RESUMO
The aim of the present work was to evaluate the effect of the water soluble fraction of hydrocarbons (WSF) on the antioxidant status of the freshwater prawn Macrobrachium borellii. First, seasonal variations were studied in a non-polluted area. Hepatopancreas and gills showed season-related fluctuations in catalase (CAT), glutathione-S-transferase (GST) activities and in lipid peroxidation levels (LPO), but not in superoxide dismutase (SOD). Then, adults were exposed semi-statically to sublethal doses for 7days. CAT, SOD, GST, and glutathione peroxidase (GPx) activities and LPO, reduced glutathione (GSH) and protein oxidation (PO) levels were determined. Exposed individuals showed significant increases in CAT, SOD, and GST activities in hepatopancreas and CAT activity in gills. GPx activity did not vary in either tissues. While LPO levels increased, GSH levels decreased significantly in hepatopancreas of exposed animals, but PO levels showed no variation. Induction of SOD was also assessed by Real-time PCR mRNA expression in hepatopancreas. The non-enzymatic antioxidant activity was also tested; ABTS 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) was higher in hemolymph of treated-prawns compared to controls, but ferric reducing activity of plasma assay (FRAP) values did not change. Taken together, the present results indicated that the antioxidant defenses of M. borellii, mainly in hepatopancreas, were significantly affected by aquatic hydrocarbon contamination, regardless of the season.
Assuntos
Antioxidantes/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo , Oxirredutases/metabolismo , Palaemonidae/efeitos dos fármacos , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Catalase/genética , Catalase/metabolismo , Água Doce/química , Regulação da Expressão Gênica/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Glutationa/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Hemolinfa/efeitos dos fármacos , Hemolinfa/metabolismo , Hepatopâncreas/efeitos dos fármacos , Hepatopâncreas/metabolismo , Oxirredução , Oxirredutases/genética , Palaemonidae/crescimento & desenvolvimento , Palaemonidae/metabolismo , Petróleo/análise , RNA Mensageiro/metabolismo , Estações do Ano , Solubilidade , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/químicaRESUMO
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.
Assuntos
Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Plantas Medicinais , Animais , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Compostos de Bifenilo , Sequestradores de Radicais Livres/administração & dosagem , Sequestradores de Radicais Livres/uso terapêutico , Masculino , Medicina Tradicional , Microssomos Hepáticos/efeitos dos fármacos , Paraguai , Picratos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Ratos , Ratos WistarRESUMO
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.
Assuntos
Fungos/química , Medicina Tradicional , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/crescimento & desenvolvimento , Animais , Astragalus propinquus , Relação Dose-Resposta a Droga , Concentração Inibidora 50 , Leucócitos/efeitos dos fármacos , Modelos Logísticos , Masculino , Medicina Tradicional Chinesa , Região do Mediterrâneo , Extratos Vegetais/efeitos adversos , Extratos Vegetais/química , Ratos , Ratos WistarRESUMO
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.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/farmacologia , Medicina Tradicional , Extratos Vegetais/farmacologia , Plantas Medicinais , Aminopirina N-Desmetilase/antagonistas & inibidores , Animais , Desoxirribose/metabolismo , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Sequestradores de Radicais Livres , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Ratos , Ratos Sprague-Dawley , Xantina Oxidase/antagonistas & inibidoresRESUMO
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.
Assuntos
Parasitologia/métodos , Trypanosoma cruzi/crescimento & desenvolvimento , Animais , Meios de Cultura/análise , Meios de Cultura/farmacologia , Vida Livre de Germes , Plasma , Temperatura , Fatores de Tempo , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/isolamento & purificação , Trypanosoma cruzi/ultraestruturaRESUMO
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.
Assuntos
Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Plantas/química , Animais , Sequestradores de Radicais Livres/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Lipídeos de Membrana/metabolismo , Ratos , Ratos WistarRESUMO
The screening for extracellular oxidases and peroxidases from autochthonous filamentous fungi isolated from different substrates is an important step towards the detection of extracellular fungal oxidative systems. Thirty-one autochthonous fungal strains from Argentina, belonging to different ecophysiological and taxonomic groups, were plate-screened for their ability to produce extracellular oxidoreductases. Modified Kirk solid medium containing the chromogen 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) was used to determine the presence of this extracellular activity. The fungi tested were grouped according to the colour intensity of the modified Kirk medium in: a) species without extracellular ABTS-oxidizing activity; b) species with low extracellular ABTS-oxidizing activity; c) species with moderate extracellular ABTS-oxidizing activity; d) species with high extracellular ABTS-oxidizing activity. The assay revealed extracellular ABTS-oxidizing activity in 90% of the strains tested. All species of Basidiomycetes used exhibited ABTS-oxidizing activity, except Laeticorticium roseum. Aspergillus terreus and Epicoccum purpurascens (Deuteromycetes) did not show extracellular oxidative activity on ABTS. Agrocybe aegerita, Amauroderma boleticeum, Cladosporium cladosporioides, Coriolopsis rigida, Grammothele subargentea, Graphium putredinis, Hexagona hydnoides, Hexagona papyraceae, Loweporus lividus, Peniophora albobadia, Phellinus everhartii, Phellinus gilvus; Phellinus linteus; Pleurotus laciniatocrenatus, Pycnoporus sanguineus, Rigidoporus ulmarius, Steccherinum rawakense, Talaromyces helicus, Trametes elegans, Trametes pavonia, Trametes villosa and Trichaptum sector are reported here for the first time as species capable of producing ABTS-oxidizing extracellular oxidorreductases.
