Extração, caracterização e avaliação bioativa do extrato de Rumex acetosa

Studies show the great influence of free radicals and other oxidants as responsible for aging and degenerative diseases. On the other hand, the natural phenolic compounds has shown great as antioxidants to inhibit lipid peroxidation and lipoxygenase in vitro. Among these, is highlighted trans-resveratrol ( 3,5,4 `- trihydroxystilbene ) phenolic compound , characterized as a polyphenol stilbene class. The vegetables popularly known as "Azedinha" (Rumex Acetosa) has trans-resveratrol in its composition and from this, the present work aimed to study on the supercritical extraction and conventional extraction (Soxhlet and sequential) in roots of Rumex Acetosa, evaluating the efficiency of extractive processes, antioxidant activity, total phenolic content and quantification of trans-resveratrol contained in the extracts. Extractions using supercritical CO2 as solvent, addition of co-solvent (ethanol) and were conducted by the dynamic method in a fixed bed extractor. The trial met a 23 factorial design with three replications at the central point, with the variable reply process yield and concentration of trans-resveratrol and pressure as independent variables, temperature and concentration of co-solvent (% v/v). Yields ( mass of dry extract / mass of raw material used ) obtained from the supercritical extraction ranged from 0,8 to 7,63 % , and the best result was obtained at 250 bar and 90 °C using the co-solvent 15% ethanol (% v/v). The value was calculated for YCER a flow rate of 1,0 ± 0,17 g/min resulting in 0,0469 CO2 ( g solute / g solvent ). The results of the mass yield varied between conventional extractions 0,78 % ( hexane) and 9,97 % (ethanol). The statistical model generated from the data of the concentration of trans-resveratrol performed as meaningful and predictive for a 95% confidence. GC analysis on HPLC (High Performance Liquid Chromatography), transresveratrol was quantified in all extracts and concentration values ranged between 0,0033 and 0,42 ( mg / g extract) for supercritical extracts and between 0,449 and 17,046 (mg / g extract) to conventional extractions and therefore, the Soxhlet extraction with ethanol for more selective trans-resveratrol than the supercritical fluid. Evaluation of antioxidant (radical method to sequester 2,2- diphenyl-1- picryl - hydrazyl - DPPH) the supercritical extracts resulted in EC50 values (concentration effective to neutralize 50% of free radicals) of between 7,89 and 18,43 mg/mL , while resulting in a Soxhlet extraction with EC50 values in the range of 6,05 and 7,39 mg/mL. As for quantification of the phenolic compounds (Method Spectrophotometer Folin-Ciocalteau) the supercritical extracts resulted in values between 85,3 and 194,79 mg GAE / g extract, whereas values derived from the Soxhlet extract resulted in values between 178,5 and 237,8 mg GAE / g extract. The high antioxidant activity can not be attributed solely to the presence of phenolic compounds, but the presence of other antioxidants in the existing Rumex acetosa

Uso da tecnologia de troca iônica no tratamento de águas contaminadas com Nitrato do Aqüífero Dunas-Barreiras, Natal/RN-Brasil

The city of Natal comprises an area of about 170 km² (65,63 squares miles). The Dunas-Barreiras Aquifer is the most important reservoir of the coastal basin of RN. It is being responsible for the water supplying of about 70% of the population, however, due to the sewage disposal system by cesspools and drains, it is presently affected in a great extent by nitrates contamination. Thus, the present work proposes to research the utilization of contaminated water by nitrates of this fountainhead and find cost of the potable water through the ionic exchange technology. This technology consists in the removal of mineral salts by the exchange of cations for one ion of hydrogen (H+), through the passage of water by cationic resin bed and, secondly, by the exchange of the anions for hydroxyl ions (OH-) through a anionic resin bed. The obtained results have showed the waters derived from fountains, big water holes and shallow wells were microbiologically contaminated, while the waters derived from deep wells (above 70 m 76,58 yards) were free of contamination. Thus, only these ones are suitable to the use of ionic technology. The experiments were conducted with the resin IMAC-HP-555 such as kinetic, thermodynamic, and adsorption by fixed bed studies, being obtained several project variables for the experimental column, as follow: work temperature of 25oC; resin maximum capacity maximum e mean of adsorption ==0,01692 g NO3-1/g R e 0,0110 g NO3-1/g R, respectively. On the experimental column were performed breakthrough tests which pointed for an average ideal average speed of work of 13.2 m / h, with an average efficiency of 45% of adsorption, an optimal concentration of NaCl desorption of 8%, and an ideal desorption time of 80 minutes for the equilibrium conditions of water from the Dunas-Barreiras aquifer. Scale projection for ion-exchange column for denitrification, for these variables, using a computer modeling programme, to project the column of ion exchange ROREX-420/2000, obtained a cost for the drinking water denitrified by this system of R$ 0,16 / m3

