Antioxidant activity of decoction, infusion and hydroalcoholic extract of cultivated thyme (Thymus vulgaris l.)

Thymus vulgaris L. (commonly known as thyme) is a perennial subshrub, widely cultivated around the world and belonging to the Lamiaceae (lipped) family. The use of thyme, for various purposes, is a very old tradition and remains until now. In ancient times, it was used both for medicinal purposes and for cooking or magical properties [1,2]. Therefore, in face of the historical descriptions, it is conceived that the use of this plant have multiple health benefits, at different levels, and that many of the responsible components for those effects have not yet been discovered. Much more research is still need in order to prove all the potential effects of this plant. In the present work, flowering aerial parts (leaves and flowers, separated of branches), previously dried supplied for Soria Natural (Garray - Soria, Spain), were prepared (decoction, infusion and hydroalcoholic extract) and submitted to evaluation and comparison of the antioxidant properties. Four different in vitro assays were performed: scavenging effects on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals, reducing power (measured by ferricyanide Prussian blue assay), inhibition of β-carotene bleaching and inhibition of lipid peroxidation in brain cell homogenates by TBARS (thiobarbituric acid reactive substances) assay. In general, all the preparations revealed antioxidant potential measured by the different assays. Decoction preparation showed higher potential in DPPH and reducing power assays (EC50 values 112.3 and 100.7 µg/mL, respectively), while infusion revealed higher potential in TBARS assays (7.1 µg/mL). Concerning the hydroalcoholic extract, the results were only higher in β-carotene bleaching test (31.5 µg/mL). According to the obtained results, it is possible to conclude that the use of infusions and decoctions of thyme, as complementary of daily food, could provide considerable benefits for health, not only in the treatment of related diseases to reactive species production and oxidative stress, but also prevention of aging and cellular damage [3]. These benefits conferred by thyme can be achieved by both internal and external use. Other studies confirm the high antioxidant activity of thyme samples from Croatia and Egypt [4,5] and that its use, at the recommended doses, is safe and no adverse reactions have been described. Nevertheless, further experiments are required in order to explore the mechanisms of action involved.Instituto Politécnico de BragançaCentro de Investigação de Montanha (CIMO) - Escola Superior Agrári

Biodegradation of textile azo dyes by Phanerochaete chrysosporium

Instituto de Biotecnologia e Química Fina / Universidade do Minho (IBQF/UM) - Praxis XXI, Praxis XXI 2/2.1/QUI/44/94, Praxis XXI/BD/9120/96

Antimicrobial potential of Eucalyptus globulus against biofilms of Staphylococcus aureus isolated from bovine mastitis

Staphylococcus aureus are among the most common species isolated from bovine mastitis. The pathogenesis of this bacterium is facilitated by a number of virulence factors, including the ability to adhere to abiotic surfaces and/or host tissues often leading to biofilms formation. From the clinical perspective, the most important feature of Staphylococcus species biofilms is their high tolerance to the conventional antimicrobial therapy. So, the increasing number of bovine mastitis and the higher levels of Staphylococcus species resistance to traditional antimicrobial agents are considered an important alert for the necessity to focus the future research on identification and development of new strategies to combat S. aureus mastitis. Recently, the interest in natural alternatives based on plant extracts has been rising. In addition to their health benefits, their antimicrobial potential has been increasingly reported. Taking this into consideration, the evaluation of hydromethanolic extracts of E. globulus against S. aureus biofilms was tested and compared with penicillin, one of the antibiotics most often used in the treatment of cattle infections. All mastitis isolates tested were good-biofilm producers. As expected penicillin has demonstrated poor activity against S. aureus biofilms (<1 log reduction). However, E. globulus Labill was bactericidal, promoting a biofilm cell reduction of 2-3 log. Therefore, the present work showed the potential antimicrobial activity of E. globulus against S. aureus from bovine mastitis, namely in biofilm mode of growth and drew attention to its promising use as an alternative to penicillin

Biodegradation of bioaccessible textile azo dyes by Phanerochaete chrysosporium

Azo dyes are important chemical pollutants of industrial origin. Textile azo dyes with bioaccessible groups for lignin degrading fungi, such as 2-methoxyphenol (guaiacol) and 2,6-dimethoxyphenol (syringol), were synthesised using different aminobenzoic and aminosulphonic acids as diazo components. The inocula of the best biodegradation assays were obtained from a pre-growth medium (PAM), containing one of the synthesised dyes. The results of the dye biodegradation assays were evaluated every 7 days, by the decrease of the absorbance at the maximum wavelength of the dye, by the decrease of the sucrose concentration in the culture medium and by the increase of the biomass during the 28 days of assay. It was observed that the extent of dye biodegradation depended on the sucrose concentration, on the degraded dye structure and, on the dye present in the PAM medium.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI/BD/15878/98, PRAXIS XXI/BD/9120/96.Instituto de Biotecnologia e Química Fina (IBQF)

