Consumption of mate Ilex paraguariensis: a folk beverage with antioxidant power against myocardial ischemic injury

The effects of the aqueous extract of Ilex paraguariensis (Ip)and the flavonoid quercetin were tested during the induction of in vivomyocardial ischemia/ reperfusion in Rattus norvegicus. The antioxidant power of the extract and quercetin were chemically determined. The experimental groups were: control, ischemia/reperfusion induction, Iporal treatment, Iporal treatment and ischemia /reperfusion, quercetin oral treatment, and quercetin oral treatment and ischemia/reperfusion. Rats were anesthetized with sodium thiopental and xylazine via intraperitoneal injection and subsequently underwent 15 minutes of ischemia followed by 15 minutes of reperfusion. Ischemia was promoted by tying the left anterior descending coronary artery. Areas of risk and infarction were stained by intravenous Evans blue and triphenyl tetrazolium chloride. Reactive oxygen species (ROS), antioxidant capacity against peroxylradicals, and lipid peroxidation of the myocardium were quantified. A significant reduction in areas of risk and infarction was detected in the ischemic myocardium treated with Ipand quercetin; ROS generation and lipid peroxidation were significantly reduced, and the antioxidant capacity was elevated. Oral administration of Ippromoted antioxidant benefits in the myocardium during ischemia and reperfusion, which reduced infarction. We suggest that Mate (a hot drink made from steeped dried leaves of Ip) consumption is a potential cardioprotective habit of indigenous people from southern South American countries, which must be better understood scientifically and ethnographically.

Nanoformulations of quercetin: a potential phytochemical for the treatment of uv radiation induced skin damages

Abstract The continuous prolonged exposures of sun light especially the ultra violet (UV) radiation present in it, cause not only the risk of skin cancer but also it may cause premature skin aging, photodermatoses and actinic keratoses. Flavonoids (including Flavane, Flavanone, Flavone, Flavonol, Isoflavone, Neoflavone etc.) having potent antioxidant activity, used as topical applications for protection against UV induced skin damages as well as for skin care. Most commonly used flavonoid is quercetin (Flavonol), which is present in fruits, vegetables, and herbs. We aim to review the research focused on development of different novel formulations to treat UV radiations induced skin diseases. In this review, several formulations of flavonoid quercetin were discussed and their outcomes were compiled and compared in context to solubility, stability and efficiency of application. On the basis this comparative analysis we have concluded that three formulations, namely glycerosomes, nanostructured lipid carriers and deformable liposomes hold good applications for future aspects for topical delivery of quercetin. These formulations showed enhanced stability, increased quercetin accumulation in different skin layers, facilitated drug permeation in skin and long-lasting drug release.

Extract of Solidago chilensis Meyen inflorescences: cytotoxicity and inhibitory activity on nitric oxide synthesis in activated macrophage cell line J774A. 1

Solidago chilensis Meyen (= Solidago microglossa) popularly known as "Brazilian arnica" is used to treat of inflammatory disorders. S. chilensis is constant in the Therapeutic Memento of the Rio de Janeiro city and belongs to the medicinal species of Brazilian National List of Medicinal Plants of Interest of the Unified National Health System (SUS). There are no studies in the literature showing the direct activity of this plant species on immune system cells. The present study evaluated the chemical composition as well as the cytotoxic and pharmacological activity of the ether-ethanol extract from S. chilensis inflorescences (SCIE) in murine macrophage cell line J774A.1. The results showed that higher concentrations (50 to 200 µg/mL) of SCIE had significant cytotoxicity on J774A.1 cells, however, lower concentrations (from 10 to 0.1 µg/mL) did not produce significant cytotoxic effects and exhibited an inhibitory effect on nitric oxide production in LPS-stimulated J774A.1 cell line. The chemical analysis by HPLC-UV-PDA indicated that the SCIE contains flavonoid derived from quercetin and kaempferol; and diterpenes, probably labdanes. These findings complement data in the literature regarding the activity of this plant species on an important cell from the immune system involved in the innate and acquired immune response, the macrophages.

