Rui Pedrosa - Academia.edu (original) (raw)

Papers by Rui Pedrosa

Research paper thumbnail of Antioxidants from Fucus spiralis: in-vitro testing to assess the bioaccessibility

Frontiers in Marine Science, 2016

Research paper thumbnail of Evaluation of seaweed extracts functionality as post-harvest treatment for minimally processed Fuji apples

Innovative Food Science & Emerging Technologies, 2016

Abstract The potential application of Fucus spiralis, Bifurcaria bifurcata, Codium tomentosum and... more Abstract The potential application of Fucus spiralis, Bifurcaria bifurcata, Codium tomentosum and Codium vermilara extracts as post-harvest treatments in minimally processed (MP) Fuji apple was investigated. 0.5% solutions of each extract were applied to MP Fuji apple and its effect on product quality was assessed over 20 days of storage at 4 ± 2 °C in terms of moisture content, soluble solids concentration (SSC), firmness, browning index (BI) and POD and PPO activities. Application of Codium tomentosum extract resulted in a significant reduction in BI in comparison to all other tested treatments. POD and PPO activities were also significantly lower in MP apple treated with Codium tomentosum extract. These results identify Codium tomentosum extract functionality of reducing enzymatic browning, suggesting the potential application of this extract as a natural additive in MP fruit. Industrial relevance This study shows the advantages of using a novel post-harvest treatment based in edible seaweed extracts to preserve fresh-cut fruits, in particular Fuji apple. The results show clearly that this type of dipping treatment decreases browning index and inhibits enzymatic activities when compared with citric acid and control treatment (water). Codium tomentosum extract solution showed the highest efficacy, suggesting the potential application of this extract as a natural additive to be a substitute of chemicals used in food industry and its use has been restricted. This process is efficient, versatile and of simple implementation at the industrial level once the only change in the industrial process consists in the type of post-harvest solution treatment. Associated to the easy adaptation in the industrial process, the exponential development in aquaculture sector allows the obtention of this raw material in a sustained way. Extract functionality was attributed to its demarked inhibitory action on enzymatic activities of polyphenol oxidase and peroxidase, two major enzymes involved in enzymatic browning processes.

Research paper thumbnail of New Insights into the Dermocosmetic Potential of the Red Seaweed Gelidium corneum

Antioxidants

This work addresses the potential of the red seaweed Gelidium corneum as a source of bioactive in... more This work addresses the potential of the red seaweed Gelidium corneum as a source of bioactive ingredients for skin health and wellness in response to the growing awareness regarding the significance of sustainable strategies in developing new nature-based dermocosmetic products. Hydroalcoholic extracts from the dried biomass were subjected to sequential liquid–liquid partitions, affording five different fractions (F1–F5). Their cosmetic potential was assessed through a set of in vitro assays concerning their antioxidant, photoprotective, and healing properties. Additionally, their cytotoxicity in HaCaT cells and their capacity to induce inflammation in RAW 264.7 cells were also evaluated. As a proof-of-concept, O/W emulsions were prepared, and emulsion stability was assessed by optical microscopy, droplet size analysis, centrifugation tests, and rheology analysis. Furthermore, in vivo tests were conducted with the final formulation to assess its antioxidant capacity. At subtoxic co...

Research paper thumbnail of Marine-Derived Components: Can They Be a Potential Therapeutic Approach to Parkinson’s Disease?

Marine Drugs

The increase in the life expectancy average has led to a growing elderly population, thus leading... more The increase in the life expectancy average has led to a growing elderly population, thus leading to a prevalence of neurodegenerative disorders, such as Parkinson’s disease (PD). PD is the second most common neurodegenerative disorder and is characterized by a progressive degeneration of the dopaminergic neurons in the substantia nigra pars compacta (SNpc). The marine environment has proven to be a source of unique and diverse chemical structures with great therapeutic potential to be used in the treatment of several pathologies, including neurodegenerative impairments. This review is focused on compounds isolated from marine organisms with neuroprotective activities on in vitro and in vivo models based on their chemical structures, taxonomy, neuroprotective effects, and their possible mechanism of action in PD. About 60 compounds isolated from marine bacteria, fungi, mollusk, sea cucumber, seaweed, soft coral, sponge, and starfish with neuroprotective potential on PD therapy are r...