Estudos de biodegradabilidade de corantes azo de aplicação têxtil por Phanerochaete chrysosporium

Sintetizaram-se corantes azo de aplicação têxtil, usando como componentes diazo ácidos aminobenzóicos e aminossulfónicos e como componentes de acoplamento 2- metoxifenol e 2,6-dimetoxifenol. A utilização destas componentes de acoplamento teve como objectivo aumentar a bioacessibilidade dos corantes ao fungo lenhinolítico da podridão branca Phanerochaete chrysosporium, já que estes grupos estão presentes na estrutura da lenhina e têm sido referidos como pontos de acesso para o sistema enzimático lenhinolítico do fungo. As experiências de biodegradação realizaram-se em meio líquido, com sacarose e em condições limitantes de azoto, com agitação e temperatura controladas. A biodegradação dos corantes foi acompanhada por espectrofotometria UV-Visível, quantificando a diminuição da intensidade da banda de absorção máxima (λmax) do corante. Em estudos preliminares estabeleceram-se condições experimentais optimizadas relativamente ao meio de préadaptação e à concentração de sacarose utilizada. Estabeleceram-se algumas correlações entre a estrutura química dos corantes e a sua biodegradação.Praxis XX

Bioactivity of phenolic acids: Metabolites versus parent compounds: A review

Phenolic acids are present in our diet in different foods. In particular, mushrooms are a good source of these molecules. Due to their bioactive properties, phenolic acids are extensively studied and there is evidence of their role in disease prevention. Nevertheless, in vivo, these compounds are metabolized and circulate in the organism as glucuronated, sulfated and methylated metabolites, displaying higher or lower bioactivity. To clarify the importance of the metabolism of phenolic acids, the knowledge about the bioactivity of the metabolites is extremely important. In this review, chemical features, biosynthesis and bioavailability of phenolic acids are discussed as well as the chemical and enzymatic synthesis of their metabolites. Finally, the metabolites bioactive properties are compared with that of the corresponding parental compounds.The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) and FEDER-COMPETE/QREN/EU for the financial support through the research centres (PEst-C/QUI/UI0686/2011 and PEst-OE/AGR/UI0690/2011). S.A. Heleno (BD/70304/2010) also thanks FCT, POPH-QREN and FSE for her grant

Bioactivity and phenolic characterization of different medicinal and aromatic plants

Introduction: Plants are widely used to treat various diseases and have been widely recognized as a rich source of phytochemicals with antimicrobial potential. In fact, plants have received considerable attention by researchers being their biological properties widely explored. Hypothesis and aims: Medicinal and aromatic plants are known to have a wide range of uses and health benefits, and should be exploited concerning their bioactivity. Therefore, the antimicrobial activity of Satureja montana L., Origanum majorana L., Allium schoenoprasum L. and Anethum graveolens L. were evaluated and its phytochemical composition was profiled. Methodology: The antimicrobial susceptibility of Gram-positive and Gram-negative bacteria to four decoction and hydroethanolic (80:20, v/v) extracts, obtained from medicinal and aromatic plants (S. montana , O. majorana , A. schoenoprasum and A. graveolens ), was assessed aiming to identify the active extracts and the most effective were then tested against biofilms. Furthermore, the decoctions were characterized in terms of phenolic compounds by HPLC-DAD-ESI/MSn. Results: Overall, S. montana and O. majorana extracts were the most effective against Gram-positive (Staphylococcus aureus , Enterococcus faecalis and Streptococcus dysgalactiae ) and Gram-negative (Klebsiella pneumonia and Pseudomonas aeruginosa ) bacteria, with decoction presenting the most pronounced effects. O. majorana and S. montana decoction, at minimum inhibitory concentrations, were significantly effective against planktonic cells of S. aureus ATCC 25923. Concerning biofilm cells, S. montana promoted a slight antimicrobial activity against S. aureus ATCC 25923. A total of twentyfour phenolic compounds (9 phenolic acids and 15 flavonoids glycosides) were identified in S. montana and O. majorana decoctions, being rosmarinic acid the main molecule in the extracts. Conclusion: This study confirmed the bioactive potential of the medicinal and aromatic herbs, being S. montana and O. majorana decoction extracts those that showed the most promising applicability for the development of novel formulations with antimicrobial properties.info:eu-repo/semantics/publishedVersio

In vitro study of the antifungal potential of Glycyrrhiza glabra L. against Candida species

