H A Tournier

National University of La Plata, La Plata, Provincia de Buenos Aires, Argentina

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Publications (8)13.45 Total impact

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    ABSTRACT: Our objective was to compare the antioxidant properties and cardiovascular effects in ischemia–reperfusion of leaves aqueous extracts of Ilex brasiliensis (B) and Ilex paraguariensis (P). In vitro systems were used to assess the antioxidant properties of the extracts. Isolated rat hearts were treated with both extracts before ischemia and myocardial function was assessed. Thiobarbituric acid reactive substances (TBARS) concentration and reduced glutathione (GSH) were also measured. B extract showed higher total phenols and ascorbic acid contents and a higher scavenging activity of peroxynitrite and ferric reducing antioxidant power (FRAP) than P extract. Postischemic systolic and diastolic functions were improved after B and P treatment. Both extracts decreased TBARS and preserved GSH content. The present study demonstrates that an aqueous extract of I. brasiliensis, similar to I. paraguariensis, protects the myocardium against ischemia–reperfusion injury and attenuates oxidative damage. These effects may be attributed to the potent antioxidant properties of the extract.
    Food Research International 01/2009; 42:1403-1409. · 3.05 Impact Factor
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    ABSTRACT: The antioxidant properties of six medical herbs used in the traditional Paraguayan medicine were studied using free radical-generating systems. The methanol extracts from Aristolochia giberti, Cecropia pachystachya, Eugenia uniflora, Piper fulvescens, Schinus weinmannifolia and Schinus terebinthifolia protected against enzymatic and non-enzymatic lipid peroxidation in microsomal membranes of rat. C. pachystachya, E. uniflora, S. weinmannifolia and S. terebinthifolia showed the highest scavenging activity on the superoxide and DPPH radicals.
    Fitoterapia 03/2003; 74(1-2):91-7. · 2.23 Impact Factor
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    ABSTRACT: This study describes the screening of extracts obtained from 18 plants and two fungi used in the Chinese and Mediterranean traditional medicines on epimastigote forms of Trypanosoma cruzi. The extracts were tested against epimastigote of T. cruzi Bra C15C2 clone in vitro at 27 degrees C and at a concentration of 250 microg/ml in axenic culture. Angelica dahurica, A. pubescens, A. sinensis, Astragalus membranaceus, Coptis chinensis, Haplophyllum hispanicum, Phellodendron amurense, Poria cocos, Ranunculus sceleratus and Scutellaria baicalensis showed significant effects against the parasite with a percentage of growth inhibition between 20 and 100%. C. chinensis and R. sceleratus showed the greatest activity with IC(50) values of 1.7 microg/ml for C. chinensis and 10.7 microg/ml for R. sceleratus. These activities are greater than that of allopurinol. C. chinesis and R. sceleratus extracts did not show cytotoxic effects on rat polimorphonuclear cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and lactic dehydrogenase assays. These results allowed us to suggest that R. sceleratus and C. chinensis could be a source of new compounds clinically active against T. cruzi.
    Fitoterapia 01/2003; 73(7-8):569-75. · 2.23 Impact Factor
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    ABSTRACT: The antioxidant properties of twenty medical herbs used in the traditional Mediterranean and Chinese medicine were studied. Extracts from Forsythia suspensa, Helichrysum italicum, Scrophularia auriculata, Inula viscosa, Coptis chinensis, Poria cocos and Scutellaria baicalensis had previously shown anti-inflammatory activity in different experimental models. Using free radical-generating systems H. italicum. I. viscosa and F. suspensa protected against enzymatic and non-enzymatic lipid peroxidation in model membranes and also showed scavenging property on the superoxide radical. All extracts were assayed at a concentration of 100 microg/ml. Most of the extracts were weak scavengers of the hydroxyl radical and C. chinensis and P. cocos exhibited the highest scavenging activity. Although S. baicalensis inhibited the lipid peroxidation in rat liver microsomes and red blood cells, the extract showed inhibitory actions on aminopyrine N-demethylase and xanthine oxidase activities as well as an pro-oxidant effect observed in the Fe3+-EDTA-H2O2 system. The results of the present work suggest that the anti-inflammatory activities of the same extracts could be explained, at least in part, by their antioxidant properties.
    Life Sciences 02/2002; 70(9):1023-33. · 2.56 Impact Factor
