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Tavares L.,New University of Lisbon | Fortalezas S.,New University of Lisbon | Tyagi M.,New University of Lisbon | Barata D.,New University of Lisbon | And 12 more authors.
Pharmaceutical Biology | Year: 2012

Context: Natural products are reported to have substantial neuroprotective activity due to their radical scavenging capacity, and also acetylcholinesterase (AChE) inhibitory capacity, both activities important in neurodegeneration. Objective: The undesirable side effects of compounds in pharmacological use make it important to identify natural neuroprotective molecules. This work assesses the potential of five endemic Portuguese plants as sources of neuroprotective compounds. Materials and methods: Antioxidant capacity for peroxyl radical was determined by Oxygen Radical Absorbance Capacity method and for hydroxyl by Electron Paramagnetic Resonance, as well as AChE inhibitory capacity of the plant hydroethanolic extracts. The molecules responsible for these valuable properties were also tentatively identified by HPLC. Results and discussion: Armeria rouyana and Thymus capitellatus presented some of the highest phenolic contents (76.60±7.19 and 12.82±0.24mg GAE g -1 dw, respectively) and antioxidant capacities (592±116 and 449±57 μmol TE g -1 dw, respectively). The flavonoids were identified as the phytomolecules related to the antioxidant capacity of these plant extracts; in the case of A. rouyana, l-ascorbic acid also made an important contribution (3.27±0.26mg g -1 dw). Plant extracts clearly demonstrated effective AChE inhibitory activity (480±98 and 490±46 μg mL -1, respectively), that could be associated to polyphenols. Conclusions: The extracts of A. rouyana and T. capitellatus and their active components, especially polyphenols, demonstrate interesting neuroprotective potential. They, therefore, deserve further study as their phytomolecules are promising sources of either natural neuroprotective products and/or novel lead compounds. © 2012 Informa Healthcare USA, Inc. Source


Matias A.A.,Institute Biologia Experimental e Tecnolgica | Serra A.T.,New University of Lisbon | Silva A.C.,New University of Lisbon | Perdigao R.,New University of Lisbon | And 10 more authors.
International Journal of Food Sciences and Nutrition | Year: 2010

To date there are no licensed systemic or topical treatments in Europe or the USA for adenovirus infections. In the present paper, we evaluate the effect of a polyphenol-based grape extract (NE) obtained from Portuguese white-winemaking by-products, and Resveratrol in pure form, on adenovirus type 5 infection. For this purpose, recombinant adenovirus vectors (Ad-5) and a human-derived cell line (293) were used as models. The NE and Resveratrol at the used concentrations do not induce cell cytotoxicity or direct virucidal activity; however, they reduce 4.5 and 6.5 log (TCID50/ml) on total infectious Ad-5 production, respectively. The capacity of Ad-5 replication upon removal of NE and Resveratrol after 24 h post infection was also evaluated. In contrast to Resveratrol, the highest evaluated NE concentration inhibits irreversibly the Ad-5 replication. These results provide useful information for the use of NE and Resveratrol as potential sources of promising natural antiviral agents on Ad-5 infection. © 2010 Informa UK Ltd. Source


Roldao A.,New University of Lisbon | Roldao A.,Institute Biologia Experimental e Tecnolgica | Mellado M.C.M.,Institute Biologia Experimental e Tecnolgica | Mellado M.C.M.,Federal University of Rio de Janeiro | And 5 more authors.
Expert Review of Vaccines | Year: 2010

Virus-like particles (VLPs) are multiprotein structures that mimic the organization and conformation of authentic native viruses but lack the viral genome, potentially yielding safer and cheaper vaccine candidates. A handful of prophylactic VLP-based vaccines is currently commercialized worldwide: GlaxoSmithKlines Engerix® (hepatitis B virus) and Cervarix ® (human papillomavirus), and Merck and Co., Inc.s Recombivax HB® (hepatitis B virus) and Gardasil® (human papillomavirus) are some examples. Other VLP-based vaccine candidates are in clinical trials or undergoing preclinical evaluation, such as, influenza virus, parvovirus, Norwalk and various chimeric VLPs. Many others are still restricted to small-scale fundamental research, despite their success in preclinical tests. This article focuses on the essential role of VLP technology in new-generation vaccines against prevalent and emergent diseases. The implications of large-scale VLP production are discussed in the context of process control, monitorization and optimization. The main up- and down-stream technical challenges are identified and discussed accordingly. Successful VLP-based vaccine blockbusters are briefly presented concomitantly with the latest results from clinical trials and the recent developments in chimeric VLP-based technology for either therapeutic or prophylactic vaccination. © 2010 Expert Reviews Ltd. Source

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