Center for Innovative Biomedicine and Biotechnology

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Secondary metabolites (essential oils) from sand-dune plants induce cytotoxic effects in cancer cells

Publication . Beeby, Ellie; Magalhães, Mariana; Poças, Juliana; Collins, Thomas; Lemos, Marco F.L.; Barros, Lillian; Ferreira, Isabel C.F.R.; Cabral, Célia; Pires, Isabel M.

Ethnopharmacological relevance: Despite advances in modern therapeutic strategies, cancer remains the second leading cause of death worldwide. Therefore, there is a constant need to develop more efficient anticancer targeting strategies. The anticancer therapeutic proprieties of medicinal plants and their bioactive compounds have been reported for several years, making natural extracts and/or compounds derived from these a promising source of novel anticancer agents. Sand dune plants are subjected to severe environmental stresses, leading to the development of adaptations, including the production of secondary metabolites with a wide range of bioactivities, such as: anti-inflammatory, analgesic, antiseptic, hypoglycaemic, hypotensive, antinociceptive, antioxidant and anticancer. Aim of the study: The anticancer potential of sand dune plants remains under-investigated, so this research describes the characterisation of the composition of bioactive EOs from sand-dune plants of Peniche (Portugal), and assessment of their activity in vitro and potential mechanism of action. Materials and methods: EOs were extracted from six sand-dune species of plants from Peniche sand dunes: Crithmum maritimum L., Seseli tortuosum L., Artemisia campestris subsp. maritima (DC.) Arcang., Juniperus phoenicea var. turbinata (Guss.) Parl., Otanthus maritimus (L.) Hoffmanns. & Link, and Eryngium maritimum L.. EOs composition was fully characterised chemically using Gas Chromatography-Mass Spectrometry (GC-MS). The assessment of anticancer activity and mechanism of action was performed in vitro using breast and colorectal cancer 2D and 3D spheroid cell line models, through cell proliferation assay, western blotting analysis, and cell cycle analysis. Results: EOs from the majority of the species tested (S. tortuosum, A. campestris subsp. maritima, O. maritimus, and E. maritimum) were mainly composed by hydrocarbon compounds (sequisterpenes and monoterpenes), showing antiproliferative activity in both 2D and 3D models. EO extracted from S. tortuosum and O. maritimus were identified as having the lowest IC50 values for both cell lines when compared with the other species tested. Furthermore, this antiproliferative activity was associated with increased p21 expression and induction of apoptosis. Conclusions: The present study suggests that EOs extracted from S. tortuosum and O. maritimus present promising cytotoxic properties. Further evaluation of the extracts and their key components as potential anticancer agents should therefore be explored.

2020Journal article

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Fortified chocolate mousse with powder and extract from Moringa oleifera leaves for nutritional value improvement

Publication . Gomes, Olívia J.S.; Leitão, Anabela; Gaspar, Marisa C.; Vitorino, Carla; Sousa, João J.S.; Sousa, Hermínio C. de; Braga, Mara E.M.; Gando-Ferreira, Licínio M.

This study focuses on the characterisation and incorporation of Moringa oleifera leaf powder (MOP) from Luanda (Angola) and its extract (MOE) in fortified chocolate mousse. Dark green (DG) leaves presented superior nutritional values compared to other leaves. DG contained a higher concentration of mineral salts (10 ± 1 mg/100 g of dry leaves), phenolic compounds (267 ± 4 mg GAE/g), vitamins (1.9 ± 0.2 mg/g of dry extract) and strong antioxidant capacity (IC50, 115 ± 8 µg/mL). Therefore, DG leaves were used to fortify the chocolate mousse. The leaves were prepared in three samples: control, 2 % MOP (w/w) and 2 % MOE (v/v). Textural and rheological analysis of chocolate mousse samples revealed a pseudoplastic profile for all samples, with decreased texture attributes and viscosity due to the incorporation. The sensory evaluation demonstrated that MOP and MOE samples presented 93 % and 88 % resemblance to the original product regarding general acceptance, respectively.

