Percorrer por autor "Oliveira, Paulo"
A mostrar 1 - 3 de 3
Resultados por página
Opções de ordenação
- Côa Valley’s medicinal plants as potential cosmetic ingredients: cytotoxic and antioxidant screeningPublication . Marques, Mário Pedro; Landim, Euclides; Varela, Carla; Marques, Joana; Costa, Ricardo; Carvalho, Luís de; Carvalho, Aida; Oliveira, Paulo; Cabral, CéliaCôa Valley is a Northeast region of Portugal, classified as a UNESCO World Her- itage Site since 1998, and recognised as “the most important open-air Paleo- lithic rock art site”. So far, little is known about the natural endogenous resourc- es of this territory, namely medicinal plants. According to a preliminary ethnobotanical survey in this region, several medicinal plants were mentioned to have skin-beneficial effects. However, many of them still lacking scientific validation. Taking into account the results gathered during the survey carried in the CôaMedPlants project, the main goal of this investigation is to assess the cytotoxicity and antioxidant activity of selected species to incorporate them into scientific-validated plant- based cosmetic formulations and create an ex- clusive cosmetic brand for Côa Valley. Therefore, nine species were selected and their hydroalcoholic extracts (EtOH 80 %) were prepared. Their non-cyto- toxic concentrations were determined in vitro using the Normal Human Dermal Fibroblasts (NHDF) cell line, by the evaluation of metabolic activity through the Alamar Blue assay, and cell mass estimation according to the sulforhodamine B (SRB) assay. Most of the extracts revealed non-toxic concentrations ≤ 0.2 mg/mL using the NHDF cell model. Afterwards, non-cellular techniques were used to screen the antioxidant activity of these ethanolic extracts, through DPPH, ABTS, CUPRAC and FRAP assays. From the 9 species studied, the most promising so far are: Arbutus unedo L., Cistus albidus L., Cistus salviifolius L., Lavandula pedunculata (Mill.) Cav. and Pistacia terebinthus L., which will be further investigated in- depth, to characterise their antioxidant potential using in vitro cell models.
- A performance comparison between different industrial real-time indoor localization systems for mobile platformsPublication . Rebelo, Paulo M.; Lima, José; Soares, Salviano Pinto; Oliveira, Paulo; Sobreira, Héber; Costa, PedroThe flexibility and versatility associated with autonomous mobile robots (AMR) have facilitated their integration into different types of industries and tasks. However, as the main objective of their implementation on the factory floor is to optimize processes and, consequently, the time associated with them, it is necessary to take into account the environment and congestion to which they are subjected. Localization, on the shop floor and in real time, is an important requirement to optimize the AMRs’ trajectory management, thus avoiding livelocks and deadlocks during their movements in partnership with manual forklift operators and logistic trains. Threeof the most commonly used localization techniques in indoor environments (time of flight, angle of arrival, and time difference of arrival), as well as two of the most commonly used indoor localization methods in the industry (ultra-wideband, and ultrasound), are presented and compared in this paper. Furthermore, it identifies and compares three industrial indoor localization solutions: Qorvo, Eliko Kio, and Marvelmind, implemented in an industrial mobile platform, which is the main contribution of this paper. These solutions can be applied to both AMRs and other mobile platforms, such as forklifts and logistic trains. In terms of results, the Marvelmind system, which uses an ultrasound method, was the best solution.
- Study of the edible Rumex induratus from Côa Valley in hepaticocarcinoma cellsPublication . Varela, Carla; Farinha, Diana; Jorge, Joana; Alves, Raquel de Oliveira; Dias, Maria Inês; Barros, Lillian; Oliveira, Paulo; Gonçalves, Ana Cristina; Cabral, CéliaHepatocellular carcinoma (HCC) is the most common form of liver cancer (about 90%) which remains a worldwide health challenge due to its incidence growth and yet scarce and not specific treatments.HCC is characterized by a metabolic and oxidative stress which induces a prolonged pathological inflammation and cell damage, and also an evident increase in the production of reactive oxygen species (ROS) which will lead to an increase of cellular lipid peroxidation and of hepatic enzymes. Available treatments are not very effective being usually adapted from other illnesses. Plants are considered very important sources for the discovery of new compounds to prevent and treat diseases (1). There are several natural drug leads presently used in chemotherapy including in HCC. Rumex induratus is native in Iberian Peninsula and spontaneous in northwest Portugal where it is used in local cuisine. Its extracts have significative antioxidant activity (2). This work aimed to add value to this species focused on the evaluation of the antitumoral activity of different extracts. Extractions of Rumex induratus (collected in Vale do Côa, Portugal, between March and May 2021) were made in water, ethanol 80% and ethanol 100% and tested in HCC in vitro models using HepG2, HuH7 and Hep3B cells lines. Metabolic activity, cellular morphology, cellular death and the quantification of reactive oxygen species (ROS) (superoxide anion and hydrogen peroxide) were assayed. A reduction in the metabolic activity was dependent on the extract and its concentration: it was observed that the infusion was more cytotoxic and Hep3B the most sensitive cell line. As for cellular morphology, in HuH7 was observed the condensation of the nucleus after treatment with infusion, and in Hep3B the hydroethanolic extract led to cellular contraction. Cellular death evaluated by the membrane potential revealed that HepG2 and HuH7 suffered from exposure to infusion and hydroethanolic extracts, while Hep3B was not so sensitive. As for ROS quantification, a growth pattern in the concentration of the superoxide anion and a decrease in peroxides were detected with an increase in the concentration of R. induratus extracts. Although not so robust, results of this study still revealed an evident influence of R. induratus extracts in the cellular activity and intracellular ROS production in the studied hepatocellular carcinoma cell lines. It is understandable that these biologic activities are directly associated to the existent phenolic compounds which antioxidant potential allows the understanding that the extracts led to an increase in membrane potential in all cell lines, with HepG2 presenting the highest values. In conclusion, the plant extract provides intracellular differences that can lead to the triggering of apoptosis in tumor cells. Nevertheless, future assays will allow to understand the mechanism of action of R. induratus extracts in HCC and to potentiate its use.