References of "Noirfalise, Alfred"
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See detailCharacterization of the neurotoxicity induced by the extract of Magnistipula butayei (Chrysobalanaceae) in rat: Effects of a new natural convulsive agent
Karangwa, Charles; Esters, Virginie ULg; Tits, Monique ULg et al

in Toxicon (2007), 49(8), 1109-1119

This study was designed to document convulsant and neurotoxic properties of extracts of a tropical tree, Magnistipula butayei subsp. Montana, and to investigate the involvement of the glutamatergic system ... [more ▼]

This study was designed to document convulsant and neurotoxic properties of extracts of a tropical tree, Magnistipula butayei subsp. Montana, and to investigate the involvement of the glutamatergic system in these effects. Continuous behavioral observations and electroencephalographic (EEG) records were obtained after per os administration of an aqueous extract of Magnistipula (MBMAE) in rats. MBMAE (800 mg/kg) induced behavioral changes resembling motor limbic seizures: staring and head tremor, automatisms, forelimb clonic movements and violent tonic-clonic seizures leading to death in all animals. Concomitantly, important seizure activity that gradually evolved to epileptiform activity was recorded on the EEG. Moreover, c-Fos immunohistochemistry has revealed an increased c-Fos expression in the dentate gyrus and in piriform, peri- and entorhinal cortices 2 and 4h after treatment. This expression pattern suggested that the mechanism of action for the MBMAE is similar to that observed in glutamate-induced models of epilepsy. The MBMAE increased cell death also in hippocampal cell cultures. Furthermore, the build-up of convulsive activity and epileptic discharges induced by MBMAE in rat were abolished by MK-801, an NMDA receptor antagonist. Our study suggests that MBMAE contains a potent toxin, with a powerful neurotoxic activity in rat, and corresponding to a new natural component(s) that act as an NMDA-mediated convulsant molecule. [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 detailCannabis, situation en 2001-2002
Noirfalise, Alfred ULg; Gosset, Christiane ULg; Maisse, L.

in Revue Médicale de Liège (2002), 57(11), 692-4

Even though its use becomes common, cannabis remains a narcotic, the risks of which are nowadays better known. Its therapeutic value still needs to be scientifically demonstrated.

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See detailOptimization and validation of arsenic determination in foods by hydride generation flame atomic absorption spectrometry
Kabengera, C.; Bodart, P.; Hubert, Philippe ULg et al

in Journal of AOAC International (2002), 85(1, Jan-Feb), 122-127

A hydride generation flame atomic absorption spectrometric method was developed and optimized to quantitate arsenic (As) in foods. A wet digestion of the samples with HNO3 + H2O2 was performed and excess ... [more ▼]

A hydride generation flame atomic absorption spectrometric method was developed and optimized to quantitate arsenic (As) in foods. A wet digestion of the samples with HNO3 + H2O2 was performed and excess oxidants were eliminated by addition of hydrochloric acid and urea. As5+ in As3+ was then reduced by potassium iodide. The As3+ solution was analyzed by generation of arsine with sodium tetrahydroborate. As determination ranged from 2.5 to 20 microg/L, with a determination coefficient of 0.997. The limits of detection (LOD) and quantitation (LOQ) were 0.6 and 2.1 microg/L, respectively. The method was validated and good results were obtained for recovery, precision, accuracy, LOD, and LOQ. This method is now used to analyze foods from Rwanda. [less ▲]

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See detailDetermination of total arsenic in foods by HGAAS
Kabengera, Ch.; Bodart, P.; Hubert, Philippe ULg et al

Conference (2000)

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See detailDetermination of Alpha-Solanine and Alpha-Chaconine in Potatoes by High-Performance Thin-Layer Chromatography/Densitometry
Bodart, P.; Kabengera, C.; Noirfalise, Alfred ULg et al

in Journal of AOAC International (2000), 83(6, Nov-Dec), 1468-73

A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from ... [more ▼]

A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from dehydrated potatoes with boiling methanol-acetic acid (95 + 5, v/v). The analytes are separated on a Silica Gel 60 F254 HPTLC plate by a saturated mixture of dichloromethane-methanol-water-concentrated ammonium hydroxide (70 + 30 + 4 + 0.4, v/v), which is used for vertical development of the plate up to a distance of 85 mm. For visualization, the plate is dipped 3 times into a modified Carr-Price reagent, 20% (w/v) antimony(III) chloride in acetic acid-dichloromethane (1 + 3, v/v), and subsequently heated on a hot plate at 105 degrees C for 5 min. The glycoalkaloids all appear as red chromatographic zones on a colorless background. Densitometric quantification is performed at 507 nm by reflectance scanning. After determination of the appropriate response function, the proposed method was validated. Good results with respect to linearity, accuracy, and precision were obtained in the concentration range studied. [less ▲]

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See detailMulti-city network on drug mesure trends
Honore, A.; Amraei, M.; Bils, L. et al

Report (1999)

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See detailConsommation et milieux de vie. Gestion des drogues en 2000
De Ruyver, B.; De Winter, C.; Gosset, Christiane ULg et al

Book published by Maklu/Bruylant (1999)

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See detailDirect Quantitative Analysis of Linamarin in Cassava by High-Performance Thin Layer Chromatography
Bodart, Patricia; Penelle, Jacques; Angenot, Luc ULg et al

in Journal of Planar Chromatography- Modern TLC (1998), 11(January/February), 38-42

A simple, rapid and accurate HPTLC quantitative procedure is presented for the direct determination of linamarin. A cassava sample was extracted with boiling 80% v/v methanol and the extract and linamarin ... [more ▼]

A simple, rapid and accurate HPTLC quantitative procedure is presented for the direct determination of linamarin. A cassava sample was extracted with boiling 80% v/v methanol and the extract and linamarin were applied to silicagel HPTLC plates prewashed by development with methanol.The plates were first developed to a distance of 30mm with ethyl acetate-acetone-water, 40+50+10 (v/v), then to a distance of 85 mm with ethyl acetate-formic acid-water, 60+10+10 (v/v). the spots were visualized by dipping the plate into a solution af aniline (2%), and phosphoric acid 15% in acetone, then heating at 105°C for 60 min. Densitometric quantification was effected at lambda= 525 nm by transmission scanning. The method was validated for accuracy, intraday, and interday reproducibility of peak area, linearity, and detection limit. [less ▲]

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See detailDirect quantitative analysis of linamarin in cassava by high performance thin-layer chromatography
Bodart, Patricia; Muzembe, K. F.; Penelle, Jacques et al

Conference (1997, April)

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