Evaluation of chemotherapeutic potential of natural extracts using 3D models of colon cancer

Dissertation to obtain master degree in Biotechnology

Development of a "green process" for the isolation of natural functional extracts with anti-cancer activity - Application of high-pressure technology

Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica

Fractionation of hydro-ethanolic extracts from grape pomace through membrane processing: the effect of membrane and extracting media on process performance

The EM3E Master is an Education Programme supported by the European Commission, the European Membrane Society (EMS), the European Membrane House (EMH), and a large international network of industrial companies, research centers and universities

Evaluation of neuroprotective effects of natural extracts obtained from portuguese agro-food residues

Countries are currently faced with problems derived from changes in lifespan and an increase in lifestyle-related diseases. Neurodegenerative disorders such Parkinson’s (PD) and Alzheimer’s (AD) diseases are an increasing problem in aged societies. Data from World Alzheimer Report 2011 indicate that 36 million people worldwide are living with dementia. Oxidative stress has been associated with the development of AD and PD. Therefore there is interest to search for effective compounds or therapies to combat the oxidative damage in these diseases. Current evidence strongly supports a contribution of phenolic compounds present in fruits and vegetables to the prevention of neurodegenerative diseases such AD and PD. The industrial processing of a wide variety of fruits results in the accumulation of by-products without commercial value. Opuntia ficus-indica (cactus pear) is consumed fresh and processed like in juice. Prunnus avium (sweet cherry) is consumed fresh but the organoleptics characteristics of the fruits leads to the smaller and ragged fruits have no commercial value. Fruit extracts of both species has described to be rich in phenolic compounds and to have high antioxidant activities due to its composition. The aim of this work was assessing the efficacy of O. ficus-indica and P. avium by-products extracts obtained with conventional solvent extraction and pressurized liquid extraction in a neurodegeneration cell model. All extracts have protected neuroblastoma cells from H2O2-induced death at low, non-toxic levels, which approach to physiologically-relevant serum concentration. However, cherry extract has a slighter neuroprotective activity. The protective effect of Opuntia extracts are not conducted by a direct antioxidant activity since there are not decreases in intracellular ROS levels in cell treated with extracts and challenged with H2O2, while cherry extract neuroprotection seems to be due to a direct scavenging activity. Extracts from different biological matrixes seems to protect neuronal cells trough different cellular mechanisms.

Estudo fitoquímico de Solanum cernuum Vell. Síntese de cromóforos derivados de cumarinas com possíveis aplicações em dispositivos fotovoltaicos

A Parte I teve como objectivo a pesquisa de novos constituintes bioactivos da planta Solanum cernuum Vell. Identificaram-se, pela primeira vez no género Solanum, três triterpenos com um esqueleto de 31-norcicloartanona((+)-cicloeucalenona, (+)-24-oxo-31 norcicloartanona e (+)-24(1,3-dioxetano)-31-norcicloartanona) e quatro alcalóides com uma unidade (2-aminopirrolidin-1-il)carboxamidina acilada com o ácido isoferúlico assumindo configurações E e Z (cernumidina,isocernumidina, cernumidina B e isocernumidina B). A (+)-24-oxo-31-norcicloartanona apresentou actividade anti-neoplásica selectiva para as células de pulmão NCIH460, actividade anti-inflamatória relevante e uma inibição acentuada da expressão da COX-2. A (+)-24(1,3-dioxetano)-31-norcicloartanona apresentou também actividade para as células de leucemia K562. A cernumidina provocou inibição da interleuquina-8 (IL-8) em células do carcinoma do cólon HT-29 superior a 50%. Foram também identificados quercitrina, afzelina, hiperina, ácido ferúlico e Nacetildopamina. Na Parte II desenvolveram-se estudos sobre metodologias de síntese de novos cromóforos derivados da 7-amino-4-metilcumarina. Foi realizado um estudo da reacção de Buchwald-Hartwig para a introdução de grupo(s) electrodoador(es) na posição 7 e de um grupo electroatractor na posição 3 com rendimentos razoáveis. Foram obtidos os compostos 7-(4-metoxifenilamino)-4-metil-2H-cromen-2-ona, 4-metil-7-(fenilamino)- 2H-cromen-2-ona, 3-bromo-7-(4-metoxi-fenilamino)-4-metil-2H-cromen-2-ona e 3- bromo-4-metil-7-(fenilamino)- 2H-cromen-2-ona. Os espectros de absorção destes quatro cromóforos apresentaram c.d.o. máximos desviados para a zona do vermelho. Para a expansão do sistema π pela introdução de um grupo etinileno como ponte conjugada na posição 3 foi necessário a activação desta posição. Para tal, procedeu-se à bromação da N-(4-metil-2-oxo-2H-cromen-7-il)octanamida seguida da reacção de Sonogashira-Hagihara com o álcool propagílico. A oxidação posterior ao aldeído formou a N-(4-metil-2-oxo-3-(3-oxoprop-1- inil)2H-cromen-7-il)octanamida. Numa aproximação convergente foi testada a síntese do ácido 2-cianopent-2-en-4-óico (sem sucesso) para posterior reacção de Sonogashira-Hagihara com 3-bromo-N-(4-metil-2-oxo-2Hcromen-7-il)octanamida.

Proteomic analysis of a neurodegeneration cell model, treated with plant extracts with potential neuroprotective activity

Nowadays, a significant increase in chronic diseases is observed. Epidemiological studies showed a consistent relationship between the consumption of fruits and vegetables and a reduced risk of certain chronic diseases, namely neurodegenerative disorders. One factor common to these diseases is oxidative stress, which is highly related with proteins, lipids, carbohydrates and nucleic acids damage, leading to cellular dysfunction. Polyphenols, highly abundant in berries and associated products, were described as having antioxidant properties, with beneficial effect in these pathologies. The aims of this study were to evaluate by proteomic analyses the effect of oxidative insult in a neuroblastoma cell line (SK-N-MC) and understand the mechanisms involved in the neuroprotective effects of digested extracts from commercial and wild blackberry (R. vagabundus Samp.). The analysis of the total proteome by two-dimensional electrophoresis revealed that oxidative stress in SK-N-MC cells resulted in altered expression of 12 protein spots from a total of 318. Regarding some redox proteomics alterations, particularly proteins carbonylation and glutathionylation, protein carbonyl alterations during stress suggest that cells produce an early and late response; on the other hand, no glutathionylated polypeptides were detected. Relatively to the incubation of SK-N-MC cells with digested berry extracts, commercial blackberry promotes more changes in protein pattern of these cells than R. vagabundus. From 9 statistically different protein spots of cells incubated with commercial blackberry, only β-tubulin and GRP 78 were until now identified by mass spectrometry. Further studies involving the selection of sub proteomes will be necessary to have a better understanding of the mechanisms underlying the neuroprotective effects of berries.