Quercetin modulates age-induced changes in the transcript levels of some apoptosis related genes in the skeletal muscles of male rats

Adverse changes occur gradually in the skeletal muscles with age via continuous exposure to oxidative stress. Quercetin, a member of the flavonoids family, possesses anti-oxidative and radical-scavenging activities. Therefore, this study investigated the role of quercetin to modulate age-induced changes in the transcript levels of some apoptosis-related genes in rat's gastrocnemius muscles, up to 15 months-old. Half of the rats at each age (1, 5, 10 and 15 months old) were given a vehicle and the other half was given 200 mg/kg quercetin for 2 weeks, respectively. With the increase of age, vehicle groups showed hyalinization of the muscle fibers and a decrease of the catalase and an increase of the malondialdehyde levels. Down-regulation of Bcl2 gene and up-regulation of both NF-κB and Bax genes were recorded. Interestingly, quercetin groups showed focal hyalinization of the muscle fibers at both 10th and 15th months old. An increase in the catalase and a decrease in malondialdehyde levels, up-regulation of Bcl2 gene and down-regulation of both NF-κB and Bax genes were recorded. In conclusion, quercetin minimized age-induced alteration in the morphological structure and the expression of the apoptosis-related genes via increasing the antioxidant defense in the gastrocnemius muscle.

Solidago chilensis Meyen (Asteraceae), a medicinal plant from South America: a comprehensive review: ethnomedicinal uses, phytochemistry and bioactivity / Solidago chilensis Meyen (Asteraceae), una planta medicinal de América del Sur: una revisión integral: usos etnomedicinales, fitoquímica y bioactividad

Solidago chilensis Meyen (Asteraceae) is a medicinal and aromatic herb widely distributed in South America. From 2000 to the present numerous articles on this species have been published, mainly in the last decade where the pharmacological studies and articles on its secondary metabolites have risen sharply. S. chilensis has potential beneficial effects on human health, particularly as an anti- inflammatory because of its high flavonoid content. This work describes the research carried out on this species with emphasis on biological and phytochemical studies.

Solidago chilensis Meyen (Asteraceae) es una hierba aromática y medicinal, ampliamente difundida en Sudamérica. A partir del año 2000 se publicaron numerosos estudios sobre esta planta, particularmente en la última década donde se incrementó sensiblemente el estudio de sus propiedades farmacológicas y de la química de sus metabolitos secundarios. Es una planta con propiedades potencialmente beneficiosas para la salud humana, destacándose particularmente por su actividad antiinflamatoria que puede ser atribuida al elevado contenido en flavonoides. En este trabajo revisamos exhaustivamente los antecedentes de esta planta desde un enfoque cronológico, con énfasis en los estudios biológicos y fitoquímicos.

Efeito de extratos orgânicos de variedades de cebola sobre o quorum sensing bacteriano / Effect of organic extracts of onion varieties on bacterial quorum sensing