Research paper thumbnail of Antiulcerogenic Potential of the Ethanolic Extract of Ceiba speciosa (A. St.-Hil.) Ravenna Evaluated by In Vitro and In Vivo Studies

International Journal of Molecular Sciences

Gastrointestinal diseases, such as peptic ulcers, are caused by a damage in the gastric mucosa pr... more Gastrointestinal diseases, such as peptic ulcers, are caused by a damage in the gastric mucosa provoked by several factors. This stomach injury is regulated by many inflammatory mediators and is commonly treated with proton-pump inhibitors, histamine H2 receptor blockers and antacids. However, various medicinal plants have demonstrated positive effects on gastric ulcer treatment, including plants of the Ceiba genus. The aim of this study was to evaluate the antiulcer and anti-inflammatory activities of the stem bark ethanolic extract of Ceiba speciosa (A. St.-Hil.) Ravenna. We performed a preliminary quantification of phenolic compounds by high-performance liquid chromatography-diode array detection (HPLC-DAD), followed by the prospection of other chemical groups through nuclear magnetic resonance (NMR) spectroscopy. A set of in vitro assays was used to evaluate the extract potential regarding its antioxidant activity (DPPH: 19.83 ± 0.34 µg/mL; TPC: 307.20 ± 6.20 mg GAE/g of extract...

Research paper thumbnail of Disclosing the antitumour potential of the marine bromoditerpene sphaerococcenol A on distinct cancer cellular models

Biomedicine & Pharmacotherapy

Nature has revealed to be a key source of innovative anticancer drugs. This study evaluated the a... more Nature has revealed to be a key source of innovative anticancer drugs. This study evaluated the antitumour potential of the marine bromoditerpene sphaerococcenol A on different cancer cellular models. Dose-response analyses (0.1-100 µM; 24 h) were accomplished in eight different tumour cell lines (A549, CACO-2, HCT-15, MCF-7, NCI-H226, PC-3, SH-SY5Y, SK-MEL-28). Deeper studies were conducted on MFC-7 cells, namely, determination of hydrogen peroxide (H2O2) levels and evaluation of apoptosis biomarkers (phosphatidylserine membrane translocation, mitochondrial dysfunction, Caspase-9 activity, and DNA changes). The ability of the compound to induce genotoxicity was verified in L929 fibroblasts. Sphaerococcenol A capacity to impact colorectal-cancer stem cells (CSCs) tumourspheres (HT29, HCT116, SW620) was evaluated by determining tumourspheres viability, number, and area, as well as the proteasome inhibitory activity. Sphaerococcenol A hepatoxicity was studied in AML12 hepatocytes. The compound exhibited cytotoxicity in all malignant cell lines (IC50 ranging from 4.5 to 16.6 µM). MCF-7 cells viability loss was accompanied by H2O2 generation, mitochondrial dysfunction, Caspase-9 activation and DNA nuclear morphology changes. Furthermore, the compound displayed the lowest IC50 on HT29-derived tumourspheres (0.70 µM), followed by HCT116 (1.77 µM) and SW620 (2.74 µM), impacting the HT29 tumoursphere formation by reducing their number and area. Finally, the compound displayed low cytotoxicity on AML12 hepatocytes without genotoxicity. Overall, sphaerococcenol A exhibits broad cytotoxic effects on different tumour cells, increasing H2O2 production and apoptosis. It also affects colorectal CSCs-enriched tumoursphere development. These data highlight the relevance to include sphaerococcenol A in further pharmacological studies aiming cancer treatments.

