Repository logo

Browsing by Author "Ribeiro, Alexandre"

Now showing 1 - 2 of 2
  • Antioxidant and Antimicrobial Activity of Plants from Portuguese Flora
    Publication . Ribeiro, Alexandre; Pinho, Cláudia Marta Libreiro de; Oliveira, Ana Isabel de Freitas Tavares de
    Through the years, we have seen the important role of plants in heallth, with valuable drugs being approved derived from phytochemicals. The diversity found in the plant kingdom makes that the properties of many medicinal plants remain unknown. Therefore, this research aims to evaluate the biological activity through antioxidante and antibacterial in vitro assays of three plants from Portuguese flora. It was prepared aqueous and methanolic extracts (AE amd ME, respectively) from Euphorbia paralias, Euphorbia hirsuta, and Trifolium tomentosum. Their total phenolic contente (TPC), capacity to scavenge DPPH radical, and ability to chelate iron ions were evaluated as well as their antibacterial activity agianst Escherichia coli and Staphylococcus aureus, through disc diffusion and broth microdilution methods. Euphorbia species presented their higher radical scavenging capacity (IC50˂50 µg/mL). The ME of E. paralias presented the highest TPC (293.37 ± 20.25 mg GAE/g) and also had the best performance in chelating iron ions. This same extract, along with ME of E. hirsuta, promoted moderate growth inhibition of S. aureus at 10 mg/ml with a MIC value of 1.0 and 2.0 mg/ml, respectively. Our findings provided preliminar knowledge about these plants and highlighted the potentialities of the Euphorbia genus.
    2021-01-07Master thesis Open access Show more
  • Atividade antioxidante de espécies de Euphorbia
    Publication . Ribeiro, Alexandre; Oliveira, Ana Isabel; Pinho, Cláudia
    As plantas constituem importantes fontes de compostos bioativos, com uma grande variedade de atividades biológicas. Quando sujeitas a stress, as células produzem espécies reativas de oxigénio que podem causar danos para a saúde humana, estando associadas a doenças cardiovasculares, neurodegenerativas e cancro. Destacam-se atualmente os compostos com potencial antioxidante, associados ao tratamento e prevenção de doenças. Muitas espécies da família das Euphorbiaceae têm sido utilizadas como medicina tradicional nos países do mediterrâneo, incluindo Portugal. O trabalho tem como objetivo avaliar a capacidade antioxidante de dois extratos metanólicos de espécies do género Euphorbia (E. paralias e E. hirsuta).
    2021-05Conference object Open access Show more