Muitos genes bacterianos são regulados pelo mecanismo de comunicação denominado quorum sensing (QS). Neste sistema, moléculas sinalizadoras ativam um comportamento de grupo, conforme a densidade celular, permitindo o controle da expressão gênica. Estudos sugerem o potencial de compostos extraídos de plantas sobre o QS, a exemplo da quercetina, um flavonol presente em concentrações elevadas em algumas frutas e hortaliças. Este composto é o flavonoide majoritário presente em cebola (Allium cepa), mas não existem estudos que mostrem a atividade anti-QS de extratos orgânicos deste vegetal. Este trabalho avaliou o potencial antimicrobiano e anti-QS de extratos orgânicos de cebola branca e cebola roxa, assim como de alguns de seus componentes majoritários identificados, em fenótipos regulados pelo QS como a produção de violaceína em Chrormobacterium violaceum ATCC 12472, a motilidade tipo swarming e a formação de biofilmes em Pseudomonas aeruginosa PAO1 e Serratia marcescens MG1. Extratos de cebola branca e roxa foram obtidos por extração em fase sólida utilizando coluna de poliamida e seus compostos identificados e quantificados pelas técnicas de Cromatografia líquida- ionização por elétron spray-espectrometria de massas e cromatografia líquida de alta eficiência acoplada a detector de arranjo de diodo. A atividade antimicrobiana foi avaliada pelas curvas de multiplicação de cada micro-organismo. O efeito dos compostos quercetina aglicona (inibidor do QS já relatado na literatura e encontrado no extrato de cebola roxa) e quercetina-3-ß-D-glicosideo (um dos compostos majoritários encontrados em ambos extratos) sobre os micro-organismos utilizados neste estudo foi também avaliado. Foram obtidos três extratos: cebola branca em metanol (CB-MeOH), cebola branca em metanol amônia (CBMeOH/ NH4) e cebola roxa em metanol (CR-MeOH). Os compostos quercetina 3,4'- diglicosídeio, quercetina-4-glicosídeo, quercetina-3-ß-D-glicosideo e quercetina aglicona foram os predominantes nos extratos das duas variedades de cebola. Cianidina-3-O-glicosideo também foi identificada no extrato de cebola roxa. A concentração inibitória mínima (MIC) dos extratos foi igual ou superior a 125 µg/ml (p/v) de extrato seco. Não foi observada inibição significativa da produção de violaceína em C. violaceum pelos extratos orgânicos de cebola e nem pela quercetina-3-ß-D-glicosideo, nas concentrações sub-inibitórias avaliadas. No entanto, a quercetina aglicona inibiu significativamente a produção de violaceína em todas as concentrações. A glicosilação da quercetina pode ter afetado sua atividade sobre a inibição da produção de violaceina, já que estudos mostram menor atividade biológica deste composto quando glicosilado. Para a motilidade tipo swarming em P. aeruginosa PAO1 houve inibição significativa pelo extrato de cebola roxa, em todas as concentrações estudadas. Os demais extratos não apresentaram inibição contra este micro-organismo. Para S. marcescens MG1, foi observada inibição da motilidade swarming somente na concentração de 125 µg/ml de CBMeOH/ NH4. As análises de comparação entre os dois tipos de quercetina revelaram que, embora para as duas bactérias testadas os dois compostos apresentaram atividade inibitória sobre a motilidade tipo swarming, a quercetina-3-ß-D-glicosideo foi menos eficiente que a quercetina aglicona na concentração de 125 µg/ml. A formação de biofilmes não foi influenciada pelos extratos e, inesperadamente, não se detectou inibição da formação de biofilmes por ambos tipos de quercetina avaliados. De forma geral, os extratos orgânicos de cebola mostraram pouco efeito sobre os fenótipos controlados pelo quorum sensing e a glicosilação da quercetina provavelmente explica a baixa atividade antimicrobiana e anti-QS dos extratos