In the last two decades, an increasing incidence of opportunistic fungal infections has been observed, not only at hospital level but also in the community. Candida albicans was identified as the main responsible agent for those infections, but other non-Candida albicans Candida (NCAC) species have also been associated with this complicated medical condition [1]. Furthermore, higher rates of fungal resistance to the current drugs have been observed and are still growing, making the discovery of new active antifungal substances very urgent. Medicinal plants can be explored for that purpose. Glycyrrhiza glabra L. is commonly used in folk medicine due to its antimicrobial and antiviral activities, as well as for a wide variety of dermal affections [2]. Some reports have described the antimicrobial potential of licorice (G. glabra roots), namely aqueous extracts [e.g., 3]. Herein, the antifungal potential of the hydroalcoholic extract prepared from rhizomes and roots of G. glabra, was evaluated against 19 Candida strains, using the disc diffusion halo assay. The licorice extract was effective against all the tested C. albicans, C. glabrata, C. parapsilosis and C. tropicalis strains. It is very interesting to highlight the broad spectrum of activity of this extract, for which were observed similar results into different strains of the same species and even between different species. The results for the inhibitory zones, at the tested concentration (50 mg/mL), after 24h, were 1.0-1.2 cm for C. albicans and C. parapsilosis, 1.0-1.3 cm for C. tropicalis and 1.2 cm for C. glabrata, maintaining the potential at 48h and even at 72h. This study demonstrates that G. glabra hydroalcoholic extract probably exerts mainly fungicidal and not so much fungistatic effects, and it could find applications in antifungal therapy. Nevertheless, further studies will be performed in order to characterize the extract, namely on phenolic composition, and to elucidate its mechanism of action

Glycyrrhiza glabra L. as a promisor candidacidal in biofilms and planktonic cells: comparison between phenolic extract and isolated compounds

Opportunistic fungal infections, particularly involving Candida species (candidiasis) have become a serious prob- lem of public health. Current antifungal agents have been loosing the effectiveness, in part due to their overuse, and appearance of resistant Candida species. Plants have been used over years and recommended by natural physicians for multitude of health conditions. The aim of the present study was to evaluate the anti-Candida potential of a hydrometh- anolic extract of rhizomes and roots of Glycyrrhiza glabra L. (licorice), in planktonic cells and biofilms, as well as to compare its effect with individual phenolic compounds identified in the extract. Licorice extract evidenced an antifungal activity against all of the nineteen tested Candida strains, including C. al- bicans, C. glabrata, C. parapsilosis and C. tropicalis species. The inhibition zones varied between 10-13 mm; MIC and MFC values varied, between 0.375-1.5 and 0.75-3 mg/mL for planktonic cells and biofilms, respectively. Considering the pronounced antifungal activity, a chemical characterization of the extract was conducted, and the main phenolic compounds identified were tested. Flavones (mainly apigenin derivatives), flavanones (mainly liquiritin derivatives), an isoflavone and a chalcone, were the most abundant compounds. However, these compounds were not active neither individually nor combined. Thus, probably synergistic effects among all components in the phenolic pool and/or other compounds present in the extract should be responsible for the observed antifungal activity. Detailed in vivo studies should be performed, not only to evaluate the actual effects in a complete organism, but also the safety of the preparation and bioavailability in systemic infection models

Synergisms in antioxidant and anti-hepatocellular carcinoma activities of artichoke, milk thistle and borututu syrups

Artichoke, borututu and milk thistle are three medicinal plants well-known for their capacity to prevent oxidative stress and many liver diseases. In a previous work, we reported the bioactivity of infusions and pills based on these plants; herein, the aim was to provide scientific information about the antioxidant and anti-hepatocellular carcinoma activities of syrups based on these medicinal plants and evaluate the synergism among the combined plants by using syrups based on the mixed plants or prepared form the combinations of individual species. The antioxidant activity was measured by radical scavenging activity, reducing power and lipid peroxidation inhibition, while the anti-hepatocellular carcinoma activity and the hepatotoxicity were evaluated using HepG2 human cell line and a primary culture of porcine liver cells, respectively. Milk thistle syrup proved to have the highest antioxidant activity in all the assayed methods, providing the best results either in single syrup or included in mixed syrups. Synergistic effects were the main interactions observed in the mixture of artichoke, borututu and milk thistle; mixing the syrups based on each single plant proved to be more efficient regarding antioxidant proposals than mixing plants in the same syrup. The latter was advantageous for anti-hepatocellular carcinoma activity.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to the research center CIMO (PEst-OE/AGR/UI0690/2011) and L. Barros researcher contract under "Programa Compromisso com Ciencia-2008