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See detailAntioxidant potential of different plum cultivars during storage
MIHALACHE ARION, Cristina; TABART, Jessica; Kevers, Claire ULg et al

in Food Chemistry (2013), 146

Plums, the most commonly consumed fruits from Romania, are fruit rich in bioactive compounds like antioxidants. This research work was carried out to investigate the antioxidant potential of twelve plum ... [more ▼]

Plums, the most commonly consumed fruits from Romania, are fruit rich in bioactive compounds like antioxidants. This research work was carried out to investigate the antioxidant potential of twelve plum cultivars, fresh and stored during 10 days at 4°C by using different methods (DPPH, ORAC and erythrocyte resistance to haemolysis). The contents of total phenolic compounds and total anthocyanins were also determined by specific spectrometric methods. Significant differences between fresh and stored plum cultivars (p < 0.05) were found. Storage at 4°C resulted in an increase in antioxidant potential and anthocyanins content of the autumn plum varieties. Autumn plum varieties showed also a higher antioxidant capacity than summer varieties, as assessed by the ORAC and the haemolysis resistance assays. Our results suggest that even after storage plums could be a good source of antioxidants, which may provides health-promoting effects for humans. [less ▲]

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See detailAntioxidant potentiality of three herbal teas consumed in Bandundu rural areas of Congo.
Mutwale Kapepula, Paulin ULg; Mbombo Mungitshi, Patricia; Franck, Thierry ULg et al

in Natural Product Research (2016)

The aim of this study was to evaluate and compare the cellular antioxidant activities of Lantana montevidensis, Lippia multiflora, and Ocimum gratissimum leaves often consumed as herbal teas in a rural ... [more ▼]

The aim of this study was to evaluate and compare the cellular antioxidant activities of Lantana montevidensis, Lippia multiflora, and Ocimum gratissimum leaves often consumed as herbal teas in a rural area of Bandundu severely affected by konzo, which is related to oxidative damage. Consequently, dietary supplements with proven antioxidant potentialities could be of real interest to promote in this area. Phytochemical screening by TLC and HPLC-DAD of extracts revealed the presence of verbascoside as a major phenolic compound. Verbascoside in L. montevidensis and O. gratissimum is reported here for the first time. All extracts displayed high ABTS and DPPH radical-scavenging activities at the concentration range of 1-40 mug mL-1 according to order: L. multiflora > O. gratissimum > L. montevidensis. L. multiflora showed the best cellular antioxidant activity using DCFH-DA on HL-60 monocytes assay at 1-20 mug mL-1. These herbal teas may be used as nutraceuticals for their potent antioxidant activity. [less ▲]

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See detailAntioxidant power of phytochemicals from Psidium guajava leaf.
Qian, He; Nihorimbere, Venant ULg

in Journal of Zhejiang University. Science. B (2004), 5(6), 676-683

ried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically ... [more ▼]

ried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 +/-15.5 and 511.6+/-6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH*) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH* color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC(50) and the time needed to reach the steady state to EC(50) concentration (T(EC(50))) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used EC(50). This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants. [less ▲]

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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 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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