Many bacterial genes are regulated by a communication mechanism called quorum sensing (QS). In this system, signaling molecules activate a group behavior according to cell density, allowing the control of gene expression. Studies suggest the inhibitory potential of compounds extracted from plants on the QS system, like quercetin, a flavonol present in high concentrations in some fruits and vegetables. This compound is the main flavonoid found in onion (Allium cepa); however, there are no studies showing the anti-QS activity of organic extracts of this plant. The objective of this work was to evaluate the antimicrobial and anti-QS potential of organic extracts of white and red onions, and their major components studied in QS-regulated phenotypes such as violacein production in Chromobacterium violaceum, swarming motility and biofilm formation in Pseudomonas aeruginosa PAO1 and Serratia marcescens MG1.White and red onion extracts were obtained by solid phase extraction using a polyamide column and its compounds were identified and quantified by Liquid Chromatography - Electron Spray-Mass Spectrometry and high performance liquid chromatography coupled to diode array detector. O The antimicrobial activity was evaluated by growth curves of each microorganism. The effect of non-glycosylated quercetin (a QS inhibitor already reported in the literature and found in red onion extract) and quercetin-3-ß-D-glycoside (one of the major compounds found in both extracts) on the microorganisms used in this study was also evaluated. Three extracts were obtained: white onion in methanol (CB-MeOH), white onion in methanol ammonia (CB-MeOH / NH4) and red onion in methanol (CR-MeOH). Our results showed that quercetin 3,4'- diglycoside, quercetin-4-glycoside, quercetin-3-ß-D-glycoside and non-glycosylated quercetin were predominant in the extracts of the two onion varieties. Cyanidin-3-O-glycoside has also been identified in the purple onion extract. The minimum inhibitory concentration (MIC) of extracts was equal or greater than 125 µg / ml (w / v) of dry extract. There was no significant inhibition of violacein production in C. violaceum by organic onion extracts or by quercetin-3-ß- D-glycoside at the sub-inhibitory concentrations evaluated. However, non-glycosylated quercetin showed a significant inhibition of violacein production in all tested concentrations. The glycosylation of Quercetin could have altered its inhibition activity towards violacein production, and in fact, some studies have shown less biological activity of some phenolic compounds when they have been glycosylated. For swarming motility in P. aeruginosa PAO1 there was significant inhibition by red onion extract, in all studied concentrations. The other extracts did not present inhibition against this microorganism. For S. marcescens MG1, inhibition of swarming motility was observed only at the concentration of 125 µg / ml of CB-MeOH / NH4. Comparative analyses between the two types of quercetin showed that, although for the two bacteria tested the two compounds showed inhibitory activity on swarming motility, quercetin-3-ß-D-glycoside was less efficient than non-glycosylated quercetin in the concentration of 125 µg / ml. Biofilm formation was not influenced by the extracts and unexpectedly, both types of quercetin evaluated did not show inhibition towards biofilm formation. In general, organic onion extracts showed little effect on quorum sensing controlled phenotypes and glycosylation of quercetin probably explains the low antimicrobial and anti-QS activity of the extracts

The effect of quercetin on cerulein-induced acute pancreatitis / Efeito da quercetina sobre a pancreatite induzida por ceruleína

OBJECTIVE: The aim of this study was to evaluate the protective and therapeutic effects of quercetin on pancreatic injury in cerulein-induced acute pancreatitis. METHOD: Thirty-two rats were randomly divided into four groups, eight per group: (CT): untreated controls, (CER) treated with cerulein, 50 µg/kg body weight; (Q+CER) pre-treatment with quercetin, 100 mg/kg body weight, followed by cerulein, 50 µg/kg; (CER+Q) post-treatment, cerulein followed by quercetin, same doses. Cerulein was divided into four doses, given at 1-hour intervals by intraperitoneal injection. Quercetin was given either 1-hour before (in pre-treatment group) or 1-hour after (in post-treatment group) cerulein. Pancreatic malondialdehyde (MDA), carbonyl, myeloperoxidase (MPO), tumor necrosis factor-alpha (TNF-a), interleukin-6 (IL-6), reduced and oxidized glutathione (GSH and GSSG, respectively) were measured. Histology of the pancreas was studied. RESULTS: (1) MDA, carbonyl, MPO, TNF-a and IL-6 levels were significantly higher in CER vs CT rats. (2) MDA, carbonyl, MPO and TNF-α decreased significantly in pre-treated rats vs. CER. (3) MDA, MPO, TNF-α, IL-6 were significantly lower in post-treated rats vs. CER. (4) The reduced vs. oxidized glutathione ratio (GSH/GSSG) of was significantly lower CER vs. CT rats. (5) Pre- and post-treatment with quercetin significantly increased this ratio. (6) Pancreatic histology showed that quercetin had no significant effect on the histological image of the pâncreas CONCLUSION: These results suggest that quercetin can attenuate the severity of cerulein-induced acute pancreatitis by acting as an antioxidant and anti-inflammatory agent and combating oxidative stress. Further studies are needed to clearly explain its utility on acute pancreatitis.