Research paper thumbnail of Marine invasive macroalgae: Turning a real threat into a major opportunity - the biotechnological potential of Sargassum muticum and Asparagopsis armata

Algal Research, 2018

Marine invasive species are widely recognized as one of the worst threats to marine ecosystems in... more Marine invasive species are widely recognized as one of the worst threats to marine ecosystems integrity, unbalancing native communities, which may lead to paramount ecological and economic impacts. Within invasive seaweeds, Sargassum muticum and Asparagopsis armata are recognized as successful invaders in Europe and America. Despite several attempts to control the spread of marine invaders, until now, all have proven to be elusive, and therefore, alternative strategies should be embraced. Worldwide, seaweeds have been increasingly explored due to their ability to produce bioactive compounds. However, one of the main problems associated with the production/extraction of these bioactive compounds for new products development, is the source availability and the potential negative environmental consequences of this exploitation. Within this framework, the use of invasive species to obtain natural bioactive compounds presents us with a two-folded opportunity-high availability of the biological material for the extraction of unique bioactive compounds for new products development, and through specimen collection, mitigating negative effects caused by alien species, contributing for ecosystem integrity and sustainability. Over the last decades, the brown seaweed S. muticum and the red A. armata have been studied all over the world for their capacity to produce bioactive compounds, with main results pointing towards their high potential as producers of antioxidant, antifouling, antimicrobial, and antitumor compounds. The present review summarizes the biotechnological potential of S. muticum and A. armata as producers of bioactive compounds, while addressing the potential use of global threats as important blue growth pawns. 1. State of the art Marine environments are among the richest and most complex ecosystems, encompassing a wide and yet not fully known diversity of species, genetic diversity, and also a vast array of habitats molding organism's presence and responses [1,2]. Normally, these ecosystems are balanced, however with marine resources over-exploration, pollution, and climate changes, marine ecosystems are continuously changing, promoting drivers for invasive species emergence and success. An invasive species was defined as "one that has been introduced by human activity, either deliberately or accidentally, to a new geographic area or ecosystem outside of its natural distribution range, and which has then established and spread" [3-5]. The emergence of invasive species is a serious environmental problem that affects entire biological communities. They compete with native ones (leading to their displacement) and alter habitat's structures promoting biodiversity loss and cascading effects or trophic web shifts that can result in major negative impacts on the ecosystem [6-9]. Ultimately, invasive species can promote the eradication of native ones impoverishing local genetic variability, in a process known as "biotic homogenization" [10]. As a result, invasive seaweeds play a key role in marine ecosystem's equilibrium, structure and function by modifying, creating, maintaining, or

Research paper thumbnail of Adjunctive role of Calyptranthes tricona extract with probiotic Kluyveromyces marxianus on colorectal adenocarcinoma Caco-2 cells

Phytochemistry Letters, 2019

The composition of microbiota may influence the development of colorectal cancer (CRC). In additi... more The composition of microbiota may influence the development of colorectal cancer (CRC). In addition, probiotics can decrease the chance of developing cancer or its progress. For that reason, it is encouraging to assess the influence of plant extracts as adjuvants of the health-promoting effects of probiotics. Thus, this study aimed to investigate the in vitro beneficial properties of Calyptranthes tricona leaf ethanol extract in association or not with the lactic yeast Kluyveromyces marxianus on colon adenocarcinoma Caco-2 cells. C. tricona extract inhibited the in vitro p38α MAPK activity and exhibited immunomodulation on isolated human lymphocytes. Further, the extract did not induce cytotoxicity towards K. marxianus or Caco-2 cells; leading to an increased yeast adhesion to cells in a dose-dependent manner. In conclusion, this preliminary study demonstrates that C. tricona extract has effects on enzyme inhibition and immune function. In addition, when associated with K. marxianus, C. tricona may possess beneficial properties for application as enhancer of probiotic's protective role on CRC cells. However, further studies are necessary in order to elucidate the mechanisms involved.