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    ABSTRACT: To establish whether the total antioxidant capacity of nonalcoholic extracts of three Argentine red wines (RWE) is correlated with their protection against ischemia-reperfusion injury. The antioxidant properties of three RWE were determined using different free radical-generating systems. To examine the effects of these RWE during a 20 min global ischemic period followed by 30 min of reperfusion, isolated rat hearts received 50 mug/mL of RWE 1 (cabernet-sauvignon), RWE 2 (malbec) or RWE 3 (a commercial mixture of cabernet-sauvignon, malbec and merlot) 10 min before and after ischemia. Left ventricular developed pressure (LVDP), maximal velocity of rise of left ventricular pressure (+dP/dt(max)) and left ventricular end-diastolic pressure (LVEDP) were used to assess contractility and diastolic function. All RWE inhibited lipid peroxidation induced by the Cl(4)C/NADPH system in a similar proportion (42+/-4%, 47+/-9% and 43+/-14% for RWE 1, RWE 2 and RWE 3, respectively). The scavenging activity of superoxide anion and 2,2-diphenyl-1-picryl-hydrazyl radical was about the same with the three RWE. In hearts without RWE treatment, LVDP and +dP/dt(max) were 61+/-4% and 62+/-5%, respectively, at the end of the reperfusion period. Infusion of RWE 1 and RWE 2 significantly improved postischemic recovery (LVDP and +dP/dt(max) were 102+/-4% and 101+/-4% for RWE 1 and 92+/-5% and 91+/-5% for RWE 2, respectively) and attenuated the increase of LVEDP. RWE 3 did not improve either systolic or diastolic dysfunction. These data show that although the three non-alcoholic RWE exhibit a similar total antioxidant capacity, only two of them protect the heart against myocardial stunning, suggesting that the protective effect is not primarily linked to the anti-oxidant properties of the extracts.
    Experimental and clinical cardiology 01/2001; 6(4):183-7. · 1.10 Impact Factor
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    ABSTRACT: In this work we investigate the antioxidant properties of an aqueous extract prepared from an infusion of Ilex paraguariensis (Aquifoliaceae) using free radical-generating systems. The extract inhibited the enzymatic and nonenzymatic lipid peroxidation in rat liver microsomes in a concentration-dependent fashion, with IC(50) values of 18 microg/ml and 28 microg/ml, respectively. The extract also inhibited the H(2)O(2)-induced peroxidation of red blood cell membranes with an IC(50) of 100 microg/ml and exhibited radical scavenging properties toward superoxide anion (IC(50) = 15 microg/ml) and 2,2-diphenyl-1-picrylhydrazyl radical. In the range of concentrations used, the extract was not a scavenger of the hydroxyl radical. Our results suggest that ingestion of extracts of Ilex paraguariensis could contribute to increase the antioxidant defense of an organism against free radicals attack.
    Biochemical and Biophysical Research Communications 04/2000; 269(2):357-60. · 2.28 Impact Factor
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    ABSTRACT: Adult male rats were treated orally with sodium arsenate (10 mg As/kd/day) for 2 days, and in increase in hepatic glutathione level was seen. Ascorbic acid content increased in both liver and plasma of intoxicated animals. Hepatic activities of superoxide dismutase and glutathione peroxidase did not change with the treatment and there was no increase in the level of lipid peroxidation measured as thiobarbituric acid-reacting substances (TBARS). Arsenic decreased the plasma level of uric acid and increased the plasma triglycerides content without modifying vitamin E levels. Both total lipoproteins and very low density lipoprotein plus low density lipoprotein (VLDL + LDL) fractions demonstrated greater propensity for in vitro oxidation than the corresponding untreated rats. The last finding might be a useful parameter for determining the degree of oxidative stress in the initial steps of intoxication with arsenic.
    Pharmacology &amp Toxicology 01/1997; 79(6):293-6.
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    ABSTRACT: This work describes a protocol to obtain pure populations of extracellular amastigotes of Trypanosoma cruzi. The amastigote stage was obtained by means of temperature changes and human plasma added to the culture medium. Epimastigotes (clon BraC15C2) were first grown in F69 medium at 27 degrees C during 96 h and then at 36.5 degrees C. After three subcultures of 96 h each at the latter temperature a subsequent incubation in the presence of 5% human plasma, was needed to obtain a population of amastigotes that could be maintained indefinitely in the F69 or F29 media. This amastigote population was similar morphologically to that obtained through other methods. The kinetic of growth depended on the culture medium used (F29 or Brain-Heart Infusion, BHI). When culture was incubated at 27 degrees C in both media, the pre-exponential and logarithmic phases of growth were observed at 72-96 h and 24-48 h respectively. The change in stage from amastigote to epimastigote dependent whether amastigote were subcultured or not. The growth of amastigotes in BHI medium at 36.5 degrees C did not occurred. The growth of amastigotes was similar to those observed at 27 degrees C when F29 medium was used although the transformation to epimastigotes did not take place at this temperature. A population over 99% of amastigotes were maintained at 36.5 degrees C indefinitely by means of subcultures in F29 medium.
    Revista latinoamericana de microbiología 42(1):21-6.