OBJETIVO: O objetivo deste estudo foi avaliar os efeitos protetores e terapêuticos da quercetina na lesão pancreática da pancreatite aguda induzida por ceruleína. MÉTODO: Trinta e dois ratos foram divididos aleatoriamente em quatro grupos, oito por grupo: (CT): controles não tratados (CER) tratados com ceruleína, 50 µg/kg de peso corporal; (Q+CER) pré-tratamento com quercetina, 100 mg / kg de peso corporal, seguido de ceruleína, 50 µg/kg; (CER+Q) pós-tratamento, ceruleína seguida de quercetina, mesmas doses. A ceruleína foi dividida em quatro doses, administradas a intervalos de 1 hora por injeção intraperitoneal. A quercetina foi administrada 1 hora antes (no grupo de pré-tratamento) ou 1 hora após (no pós-tratamento) a administração de ceruleína. Foram medidos o malondialdeído pancreático (MDA), carbonilo, mieloperoxidase (MPO), fator de necrose tumoral alfa (TNF-a), interleucina-6 (IL-6), glutationa reduzida e oxidada (GSH e GSSG, respetivamente). Foi estudada a histologia do pâncreas. RESULTADOS: Os níveis de MDA, carbonila, MPO, TNF-a e IL-6 foram significativamente maiores nos ratos CER vs. CT. MDA, carbonila, MPO e TNF-α diminuíram significativamente em ratos pré-tratados versus CER. MDA, MPO, TNF-α, IL-6 também foram significativamente menores em ratos pós-tratados versus CER. A proporção reduzida de glutationa oxidada (GSH/GSSG) foi significativamente menor ratos CER vs. CT; pré e pós-tratamento com quercetina aumentaram significativamente esta proporção. A histologia pancreática mostrou que a quercetina não teve efeito morfológico significativo. CONCLUSÃO: Estes resultados sugerem que a quercetina pode atenuar a gravidade da pancreatite aguda induzida por ceruleína, atuando como agente antioxidante e anti-inflamatório e combater o estresse oxidativo. Mais estudos são necessários para explicar claramente suas utilidades na pancreatite aguda.

In silico pharmacodynamics, toxicity profile and biological activities of the Saharan medicinal plant Limoniastrum feei

ABSTRACT In-silico study was performed to find the pharmacodynamics, toxicity profiles and biological activities of three phytochemicals isolated from Limoniastrum feei (Plumbagenaceae). Online pharmacokinetic tools were used to estimate the potential of Quercetin, kaempferol-3-O-ß-D-glucopyranoside (astragalin) and quercitin-7-O-ß-D-glucopyranoside as specific drugs. Then the prediction of potential targets of these compounds were investigated using PharmMapper. Auto-Dock 4.0 software was used to investigate the different interactions of these compounds with the targets predicted earlier. The permeability of quercetin was found within the range stated by Lipinski ׳s rule of five. Hematopoietic prostaglandin (PG) D synthase (HPGDS), farnesyl diphosphate synthetase (FPPS) and the deoxycytidine kinase (DCK) were potential targets for quercetin, astragalin and quercetin 7, respectively. Quercetin showed antiallergic and anti-inflammatory activity, while astragalin and quercetin 7 were predicted to have anticancer activities. The activity of Astragalin appeared to be mediated by FPPS inhibition. The inhibition of DCK was predicted as the anticancer mechanisms of quercetin 7. The compounds showed interesting interactions and satisfactory binding energies when docked into their targets. These compounds are proposed to have activities against a variety of human aliments such as allergy, tumors, muscular dystrophy, and diabetic cataracts.

