Browsing by Author "Mascarenhas, Yvonne P."
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- Anthelmintic, Antibacterial and Cytotoxicity Activity of Imidazole Alkaloids fromPilocarpus microphyllusLeavesPublication . Rocha, Jefferson A.; Andrade, Ivanilza M.; Véras, Leiz M.C.; Quelemes, Patrick V.; Lima, David F.; Soares, Maria J.S.; Pinto, Pedro L.S.; Mayo, Simon J.; Ivanova, Galya; Rangel, Maria; Correia, Manuela; Mafud, Ana Carolina; Mascarenhas, Yvonne P.; Delerue-Matos, Cristina; Moraes, Josué de; Eaton, Peter; Leite, José R.S.A.Pilocarpus microphyllus Stapf ex Wardlew (Rutaceae), popularly known as jaborandi, is a plant native to the northern and northeastern macroregions of Brazil. Several alkaloids from this species have been isolated. There are few reports of antibacterial and anthelmintic activities for these compounds. In this work, we report the antibacterial and anthelmintic activity of five alkaloids found in P. microphyllus leaves, namely, pilosine, epiisopilosine, isopilosine, epiisopiloturine and macaubine. Of these, only anthelmintic activity of one of the compounds has been previously reported. Nuclear magnetic resonance, HPLC and mass spectrometry were combined and used to identify and confirm the structure of the five compounds. As regards the anthelmintic activity, the alkaloids were studied using in vitro assays to evaluate survival time and damaged teguments for Schistosoma mansoni adult worms. We found epiisopilosine to have anthelmintic activity at very low concentrations (3.125 μg mL-1 ); at this concentration, it prevented mating, oviposition, reducing motor activity and altered the tegument of these worms. In contrast, none of the alkaloids showed antibacterial activity. Additionally, alkaloids displayed no cytotoxic effect on vero cells. The potent anthelmintic activity of epiisopilosine indicates the potential of this natural compound as an antiparasitic agent. Copyright © 2017 John Wiley & Sons, Ltd.
- HPLC-DAD, ESI-MS/MS, and NMR of Lycopene Isolated From P. guajava L. and Its Biotechnological ApplicationsPublication . Amorim, Adriany G. N.; Souza, Jessica M. T.; Santos, Raimunda C.; Gullón, Beatriz; Oliveira, Ana; Santos, Luiz F. A.; Virgino, Adamor L. E.; Mafud, Ana C.; Petrilli, Helena M.; Mascarenhas, Yvonne P.; Delerue-Matos, Cristina; Pintado, Manuela E.; Leite, José R. S. A.Psidium guajava L. have been reported to be a rich source of antioxidant compounds. Its carotenoids have been highlighted by their high antioxidant capacity, which offers several benefits for human health. In this sense, lycopene isomers need to be identified. In this work, the comprehensive chemical characterization, by HPLC‐DAD, MS/MS, and NMR, of lycopene isolated from P. guajava L., antioxidant and antimicrobial activity of lycopene extracts and isolated lycopene are evaluated. The FTIR results reported a structure with Z configuration, confirmed by UV‐Vis, with λmax = 448, 473, and 505 nm for 5‐Z lycopene. Furthermore, MS/MS positive ionization shows one fragment m/z 309 [M‐227]+, relatively abundant for isolated lycopene. Experimental and Theoretical NMR studies revealed that guava may contain 5‐Z lycopene because of the similarity found among the peaks. Lycopene extracts presented higher antioxidant activity than isolated lycopene, from both P. guajava L. and tomato, when measured by ABTS and ORAC (r2 = 0.9995 and r2 = 0.9992, respectively). In addition, lycopene extract shows antibacterial efficacy against E. coli, S. aureus, and L. innocua, presenting MBC values of 20 mg mL−1. These results suggest that lycopene extract have potential applicability for food, cosmetics, and pharmaceutical industry.Practical Applications: Lycopene from P. guajava L. is characterized by HPLCDAD, MS, NMR, FTIR, and X-Ray, presented antioxidant capacity by ORAC and antibacterial efficacy against food pathogens.
- In Silico, In Vitro and In Vivo Toxicological Assessment of BPP-BrachyNH2, A Vasoactive Proline-Rich Oligopeptide from Brachycephalus ephippiumPublication . Arcanjo, Daniel D. R.; Mafud, Ana Carolina; Vasconcelos, Andreanne G.; Silva-Filho, José Couras da; Amaral, Maurício P. M.; Brito, Lucas M.; Bemquerer, Marcelo P.; Kückelhaus, Selma A. S.; Plácido, Alexandra; Delerue-Matos, Cristina; Vale, Nuno; Mascarenhas, Yvonne P.; Carvalho, Fernando Aécio A.; Oliveira, Aldeidia P.; Leite, José Roberto Souza AlmeidaBPP-BrachyNH2 is a proline-rich oligopeptide (PRO) firstly identified in skin secretion of the frog Brachycephalus ephippium, which possess in vitro inhibitory activity of angiotensin-I converting enzyme (ACE) and endothelium-dependent vasorelaxant activity. Considering its potential application in the treatment of cardiovascular diseases, the present work assessed the toxicological profile of the BPP-BrachyNH2. The in silico toxicity prediction was performed from the best model obtained through the optimization of the FASTA query peptide. This prediction study revealed that BPP-BrachyNH2 induced high predicted LD50 values for both humans and rats, and then is well-tolerated in the recommended range. The MTT assay was applied for the in vitro cytotoxic evaluation in murine macrophages. In this assay, a decrease of cell viability was not observed. The in vivo acute toxicological study was performed after the intraperitoneal administration of BPP-BrachyNH2 at doses of 5 and 50 mg/kg. After intraperitoneal administration, no death, alterations in behavioral parameters or weight gain curve was observed, as well as none in the serum biochemical parameters, and gross pathological and histopathological analyses. These observations demonstrates an acceptable safety profile for BPP-BrachyNH2, leading towards further studies focused on investigation of pharmacological and therapeutical applications for this peptide.