Comportamento da produção de espécies reativas de oxigênio em miocárdio de ratos submetidos a treinamento de baixa intensidade em diferentes temperaturas

INTRODUÇÃO: A prática de exercício físico proporciona aumento da produção de espécies reativas de oxigênio (ERO) resultantes do metabolismo aeróbio e, gera uma quantidade significativa de calor, em conseqüência da produção de energia, resultando em sobrecarga orgânica. A associação entre ERO e exercício, e entre exercício e variações da temperatura ambiente têm sido estudadas, contudo, há escassez de informações que considere a associação entre produção de radicais livres no miocárdio e atividade física em temperatura elevada. OBJETIVO: Comparar a produção de ERO em miocárdio de ratos submetidos ao treinamento de baixa intensidade em diferentes temperaturas. MÉTODOS: Foram utilizados 20 ratos Wistar, machos, jovens, peso (250 a 280g), divididos em quatro grupos: G1 (n = 5) expostos ao treinamento e calor (39º ± 1C); G2 (n = 5) expostos somente ao calor durante o mesmo período de G1, sem treinamento; G3 (n = 5) expostos ao treinamento em temperatura ambiente (22º ± 1C); G4 (n = 5) expostos à temperatura ambiente sem treinamento. O treinamento foi realizado em esteira rolante climatizada por cinco semanas, evoluindo 5 minutos a cada duas sessões finalizando em 60 minutos em baixa intensidade 8m/min. O ambiente foi controlado entre 39 ± 1ºC e 22 ± 1ºC e entre 40 e 60 % de umidade relativa. A lipoperoxidação foi avaliada por Quimiluminescência (QL). A análise dos dados foi realizada a partir do teste Two Way ANOVA para análise da QL e t de student para a Capacidade Antioxidante Total (TRAP). RESULTADOS: A análise da QL revelou uma curva de emissão de luz significantemente mais baixa para o grupo exposto ao exercício em normotermia comparado aos sedentários mantidos no calor. A análise da TRAP mostrou diminuição em todos os grupos experimentais em relação ao G4. CONCLUSÃO: Concluiu-se que houve níveis menores de produção de ERO nos grupos submetidos somente ao calor ou somente ao exercício.

CARNITINE SUPPLEMENTATION EFFECTS on NONENZYMATIC ANTIOXIDANTS IN YOUNG RATS SUBMITTED TO EXHAUSTIVE EXERCISE STRESS

Bucioli, SA, de Abreu, LC, Valenti, VE, and Vannucchi, H. Carnitine supplementation effects on nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress. J Strength Cond Res 26(6): 1695-1700, 2012-Previous studies have demonstrated that exercise stress increases oxidative stress in rats. However, antioxidant supplement therapy effects on reactive oxygen substances are conflicting. We evaluated the effects of carnitine on renal nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress. Wistar rats were divided into 3 groups: (a) control group (not submitted to exercise stress), (b) exercise stress group, and (c) exercise stress and carnitine group. The rats from group 3 were treated with gavage administration of 1 ml of carnitine (5 mg.kg(-1)) for 7 consecutive days. The animals from groups 2 and 3 were submitted to a bout of swimming exhaustive exercise stress. Kidney samples were analyzed for reactive substances to thiobarbituric acid by malondialdehyde (MDA), reduced glutathione (GSH), and vitamin-E levels. Carnitine treatment attenuated MDA increase caused by exercise stress (1:0.16 +/- 0.02 vs. 2:0.34 +/- 0.07 vs. 3:0.1 +/- 0.01 mmmol per milligram of protein; p < 0.0001). It also increased the renal levels of GSH (1:23 +/- 4 vs. 2:23 +/- 2 vs. 3:58 +/- 9 mu mol per gram of protein; p, 0.0001); however, it did not change renal vitamin E (1:24 +/- 5 vs. 2:27 +/- 1 vs. 3:28 +/- 5 mu M per gram of tissue; p < 0.001). In conclusion, carnitine improved oxidative stress and partially improved the nonenzymatic antioxidant activity in young rats submitted to exhaustive exercise stress.

