275 research outputs found
Portuguese fish producers’ organisations: some concerns
info:eu-repo/semantics/publishedVersio
Anti-tumoral activity of lipophilic Eucalyptus bark extracts, enriched on triterpenic acids, against breast cancer cells
The agro-industrial exploitation of eucalyptus for pulp production generates large amounts of biomass residues, particularly bark. Eucalyptus spp. is the most important fiber source for pulp and paper production in southwestern Europe [1]
Antitumoral and antioxidant activities of lipophilic and phenolic extracts from Cynara cardunculus L. var. altilis (DC)
Cynara cardunculus L. var. altilis (DC) (Cca) grows under the semi-arid conditions as those of south of Portugal. Given to high cellulose and hemicelluloses contents, paper pulp production has been proposed [1]. Moreover, the extraction of bioactive compounds could also be considered for an integrated valorization of Cca. Sesquiterpene lactones (SL) and pentacyclic triterpenes, the major constituents of Cca leaves and capitula lipophilic fractions [2] showed lower tryglyceride levels in rat serum [3] and anti-inflammatory [4] actions, respectively. Besides, cardoon extracts displayed antioxidant [5] and antitumor properties [6, 7], mainly due to hydroxycinnamic acid derivatives. The present work aims to determine the chemical composition of Cca lipophilic and phenolic fractions, by analyzing respectively their dichloromethane (DCM) and methanol/water/acetic acid (MWAA) (49.5:49.5:1) extracts, by gas chromatography and high temperature-ultra-high pressure liquid chromatography coupled with mass spectrometry. Furthermore, the antitumoral activity of Cca DCM extracts was evaluated on human breast cancer cells (MDA-MB-231), by assessing cell proliferation (2 – 500 µg/mL), cell cycle and Akt molecular signaling (10.4 µg/mL). Additionally, the antioxidant activity of MWAA extracts (7.5 – 400 µg/mL) was determined by DPPH scavenging assay. Cca leaves DCM extract, containing 48.5 ± 3.1% SLs (Table 1), and the major compound, cynaropicrin (2), strongly inhibited MDA-MB-231 cellular viability, inducing cell cycle arrest at G2 phase, with inhibition of Akt phosphorylation at serine 473. In addition, MWAA extracts from Cca stalks outer part, containing 5.9 ± 0.5% hydroxycinnamic acids (HA), were the most effective to scavenge DPPH free radicals. The antioxidant activity was correlated to phenolic (r =-0.897) and HAs (r =-0.990) contents. In conclusion, Cca leaves and stalks outer part are valuable sources of respectively SLs and HAs, with a great antitumoral and antioxidant potential
Em busca de uma teoria da burocracia pública não-estatal: política e administração no terceiro setor
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