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See detailThe antioxidant properties of non stroidal anti-inflammatory drugs
Henrotin, Yves ULg; Mouithys-Mickalad, Ange ULg; Mathy-Hartert, M et al

in Osteoarthritis and Cartilage (2000), 8

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See detailThe antioxidant responses differ between Symbiodinium strains from different geographic origins
Roberty, Stéphane ULg; Furla, Paola; Plumier, Jean-Christophe ULg

Conference (2016, June)

Studies conducted these last two decades have revealed that high sea surface temperatures accompanied by high levels of solar irradiance are responsible for an over production of reactive oxygen species ... [more ▼]

Studies conducted these last two decades have revealed that high sea surface temperatures accompanied by high levels of solar irradiance are responsible for an over production of reactive oxygen species (ROS) leading to the disruption of the symbiosis between cnidarians and their symbiotic Symbiodinium. But, all coral species do not show the same sensitivity to stress. In this context we examined how the antioxidant network of different Symbiodinium species responds to oxidative stress. We bypassed the various thermal and light tolerances existing among the genus Symbiodinium by using a chemical approach, i.e., a treatment with menadione. ROS produced during this oxidative burst reduced photosynthesis by 30 to 50% and significantly decreased the activity of superoxide dismutase. In addition, the low level of lipid peroxidation concomitantly with the decrease in the concentration of diatoxanthin and other carotenoids during the oxidative stress confirms their function of antioxidants and their role in the stabilization of membrane lipids. The analysis of the cellular damages also indicates that proteins were damaged and most likely eliminated by the ubiquitin-proteasome pathway. Finally, caspase-like activity decreased suggesting that cell death mechanisms are not initiated at the early stage of the stress. Although, the mechanisms at play seem to be the same, we found that the temperate Symbiodinium strain (A1) was less impacted by the treatment with menadione than the tropical strain (F1) suggesting that the variations observed are related to their geographic origin. [less ▲]

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See detailAntioxidant Status after Cold Ischemia of Rabbit Lung
Pincemail, Joël ULg; Kolh, Philippe ULg; Detry, Olivier ULg et al

in Transplantation Proceedings (2000), 32(2), 484-5

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See detailAntioxidant Therapy in Intensive Care
Lovat, R.; Preiser, Jean-Charles ULg

in Current Opinion in Critical Care (2003), 9(4), 266-70

PURPOSE OF REVIEW: This review intends to summarize the recent findings regarding the presence of increased oxidative stress in critically ill patients and its potential pathophysiologic role, as well as ... [more ▼]

PURPOSE OF REVIEW: This review intends to summarize the recent findings regarding the presence of increased oxidative stress in critically ill patients and its potential pathophysiologic role, as well as the results of recent clinical trials of antioxidant therapies. RECENT FINDINGS: Several lines of evidence confirm the increase in oxidative stress during critical illness. The oxidative damage to cells and tissues eventually contributes to organ failure. Prophylactic administration of antioxidant vitamins or glutamine, incorporated in the nutritional support or given as separate medications, efficiently attenuates the oxidative stress and in some studies improves the outcome of critically ill patients. Few data on the effects of N-acetylcysteine or trace elements have been published during the last two years. SUMMARY: Patients at risk of organ failure could benefit from the early adjunction of antioxidant treatment, including vitamins and glutamine. [less ▲]

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See detailAntioxidant to treat osteoarthritis: dream or reality?
Henrotin, Yves ULg; Kurz, B.

in Current Drug Targets (2007), 8(2), 347-57

Osteoarthritis is one of the most common chronic diseases that causes pain and physical disability in patient. Although OA is considered as a global disease affecting all joint tissues, cartilage ... [more ▼]

Osteoarthritis is one of the most common chronic diseases that causes pain and physical disability in patient. Although OA is considered as a global disease affecting all joint tissues, cartilage degradation is the end point. The degradation of cartilage results of the combination of mechanical stress and biochemical factors, mainly metalloproteinases and reactive oxygen species (ROS). The activity of reactive oxygen species is balanced by enzymatic and non-enzymatic antioxidants, that act by inhibiting oxidative enzymes, scavenging free radicals or chelating ion metals. Until now, few information is available on the antioxidative status of chondrocytes. Further, the modification of the antioxidative system in osteoarthritis remains unknown. Some antioxidant supplements or drugs with antioxidant properties have been developed to reinforce the cellular antioxidant status. However, until now, there is no consistent evidence that additional antioxidant supply is efficient to relieve OA symptoms or to prevent structural changes in OA cartilage. [less ▲]