Research paper thumbnail of Antitumor activities of Sphaerococccus coronopifolius bromoditerpenes on in vitro human cancer cell lines

Frontiers in Marine Science, 2018

Research paper thumbnail of Sulfated Polysaccharides from Macroalgae—A Simple Roadmap for Chemical Characterization

Polymers

The marine environment presents itself as a treasure chest, full of a vast diversity of organisms... more The marine environment presents itself as a treasure chest, full of a vast diversity of organisms yet to be explored. Among these organisms, macroalgae stand out as a major source of natural products due to their nature as primary producers and relevance in the sustainability of marine ecosystems. Sulfated polysaccharides (SPs) are a group of polymers biosynthesized by macroalgae, making up part of their cell wall composition. Such compounds are characterized by the presence of sulfate groups and a great structural diversity among the different classes of macroalgae, providing interesting biotechnological and therapeutical applications. However, due to the high complexity of these macromolecules, their chemical characterization is a huge challenge, driving the use of complementary physicochemical techniques to achieve an accurate structural elucidation. This review compiles the reports (2016–2021) of state-of-the-art methodologies used in the chemical characterization of macroalgae ...

Research paper thumbnail of Antioxidant and antimicrobial potential of six Fucoids from the Mediterranean Sea and the Atlantic Ocean

Journal of the Science of Food and Agriculture

BACKGROUD In recent years, research on the bioactive properties of macroalgae has increased, due ... more BACKGROUD In recent years, research on the bioactive properties of macroalgae has increased, due to the great interest in exploring new products that can contribute to improve human health and well-being. In the present study, the antioxidant and antimicrobial potential of six different brown algae of the Fucales order were evaluated, namely Ericaria selaginoides, Ericaria amentacea, Gongolaria baccata, Gongolaria usneoides, Cystoseira compressa and Sargassum vulgare (collected along the Mediterranean and Atlantic coasts). The antioxidant capacity was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, the Oxygen Radical Absorbent Capacity (ORAC) and the Ferric reducing antioxidant power (FRAP) and were related to the total phenolic content (TPC). The antimicrobial activity was evaluated measuring the growth inhibition of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. RESULTS The highest antioxidant capacity was obtained for Ericaria selaginoides revealing the highest capacity to scavenge DPPH radical (EC50 = 27.02 μg/mL), highest FRAP (1761.19 μM FeSO4 E/ g extract), high ORAC (138.92 μmol TE/g extract), alongside to its high TPC (121.5 GAE/ g extract). This species also reported the highest antimicrobial capacity against Staphylococcus aureus (IC50 = 268 μg/mL). CONCLUSIONS Among all studied seaweed, Ericaria selaginoides reveals the highest antioxidant and antimicrobial activities, and thus should be explored as a natural food additive and/or functional ingredient. This article is protected by copyright. All rights reserved.

Research paper thumbnail of Chlorella

Nonvitamin and Nonmineral Nutritional Supplements, 2019

Research paper thumbnail of Boosting Antimicrobial Activity of Ciprofloxacin by Functionalization of Mesoporous Silica Nanoparticles

Pharmaceutics, 2021

Mesoporous silica nanoparticles (MSNs) are very promising nanomaterials for treating bacterial in... more Mesoporous silica nanoparticles (MSNs) are very promising nanomaterials for treating bacterial infections when combined with pharmaceutical drugs. Herein, we report the preparation of two nanomaterials based on the immobilization of ciprofloxacin in mesoporous silica nanoparticles, either as the counter-ion of the choline derivative cation (MSN-[Ch][Cip]) or via anchoring on the surface of amino-group modified MSNs via an amide bond (MSN-Cip). Both nanomaterials were characterized by TEM, FTIR and solution 1H NMR spectroscopies, elemental analysis, XRD and N2 adsorption at 77 K in order to provide the desired structures. No cytotoxicity from the prepared mesoporous nanoparticles on 3T3 murine fibroblasts was observed. The antimicrobial activity of the nanomaterials was determined against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Klebsiella pneumoniae) bacteria and the results were promising against S. aureus. In the case of B. subtilis, both nano...

