipped into a modified anisaldehyde reagent and heated at 120 degrees C for 30 min in a drying oven. Glucosamine appeared as brownish-red chromatographic zones on a colourless background. Densitometric quantification was performed at lambda = 415 nm by reflectance scanning. The HPTLC method was successfully validated by applying the novel validation protocol proposed by a commission of the "Societe Francaise des Sciences et Techniques Pharmaceutiques" (SFSTP). In the pre-validation phase, the appropriate response function was determined, while in the validation phase the method showed good performance thereby fulfilling its objective of quantifying accurately. The relative standard deviations for repeatability and intermediate precision were between 4.9 and 8.6%. Moreover, the method was found to be accurate, as the two-sided 95% beta-expectation tolerance interval did not exceed the acceptance limits of 85 and 115% on the whole analytical range (800-1,200 ng of glucosamine). [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 detailChemical and biological investigations of a toxic plant from Central Africa, Magnistipula butayei subsp montana
Karangwa, Charles; Esters, Virginie ULg; Frederich, Michel et al

in Journal of Ethnopharmacology (2006), 103(3), 433-438

Magnistipida butayei subsp. montana (Chrysobalanaceae) is known, in the Great Lakes Region, to possess toxicological properties. In this paper, we investigated the acute toxicity (dose levels 50-1600 mg ... [more ▼]

Magnistipida butayei subsp. montana (Chrysobalanaceae) is known, in the Great Lakes Region, to possess toxicological properties. In this paper, we investigated the acute toxicity (dose levels 50-1600 mg/kg) of its aqueous extract, administered orally to adult Wistar rats. This study demonstrated that the freeze-dried aqueous extract (5%, w/w) possesses high toxicity. The extract caused hypothermia, neurological disorders, including extensor reflex of maximal convulsive induced-seizures at about 2h after the administered dose, and death occurred (LD50 = 370 mg/kg) in a dose dependent manner. Blood parameter evaluation revealed slight variations, but these might not have clinical relevance. Histological examination of internal organs (lungs, liver, heart and kidneys) did not reveal any abnormality in the treated group compared to the control. Therefore, it can be concluded that Magnistipida butayei subsp. montana aqueous extract, given orally, is toxic and that its target is the central nervous system. General phytochemical screening revealed that the plant did not contain significant amounts of products known to be toxic, such as alkaloids or cardioactive glycosides, but only catechic tannins, amino acids, saponins and other aphrogen principles in the three parts of the species (fruit, leave and bark). (c) 2005 Elsevier Ireland Ltd. All rights reserved. [less ▲]

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See detailStudy of the interaction of antiplasmodial strychnine derivatives with the glycine receptor
Philippe, Geneviève ULg; Nguyen, Laurent ULg; Angenot, Luc ULg et al

in European Journal of Pharmacology (2006), 530(1-2), 15-22

Strychnos icaja Baill. (Loganiaccae) is a liana found in Central Africa known to be an arrow and ordeal poison but also used by traditional medicine to treat malaria. Recently, many dimeric or trimeric ... [more ▼]

Strychnos icaja Baill. (Loganiaccae) is a liana found in Central Africa known to be an arrow and ordeal poison but also used by traditional medicine to treat malaria. Recently, many dimeric or trimeric indolomonoterpenic alkaloids with antiplasmodial properties have been isolated from its rootbark. Since these alkaloids are derivatives of strychnine, it was important, in view of their potential use as antimalarial drugs, to assess their possible convulsant strychnine-like properties. In that regard, their interaction with the strychnine-sensitive glycine receptor was investigated by whole-cell patch-clamp recordings on glycine-gated currents in mouse spinal cord neurons in culture and by [H-3]strychnine competition assays on membranes from adult rat spinal cord. These experiments were carried out on sungucine (leading compound of the chemical class) and on the antiplasmodial strychnogucine B (dimeric) and strychnohexamine (trimeric). In comparison with strychnine, all compounds interact with a very poor efficacy and only at concentrations > I mu M with both [H-3]strychnine binding and glycine-gated currents. Furthermore, the effects of strychnine and protostrychnine, a monomeric alkaloid (without antiplasmodial activity) also isolated from S. icaja and differing from strychnine only by a cycle opening, were compared in the same way. The weak interaction of protostrychnine confirms the importance of the G cycle ring structure in strychnine for its binding to the glycine receptor and its antagonist properties. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailExtraction and fractionation of cytotoxic metabolites from Galanthus lagodechianus Kem.-Nath
Jokhadze, Malkhaz; Kutchukhidze, J.; Murtazashvilia, T. et al

in Allergology and Immunology (Moscou) (2006), 7

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See detailRecent developments in the field of arrow and dart poisons
Philippe, Geneviève ULg; Angenot, Luc ULg

in Journal of Ethnopharmacology (2005), 100(1-2), 85-91

Arrow and dart poisons, considered as conventional natural sources for future drug discovery, have already provided numerous biologically active molecules used as drugs in therapeutic applications or in ... [more ▼]