RESUMO
This study examines the anti-ulcerogenic activity of a chloroform extract of Tanacetum vulgare and purified parthenolide, the major sesquiterpene lactone found in the extract. Gastric ulcers induced by oral administration of absolute ethanol to rats were reduced dose-dependently by oral pretreatment of animals with the chloroform extract (2.5-80 mg kg(-1)) or parthenolide (5-40 mg kg(-1)). When administered 30 min before challenge with the alcohol the protection ranged between 34 and 100% for the extract and 27 and 100% for parthenolide. When the products were administered orally 24 h before treatment with ethanol, 40 mg kg(-1) of the extract and of the lactone reduced the mean ulcer index from 4.8+/-0.3 for control animals to 1.4+/-0.2 and 0.5+/-0.1, respectively. The products also prevented alcohol-induced reduction of the number of sulphydryl groups within the gastric mucosa (50.6+/-2.3 microg (mgprotein)(-1) for normal animals compared with 17.7+/-3.0 microg (mg protein)(-1) for alcohol-treated animals). Administration of the extract (80 mg kg(-1)) or parthenolide (40 mg kg(-1)) 24 h before ethanol treatment restored the numbers of mucosal -SH groups to values near those found for normal animals. These results suggest that the products assayed, in particular parthenolide, might find therapeutic application, although further work is required to establish their profit/risk ratio.
Assuntos
Extratos Vegetais/uso terapêutico , Plantas Medicinais/química , Sesquiterpenos/uso terapêutico , Úlcera Gástrica/prevenção & controle , Animais , Clorofórmio , Relação Dose-Resposta a Droga , Etanol/efeitos adversos , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/patologia , Masculino , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Sesquiterpenos/farmacologia , Índice de Gravidade de Doença , Solventes/efeitos adversos , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/patologia , Compostos de Sulfidrila/metabolismoRESUMO
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.
Assuntos
Arseniatos/farmacologia , Peroxidação de Lipídeos , Lipoproteínas/metabolismo , Fígado/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Glutationa/metabolismo , Fígado/metabolismo , Masculino , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Vitamina E/metabolismoRESUMO
The effect of lovastatin, a hypocholesterolemic drug, on tumor growth and desaturase activity was studied in a human lung mucoepidermoid carcinoma (HLMC) grown in nude mice. After administration of a diet supplemented with 25 mg% (w/w) lovastatin for 30 days the growth of HLMC was not inhibited. Liver and tumor phospholipid/cholesterol ratio was increased in lovastatin group but serum cholesterol was unaffected. Treatment with lovastatin increased delta 5 and delta 9 desaturation in tumor microsomes, whereas delta 6 desaturation did not change in tumors of treated mice. The changes were not reflected in the fatty acid composition of total tumor lipids.
Assuntos
Anticolesterolemiantes/administração & dosagem , Carcinoma Mucoepidermoide/metabolismo , Ácidos Graxos/metabolismo , Lovastatina/administração & dosagem , Neoplasias Pulmonares/metabolismo , Neoplasias Experimentais/metabolismo , Animais , Dieta , Humanos , Camundongos , Camundongos Nus , Transplante de NeoplasiasRESUMO
We have studied the effect of a gamma-linolenic acid (18:3 n-6, GLA)-supplemented diet on the growth of a human lung mucoepidermoid carcinoma (HLMC) implanted in athymic mice and on its uptake of human low density lipoproteins labeled with 99mTc (99mTc-LDL). Mice bearing the HLMC were divided into two experimental groups. One of them was administered a control diet (C diet) and the other one was given a diet supplemented with 25 mg GLA/g pellet (GLA diet) for three weeks (Table 1). A tumor growth inhibition with the GLA diet was evident at the second week of treatment, and a marked inhibition (56%) was reached at the end of the third week (Fig. 1). The GLA diet produced some changes in the total fatty acid composition of tumor, plasma and liver of host mice: GLA and arachidonic acid (20:4 n-6, AA) induced significant increases, whereas oleic (18:1 n-9, OA) and linoleic acids (18:2 n-6, LA) were decreased (Table 2). Tumors of those animals fed both diets were labeled by 99mTc-LDL, and no difference was observed in the ratio of tumor/liver and tumor/kidney uptake of host animal (Table 3). Results obtained using this experimental model suggest that the inhibitory effect of GLA on tumor growth is not related to the LDL tumor uptake.