Research paper thumbnail of Seaweed’s Role in Energetic Transition from Environmental Pollution Challenges to Enhanced Electrochemical Devices

Biology, 2022

Resulting from the growing human population and the long dependency on fossil-based energies, the... more Resulting from the growing human population and the long dependency on fossil-based energies, the planet is facing a critical rise in global temperature, which is affecting all ecosystem networks. With a growing consciousness this issue, the EU has defined several strategies towards environment sustainability, where biodiversity restoration and preservation, pollution reduction, circular economy, and energetic transition are paramount issues. To achieve the ambitious goal of becoming climate-neutral by 2050, it is vital to mitigate the environmental footprint of the energetic transition, namely heavy metal pollution resulting from mining and processing of raw materials and from electronic waste disposal. Additionally, it is vital to find alternative materials to enhance the efficiency of energy storage devices. This review addresses the environmental challenges associated with energetic transition, with particular emphasis on the emergence of new alternative materials for the develo...

Research paper thumbnail of Spirulina

Nonvitamin and Nonmineral Nutritional Supplements, 2019

Research paper thumbnail of Red Algae

Nonvitamin and Nonmineral Nutritional Supplements, 2019

Research paper thumbnail of Reproductive biological characteristics and fatty acid profile of Holothuria mammata ( Grube , 1840 )

In southern Europe, the interest in sea cucumbers is relatively recent, but several fisheries hav... more In southern Europe, the interest in sea cucumbers is relatively recent, but several fisheries have now been developed, as well as aquaculture projects. Holothuria mammata is one of the holothurian species targeted. In this study, some reproductive biological characteristics of H. mammata were studied, such as sex ratio, weight, gonadosomatic index, gonadal tubules morphology, and oocytes diameter in different stages of maturation. The lipid profile was also analysed in order to highlight the fatty acid requirements in a diet for broodstock conditioning. The spring period, from March to April, corresponds to maturation and subsequent spawning. Total fat content was 1.00% ± 2.45, and highest values of fatty acids were obtained for stearic acid (C18:0) (8.91% ± 1.44), arachidonic acid (C20:4 ω6) (19.97% ± 1.30), and eicosapentaenoic acid (C20:5 ω3) (10.85% ± 0.37). The findings lead us to consider higher requirements of long-chain polyunsaturated fatty acids (or LC–PUFAs) in broodstock...

Research paper thumbnail of Marine endophytic fungi associated with Halopteris scoparia (Linnaeus) Sauvageau as producers of bioactive secondary metabolites with potential dermocosmetic application

PLOS ONE, 2021

Marine fungi and, particularly, endophytic species have been recognised as one of the most prolif... more Marine fungi and, particularly, endophytic species have been recognised as one of the most prolific sources of structurally new and diverse bioactive secondary metabolites with multiple biotechnological applications. Despite the increasing number of bioprospecting studies, very few have already evaluated the cosmeceutical potential of marine fungal compounds. Thus, this study focused on a frequent seaweed in the Portuguese coast,Halopteris scoparia, to identify the endophytic marine fungi associated with this host, and assess their ability to biosynthesise secondary metabolites with antioxidative, enzymatic inhibitory (hyaluronidase, collagenase, elastase and tyrosinase), anti-inflammatory, photoprotective, and antimicrobial (Cutibacterium acnes,Staphylococcus epidermidisandMalassezia furfur) activities. The results revealed eight fungal taxa included in the Ascomycota, and in the most representative taxonomic classes in marine ecosystems (Eurotiomycetes,SordariomycetesandDothideomy...

Research paper thumbnail of The marine invasive seaweeds Asparagopsis armata and Sargassum muticum as targets for greener antifouling solutions

Science of The Total Environment, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of Fluoroquinolone-Based Organic Salts and Ionic Liquids as Highly Bioavailable Broad-Spectrum Antimicrobials

Proceedings, 2020

The majority of antibiotics display low oral bioavailability due to reduced solubility in water a... more The majority of antibiotics display low oral bioavailability due to reduced solubility in water and/or inefficient permeability across biological membranes. Their efficiency is further limited by the frequent presence of polymorphic structures with different pharmaceutical activities. In this communication, we present our latest results on the development of organic salts and ionic liquids from fluoroquinolones (FQ-OSILs) as highly efficient ionic formulations of this family of antimicrobials. Ciprofloxacin and norfloxacin were used as anions and as cations, by combination with biocompatible organic counter-ions. In vitro bioavailability studies showed that all prepared FQ-OSILs presented higher solubility in water than the original drugs. All compounds were found to be isomorphic and with tailorable antimicrobial activity according to the cation–anion combination against Staphylococcus aureus, Bacillus subtilis and Klebsiella pneumoniae strains.