High resveratrol or quercetin concentrations reduce the oscillation index of frozen goat semen / Altas concentrações de resveratrol ou quercetina reduzem o índice de oscilação do sêmen congelado caprino

The aim of this study was to evaluate the effect of different concentrations of trans-resveratrol or quercetin on the ability of goat sperm to withstand being frozen. Six pools of semen obtained from six male goats were processed with different concentrations of resveratrol or quercetin (Experiment 1: 0, 15, 25, 50, 75 or 100µM resveratrol; Experiment 2: 0, 15, 25, 50, 75 or 100µM quercetin) and frozen. After thawing, the semen was evaluated for sperm kinematics, plasma membrane and acrosome integrity, morphology and oxidative stress following 0 and 1h of incubation. Immediately after thawing (0h), wobble (oscillation index) in the groups treated with 100µM of quercetin or resveratrol was lower (P<0.05) than in those treated with 0 and 25µM resveratrol and 0µM quercetin, respectively. After 1h of incubation, the total motility in treatments with 15, 50 and 75µM quercetin, as well as the plasma membrane integrity in all quercetin concentrations were lower (P<0.05) than at 0h. In opposition, the linearity of semen samples treated with 100µM quercetin and the straightness of those treated with 75 and 100µM quercetin were lower (P<0.05) at 0h than at 1h after thawing. Thus, it can be concluded that resveratrol and quercetin at high concentrations (100µM) transiently reduce the wobble of goat sperm submitted to frozen storage, and that quercetin (75 and 100µM) increases the linearity and straightness over time, which can be favorable for fertility.(AU)

O objetivo deste estudo foi avaliar o efeito de diferentes concentrações de transresveratrol ou quercetina sobre a capacidade dos espermatozoides caprinos de resistirem à congelação. Seis pools de sêmen, obtidos de seis reprodutores caprinos, foram processados com diferentes concentrações de resveratrol ou quercetina (Experimento 1: 0, 15, 25, 50, 75 ou 100µM de resveratrol; Experimento 2: 0, 15, 25, 50, 75 ou 100µM de quercetina) e congelados. Após o descongelamento, o sêmen foi avaliado quanto à cinética espermática, à integridade das membranas plasmática e acrossomal, à morfologia e ao estresse oxidativo nos tempos zero e uma hora de incubação. Imediatamente após a descongelação (zero hora), o wobble (índice de oscilação) nos grupos tratados com 100µM de quercetina ou de resveratrol foi menor (P<0,05) do que nos tratados com 0 e 25µM de resveratrol e com 0µM de quercetina, respectivamente. Após uma hora de incubação, a motilidade total dos tratamentos com 15, 50 e 75µM de quercetina, assim como a integridade de membrana plasmática em todas as concentrações de quercetina, foi menor (P<0,05) do que à zero hora. Em oposição, a linearidade das amostras de sêmen tratadas com 100µM de quercetina e a retilinearidade daquelas tratadas com 75µM e 100µM de quercetina foram menores (P<0,05) à zero hora do que à uma hora após descongelação. Assim, pode-se concluir que o resveratrol e a quercetina, em concentrações elevadas (100µM), reduzem, transitoriamente, o índice de oscilação de espermatozoides caprinos submetidos à congelação e que a quercetina (75 e 100µM) aumenta a linearidade e a retilinearidade ao longo do tempo, o que pode ser favorável à fertilidade.(AU)

Relaxant effects of a hydroalcoholic extract of Ruta graveolens on isolated rat tracheal rings

BACKGROUND: Ruta graveolens L. (R. graveolens) is a medicinal plant employed in non-traditional medicines that has various therapeutic properties, including anthelmintic, and vasodilatory actions, among others. We evaluated the trachea-relaxant effects of hydroalcoholic extract of R. graveolens against potassium chloride (KCl)- and carbachol-induced contraction of rat tracheal rings in an isolated organ bath. RESULTS: The results showed that the airway smooth muscle contraction induced by the depolarizing agent (KCl) and cholinergic agonist (carbachol) was markedly reduced by R. graveolens in a concentration-dependent manner, with maximum values of 109 ± 7.9 % and 118 ± 2.6 %, respectively (changes in tension expressed as positive percentages of change in proportion to maximum contraction), at the concentration of 45 µg/mL (half-maximal inhibitory concentration IC50: 35.5 µg/mL and 27.8 µg/mL for KCl- and carbachol-induced contraction, respectively). Additionally, the presence of R. graveolens produced rightward parallel displacement of carbachol dose-response curves and reduced over 35 % of the maximum smooth muscle contraction. CONCLUSIONS: The hydroalcoholic extract of R. graveolens exhibited relaxant activity on rat tracheal rings. The results suggest that the trachea-relaxant effect is mediated by a non-competitive antagonistic mechanism. More detailed studies are needed to identify the target of the inhibition, and to determine more precisely the pharmacological mechanisms involved in the observed biological effects.

