Chemical characterization and cytotoxic potential of an ellagitannin-enriched fraction from Fragaria vesca leaves

The hepatocellular carcinoma, a primary malignancy of the liver, has a very poor prognosis and a lower survival rate. Moreover, the inefficacy of conventional therapies emphasizes the importance of discovering new bioactive compounds. Several studies clearly state that plant-derived polyphenols, namely ellagitannins, have several health benefits. Fragaria vesca leaves contain high amounts of polyphenols, being especially rich in ellagitannins. Therefore, this study aimed to characterize an ellagitannin-enriched fraction (EEF) from F. vesca leaves and to unveil the anticancer potential of this fraction on human hepatocellular carcinoma cells. The analysis of EEF by HPLC-PDA-ESI/MSn allowed the detection of 12 ellagitannins. The cell viability of both EEF and crude extract was determined after 24 h of cells treatment and the halfmaximal inhibitory concentration (IC50) was evaluated. The IC50 of the EEF (113 lg/mL) was about 6 times lower than the IC50 of the crude extract (690 lg/mL). Furthermore, EEF induced cell cycle arrest at G2/M checkpoint and decreased cell proliferation in a dose-dependent way. This fraction also induced an accumulation of LC3-II protein through blockage of autophagic flux, and inhibited chymotrypsin-like activity of 26S proteasome. These results showed, for the first time, that EEF from F. vesca leaves inhibits both, autophagic and ubiquitin-proteasome system pathways, two main intracellular protein degradation systems that are targets for anticancer therapies. Additionally, a proteomic analysis allowed the identification of 914 proteins, among which 133 were modulated after cells treatment with EEF, most of them related to metabolic pathways. Overall, this study shows that the EEF from F. vesca leaves decreased cell proliferation, inhibited the proteolytic mechanisms and modulated the metabolic pathways of the cell. Additionally this study points out F. vesca as a source of valuable molecules with anticancer potential, suggesting that ellagitannins, the polyphenols identified in this fraction, could be useful in the development of new fine-tuned therapeutic strategies against carcinogenesis

Portuguese botanical gardens: before and after 2020

info:eu-repo/semantics/publishedVersio

Optimisation of cationic liposome/DNA complexes for transfection of neuronal cells

Tese de doutoramento em Bioquímica (Tecnologia Bioquímica) apresentada à Fac. de Ciências e Tecnologia de CoimbraO transporte e cedência intracelulares de genes e oligonucleotídeos é hoje considerado uma promissora estratégia terapêutica para o tratamento das doenças do sistema nervoso central (SNC), dado que as estratégias convencionais se têm revelado pouco eficazes. A aplicação bem sucedida desta metodologia passa pela concepção de veículos específicos para o transporte do material genético para as células alvo, de modo a que aí se possam verificar níveis adequados de expressão génica. Este projecto visou, fundamentalmente, desenvolver vectores não virais do tipo lipossómico, para um transporte e cedência eficazes de genes em células neuronais em cultura e in vivo. O nosso objectivo consistiu, especificamente, na promoção da internalização celular mediada por receptores dos complexos ternários – lipossoma catiónico/ADN/transferrina (lipoplexos-Tf) – e em garantir uma maior eficácia na cedência intracelular do material genético. Foi ainda nosso objectivo contribuir para o esclarecimento dos mecanismos pelos quais os lipoplexos cedem ADN ao citoplasma, realizando estudos sistemáticos de associação celular. Visando a utilização destes sistemas no tratamento de doenças do SNC, propusemo-nos testar estas estratégias na transfecção de células neuronais, incluindo o transporte de potenciais genes terapêuticos em modelo animal de lesão neuronal. A associação de Tf aos lipoplexos mostrou ser eficaz na potenciação da actividade e eficiência de transfecção das células neuronais, quer in vitro, quer in vivo após administração estereotáxica no estriado de ratos Wistar. A administração in vivo do plasmídeo codificando para o factor de crescimento neuronal (NGF), mediada por lipoplexos-Tf, revelou-se eficaz na diminuição da lesão excitotóxica causada pela injecção intraestriatal de ácido caínico, sugerindo que estes sistemas constituem uma estratégia promissora para a prevenção e/ou recuperação da degeneração neuronal

Making Known and Available: The importance of digitization of a historical malacological collection in the Science Museum of the University of Coimbra