Research paper thumbnail of Antioxidants from Fucus spiralis: in-vitro testing to assess the bioaccessibility

Frontiers in Marine Science, 2016

Research paper thumbnail of Evaluation of seaweed extracts functionality as post-harvest treatment for minimally processed Fuji apples

Innovative Food Science & Emerging Technologies, 2016

Abstract The potential application of Fucus spiralis, Bifurcaria bifurcata, Codium tomentosum and... more Abstract The potential application of Fucus spiralis, Bifurcaria bifurcata, Codium tomentosum and Codium vermilara extracts as post-harvest treatments in minimally processed (MP) Fuji apple was investigated. 0.5% solutions of each extract were applied to MP Fuji apple and its effect on product quality was assessed over 20 days of storage at 4 ± 2 °C in terms of moisture content, soluble solids concentration (SSC), firmness, browning index (BI) and POD and PPO activities. Application of Codium tomentosum extract resulted in a significant reduction in BI in comparison to all other tested treatments. POD and PPO activities were also significantly lower in MP apple treated with Codium tomentosum extract. These results identify Codium tomentosum extract functionality of reducing enzymatic browning, suggesting the potential application of this extract as a natural additive in MP fruit. Industrial relevance This study shows the advantages of using a novel post-harvest treatment based in edible seaweed extracts to preserve fresh-cut fruits, in particular Fuji apple. The results show clearly that this type of dipping treatment decreases browning index and inhibits enzymatic activities when compared with citric acid and control treatment (water). Codium tomentosum extract solution showed the highest efficacy, suggesting the potential application of this extract as a natural additive to be a substitute of chemicals used in food industry and its use has been restricted. This process is efficient, versatile and of simple implementation at the industrial level once the only change in the industrial process consists in the type of post-harvest solution treatment. Associated to the easy adaptation in the industrial process, the exponential development in aquaculture sector allows the obtention of this raw material in a sustained way. Extract functionality was attributed to its demarked inhibitory action on enzymatic activities of polyphenol oxidase and peroxidase, two major enzymes involved in enzymatic browning processes.

Research paper thumbnail of New Insights into the Dermocosmetic Potential of the Red Seaweed Gelidium corneum

Antioxidants

This work addresses the potential of the red seaweed Gelidium corneum as a source of bioactive in... more This work addresses the potential of the red seaweed Gelidium corneum as a source of bioactive ingredients for skin health and wellness in response to the growing awareness regarding the significance of sustainable strategies in developing new nature-based dermocosmetic products. Hydroalcoholic extracts from the dried biomass were subjected to sequential liquid–liquid partitions, affording five different fractions (F1–F5). Their cosmetic potential was assessed through a set of in vitro assays concerning their antioxidant, photoprotective, and healing properties. Additionally, their cytotoxicity in HaCaT cells and their capacity to induce inflammation in RAW 264.7 cells were also evaluated. As a proof-of-concept, O/W emulsions were prepared, and emulsion stability was assessed by optical microscopy, droplet size analysis, centrifugation tests, and rheology analysis. Furthermore, in vivo tests were conducted with the final formulation to assess its antioxidant capacity. At subtoxic co...

Research paper thumbnail of Marine-Derived Components: Can They Be a Potential Therapeutic Approach to Parkinson’s Disease?