Arrow and dart poisons, considered as conventional natural sources for future drug discovery, have already provided numerous biologically active molecules used as drugs in therapeutic applications or in pharmacological research. Plants containing alkaloids or cardiotonic glycosides have generally been the main ingredients responsible for the efficacy of these poisons, although some animals, such as frogs, have also been employed. This paper, without being exhaustive, reports the greater strides made during the past 15 years in the understanding of the chemical nature and biological properties of arrow and dart poison constituents. Examples both of promising biological properties shown by these molecules and of crucial discoveries achieved by their use as pharmacological tools are given. Further studies of these toxic principles are likely to enable scientists to find new valuable lead compounds, useful in many fields of research, like oncology, inflammation and infectious diseases. 2005 Elsevier Ireland Ltd. All rights reserved. [less ▲]

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See detailIn vitro screening of some Strychnos species for antiplasmodial activity
Philippe, Geneviève ULg; Angenot, Luc ULg; De Mol, Patrick ULg et al

in Journal of Ethnopharmacology (2005), 97(3), 535-539

The antiplasmodial activity of crude extracts of 19 species of Strychnos (Loganiaceae) was assessed in vitro against a chloroquine-susceptible strain of Plasmodium falciparum. For each species, ethyl ... [more ▼]

The antiplasmodial activity of crude extracts of 19 species of Strychnos (Loganiaceae) was assessed in vitro against a chloroquine-susceptible strain of Plasmodium falciparum. For each species, ethyl acetate (EtOAc) extracts were analysed and, for the most active species, methanolic (MeOH) extracts were also tested. Among them, Strychnos variabilis De Wild. seemed to be very promising (inhibitory concentration 50% (IC50) < 5 microg/ml) whereas two other species, Strychnos gossweileri Exell and Strychnos mellodora S. Moore, could be interesting (IC50 < 15 microg/ml) in further antimalarial studies. [less ▲]

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See detailSupercritical carbon dioxide extraction of tagitinin C from Tithonia diversifolia
Ziemons, Eric ULg; Goffin, Eric ULg; Lejeune, Robert ULg et al

in Journal of Supercritical Fluids (2005), 33(1), 53-59

Different parameters as temperature, pressure, solvent mass and sample granulometry governing the extraction yield of tagitinin C from the aerial parts of Tithonia diversifolia were optimised. An ... [more ▼]

Different parameters as temperature, pressure, solvent mass and sample granulometry governing the extraction yield of tagitinin C from the aerial parts of Tithonia diversifolia were optimised. An experimental design was carried out to map the effects of pressure (at 20.3, 30.4 and 40.5 MPa) and temperature (at 40, 60 and 80degreesC) on the extraction yield of the active component and to determine the optimal conditions for the extraction of tagitinin C from T diversifolia. The best conditions are met for a pressure of 35.0 MPa and a temperature of 68degreesC. The effect of the particle size was studied under low pressure (13.7 MPa) and temperature (40degreesC) conditions, which failed to extract quantitatively the tagitinin C from leaves sieved to 250 mum size. The reduction of the particle size increased the extraction yield which became comparable to that of the optimised SFE for the particle in the range of 0-63 mum. From the analysis of extraction kinetic curves of 200 mg of plant with supercritical carbon dioxide (range of 5-30 g), it appears that 15 g of this supercritical fluid is never limiting. The optimised supercritical fluid extraction (SFE) was compared favourably to Soxhlet extraction with dichloromethane (S) and to maceration followed by lixiviation with diethyl ether (ML), which gave similar extraction yields but higher extract content of tagitinin C were found using SFE (15.6 and 30.7% w/w tagitinin C in S and ML extracts, respectively, versus 52.8% in SFE extract). [less ▲]