Amphotericin B mediates killing in Cryptococcus neoformans through the induction of a strong oxidative burst

We studied the effects of Amphotericin B (AmB) on Cryptococcus neoformans using different viability methods (CFUs enumeration, XTT assay and propidium iodide permeability). After 1 h of incubation, there were no viable colonies when the cells were exposed to AmB concentrations >= 1 mg/L. In the same conditions, the cells did not become permeable to propidium iodide, a phenomenon that was not observed until 3 h of incubation. When viability was measured in parallel using XTT assay, a result consistent with the CFUs was obtained, although we also observed a paradoxical effect in which at high AmB concentrations, a higher XTT reduction was measured than at intermediate AmB concentrations. This paradoxical effect was not observed after 3 h of incubation with AmB, and lack of XTT reduction was observed at AmB concentrations higher than 1 mg/L. When stained with dihydrofluorescein, AmB induced a strong intracellular oxidative burst. Consistent with oxidative damage, AmB induced protein carbonylation. Our results indicate that in C. neoformans, Amphotericin B causes intracellular damage mediated through the production of free radicals before damage on the cell membrane, measured by propidium iodide uptake. (C) 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Inhibitory Effect of Gallic Acid and Its Esters on 2,2 '-Azobis(2-amidinopropane)hydrochloride (AAPH)-Induced Hemolysis and Depletion of Intracellular Glutathione in Erythrocytes

The protective effect of gallic acid and its esters, methyl, propyl, and lauryl gallate, against 2,2'-azobis(2-amidinopropane)hydrochloride (AAPH)-induced hemolysis and depletion of intracellular glutathione (GSH) in erythrocytes was studied. The inhibition of hemolysis was dose-dependent, and the esters were significantly more effective than gallic acid. Gallic acid and its esters were compared with regard to their reactivity to free radicals, using the DPPH and AAPH/pyranine free-cell assays, and no significant difference was obtained. Gallic acid and its esters not only failed to inhibit the depletion of intracellular GSH in erythrocytes induced by AAPH but exacerbated it. Similarly, the oxidation of GSH by AAPH or horseradish peroxidase/H(2)O(2) in cell-free systems was exacerbated by gallic acid or gallates. This property could be involved in the recent findings on proapoptotic and pro-oxidant activities of gallates in tumor cells. We provide evidence that lipophilicity and not only radical scavenger potency is an important factor regarding the efficiency of antihemolytic substances.

Free radical scavenging profile and myeloperoxidase inhibition of extracts from antidiabetic plants: Bauhinia forficata and Cissus sicyoides

There is abundant evidence that reactive oxygen species are implicated in several physiological and pathological processes. To protect biological targets from oxidative damage. antioxidants must react with radicals and other reactive species faster than biological substrates do. The aim of the present study was to determine the in vitro antioxidant activity of aqueous extracts from leaves of Bauhinia forficata Link (Fabaceae - Caesalpinioideae) and Cissus sicyoides L. (Vitaceae) (two medicinal plants used popularly in the control of diabetes mellitus), using several different assay systems, namely, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) decolorization. superoxide anion radical (O-2 center dot-) scavenging and myeloperoxidase (MPO) activity. In the ABTS assay for total antioxidant activity, B. forficata showed IC50 8.00 +/- 0.07 mu g/mL, while C. sicyoides showed IC50 13.0 +/- 0.2 mu g/mL. However, the extract of C. sicyoides had a stronger effect on O-2 center dot- (IC50 60.0 +/- 2.3 mu p/mL) than the extract of B. forficata (IC50 90.0 +/- 4.4 mu g/mL). B. forficata also had a stronger inhibitory effect on MPO activity, as measured by guaiacol oxidation, than C. sicyoides. These results indicate that aqueous extracts of leaves of B. forficata and C. sicyoides are a potential source of natural antioxidants and may be helpful in the prevention of diabetic complications associated with oxidative stress.

Overall-Mouth Disinfection by Photodynamic Therapy Using Curcumin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photodynamic Effects of Curcumin Against Cariogenic Pathogens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antioxidant activity of Maytenus ilicifolia root bark

Maytenus ilicifolia is an important plant with potential on cancer treatment and has been largely used in Brazil and other countries. We have evaluated the crude ethanolic extract of M. ilicifolia as a potential antioxidant source using an assay based on the bleaching of the radical monocation 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(center dot+)) and by HOCl scavenger capacity. Trolox and uric acid were used as positive controls. The results indicated M. ilicifolia root bark as a great source of antioxidants based on its potential as scavenger of radicals. (c) 2006 Elsevier B.V. All rights reserved.

Synthesis, X-ray structure and antimycobacterial activity of silver complexes with alpha-hydroxycarboxylic acids