Quercetin: a flavonoid with the potential to treat asthma

Allergic asthma is a complex inflammatory disorder characterized by airway hyperresponsiveness, eosinophilic inflammation and hypersecretion of mucus. Current therapies include β2-agonists, cysteinyl leukotriene receptor 1 antagonists and corticosteroids. Although these drugs demonstrate beneficial effects, their adverse side effects limit their long-term use. Thus, the development of new compounds with similar therapeutic activities and reduced side effects is both desirable and necessary. Natural compounds are used in some current therapies, as plant-derived metabolites can relieve disease symptoms in the same manner as allopathic medicines. Quercetin is a flavonoid that is naturally found in many fruits and vegetables and has been shown to exert multiple biological effects in experimental models, including the reduction of major symptoms of asthma: bronchial hyperactivity, mucus production and airway inflammation. In this review, we discuss results from the literature that illustrate the potential of quercetin to treat asthma and its exacerbations.

A asma alérgica é uma doença inflamatória complexa caracterizada por hiperresponsividade das vias aéreas, inflamação eosinofílica e hipersecreção de muco. As terapias atuais incluem β2-agonistas, antagonistas do receptor 1 de cisteinil leucotrienos e corticosteróides. Embora estes fármacos demonstrem efeitos benéficos, seus efeitos adversos limitam seus usos a longo prazo. Assim, o desenvolvimento de novos compostos com atividades terapêuticas similares e reduzido efeitos adversos é tanto desejável quanto necessário. Compostos naturais podem ser utilizados nas terapias atuais, uma vez que metabólitos derivados de plantas são capazes de aliviar os sintomas de forma comparável aos medicamentos alopáticos. A quercetina é um flavonóide que ocorre naturalmente em muitas frutas e vegetais e tem mostrado vários efeitos biológicos, principalmente em modelos experimentais, incluindo a redução dos principais fenótipos da asma: hiperreatividade brônquica, produção de muco e inflamação das vias aéreas. Nesta revisão, nós discutimos os resultados da literatura que revelam o potencial da quercetina para tratar a asma e suas exacerbações.

BEAUVERIA BASSIANA: quercetinase production and genetic diversity

Beauveria bassiana genetic diversity and ability to synthesize quercetin 2,3-dioxygenase (quercetinase) were analyzed. B. bassiana isolates, obtained from Brazilian soil samples, produced quercetinase after induction using 0.5 g/L quercetin. B. bassiana ATCC 7159 (29.6 nmol/mL/min) and isolate IP 11 (27.5 nmol/ml/min) showed the best performances and IP 3a (9.5 nmol/mL/min) presented the lowest level of quercetinase activity in the culture supernatant. A high level of polymorphism was detected by random amplified polymorphic DNA (RAPD) analysis. The use of internal-transcribed-spacer ribosomal region restriction fragment length polymorphism (ITS-RFLP) did not reveal characteristic markers to differentiate isolates. However, the ITS1-5.8S-ITS2 region sequence analysis provided more information on polymorphism among the isolates, allowing them to be clustered by relative similarity into three large groups. Correlation was tested according to the Person's correlation. Data of our studies showed, that lower associations among groups, level of quercetinase production, or geographical origin could be observed. This study presents the production of a novel biocatalyst by B. bassiana and suggests the possible industrial application of this fungal species in large-scale biotechnological manufacture of quercetinase.