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See detailAntioxidant vitamin cocktail does not improve calves'lung function and airway inflammation in ozone-induced pulmonary disease
Kirschvink, Nathalie; Jacqmot, Olivier ULg; Fievez, Laurence ULg et al

in Pflügers Archiv : European Journal of Physiology (2001), 442(R42),

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See detailAntioxidants involvement in the Ageing of Non-Green Organs
Delaplace, Pierre ULg; Fauconnier, Marie-Laure ULg; du Jardin, Patrick ULg

in Gupta, S. Dutta (Ed.) Reactive oxygen species and antioxidants in higher plants (2010)

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See detailAntioxydant activity of β-carboline derivatives in the LDL oxidation model
Hadjaz, Fariza; Besret, Soizic; Martin-Nizard, Françoise et al

in European Journal of Medicinal Chemistry (2001), 46

A series of b-carboline compounds were synthesized, starting from compound GWC22, their antioxidant activity was determined by inhibition of lipid peroxidation. The oxidation of LDL was induced in the ... [more ▼]

A series of b-carboline compounds were synthesized, starting from compound GWC22, their antioxidant activity was determined by inhibition of lipid peroxidation. The oxidation of LDL was induced in the presence of CuSO4 or 2,20-azobis(2-amidinopropane) dihydrochloride (AAPH). The protective actions of these compounds against the cytotoxicity were evaluated with lactate dehydrogenase (LDH) activity in bovine aortic endothelial cells (BAECs) and cellular vitality by measuring mitochondrial activity in the presence of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). Most of compounds showed an higher antioxidant activity than GWC22 derivative (R = 1.6 for 5 mM CuSO4). The best antioxidant activities are phenolic and benzyloxy derivatives with ratio R = 1.9 to 2.8 for 1 mM CuSO4. These substances have protective actions and increase significantly the cell viability. [less ▲]

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See detailAntioxydants et santé : conseils pratiques.
PINCEMAIL, Joël ULg

Conference (2015, January)

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See detailAntiparasitic activities of two sesquiterpenic lactones isolated from Acanthospermum hispidum D.C
Ganfon; Bero, Joanne; Tchinda Tiabou, Alembert ULg et al

in Journal of Ethnopharmacology (2012), 141(0), 411-417

Ethnopharmacological relevance : Aerial parts of Acanthospermum hispidum D.C. are often used by traditional healers in Benin for various diseases and especially for malaria Aim of the study : Identify ... [more ▼]

