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2024
Optimization of Antiproliferative Properties of Triimine Copper(II) Complexes, Choroba, K., Zowislok B., Kula S., Machura B., Maron A. M., Erfurt K., Cordeiro S., Baptista P. V., and Fernandes {Alexandra R. } , Journal Of Medicinal Chemistry, nov, Volume 67, Number 21, p.19475–19502, (2024) Abstract

Cu(II) complexes with 2,2′:6′,2″-terpyridines (terpy) and 2,6-bis(thiazol-2-yl)pyridines (dtpy) with 1- or 2-naphtyl and methoxy-naphtyl were synthesized to elucidate the impact of the triimine core, naphtyl linking mode, and presence of methoxy groups on the antiproliferative activity of [CuCl2(Ln)]. Their antiproliferative effect was analyzed in ovarian (A2780) and colorectal (HCT116) carcinomas and colorectal carcinoma resistant to doxorubicin (HCT116-DoxR) cell lines and in normal human fibroblasts. Among all complexes, the 1- and 2-naphtyl substituted terpy Cu(II) complexes (Cu1a and Cu1b) showed the strongest cytotoxicity, namely, in HCT116-DoxR 2Dcells and were also capable of inducing the loss of cell viability in 3D HCT116-DoxR spheroids. Their intracellular localization, capability to increase reactive oxygen species (ROS), and interaction with DNA (nonintercalative mode) trigger oxidative DNA cleavage leading to cell death by apoptosis and autophagy. Cu1a and Cu1b do not show in vivo toxicity in a chicken embryo and can interact with bovine serum albumin (BSA).

Optimization of Antiproliferative Properties of Triimine Copper(II) Complexes, Choroba, Katarzyna, Zowiślok Bartosz, Kula Sławomir, Machura Barbara, Maroń {Anna M. }, Erfurt Karol, Marques Cristiana, Cordeiro Sandra, Baptista {Pedro V. }, and Fernandes {Alexandra R. } , Journal Of Medicinal Chemistry, nov, (2024) Abstract

Cu(II) complexes with 2,2':6',2″-terpyridines (terpy) and 2,6-bis(thiazol-2-yl)pyridines (dtpy) with 1- or 2-naphtyl and methoxy-naphtyl were synthesized to elucidate the impact of the triimine core, naphtyl linking mode, and presence of methoxy groups on the antiproliferative activity of [CuCl 2(L n )]. Their antiproliferative effect was analyzed in ovarian (A2780) and colorectal (HCT116) carcinomas and colorectal carcinoma resistant to doxorubicin (HCT116-DoxR) cell lines and in normal human fibroblasts. Among all complexes, the 1- and 2-naphtyl substituted terpy Cu(II) complexes ( Cu1a and Cu1b) showed the strongest cytotoxicity, namely, in HCT116-DoxR 2Dcells and were also capable of inducing the loss of cell viability in 3D HCT116-DoxR spheroids. Their intracellular localization, capability to increase reactive oxygen species (ROS), and interaction with DNA (nonintercalative mode) trigger oxidative DNA cleavage leading to cell death by apoptosis and autophagy. Cu1a and Cu1b do not show in vivo toxicity in a chicken embryo and can interact with bovine serum albumin (BSA).

Anti-inflammatory and antiproliferative activity of Helichrysum odoratissimum sweet. Against lung cancer, Esmear, Tenille, Twilley Danielle, Thipe {Velaphi Clement}, Katti {Kattesh V. }, Mandiwana Vusani, Kalombo {Michel Lonji}, Ray {Suprakas Sinha}, Rikhotso-Mbungela Rirhandzu, Bovilla {Venugopal Reddy}, Madhunapantula {Subba Rao}, Langhanshova Lenka, Roma-Rodrigues Catarina, Fernandes {Alexandra R. }, Baptista Pedro, Hlati Silvestre, Pretorius Judey, and Lall Namrita , South African Journal of Botany, Volume 166, p.525–538, (2024) Abstract

