Antioxidant properties of different dietary supplements based on Agaricus blazei Murrill

In 2012, the market for nutraceuticals earned $90 billion worldwide and it is predicted to reach$33.6 billion in the next four years. Agaricus blazei Murrill mushroom is native to Brazil and widely cultivated due to nutritional and medicinal value [I ,2]. Its beneficial effects have long been recognized, becoming popular as ordinary food, increasing also its production and marketing as dietary supplements (3]. A. blazei is traditionally used to combat a variety of diseases such as cancer, diabetes, hepatitis and hypercholesterolemia [2]. The use of dietary supplements based on A. blazei has grown significantly, due to pharmacological studies reporting antioxidant, antitumor, anti-inflammatory, antimicrobial, immunostimulant, apoptotic and chemopreventive effects [2,3], attributed to ®-glucans and other bioactive compounds, such as steroids, tocopherols and phenolic compounds [4]. Herein, the antioxidant activity of A. blazei capsules enriched with fmits of Malpighia glabra L. (acerola), Solanum melongena L. (eggplant) and Euterpe oleracea Mart. (açai), calcium and chitosan, were evaluated though in vitro assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of G-carotene bleaching and inhibition of lipid peroxidation in brain homogenates by thiobarbituric acid reactive substances (TSARS) assay. Two capsules (daily recommended dose) were dissolved in 100 mL of distilled water in order to prepare a stock solution. Several dilutions were tested until determination of EC50 values (concentration responsible for 50% of antioxidant activity or 0.5 of absorbance in reducing power assay). Globally, all the tested formulations showed high antioxidant activity. A. blazei with acerola gave the highest DPPH scavenging activity (EC50=0.81±0.0 1 mg/mL) and reducing power (EC50=0.53±0.0 1 mg/mL). Nevertheless, A. blazei with ayai showed the highest activity in the lipophilic assays: f3 - carotene bleaching inhibition (EC50=0.55±0.02 mg/mL) and lipid peroxidation inhibition by TSARS assay (EC50=O. 14±0.01 mg/mL). The studied formulations might be useful as antioxidants-enriched supplements to prevent some of the diseases related to oxidative stress

Atividade antimicrobiana do extrato bruto de Açaí (Euterpe oleracea Mart.) em isolados clínicos

O presente trabalho teve como objetivo avaliar a atividade antimicrobiana do extrato de açaí (Euterpe Oleracea Mart.) em isolados clínicos com elevados perfis de resistência a diferentes antimicrobianos provenientes do Centro Hospitalar de Trás – os – Montes e Alto Douro – Unidade de Vila Real. A concentração mínima inibitória (CMI) foi determinada utilizando o ensaio colorimétrico rápido que utiliza o corante cloreto de p-iodonitrotetrazólio (INT) após já ter sido efetuado o método da microdiluição. De acordo com os resultados obtidos, o extrato bruto de açaí possui atividade antimicrobiana para todas as bactérias Gram positivo testadas. A CMI mais baixa (0,25 mg/ml) foi detectada para Staphylococcus aureus sensível à meticilina (MSSA) seguida da CMI 0,5 mg/ml para Staphylococcus aureus resistente à meticilina (MRSA), Streptococcus agalactiae e Enterococcus faecalis. Relativamente às bactérias Gram negativo foi verificada atividade antimicrobiana do açai para Morganella morganii, Pseudomonas aeruginosa e Acinetobacter baumannii com CMI de 1 mg/ml e 2 mg/ml respectivamente. Foram obtidos melhores resultados para bactérias Gram positivo comparativamente com as bactérias Gram negativo. Assim, podemos constatar que mesmo recorrendo a baixas concentrações (2 mg/ml) os resultados são muito promissores mesmo em bactérias Gram negativo com perfis de resistência elevados e relacionadas com as infeções associadas aos cuidados de Saúde (IACS) como a Pseudomonas aeruginosa e Acinetobacter baumannii

