Browsing by Author "Saraiva, Lucilia"
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- Enhanced anticancer activity of Hymenocardia acida stem bark extract loaded into PLGA nanoparticlesPublication . Adedokun, Oluwasegun; Ntungwe, Epole N.; Viegas, Cláudia; Adesina Ayinde, Bunyamin; Barboni, Luciano; Maggi, Filippo; Saraiva, Lucilia; Rijo, Patrícia; Fonte, PedroHymenocardia acida (H. acida) is an African well-known shrub recognized for numerous medicinal properties, including its cancer management potential. The advent of nanotechnology in delivering bioactive medicinal plant extract with poor solubility has improved the drug delivery system, for a better therapeutic value of several drugs from natural origins. This study aimed to evaluate the anticancer properties of H. acida using human lung (H460), breast (MCF-7), and colon (HCT 116) cancer cell lines as well as the production, characterization, and cytotoxicity study of H. acida loaded into PLGA nanoparticles. Benchtop models of Saccharomyces cerevisiae and Raniceps ranninus were used for preliminary toxicity evaluation. Notable cytotoxic activity in benchtop models and human cancer cell lines was observed for H. acida crude extract. The PLGA nanoparticles loading H. acida had a size of about 200 nm and an association efficiency of above 60%, making them suitable to be delivered by different routes. The outcomes from this research showed that H. acida has anticancer activity as claimed from an ethnomedical point of view; however, a loss in activity was noted upon encapsulation, due to the sustained release of the drug.
- Naphthoylhydrazones: coordination to metal ions and biological screeningPublication . Ribeiro, Nadia; Galvao, Adelino M.; Gomes, Clara S. B.; Ramos, Helena; Pinheiro, Rute; Saraiva, Lucilia; Ntungwe, Epole; Isca, Vera; Rijo, Patricia; Cavaco, Isabel; Ramilo-Gomes, Filipa; Guedes, Rita C.; Pessoa, Joao Costa; Correia, IsabelWe report the synthesis of 3-hydroxyl-2-naphthoylhydrazones containing pyrrole (HL1), furane (HL2) and thiophene (HL3) moieties and their V(IV)O-, Cu(II)- and Zn(II)-complexes. All compounds are characterized by the usual analytical techniques and coordination of the ligands to the metal ions is discussed based on spectroscopic data (FTIR, UV-vis, EPR and NMR) as well as CAMB3LYP DFT/TDDFT calculations, indicating the formation of neutral ML2 type complexes. The photophysical properties of ligands and complexes are disclosed. The binding to Bovine Serum Albumin (BSA) is evaluated in detail using several spectroscopic tools. Circular dichroism shows that the compounds, and particularly the ligand precursors, stabilize BSA, increasing its a-helical content. Fluorescence studies indicate the formation of 1 : 1 protein-compound adducts, which is corroborated by molecular docking studies that show the interaction between Trp 213 of BSA and the naphthalene rings. The general toxicity is evaluated using the Artemia salina lethality assay, with all compounds showing general toxicity towards the brine shrimp model. The cytotoxicity on human cancer cells (H1299, MCF7, and HCT116) is assessed for all compounds and the half-maximal inhibitory concentration (IC50) values are in the range from 0.57 to 27.35 mu M. Compounds containing L-1 (pyrrole derivative) are the most cytotoxic, with the vanadium and zinc complexes performing better than the copper ones, and some of them depicting IC50 values lower than 1.1 mM. However, selectivity needs improvement as the compounds show toxicity towards Artemia salina and normal fibroblasts.