Lung cancer remains the top killing cancer worldwide despite advances in treatment. Seven ethanolic plant extracts were selected and evaluated for their antiproliferative activity against the two main types of lung cancers: non-small cell (A549) and small cell lung cancer cells (SHP-77). An ethanolic extract of Helichrysum odoratissimum Sweet (HO) showed significant antiproliferative activity against lung cancer, with a fifty percent inhibitory concentration (IC50) of 83.43 ± 1.60 µg/mL (A549), 49.46 ± 0.48 µg/mL (SHP-77) and 50.71 ± 2.27 µg/mL, against normal lung epithelial cells (MRC-5), resulting in a selectivity index (SI) value of 0.61 on A549 cells and 1.03 on SHP-77 cells, which was compared to the positive drug control, actinomycin D where the SI values were found to be 2 and 0.25 against A549 and SHP-77 cells, respectively. Against murine macrophages (RAW 264.7) and hepatocytes (HepG2), the HO ethanolic extract showed IC50 values of 60.15 ± 1.98 µg/mL and 23.61 ± 1.06 µg/mL, respectively. Microscopy showed that the HO ethanolic extract induced apoptosis in the A549 and HepG2 cells at 50 µg/mL and 300 µg/mL, respectively. The HO ethanolic extract, furthermore, inhibited the pro-inflammatory enzymes, cyclooxygenase 2 (COX-2) and 5-lipoxygenase (5-LOX) with IC50 values of 7.94 ± 3.84 µg/mL and 2.08 ± 1.35 µg/mL, respectively, whereas the positive controls Ibuprofen (COX-2) and Zileuton (5-LOX) showed IC50 values of 0.85 ± 0.14 µg/mL and 0.06 ± 0.05 µg/mL, respectively. The activity of NAD(P)H quinone oxidoreductase-1 (NQO1), which is a direct target of nuclear factor erythroid-2-related factor-2 (NRF2), was significantly inhibited in the A549 cells by the HO ethanolic extract (at 125 µg/mL) when compared to the positive control, brusatol (at 500 nM). Using the ex ovo yolk sac membrane (YSM) assay, the HO ethanolic extract (at 18.5 µg/egg) showed a 31.65 ± 12.80% inhibition of blood vessel formation. This is the first report of the noteworthy antiproliferative activity of the HO ethanolic extract on lung cancer cells including its potential to target several enzymes associated with inflammation and therefore, should be considered for further analysis.

Optimization of Antiproliferative Properties of Triimine Copper(II) Complexes, Choroba, Katarzyna, Zowiślok Bartosz, Kula Sławomir, Machura Barbara, Maroń {Anna M. }, Erfurt Karol, Marques Cristiana, Cordeiro Sandra, Baptista {Pedro V. }, and Fernandes {Alexandra R. } , Journal Of Medicinal Chemistry, Volume 67, Number 21, p.19475–19502, (2024) Abstract

Cu(II) complexes with 2,2′:6′,2″-terpyridines (terpy) and 2,6-bis(thiazol-2-yl)pyridines (dtpy) with 1- or 2-naphtyl and methoxy-naphtyl were synthesized to elucidate the impact of the triimine core, naphtyl linking mode, and presence of methoxy groups on the antiproliferative activity of [CuCl2(Ln)]. Their antiproliferative effect was analyzed in ovarian (A2780) and colorectal (HCT116) carcinomas and colorectal carcinoma resistant to doxorubicin (HCT116-DoxR) cell lines and in normal human fibroblasts. Among all complexes, the 1- and 2-naphtyl substituted terpy Cu(II) complexes (Cu1a and Cu1b) showed the strongest cytotoxicity, namely, in HCT116-DoxR 2Dcells and were also capable of inducing the loss of cell viability in 3D HCT116-DoxR spheroids. Their intracellular localization, capability to increase reactive oxygen species (ROS), and interaction with DNA (nonintercalative mode) trigger oxidative DNA cleavage leading to cell death by apoptosis and autophagy. Cu1a and Cu1b do not show in vivo toxicity in a chicken embryo and can interact with bovine serum albumin (BSA).