Ethnopharmacological relevance : Aerial parts of Acanthospermum hispidum D.C. are often used by traditional healers in Benin for various diseases and especially for malaria Aim of the study : Identify active compounds from extracts of Acanthospermum hispidum D.CV. leaves previously shown to possess antimalarial properties and analyse in vivo activity and toxicity of crude extracts. Materials and methods : Compounds were isolated from aerial part of A. hispidum D.C. and structurally elucidated using extensive spectroscopic analysis. Antiplasmodial activity was evaluated in vitro against a chloroquinosensitive strain of Plasmodium falciparum (3D7) using the measurement of the plasmodial lactate dehydrogenase activity and in vivo against P. berghei berghei by the 4-days suppressive test. Selectivity of extract and purified compounds on Plasmodium parasites were evaluated by using MTT test on J774 macrophage like murine cells and WI38 human normal fibroblasts and also against two other parasites: Trypanosoma brucei brucei and Leishmania mexicana mexicana. Acute and sub-acute toxicities of a crude extract were evaluated on mice. Results : Two known sesquiterpenic lactones were isolated: 1 (15-acetoxy-8β-[(2-methylbutyryloxy)]-14-oxo-4, 5-cis-acanthospermolide) and 2 (9α-acetoxy-15-hydroxy-8β-(2-methylbutyryloxy) -14-oxo-4, 5-trans-acanthospermolide). 1 and 2 showed in vitro antiplasmodial activity against the chloroquino-sensitive strain (3D7) with IC50 of 2.9 ± 0.5 and 2.23 ± 0.09 μM respectively. Only 2 showed a high selectivity index (SI: 18.4) on Plasmodium compared to cytotoxicity against human fibroblasts cell line (WI38). 1 and 2 also showed interesting antiparasitic activities in vitro against Trypanosoma brucei brucei (IC50 of 2.45 ± 0.49 and 6.36 ± 1.42 μM respectively) and Leishmania mexicana mexicana (IC50 of 0.94 ± 0.05 and 2.54 ± 0.19 μM respectively). Furthermore, crude acidic water extract and fractions containing one of the two isolated compounds displayed a weak in vivo antimalarial activity against P. berghei berghei with a long half-life causing a delayed effect. In vivo acute (2000 mg/kg) and sub-acute (1000 mg/kg) toxicity tests on the crude acidic water extract did not show toxicity. Conclusion : Crude acidic water extract, fractions and pure isolated compounds from A.hispidum showed promising in vitro antiplasmodial activity. Despite our study did not show in vivo acute and subacute toxicities of the crude acidic water extract, its weak in vivo antimalarial activity and the in vitro cytoxicity of pure compounds and enriched extracts containing 1 and 2 indicate that the aerial parts of A. hispidum should be used with caution for malaria treatments. [less ▲]

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See detailAntiparasitic hybrids of Cinchona alkaloids and bile acids.
Leverrier, Aurelie; Bero, Joanne; Frederich, Michel ULg et al

in European journal of medicinal chemistry (2013), 66

A series of 16 hybrids of Cinchona alkaloids and bile acids (4a-h, 5a-h) was prepared by means of a Barton-Zard decarboxylation reaction. Quinine, quinidine, cinchonine and cinchonidine were ... [more ▼]

A series of 16 hybrids of Cinchona alkaloids and bile acids (4a-h, 5a-h) was prepared by means of a Barton-Zard decarboxylation reaction. Quinine, quinidine, cinchonine and cinchonidine were functionalized at position C-2 of the quinoline nucleus by radical attack of a norcholane substituent. The newly synthesized hybrids were evaluated in vitro for their antitrypanosomal, antileishmanial and antiplasmodial activities, along with their cytotoxicity against WI38, a normal human fibroblast cell line. Seven compounds (4d, 4f, 4h, 5b, 5d, 5f, 5h) showed promising trypanocidal activity with IC(5)(0) values in the same range as the commercial drug suramine. Moreover all the 16 hybrids showed antiplasmodial activity (IC(5)(0) </= 6 mug/ml), particularly those containing a nor-chenodeoxycholane moiety (4b, 4d, 4f, 4h, 5b, 5d, 5f, 5h) with IC(5)(0) values comparable to those of the natural alkaloids, and selectivity indices in the range of 5.6-15.7. [less ▲]

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See detailAntiparasitic Properties of Diploceline, a Quaternary Alkaloid from Strychnos gossweileri
Gasquet, Monique; Quetin-Leclercq, Joëlle; Timon-David, Pierre et al

in Planta Medica (1992), 58

The activity of diploceline is relatively weak as compared to metronidazole on Entamoeba histolytica and Trichomonas vaginalis. The quaternary alkaloid does not produce any inhibition of Plasmodium ... [more ▼]

The activity of diploceline is relatively weak as compared to metronidazole on Entamoeba histolytica and Trichomonas vaginalis. The quaternary alkaloid does not produce any inhibition of Plasmodium falciparum growth at 25 micrograms/ml (maximum tested concentration). [less ▲]

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See detailAntipeptide antibody against the bovine IGF-BP-2 : application to the detection of BST-treated cows
Scippo, Marie-Louise ULg; Degand, Guy ULg; Duyckaerts, Anne et al

in Food & Agricultural Immunology (1996), 8

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See detailAntiphase synchronization of electrically shaken conducting beads
Mersch, Eric ULg; Vandewalle, Nicolas ULg

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2011), 84

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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 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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