Antibacterial activity of Euterpe oieracea Mart. seeds against clinical isolates

Introduction: The use of antibiotics – including the over- and misuse – in human and veterinary practices selected for resistant pathogens led to their emergence and dissemination along with the transmission of resistant bacteria [1]. Due to this problem, there is a need to investigate new strategies to reverse this tendency in order to achieve the appropriate and effective treatment against infections. Aims: The present work aimed to evaluate the antibacterial activity of an aqueous extract prepared from Euterpe Oleracea Mart. (açai) seeds (originated from Brazil [2]), against clinical isolates from “Centro Hospitalar de Trás-os-Montes e Alto Douro- Unidade de Vila Real”, with high resistance profiles to different antibiotics. Material and Methods: The minimal inhibitory concentrations (MIC) of the growth of Gram-positive and Gram-negative bacteria were determined by the colorimetric assay based on the use of p-iodonitrotetrazolium chloride (INT) dye, after application of the microdilution method. Results and discussion: The açaí aqueous extract showed antimicrobial activity against all the tested Gram-positive bacteria. The lowest MICs (0.25 mg/ml) were obtained against Methicillin Susceptible Staphylococcus aureus (MSSA) and Methicillin Resistant S. aureus (MRSA), followed by the MIC 0.5 mg/ml correspondent to Streptococcus agalactiae and Enterococcus faecalis. Regarding the inhibition of the growth of Gram-negative bacteria, the extract was active against Morganella morganii, Pseudomonas aeruginosa and Acinetobacter baumannii with MICs 1 mg/ml e 2 mg/ml, respectively. The results were better for Gram-positive bacteria in comparison with Gram-negative bacteria. Conclusion: However, even at low concentration (2 mg/ml) the results are very promising for Gram-negative bacteria with high resistance profiles and commonly related with health care-associated infections, namely Pseudomonas aeruginosa and Acinetobacter baumannii

The powerful in vitro bioactivity of Euterpe oleracea Mart. seeds and related phenolic compounds

The Euterpe oleracea Mart. (açaí) is a plant from the Amazon region, classified as "super fruit" because of its various functional properties. However, limited investigation has been performed on açaí by-products, such as seeds. Therefore, the aim of this work was to characterized the phenolic compounds of the aqueous extract of açaí seeds and further evaluate its bioactivity (antioxidant and cytotoxic activities. Only proanthocyanidins were detected, being a B-type (epi)catechin tetramer the most abundant; however, procyanidin trimmers were the most predominant form. Açaí seeds extract revealed a high antioxidant (EC50 ranging from 3.6 to 19.4 μg/mL) and cytotoxic activity, being more effective in the cervical carcinoma cell line (HeLa; GI50 = 18 μg/mL); it did not show toxicity for non-tumor cells. Açaí seeds are considered a waste and could have an added economic benefit, through the extraction of natural antioxidants, particularly proanthocyanidins, that could find applications in food and pharmaceutical industries.The authors are grateful to Foundation for Science and Technology (FCT, Portugal) for financial support to the research centre CIMO (strategic project PEst OE/AGR/UI0690/2011) and L. Barros researcher contract under “Programa Compromisso com Ciência - 2008”. The authors are also grateful to Jamil S. Oliveira by the initial discussions on the preparation of samples

Atividade antibacteriana de sementes de açaí (Euterpe oleracea Mart.)

O presente trabalho teve como objetivo avaliar a atividade antibacteriana de um extrato aquoso de sementes de açaí (Euterpe oleracea Mart.), proveniente do Brasil, em isolados clínicos. O extrato revelou atividade antibacteriana em todos os isolados clínicos testados com a exceção de Escherichia coli e de Klebsiella pneumoniae. Os melhores valores de CMIs (concentrações mínimas inibitórias) foram observados para Staphylococcus aureus resistente à meticilina (MRSA) (0,25 mg/mL), Staphylococcus aureus sensível à meticilina (MSSA), Enterococcus faecalis e Streptococcus agalactiae com um valor de 0,5 mg/mL. O extrato testado parece ser uma opção a explorar no combate de bactérias resistentes