2022
Antiproliferative Activity of Buddleja saligna (Willd.) against Melanoma and In Vivo Modulation of Angiogenesis, Twilley, Danielle, Thipe {Velaphi C. }, Kishore Navneet, Bloebaum Pierce, Roma-Rodrigues Catarina, Baptista {Pedro V. }, Fernandes {Alexandra R. }, Selepe {Mamoalosi A. }, Langhansova Lenka, Katti Kattesh, and Lall Namrita , Pharmaceuticals, nov, Volume 15, Number 12, (2022) Abstract

Melanoma cells secrete pro-angiogenic factors, which stimulates growth, proliferation and metastasis, and therefore are key therapeutic targets. Buddleja saligna (BS), and an isolated triterpenoid mixture (DT-BS-01) showed a fifty percent inhibitory concentration (IC50) of 33.80 ± 1.02 and 5.45 ± 0.19 µg/mL, respectively, against melanoma cells (UCT-MEL-1) with selectivity index (SI) values of 1.64 and 5.06 compared to keratinocytes (HaCat). Cyclooxygenase-2 (COX-2) inhibition was observed with IC50 values of 35.06 ± 2.96 (BS) and 26.40 ± 4.19 µg/mL (DT-BS-01). BS (30 µg/mL) significantly inhibited interleukin (IL)-6 (83.26 ± 17.60%) and IL-8 (100 ± 0.2%) production, whereas DT-BS-01 (5 µg/mL) showed 51.07 ± 2.83 (IL-6) and 0 ± 6.7% (IL-8) inhibition. Significant vascular endothelial growth factor (VEGF) inhibition, by 15.84 ± 4.54 and 12.21 ± 3.48%, respectively, was observed. In the ex ovo chick embryo yolk sac membrane assay (YSM), BS (15 µg/egg) significantly reduced new blood vessel formation, with 53.34 ± 11.64% newly formed vessels. Silver and palladium BS nanoparticles displayed noteworthy SI values. This is the first report on the significant anti-angiogenic activity of BS and DT-BS-01 and should be considered for preclinical trials as there are currently no US Food and Drug Administration (FDA) approved drugs to inhibit angiogenesis in melanoma.

2021
Copper(ii) complexes with tridentate halogen-substituted Schiff base ligands: synthesis, crystal structures and investigating the effect of halogenation, leaving groups and ligand flexibility on antiproliferative activities, Kordestani, Nazanin, {Amiri Rudbari} Hadi, Fernandes {Alexandra R. }, Raposo {Luís R. }, Luz André, Baptista {Pedro V. }, Bruno Giuseppe, Scopelliti Rosario, Fateminia Zohreh, Micale Nicola, Tumanov Nikolay, Wouters Johan, {Abbasi Kajani} Abolghasem, and Bordbar {Abdol Khalegh} , Dalton Transactions, mar, Volume 50, Number 11, p.3990–4007, (2021) Abstract

To investigate the effect of different halogen substituents and leaving groups and the flexibility of ligands on the anticancer activity of copper complexes, sixteen copper(ii) complexes with eight different tridentate Schiff-base ligands containing pyridine and 3,5-halogen-substituted phenol moieties were synthesized and characterized by spectroscopic methods. Four of these complexes were also characterized by X-ray crystallography. The cytotoxicity of the complexes was determined in three different tumor cell lines (i.e.the A2780 ovarian, HCT116 colorectal and MCF7 breast cancer cell line) and in a normal primary fibroblast cell line. Complexes were demonstrated to induce a higher loss of cell viability in the ovarian carcinoma cell line (A2780) with respect to the other two tumor cell lines, and therefore the biological mechanisms underlying this loss of viability were further investigated. Complexes with ligandL1(containing a 2-pycolylamine-type motif) were more cytotoxic than complexes withL2(containing a 2-(2-pyridyl)ethylamine-type motif). The loss of cell viability in A2780 tumor cells was observed in the orderCu(Cl2-L1)NO3>Cu(Cl2-L1)Cl>Cu(Br2-L1)Cl>Cu(BrCl-L1)Cl. All complexes were able to induce reactive oxygen species (ROS) that could be related to the loss of cell viability. ComplexesCu(BrCl-L1)ClandCu(Cl2-L1)NO3were able to promote A2780 cell apoptosis and autophagy and for complexCu(BrCl-L1)Clthe increase in apoptosis was due to the intrinsic pathway.Cu(Cl2-L1)ClandCu(Br2-L1)Clcomplexes lead to cellular detachment allowing to correlate with the results of loss of cell viability. Despite the ability of theCu(BrCl-L1)Clcomplex to induce programmed cell death in A2780 cells, its therapeutic window turned out to be low making theCu(Cl2-L1)NO3complex the most promising candidate for additional biological applications.

