6 resultados para Anti-bacterial activity

em Repositório Científico da Universidade de Évora - Portugal


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Chemotherapy is a major cancer treatment option. The synthesis of new compounds with anti-proliferative properties and specificity is a current challenge in drug-discovery today. Our goal was to develop compounds, either hydroxyamides derived from D-glucuronic acid or triazole-cinchone hybrids, and to evaluate their anti-proliferative properties. Anti-proliferative activity of the newly synthesized compounds was examined against human breast adenocarcinoma (MCF-7) and human colon carcinoma (MDST8) cell-lines. Cell growth and viability was analysed by the Cell-Counting Kit-8 method. The 5-fluoroacil was used as a positive control. The compounds were studied between 10-9-10-5M. Fifteen compounds from the hydroxyamide family and two triazole compounds were investigated. Most of the compounds from the hydroxyamide family revealed mild (~20%) to moderate (50%) anti-proliferative effects in both cell-lines, with the exception of Hydroxyamide B1 which did not affect MDST8 proliferation, and hydroxyamide B3 where proliferation of MDST8 was inhibited by 90%. Triazoles (A and B) evoked a strong (~100%) anti-proliferative effect of MDST8 cell-lines. Proliferation of MCF-7 was selectively and effectively (~98%) inhibited by triazole B while triazole A had a mild effect. In conclusion, when compared to hydroxyamides, triazoles evoked a stronger anti-proliferative effect and might be promising anti-tumoral drugs.

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The Columbia root-knot nematode (CRKN), Meloidogyne chitwoodi, is an EPPO A2 type quarantine pest since 1998. This nematode causes severe damage in economically important crops such as potato and tomato, making agricultural products unacceptable for the fresh market and food processing. Commonly used nematicidal synthetic chemicals are often environmentally unsafe. Essential oils (EOs) may constitute safer alternatives against RKN. EOs, isolated from 56 plant samples, were tested against CRKN hatching, in direct contact bioassays. Some of the most successful EOs were fractionated and the hydrocarbon molecules (HM) and oxygen-containing molecules (OCM) fractions tested separately. 24 EOs displayed very strong hatching inhibitions (≥90 %) at 2 µL mL−1 and were further tested at lower concentrations. Dysphaniaambrosioides, Filipendula ulmaria, Ruta graveolens, Satureja montana and Thymbra capitata EOs revealed the lowest EC50 values (<0.15 µL mL−1). The main compounds of these EOs, namely 2-undecanone, ascaridol, carvacrol, isoascaridol, methyl salicylate, p-cymene and/or γ-terpinene, were putatively considered responsible for CRKN hatching inhibition. S. montana and T. capitata OCM fractions showed hatching inhibitions higher than HM fractions. The comparison of EO and corresponding fractions EC50 values suggests interactions between OCM and HM fractions against CRKN hatching. These species EOs showed to be potential environmentally friendly CRKN hatching inhibitors; nonetheless, bioactivity should be considered globally, since its HM and OCM fractions may contribute, diversely, to the full anti-hatching activity.

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No presente trabalho estudaram-se três espécies do género Lavandula, do sul de Portugal: L. luisieri e L. pedunculata (Alentejo) e L.viridis (Algarve), com vista caraterizar a composição química dos óleos essenciais das diferentes espécies, parte vegetativa (folha) e espiga floral, e dos respetivos extratos de hidrodestilação, e avaliar as propriedades antioxidante, antimicrobiana, toxicológica, analgésica e antiinflamatória de alguns dos seus óleos essenciais e extratos aquosos, mais promissores. Os resultados mostraram importantes diferenças na composição química dos óleos essenciais, quanto à diversidade e à proporção dos seus constituintes. Os óleos essenciais e hidrolatos, em estudo, apresentaram importantes propriedades antioxidantes e antimicrobianas. Os estudos toxicológicos e farmacológicos mostraram que os óleos apresentaram citotoxicidade em Artemia salina, apresentaram valores de DL50 muito superiores a 2000 mg/kg em ratinhos Swiss, e que possuem importantes propriedades analgésicas e anti-inflamatória. Estes resultados sugerem o seu potencial uso para aplicações farmacológicas como agentes nutracêuticos e/ou fitoterapêuticos; ABSTRACT:The aim of present work was to develop a set of studies of three species of the genera Lavandula, at the South of Portugal: L. luisieri e L. pedunculata (Alentejo) e L.viridis (Algarve), in order to characterize the chemical composition of the essential oils (leaves and flowers) and to evaluate the antioxidant, antimicrobial, toxicological and pharmacological properties of selected essential oils and aqueous extracts. Results show important differences in chemical composition of essential oils, both in diversity as the proportion of their constituents. Essential oils and aqueous extracts of different Lavandula spp. showed important antimicrobial and antioxidant properties. Pharmacological studies have shown that essential oils showed cytotoxicity against Artemia salina, low acute toxicity, with LD50 >> 2000 mg/kg for mice, and important analgesic and anti-inflammatory properties. These results suggest their potential use for pharmacological applications as nutraceutical and/or phytotherapeutic agents.