Toxicity mechanisms of onion (Allium cepa) extracts and compounds in multidrug resistant erythroleukemic cell line

Onion (Allium cepa) is being studied as a potential anticancer agent, but little is known regarding its effect in multidrug resistance (MDR) cells. In this work, the cytotoxicity of crude onion extract (OE) and fractioned extract (aqueous, methanolic and ethyl acetate), as well as some onion compounds (quercetin and propyl disulfide) were evaluated in Lucena MDR human erythroleukemic and its K562 parental cell line. The capacity of OE to induce apoptosis and/or necrosis in these cells, the possible participation of oxidative stress and DNA damage were also assessed. Similar sensitivities were obtained for both tumoral cells, however only OE caused significant effects in the cells. In K562 cells, a significant increase of apoptosis was verified while the Lucena cells experienced a significant increase of necrosis. An antioxidant capacity was verified for OE discarding oxidative damage. However, OE provoked similar significant DNA damage in both cell lines. Thus, the OE capacity to overcome the MDR phenotype suggests anti-MDR action of OE.

Efficiency of propolis extract against mitochondrial stress induced by antineoplasic agents (doxorubicin and vinblastin) in rats.

To assess the oxidative stress and mitochondrial dysfunction associated with disease, toxic process and aging, in vivo and in vitro preventive effect of propolis extract against mitochondrial oxidative stress induced by two anticancer drugs (doxorubicin and vinblastin) have been investigated in female wistar rat using liver and heart mitochondria. The results show that doxorubicin and vinblastin altered mitochondrial functions as observed by a decrease in respiratory control value, an activation of swelling and overproduction of superoxide anion. Myocardial tissue from doxorubicin treated rats showed a marked increase in malondialdehyde production, a depletion of reduced glutathione contents and an inhibition of catalase and superoxide dismutase activities. Similar results were also observed in liver tissue. Pretreatment of rats with propolis extract (100 mg/kg/day po) (10(-4) M ip) administered 4 days prior to doxorubicin (20 mg/kg) and/or vinblastin (2 mg/kg) injection, substantially reduced the peroxidative damage in myocardium and hepatic tissues and markedly restored the tissues catalase and SOD activities. The results strongly suggest that propolis extract protects heart and liver tissues from oxidative stress by protecting the mitochondria.

Quantitative estimation of betasitosterol, lupeol, quercetin and quercetin glycosides from leaflets of Soymida febrifuga using HPTLC technique

Soymida febrifuga [Meliaceae] dried leaflets [10 gm] were extracted with petroleum ether. Unsaponifiable matter quantitatively used for sample preparation, labeled as SF-U. Another 10 gm leaflet powder was extracted with methanol and quantitatively used for sample preparation labeled as SF-A. Sample and standard solution were dosage on three different plates and developed in its respective mobile phase plates were scanned using TLC scanner III and estimated using integration software CATs 4.05. Calculations for percentage were done considering standard and sample Rf, AUC and dilution factor. Estimation of b Sitosterol, Lupeol, Quercetin, Quercetin-3-O-galactoside, Quercetin-3-O-xyloside and Quercetin-3-O-rutinoside were determined as 0.02146% w/w, 0.0377% w/w, 0.4079% w/w, 0.6197% w/w, 2.974% w/w and 3.235% w/w respectively with the help of HPLC techniques

Validación de 2 métodos espectrofotométricos para la cuantificación de taninos y flavonoides (quercetina) en Psidium guajaba, L / Validation of two spectrophometric methods for quantification of tannins and flavonoids (quercetin) in Psidium guajaba L

Se realizó la validación de 2 métodos espectrofotométricos que posibilitan cuantificar taninos y flavonoides en la droga cruda de Psidium guajaba, L., pues la literatura no cuenta con métodos oficiales que permitan cuantificar dichos compuestos en esta planta. Se determinó que ambos métodos (método del tungsto-molíbdico-fosfórico para taninos descrito por Miranda M y el método espectrofotométrico para flavonoides totales expresados como quercetina, de Kostennikova Z y modificado por Méndez G) cumplían con todos los requisitos de validación propuestos para el control químico de calidad de la especie (linealidad, precisión [repetibilidad y reproducibilidad], exactitud y especificidad)