In this paper, synthesis, characterization and antimycobacterial properties of a new water-soluble complex identified as silver-mandelate are described. Elemental and thermal analyses are consistent with the formula [Ag(C6H5C(OH)COO)](n). The polymeric structure was determined by single X-ray diffraction and the two-dimensional structure is based on the bis(carboxylate-O,O') dimer [Ag-O, 2.237(3), 2.222(3) angstrom]. The structure is extended along both the b and c axes through two oxygen atoms of a bidentate alpha-hydroxyl-carboxylate residue [Ag-OH(hydroxyl), 2.477(3) angstrom; Ag-O(carboxylate), 2.502(3) angstrom; O-Ag-O, 63.94(9)degrees]. A strong d(10)-d(10) interaction was observed between two silver atoms. The Ag...Ag distance is 2.8307(15) angstrom. The NMR C-13 spectrum in D2O shows that coordination of the ligand to Ag(l) occurs through the carboxylate group in solution. Potentiometric titration shows that only species with a molar metaHigand ratio of 2:2 are formed in aqueous solution. The mandelate complex and the silver-glycolate, silver-malate and silver-hydrogen-tartarate complexes were tested against three types of mycobacteria, Mycobacterium avium, Mycobacterium tuberculosis and Mycobacterium kansasii, and their minimal inhibitory concentration (MIC) values were determined. The results show that the four complexes are potential candidates for antiseptic or disinfectant drugs for discharged secretions of patients affected with tuberculosis. (c) 2006 Published by Elsevier B.V.

Antioxidant activity of isocoumarins isolated from Paepalanthus bromelioides on mitochondria

The isocoumarins (1-50 mu M) paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naptho(2,3c)pyran-1-one), 8,8 '-paepalantine dimer, and vioxanthin isolated from Paepalanthus bromelioides, were assessed for antioxidant activity using isolated rat liver mitochondria and non-mitochondrial systems, and compared with the flavonoid quercetin. The paepalantine and paepalantine dimers, but not vioxanthin, were effective at scavenging both 1,1-diphenyl-2-picrylhydrazyl (DPPH*) and superoxide (O-2(-)) radicals in non-mitochondrial systems, and protected mitochondria from tert-butylhydroperoxide-induced H2O2 accumulation and Fe2+ -citrate-mediated mitochondrial membrane lipid peroxidation, with almost the same potency as quercetin. These results point towards paepalantine, followed by paepalantine dimer, as being a powerful agent affording protection, apparently via O-2(-) scavenging, from oxidative stress conditions imposed on mitochondria, the main intracellular source and target of those reactive oxygen species. This strong antioxidant action of paepalantine was reproduced in HepG2 cells exposed to oxidative stress condition induced by H2O2. (C) 2007 Elsevier Ltd. All rights reserved.

Mutagenic activity promoted by amentoflavone and methanolic extract of Byrsonima crassa Niedenzu

Byrsonima crassa is a plant pertaining to the Brazilian central savannah-like belt of vegetation and popularly used for the treatment of gastric dysfunctions and diarrhoea. The methanol extract contains catechin, tannins, terpenes and flavonoids; both mutagenic potential and antioxidant properties have been ascribed to flavonoids. The mutagenicity of some flavonoids is believed to be associated with the formation of reactive oxygen species and seems to depend on the number and position of hydroxyl groups. In the present study the mutagenic activity of the methanol, chloroform and 80% aqueous methanol extracts, as well as acetate and aqueous sub-fractions, of this medicinal plant were evaluated by Salmonella typhimurium assay, using strains 100, TA98, TA102 and TA97a, and in mouse reticulocytes. The results showed mutagenic activity of the methanolic extract in the TA98 strain without S9, but no mutagenicity to mouse cells in any of the extracts. The acetate fraction showed strong signs of mutagenicity without S9, suggesting that in this enriched fraction were concentrated the compounds that induced mutagenic activity. The aqueous fraction showed no mutagenic activity. The TLC and HSCCC analyses of the acetate fraction with some standard compounds permitted the isolation of the quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, amentoflavone, methyl gallate and (+)-catechin, of which only the amentoflavone exhibited positive mutagenicity to TA98 (+S9, -S9). (c) 2006 Elsevier B.V.. All rights reserved.

Metabolismo mitocondrial, radicais livres e envelhecimento

O envelhecimento pode estar associado ao maior acúmulo de lesões celulares decorrentes das espécies reativas do oxigênio e do nitrogênio derivadas do metabolismo mitocondrial. Com a progressão da idade, há acúmulo de proteínas, lipídeos, carboidratos e DNA oxidados em relação a organismos jovens, de acordo com a teoria dos radicais livres. Entretanto, nem sempre os idosos ou animais envelhecidos apresentam maior estresse oxidativo que os jovens. Este artigo discute o paradoxo da teoria dos radicais livres de acordo com a teoria da biogênese da manutenção adequada do metabolismo mitocondrial. Diversos fatores podem contribuir para a redução do estresse oxidativo, como a hormese induzida pela prática regular de exercícios físicos, a restrição calórica, a ingestão de antioxidantes nutricionais e o aumento da produção de antioxidantes celulares que. em conjunto, estes promovem a expressão das sirtuínas e das proteínas do choque térmico, protegendo a integridade e funcionalidade mitocondriais, reduzindo o estresse oxidativo e nitrosativo, o que está associado à redução do envelhecimento e aumento da longevidade.

Cocaine induces cell death and activates the transcription nuclear factor kappa-b in pc12 cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)