2020
Antiproliferative Activities of Diimine-Based Mixed Ligand Copper(II) Complexes, Kordestani, Nazanin, Rudbari {Hadi Amiri}, Fernandes {Alexandra R. }, Raposo {Luís R. }, Baptista {Pedro V. }, Ferreira {Daniela A. }, Bruno Giuseppe, Bella Giovanni, Scopelliti Rosario, Braun {Jason D. }, Herbert {David E. }, and Blacque Olivier , ACS Combinatorial Science, feb, Volume 22, Number 2, p.89–99, (2020) Abstract

A series of Cu(diimine)(X-sal)(NO3) complexes, where the diimine is either 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) and X-sal is a monoanionic halogenated salicylaldehyde (X = Cl, Br, I, or H), have been synthesized and characterized by elemental analysis and X-ray crystallography. Penta-coordinate geometries copper(II) were observed for all cases. The influence of the diimine coligands and different halogen atoms on the antiproliferative activities toward human cancer cell lines have been investigated. All Cu(II) complexes were able to induce a loss of A2780 ovarian carcinoma cell viability, with phen derivatives more active than bpy derivatives. In contrast, no in vitro antiproliferative effects were observed against the HCT116 colorectal cancer cell line. These cytotoxicity differences were not due to a different intracellular concentration of the complexes determined by inductively coupled plasma atomic emission spectroscopy. A small effect of different halogen substituents on the phenolic ring was observed, with X = Cl being the most highly active toward A2780 cells among the phen derivatives, while X = Br presented the lowest IC50 in A2780 cells for bpy analogs. Importantly, no reduction in normal primary fibroblasts cell viability was observed in the presence of bpy derivatives (IC50 > 40 μM). Mechanistically, complex 1 seems to induce a stronger apoptotic response with a higher increase in mitochondrial membrane depolarization and an increased level of intracellular reactive oxygen species (ROS) compared to complex 3. Together, these data and the low IC50 compared to cisplatin in A2780 ovarian carcinoma cell line demonstrate the potential of these bpy derivatives for further in vivo studies.

2019
Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas strains valorizing crude glycerol by-product, Kourmentza, Constantina, Araújo Diana, Sevrin Chantal, Roma-Rodriques Catarina, Ferreira {Joana Lia}, Freitas Filomena, Dionisio Madalena, Baptista {Pedro V. }, Fernandes {Alexandra R. }, Grandfils Christian, and Reis {Maria A. M. } , Bioresource Technology, jun, Volume 281, p.31–40, (2019) Abstract

While screening for polyhydroxyalkanoate (PHA) producing strains, using glycerol rich by-product as carbon source, it was observed that extracellular polymers were also secreted into the culture broth. The scope of this study was to characterize both intracellular and extracellular polymers, produced by Pseudomonas putida NRRL B-14875 and Pseudomonas chlororaphis DSM 50083, mostly focusing on those novel extracellular polymers. It was found that they fall into the class of bioemulsifiers (BE), as they showed excellent emulsion stability against different hydrocarbons/oils at various pH conditions, temperature and salinity concentrations. Cytotoxicity tests revealed that BE produced by P. chlororaphis inhibited the growth of highly pigmented human melanoma cells (MNT-1) by 50% at concentrations between 150 and 200 μg/mL, while no effect was observed on normal skin primary keratinocytes and melanocytes. This is the first study reporting mcl-PHA production by P. putida NRRL B-14785 and bioemulsifier production from both P. putida and P. chlororaphis strains.