2024-05Journal article

Open access

Desenvolvimento de vacinas recombinantes contra Vibrio spp. usando um canal da membrana externa como alvo

Publication . Seabra, Rafaela Videira; Vieira-Pires, Ricardo Simão; Afonso, Clélia Paulete Correia Neves

Vibrio é um género de bactérias Gram-negativas ubíquas nos ecossistemas aquáticos. A Vibriose é uma doença hemorrágica septicémica mortal e está entre as doenças mais comuns que levam à mortalidade em massa de organismos marinhos de cultivo, sendo uma causa bem conhecida de graves perdas económicas na indústria de aquacultura. O uso de antibióticos tem sido uma prática comum também nesta indústria da aquacultura, mas a demanda global pela redução do seu uso devido ao fenómeno da resistência aos antimicrobianos tem promovido o desenvolvimento de medidas alternativas de control. A vacinação está entre essas estratégias de control da Vibriose. Os sistemas de secreção bacteriana são responsáveis em particular pela expulsão de componentes citotóxicos, nomeadamente antibióticos, e desempenham um papel crítico nos fenómenos de resistência aos antimicrobianos. No presente trabalho, utilizámos a proteína canal-túnel TolC da membrana externa, um componente dos sistemas de secreção do tipo I, como proteína alvo para o desenho de vacinas recombinantes. As proteínas TolCs de diferentes patógenos Vibrio de peixes foram identificadas e suas regiões extracelulares foram desenhadas expressas e purificadas como epítopos recombinantes e posteriormente caracterizadas em termos de estabilidade e rendimento de produção. Foram desenhados, clonamos e purificamos com sucesso 8 epítopos recombinantes correspondentes aos Loop-1 (L1) e Loop-2 (L2) extracelular dos seguintes patógenos Vibrio de peixes: V.anguillarum (VAU), V.parahaemolyticus (VPK), V. vulnificus (VVL) e V.harveyi (VHR). Todos eles apresentavam diferentes composições de aminoácidos, acabando por funcionar como assinaturas únicas para cada organismo. Esses novos produtos recombinantes serão a base para a formulação de vacinas para imunização ativa de peixes hospedeiros, ou mesmo para produção de anticorpos para procedimentos de imunização passiva. Além disso, os anticorpos derivados dessas vacinas podem ser usados para monitorização e diagnóstico patógenos Vibrio de peixes.

2022-01-18Master thesis

Open access

Inflammatory cells proliferate in the choroid and retina without choroidal thickness change in early Type 1 diabetes

Publication . Campos, António; Campos, Elisa J.; Martins, João; Rodrigues, Flávia S.C.; Silva, Rufino; Ambrósio, António Francisco

Increasing evidence points to inflammation as a key factor in the pathogenesis of diabetic retinopathy (DR). Choroidal inflammatory changes in diabetes have been reported and in vivo choroidal thickness (CT) has been searched as a marker of retinopathy with contradictory results. We aimed to investigate the early stages in the retina and choroid in an animal model of Type 1 diabetes. Type 1 diabetes was induced in male Wistar rats via a single i.p. streptozotocin injection. At 8 weeks after disease onset, CT, choroidal vascular density, VEGF and VEGFR2 expression, microglial cell and pericyte distribution were evaluated. Diabetic rats showed no significant change in CT and choroidal vascular density. A widened pericyte-free gap between the retinal pigment epithelium and the choroid was observed in diabetic rats. The immunoreactivity of VEGFR2 was decreased in the retina of diabetic rats, despite no statistically significant difference in the immunoreactivity of VEGF. The density of microglial cells significantly increased in the choroid and retina of diabetic rats. Reactive microglial cells were found to be more abundant in the choroid of diabetic rats. Evidences of the interconnection between the superficial, intermediate, and deep plexuses of the retina were also observed. At early stages, Type 1 diabetes does not affect choroidal thickness and choroidal vascular density. Proliferation and reactivity of microglial cells occurs in the choroidal stroma and the retina. The expression of VEGFR2 decreases in the retina.

2020-08-22Journal article

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