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See detailAcute liver failure with renal impairment related to the abuse of senna anthraquinone glycosides
Vanderperren, Bénédicte; Rizzo, Michela; Angenot, Luc ULg et al

in Annals of Pharmacotherapy (2005), 39(7-8, JUL-AUG), 1353-1357

OBJECTIVE: To report a case of chronic ingestion of very large amounts of senna fruits as an herbal tea, possibly leading to severe hepatotoxicity. CASE SUMMARY: A 52-year-old woman who had ingested, for ... [more ▼]

OBJECTIVE: To report a case of chronic ingestion of very large amounts of senna fruits as an herbal tea, possibly leading to severe hepatotoxicity. CASE SUMMARY: A 52-year-old woman who had ingested, for > 3 years, one liter of an herbal tea each day made from a bag containing 70 g of dry senna fruits, developed acute hepatic failure and renal impairment requiring intensive care therapy. The severity of the hepatic failure was reflected by the increase in prothrombin time (international normalized ratio > 7) and the development of encephalopathy. Liver transplantation was discussed, but the patient ultimately recovered with supportive therapy. Renal impairment was consistent with proximal tubular acidosis, also with marked polyuria refractory to vasopressin administration. Suprisingly, large amounts of cadmium were transiently recovered in the urine. DISCUSSION: Cassia acutifolia and angustifolia plants are widely used as laxatives. Their chronic abuse may be associated with serious manifestations, including fluid and electrolyte loss, with chronic diarrhea. Severe hepatotoxicity is unusual, but could be explained by the exposure of the liver to unusual amounts of toxic metabolites of anthraquinone glycosides (sennosides). An objective causality assessment suggests that hepatotoxicity was possibly related to senna laxative abuse. Regarding nephrotoxicity, there are no available human data on sennosides, while experimental models suggest that anthraquinone derivatives may also accumulate in the kidneys. The finding of high urinary concentrations of cadmium would suggest contamination of the herbal tea by metals, but this hypothesis could not be verified. CONCLUSIONS: Ingestion of large doses of senna laxatives may expose people to the risk of hepatotoxicity. [less ▲]

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See detailFolipidine, a new type quinoline alkaloid from plants of the Haplophyllum genus
Akhmedzhanova, V. I.; Rasulova, K. A.; Bessonova, I. A. et al

in Chemistry of Natural Compounds (2005), 41(1, JAN-FEB), 60-64

The new quinoline alkaloid folipidine, the structure of which was established by chemical transformations and spectral data (UV, IR, mass, NMR) using APT 2D H-1-H-1 COSY, NOESY, and H-1-(13)CHSQC, HMBC ... [more ▼]

The new quinoline alkaloid folipidine, the structure of which was established by chemical transformations and spectral data (UV, IR, mass, NMR) using APT 2D H-1-H-1 COSY, NOESY, and H-1-(13)CHSQC, HMBC, was isolated from two plants of the Haplophyllum mints. Folipidine is the first representative of a new type of quinoline alkaloids that contain a heteroaromatic skeleton of [3,4-b]conjugated pyrrole and quinoline fragments. The total alkaloids of these plants exhibit antitumor activity. Folipidine does not possess such activity. [less ▲]

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See detailInhibitory Effects of Proanthocyanidins from Ribes Nigrum Leaves on Carrageenin Acute Inflammatory Reactions Induced in Rats
Garbacki, Nancy ULg; Tits, Monique ULg; Angenot, Luc ULg et al

in BMC Pharmacology (2004), 4(1), 1-9

BACKGROUND: The anti-inflammatory effects of proanthocyanidins (PACs), isolated from blackcurrant (Ribes nigrum L.) leaves, were analysed using carrageenin-induced paw oedema and carrageenin-induced ... [more ▼]

BACKGROUND: The anti-inflammatory effects of proanthocyanidins (PACs), isolated from blackcurrant (Ribes nigrum L.) leaves, were analysed using carrageenin-induced paw oedema and carrageenin-induced pleurisy in rats. RESULTS: Pretreatment of the animals with PACs (10, 30, 60 and 100 mg/kg, i.p.) reduced paw oedema induced by carrageenin in a dose and time-dependent manner. PACs also inhibited dose-dependently carrageenin-induced pleurisy in rats. They reduced (A) lung injury, (B) pleural exudate formation, (C) polymorphonuclear cell infiltration, (D) pleural exudate levels of TNF-alpha, IL-1beta and CINC-1 but did not affect IL-6 and IL-10 levels. They reduced (E) pleural exudate levels of nitrite/nitrate (NOx). In indomethacin treated rats, the volume of pleural exudate was low, its content in leukocytes and its contents in TNF-alpha, IL-1beta, IL-6 and IL-10 but not in NOx were reduced. These data suggest that the anti-inflammatory properties of PACs are achieved through a different pattern from those of indomethacin. CONCLUSION: These results suggest that the main mechanism of the anti-inflammatory effect of PACs mainly lies in an interference with the migration of the leukocytes. Moreover, PACs inhibited in vivo nitric oxide release. [less ▲]