2018
Optical and Structural Characterization of a Chronic Myeloid Leukemia DNA Biosensor, Cordeiro, Mílton, Otrelo-Cardoso {Ana Rita Castro}, Svergun {Dmitri I. }, Konarev {Petr V. }, Lima {João Carlos}, Santos-Silva Teresa, and Baptista {Pedro Viana} , ACS Chemical Biology, may, Volume 13, Number 5, p.1235–1242, (2018) Abstract

Selective base pairing is the foundation of DNA recognition. Here, we elucidate the molecular and structural details of a FRET-based two-component molecular beacon relying on steady-state fluorescence spectroscopy, small-angle X-ray scattering (SAXS), microscale thermophoresis (MST), and differential electrophoretic mobility. This molecular beacon was designed to detect the most common fusion sequences causing chronic myeloid leukemia, e14a2 and e13a2. The emission spectra indicate that the self-assembly of the different components of the biosensor occurs sequentially, triggered by the fully complementary target. We further assessed the structural alterations leading to the specific fluorescence FRET signature by SAXS, MST, and the differential electrophoretic mobility, where the size range observed is consistent with hybridization and formation of a 1:1:1 complex for the probe in the presence of the complementary target and revelator. These results highlight the importance of different techniques to explore conformational DNA changes in solution and its potential to design and characterize molecular biosensors for genetic disease diagnosis.

2017
Potentiating angiogenesis arrest in vivo via laser irradiation of peptide functionalised gold nanoparticles, Pedrosa, Pedro, Heuer-Jungemann Amelie, Kanaras {Antonios G. }, Fernandes {Alexandra R. }, and Baptista {Pedro V. } , Journal of Nanobiotechnology, nov, Volume 15, Number 1, (2017) Abstract

Background: Anti-angiogenic therapy has great potential for cancer therapy with several FDA approved formulations but there are considerable side effects upon the normal blood vessels that decrease the potential application of such therapeutics. Chicken chorioallantoic membrane (CAM) has been used as a model to study angiogenesis in vivo. Using a CAM model, it had been previously shown that spherical gold nanoparticles functionalised with an anti-angiogenic peptide can humper neo-angiogenesis. Results: Our results show that gold nanoparticles conjugated with an anti-angiogenic peptide can be combined with visible laser irradiation to enhance angiogenesis arrest in vivo. We show that a green laser coupled to gold nanoparticles can achieve high localized temperatures able to precisely cauterize blood vessels. This combined therapy acts via VEGFR pathway inhibition, leading to a fourfold reduction in FLT-1 expression. Conclusions: The proposed phototherapy extends the use of visible lasers in clinics, combining it with chemotherapy to potentiate cancer treatment. This approach allows the reduction of dose of anti-angiogenic peptide, thus reducing possible side effects, while destroying blood vessels supply critical for tumour progression.

2016
Peptide-coated gold nanoparticles for modulation of angiogenesis in vivo, Roma-Rodrigues, Catarina, Heuer-Jungemann Amelie, de Fernandes {Maria Alexandra Núncio Carvalho Ramos}, Kanaras {Antonios G. }, and Baptista {Pedro Miguel Ribeiro Viana} , International journal of nanomedicine, Volume 11, p.2633–2639, (2016) Abstract

In this work, peptides designed to selectively interact with cellular receptors involved in the regulation of angiogenesis were anchored to oligo-ethylene glycol-capped gold nanoparticles (AuNPs) and used to evaluate the modulation of vascular development using an ex ovo chick chorioallantoic membrane assay. These nanoparticles alter the balance between naturally secreted pro- and antiangiogenic factors, under various biological conditions, without causing toxicity. Exposure of chorioallantoic membranes to AuNP-peptide activators of angiogenesis accelerated the formation of new arterioles when compared to scrambled peptide-coated nanoparticles. On the other hand, antiangiogenic AuNP-peptide conjugates were able to selectively inhibit angiogenesis in vivo. We demonstrated that AuNP vectorization is crucial for enhancing the effect of active peptides. Our data showed for the first time the effective control of activation or inhibition of blood vessel formation in chick embryo via AuNP-based formulations suitable for the selective modulation of angiogenesis, which is of paramount importance in applications where promotion of vascular growth is desirable (eg, wound healing) or ought to be contravened, as in cancer development.