- Layer-by-layer films containing peptides of the Cry1Ab16 toxin from Bacillus thuringiensis for potential biotechnological applicationsPublication . Plácido, Alexandra; Farias, Emanuel Airton de Oliveira; Marani, Mariela M.; Vasconcelos, Andreanne G.; Mafud, Ana C.; Mascarenhas, Yvonne P.; Eiras, Carla; Leite, José R.S.A.; Delerue-Matos, CristinaCry1Ab16 is a toxin of crystalline insecticidal proteins that has been widely used in genetically modified organisms (GMOs) to gain resistance to pests. For the first time, in this study, peptides derived fromthe immunogenic Cry1Ab16 toxin (from Bacillus thuringiensis) were immobilized as layer-by-layer (LbL) films. Given the concern about food and environmental safety, a peptide with immunogenic potential, PcL342–354C, was selected for characterization of the electrochemical, optical, and morphological properties. The results obtained by cyclic voltammetry (CV) showed that the peptide have an irreversible oxidation process in electrolyte of 0.1 mol·L−1 potassiumphosphate buffer (PBS) at pH7.2. Itwas also observed that the electrochemical response of the peptide is governed mainly by charge transfer. In an attempt to maximize the electrochemical signal of peptide, it was intercalated with natural (agar, alginate and chitosan) or synthetic polymers (polyethylenimine (PEI) and poly(sodium 4-styrenesulfonate (PSS)). The presence of synthetic polymers on the film increased the electrochemical signal of PcL342–354C up to 100 times. Images by Atomic Force Microscopy (AFM) showed that the immobilized PcL342–354C formed self-assembled nanofibers with diameters ranging from 100 to 200 nm on the polymeric film. By UV–Visible spectroscopy (UV–Vis) it was observed that the ITO/PE/PSS/PcL342–354C film grows linearly up to the fifth layer, thereafter tending to saturation. X-ray diffraction confirmed the presence on the films of crystalline ITO and amorphous polypeptide phases. In general, the ITO/PEI/PSS/PcL342–354C film characterization proved that this systemis an excellent candidate for applications in electrochemical sensors and other biotechnological applications for GMOs and environmental indicators.
- Structure-function studies of BPP-BrachyNH 2 and synthetic analogues thereof with Angiotensin I-Converting EnzymePublication . Arcanjo, Daniel D.R.; Vasconcelos, Andreanne G.; Nascimento, Lucas A.; Mafud, Ana Carolina; Plácido, Alexandra; Alves, Michel M.M.; Delerue-Matos, Cristina; Bemquerer, Marcelo P.; Vale, Nuno; Gomes, Paula; Oliveira, Eduardo B.; Lima, Francisco C.A.; Mascarenhas, Yvonne P.; Carvalho, Fernando Aécio A.; Simonsen, Ulf; Ramos, Ricardo M.; Leite, José Roberto S.A.The vasoactive proline-rich oligopeptide termed BPP-BrachyNH2 (H-WPPPKVSP-NH2) induces in vitro inhibitory activity of angiotensin I-converting enzyme (ACE) in rat blood serum. In the present study, the removal of N-terminal tryptophan or C-terminal proline from BPP-BrachyNH2 was investigated in order to predict which structural components are important or required for interaction with ACE. Furthermore, the toxicological profile was assessed by in silico prediction and in vitro MTT assay. Two BPP-BrachyNH2 analogues (des-Trp1-BPP-BrachyNH2 and des-Pro8-BPP-BrachyNH2) were synthesized, and in vitro and in silico ACE inhibitory activity and toxicological profile were assessed. The des-Trp1-BPP-BrachyNH2 and des-Pro8-BPP-BrachyNH2 were respectively 3.2- and 29.5-fold less active than the BPP-BrachyNH2-induced ACE inhibitory activity. Molecular Dynamic and Molecular Mechanics Poisson-Boltzmann Surface Area simulations (MM-PBSA) demonstrated that the ACE/BBP-BrachyNH2 complex showed lower binding and van der Wall energies than the ACE/des-Pro8-BPP-BrachyNH2 complex, therefore having better stability. The removal of the N-terminal tryptophan increased the in silico predicted toxicological effects and cytotoxicity when compared with BPP-BrachyNH2 or des-Pro8-BPP-BrachyNH2. Otherwise, des-Pro8-BPP-BrachyNH2 was 190-fold less cytotoxic than BPP-BrachyNH2. Thus, the removal of C-terminal proline residue was able to markedly decrease both the BPP-BrachyNH2-induced ACE inhibitory and cytotoxic effects assessed by in vitro and in silico approaches. In conclusion, the aminoacid sequence of BPP-BrachyNH2 is essential for its ACE inhibitory activity and associated with an acceptable toxicological profile. The perspective of the interactions of BPP-BrachyNH2 with ACE found in the present study can be used for development of drugs with differential therapeutic profile than current ACE inhibitors.