The Science Museum of the University of Coimbra (MCUC) manages the oldest zoological collections in Portugal. The molluscs are among the most relevant invertebrates within this collection, with over one hundred thousand specimens. A significant part of the Portuguese malacological collection in MCUC comes from the Madeira Archipelago, a group of oceanic islands with a high diversity of terrestrial molluscs and a hotspot of endemic taxa.  A recent review of land snails from Madeira hosted at the MCUC revealed that there were around 130 lots and 2,000 specimens offered by naturalists since the 19th Century and none of them had been previously digitized. A significant number of these specimens was offered by António da Costa de Paiva (Barão de Castelo de Paiva) who   described ten land snail species from the Madeira Archipelago in 1866 and published an extensive monograph on non-marine molluscs in 1867. The main goal of our work was to carry out the inventory of the mollusc collections from the Madeira Archipelago in the database of MCUC, and to discuss the importance of specimens’ digitization for making the collections known and available to researchers and the general public. We inserted data for 1,916 specimens of the Madeira Archipelago collection in the MCUC database ‘In Natura - Natural Heritage Management’ with information on their taxonomy, old inventory numbers (if available), correspondent lot, collector and the study areas, complemented with information about habitat, among others. In addition, we also included photographs of the lots and of some of the most remarkable individuals in the database. The specimens were then reconditioned and identified in the general mollusc collection, although the identification and designation of the type material are still lacking. Digitization is crucial in the field of biological collections in order to transfer specimen data onto worldwide accessible repositories, potentially benefiting the work of researchers and other stakeholders in the ecological and conservation communities. For instance, even when researchers are intensively searching for a type material in a certain collection, if the data are neither known nor available, they cannot trace it and compare it with their material. Thus, this work is fundamental for the accessibility of the malacological collections in the MCUC for researchers and also the society-at-large that has the possibility of consulting them through the digital museum (http://museudaciencia.inwebonline.net), as well as for the dissemination of the important historical and scientific heritage of the University of Coimbra and Portugal, both nationally and internationally

Plant Letters: A citizen science project uncovering historical biodiversity data

The XIXth century saw an enormous accumulation of biological specimens coming to Europe from all over the world, which are now part of museums, herbaria and other natural history collections. For many centuries, the exchange of letters was the privileged means of circulating information and knowledge. At the University of Coimbra (UC), the Life Sciences Department safeguards almost 5000 letters and other documentation addressed to directors, gardeners and other collaborators of the Botanic Garden. These records of Portuguese botanical science and expeditions of plant discovery, collection and identification are held in thousands of handwritten letters, species lists and assorted notebooks, in more than five different languages. Historical repositories such as this archive, but also the biological and museum collections and objects that it documents, imply added responsibilities to the University of Coimbra, as the information contained within the documentation, pertains not only to a country (in this case Portugal), but also to its developing historical roles and actions. As a colonial power for many centuries, the records of Portuguese scientific activity and occupation strategies of overseas territories, in Africa, South America, Asia and the Pacific, are also documented, and its valuable data (e.g., historical biological records) is of crucial importance to these now independent countries. Received correspondence is a great resource for understanding the process of knowledge creation and circulation in the plant sciences, including botany and agriculture, as well as the scientific colonial practices and their implication for the amassing of biological collections at the UC. In order to uncover historical biodiversity data within this archival material, we have implemented Plant Letters (https://www.zooniverse.org/projects/catedraunesco/plant-letters), a citizen science transcription project that seeks to uncover the stories within these historical archives, the tales of travelers and scientists, on the quest of recording of the world’s diversity, mostly in the Portuguese ex-colonies in sub-Saharan Africa. Using the collaborative platform Zooniverse (https://www.zooniverse.org), users are requested to engage with the archive and transcribe mostly handwritten letters in several languages, giving dimension to our continuous efforts of promoting open and widespread access to information. The project invites everyone to transcribe handwritten or typed letters received by the Botanic Garden between about 1870 and 1928, from more than 1100 correspondents from around the world. The main purpose of this project is to track plant species, locations and scientists in the correspondence received in the 19th and 20th centuries at the Botanic Garden of the University of Coimbra. To do so, Plant Letters seeks in users, both experts or simply curious, a source of participation in the construction of knowledge, making use of collective intelligence, in a lively exchange of information, experiences and knowledge. In transcribing the letters, we want to retrieve information that can include: inquiries and doubts about plant classification and taxonomy; historical plant species locations, distribution records and abundance; biological material circulation (plant and seed exchanges); track the path of herbarium and museum specimens in our collections; unravel networks of botanical knowledge. Transcribing the information contained in these documents will allow us to: track plant specimens as they travelled from their native countries to the scientists who named them; to determine historical plant locations in parts of sub-Saharan Africa; to better understand the scientific processes of plant discovery, taxonomy and botany; and to collect information that gives context to biological specimens in museum objects and other natural history collections. All of these data, valuable to the present and future conservation of tropical flora, will be made available, bearing in mind the open science principles