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See detailAbout the toxicity of some Strychnos species and their alkaloids
Philippe, Geneviève ULg; Angenot, Luc ULg; Tits, Monique ULg et al

in Toxicon (2004), 44(4), 405-416

Poisons are widespread in plants and animals and humankind has often tried to turn them to its own advantage. Owing to their poisonous properties, some species of Strychnos genus have been employed mainly ... [more ▼]

Poisons are widespread in plants and animals and humankind has often tried to turn them to its own advantage. Owing to their poisonous properties, some species of Strychnos genus have been employed mainly in hunting and fishing, as an adjunct to weapons used not only in the search of food and clothes, but also for preventing depredation by wild animals. They have been employed for martial and criminal purposes and also as a means of determining guilt or innocence. By their nature, poisons such as strychnine and curate affect the functioning of the victim's body; this also means that they have been, and are, an important source of pharmacological tools and medicines all over the world. With such potentially dangerous substances, care in medication is essential to avoid complications by overdose. All these points are approached in the present review. (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

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See detailMetabolomic analysis of Strychnos nux-vomica, Strychnos icaja and Strychnos ignatii extracts by H-1 nuclear magnetic resonance spectrometry and multivariate analysis techniques
Frederich, Michel ULg; Choi, Young Hae; Angenot, Luc ULg et al

in Phytochemistry (2004), 65(13), 1993-2001

H-1 Nuclear magnetic resonance spectrometry and multivariate analysis techniques were applied for the metabolic profiling of three Strychnos species: Strychnos nux-vomica (seeds, stem bark, root bark ... [more ▼]

H-1 Nuclear magnetic resonance spectrometry and multivariate analysis techniques were applied for the metabolic profiling of three Strychnos species: Strychnos nux-vomica (seeds, stem bark, root bark), Strychnos ignatii (seeds), and Strychnos icaja (leaves, stem bark, root bark, collar bark). The principal component analysis (PCA) of the H-1 NMR spectra showed a clear discrimination between all samples, using the three first components. The key compounds responsible for the discrimination were brucine, loganin, fatty acids.. and Strychnos icaja alkaloids such as icajine and sungucine. The method was then applied to the classification of several "false angostura" samples. These samples were, as expected, identified as S. nux-vomica by PCA, but could not be clearly discriminated as root bark or stem bark samples after further statistical analysis. (C) 2004 Published by Elsevier Ltd. [less ▲]

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See detailIn vitro and in vivo antimalarial properties of isostrychnopentamine, an indolomonoterpenic alkaloid from Strychnos usambarensis
Frederich, Michel ULg; Tits, Monique ULg; Goffin, Eric ULg et al

in Planta Medica (2004), 70(6), 520-525

Isostrychnopentamine (ISP) is an asymmetric indolomonoterpenic alkaloid isolated from the leaves of Strychnos usambarensis. The in vitro antiplasmodial activities against five Plasmodium falciparum cell ... [more ▼]

Isostrychnopentamine (ISP) is an asymmetric indolomonoterpenic alkaloid isolated from the leaves of Strychnos usambarensis. The in vitro antiplasmodial activities against five Plasmodium falciparum cell lines were evaluated: ISP possessed an in vitro IC (50) near 0.1 microM against all P. falciparum cell lines tested (chloroquine-resistant and chloroquine-sensitive lines) and showed antiplasmodial selectivity compared to cytotoxicity on human cell lines. The stage-dependent susceptibility to a short exposure of ISP was then investigated. The ring stage was shown to be the most sensitive one, but all stages were affected by ISP treatment. By means of fluorescence microscopy, it was shown that ISP was not accumulated inside the food vacuole of the parasite. Finally, the in vivo antimalarial activities against the P. berghei NK173 and P. vinckei petteri murine strains were determined. The ED (50) in vivo was about 30 mg/kg/day by the intraperitoneal route (after 4 days treatment). [less ▲]

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