Assuntos
Carcinoma Mucoepidermoide/patologia , Dieta , Alimentos Fortificados , Lipoproteínas LDL/sangue , Neoplasias Pulmonares/patologia , Ácido gama-Linolênico/administração & dosagem , Análise de Variância , Animais , Ácidos Graxos/química , Feminino , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Compostos de OrganotecnécioRESUMO
Morphogenesis of blood stream trypomastigotes in the cell free culture medium F69 at 37 degrees C for 10 days showed qualitative differences either with or without human plasma. Without human plasma, blood stream trypomastigotes performed only one cycle before disappearing and the culture kept growing as amastigotes and epimastigotes until the end of the experiment. In contrast, human plasma induced multiple cycles of transformation. The sequence was blood stream trypomastigotes, regressive parasites, amastigotes, progressive parasite and again trypomastigotes. Human plasma preserved the trypomastigote stage, produced a blockade of the epimastigote stage and inhibited the division of amastigotes. In this experimental model, human plasma modified the biological cycle of T. cruzi by inducing or inhibiting different stages.
Assuntos
Plasma , Trypanosoma cruzi/crescimento & desenvolvimento , Animais , Meios de Cultura , Humanos , Morfogênese , Fatores de TempoRESUMO
We have studied the effect of a gamma-linolenic acid (18:3 n-6, GLA)-supplemented diet on the growth of a human lung mucoepidermoid carcinoma (HLMC) implanted in athymic mice and on its uptake of human low density lipoproteins labeled with 99mTc (99mTc-LDL). Mice bearing the HLMC were divided into two experimental groups. One of them was administered a control diet (C diet) and the other one was given a diet supplemented with 25 mg GLA/g pellet (GLA diet) for three weeks (Table 1). A tumor growth inhibition with the GLA diet was evident at the second week of treatment, and a marked inhibition (56
) was reached at the end of the third week (Fig. 1). The GLA diet produced some changes in the total fatty acid composition of tumor, plasma and liver of host mice: GLA and arachidonic acid (20:4 n-6, AA) induced significant increases, whereas oleic (18:1 n-9, OA) and linoleic acids (18:2 n-6, LA) were decreased (Table 2). Tumors of those animals fed both diets were labeled by 99mTc-LDL, and no difference was observed in the ratio of tumor/liver and tumor/kidney uptake of host animal (Table 3). Results obtained using this experimental model suggest that the inhibitory effect of GLA on tumor growth is not related to the LDL tumor uptake.
Assuntos
Apolipoproteínas A/isolamento & purificação , Apolipoproteínas B/isolamento & purificação , Hiperlipoproteinemias/sangue , Adulto , Apolipoproteínas A/análise , Apolipoproteínas B/sangue , Cromatografia de Afinidade , Concanavalina A , Ácidos Graxos/sangue , Feminino , Humanos , Hipercolesterolemia/sangue , Hipertrigliceridemia/sangue , Lipídeos/sangue , Masculino , Pessoa de Meia-IdadeRESUMO
The contribution of the acyl specificity of post heparin lipolytic enzymes to changes in the plasma free fatty acid (FFA) pattern during very low density lipoproteins (VLDL) lipolysis, was studied. The effect of these changes in the 3H-choline incorporation into platelet phosphatidylcholine (PC) during incubation, was also investigated. "In vitro" experiments with post heparin plasma and isolated VLDL showed an increase of 61.1 in the percentage of linoleic acid (C 18:2) concomitant with a decrease of 57.1% in the relative concentration of stearic acid (C 18:0) during VLDL triacylglycerol lipolysis. Similarly, a decrease of 39.2% in the plasma concentration of C 18:0 and an increase of 29.4% in the C 18:2 and 9.6% in the oleic acid (C 18:1) concentration were observed after intravenous injection of low doses of heparin. The plasma FFA compositional changes that occur during "in vitro" VLDL lipolysis accelerate not only the incorporation of labeled choline but also the incorporation of C 18:2 into platelet PC. It is suggested that the above observed changes on platelet response are due to the increase in the C 18:2 concentration during incubation.