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The present study was carried out to evaluate the chemical and pharmacological properties of essential oil (EO) of Lavandula stoechas L. subsp. luisieri that is a spontaneous shrub widespread in Alentejo (Portugal). Oxygenated monoterpenes, as 1,8-cineole, lavandulol and necrodane derivatives are the main components of essential oil. It revealed important antioxidant activity with high ability to inhibit the lipid peroxidation and showed an outstanding effect against a wide spectrum of microorganisms, such as Gram-positive and Gram-negative bacteria and pathogenic yeasts. The analgesic effect studied in rats was dose dependent, reaching a maximum of 67 % at 60 min. with the dose of 200 mg/kg and the anti-inflammatory activity with this dose caused an inhibition in carrageenan-induced rat paw oedema (83 %) that is higher than dexamethasone 1 mg/Kg (69 %). Besides, animals exhibited a normal behaviour after EO administration revealing low toxicity. Essential oil of L. luisieri from Alentejo that presents important pharmacological properties and low toxicity is a promised candidate to be used as food supplement or in pharmaceutical applications.

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The flavonoids (including anthocyanins) are wine compounds with important anti-oxidant activity, protecting the cells against oxidative processes, preventing cardiovascular and neurodegenerative diseases, cancer, among others (Antoniolli et al. 2015; Castañeda-Ovando et al. 2009; Hosu et al. 2014; Huang et al. 2009; Kong et al. 2003). Anthocyanins in grapes at harvest are determinant to red wine quality and their development in the grape must be characterised in order to determine the most suitable date for the harvest. Thus the aim of this research is the evaluation of anthocyanins composition in two red wine grape varieties from véraison continuing through ripening. Anthocyanins were quantified by high resolution liquid chromatography (HPLC-DAD). Additionally, the total phenols content were quantified by UV-Vis Spectrometry. The anthocyanins’ profile evolution may be dependent on the variety and ripening phase. During ripening grape samples have shown an increase of coumaryl derivatives. This information may lead us to understand the anthocyanins biosynthesis pathway in different grape varieties. The development of anthocyanins from the véraison seems to follow a pattern that coincides with the increasing accumulation of soluble sugars.

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As biguanidas são um grupo de compostos com diversas atividades biológicas. Recentemente, esta família de compostos tem sido estudada não só pela sua atividade hipoglicemiante, mas também pela sua atividade anti-proliferativa. Um dos objetivos deste estudo foi a síntese de biguanidas, com cadeias laterais com diferentes estruturas e grupos funcionais. O trabalho desenvolvido permitiu a síntese de diversas biguanidas, tendo sido isolados quatro compostos. Outro dos objetivos deste estudo foi avaliar a atividade anti-proliferativa de biguanidas, na linha celular MDST8. Para esse efeito, foi desenvolvido inicialmente um método de quantificação celular com base na atividade ATPásica, testado nas linhas celulares MDST8, MCF7 e BRIN-BD11, tendo sido utilizado como referência a quantificação pelo método das desidrogenases. Os compostos estudados com melhor atividade anti-proliferativa apresentaram IC50 da ordem de 2,5 – 2,9 x10-3 M. Estes valores foram observados em biguanidas cujos grupos substituintes possuíam cadeias hidrocarbonadas cíclicas, alifáticas ou aromáticas p-substituídas, na sua estrutura; Abstract: Synthesis of biguanides and evaluation of their biologic activity in tumor cell lines Biguanides are a group of compounds which have diverse biological activities. Recently, this family of compounds has been studied not only for its hypoglycemic activity, but also for its anti-proliferative activity. One purpose of this study was the synthesis of biguanides, with side chains with different structures and functional groups. The work led to the synthesis of several biguanides, with the isolation of four compounds. Another objective of this study was the evaluation of the anti-proliferative activity of biguanides, in the cell line MDST8. To this aim, it was initially developed a cell quantification method based on the ATPase activity, tested in MDST8, MCF7 and BRIN-BD11 cell lines, with the dehydrogenases method used as reference. The studied compounds with better anti-proliferative activity had IC50 in the range from 2.5 to 2.9 x10-3 M for biguanides whose substituent groups had cyclic hydrocarbon, aliphatic or p-substituted aromatic chains in their structure.