Marine Drugs

The increase in the life expectancy average has led to a growing elderly population, thus leading... more The increase in the life expectancy average has led to a growing elderly population, thus leading to a prevalence of neurodegenerative disorders, such as Parkinson’s disease (PD). PD is the second most common neurodegenerative disorder and is characterized by a progressive degeneration of the dopaminergic neurons in the substantia nigra pars compacta (SNpc). The marine environment has proven to be a source of unique and diverse chemical structures with great therapeutic potential to be used in the treatment of several pathologies, including neurodegenerative impairments. This review is focused on compounds isolated from marine organisms with neuroprotective activities on in vitro and in vivo models based on their chemical structures, taxonomy, neuroprotective effects, and their possible mechanism of action in PD. About 60 compounds isolated from marine bacteria, fungi, mollusk, sea cucumber, seaweed, soft coral, sponge, and starfish with neuroprotective potential on PD therapy are r...

Research paper thumbnail of Antiulcerogenic Potential of the Ethanolic Extract of Ceiba speciosa (A. St.-Hil.) Ravenna Evaluated by In Vitro and In Vivo Studies

International Journal of Molecular Sciences

Gastrointestinal diseases, such as peptic ulcers, are caused by a damage in the gastric mucosa pr... more Gastrointestinal diseases, such as peptic ulcers, are caused by a damage in the gastric mucosa provoked by several factors. This stomach injury is regulated by many inflammatory mediators and is commonly treated with proton-pump inhibitors, histamine H2 receptor blockers and antacids. However, various medicinal plants have demonstrated positive effects on gastric ulcer treatment, including plants of the Ceiba genus. The aim of this study was to evaluate the antiulcer and anti-inflammatory activities of the stem bark ethanolic extract of Ceiba speciosa (A. St.-Hil.) Ravenna. We performed a preliminary quantification of phenolic compounds by high-performance liquid chromatography-diode array detection (HPLC-DAD), followed by the prospection of other chemical groups through nuclear magnetic resonance (NMR) spectroscopy. A set of in vitro assays was used to evaluate the extract potential regarding its antioxidant activity (DPPH: 19.83 ± 0.34 µg/mL; TPC: 307.20 ± 6.20 mg GAE/g of extract...

Research paper thumbnail of Disclosing the antitumour potential of the marine bromoditerpene sphaerococcenol A on distinct cancer cellular models

Biomedicine & Pharmacotherapy

Nature has revealed to be a key source of innovative anticancer drugs. This study evaluated the a... more Nature has revealed to be a key source of innovative anticancer drugs. This study evaluated the antitumour potential of the marine bromoditerpene sphaerococcenol A on different cancer cellular models. Dose-response analyses (0.1-100 µM; 24 h) were accomplished in eight different tumour cell lines (A549, CACO-2, HCT-15, MCF-7, NCI-H226, PC-3, SH-SY5Y, SK-MEL-28). Deeper studies were conducted on MFC-7 cells, namely, determination of hydrogen peroxide (H2O2) levels and evaluation of apoptosis biomarkers (phosphatidylserine membrane translocation, mitochondrial dysfunction, Caspase-9 activity, and DNA changes). The ability of the compound to induce genotoxicity was verified in L929 fibroblasts. Sphaerococcenol A capacity to impact colorectal-cancer stem cells (CSCs) tumourspheres (HT29, HCT116, SW620) was evaluated by determining tumourspheres viability, number, and area, as well as the proteasome inhibitory activity. Sphaerococcenol A hepatoxicity was studied in AML12 hepatocytes. The compound exhibited cytotoxicity in all malignant cell lines (IC50 ranging from 4.5 to 16.6 µM). MCF-7 cells viability loss was accompanied by H2O2 generation, mitochondrial dysfunction, Caspase-9 activation and DNA nuclear morphology changes. Furthermore, the compound displayed the lowest IC50 on HT29-derived tumourspheres (0.70 µM), followed by HCT116 (1.77 µM) and SW620 (2.74 µM), impacting the HT29 tumoursphere formation by reducing their number and area. Finally, the compound displayed low cytotoxicity on AML12 hepatocytes without genotoxicity. Overall, sphaerococcenol A exhibits broad cytotoxic effects on different tumour cells, increasing H2O2 production and apoptosis. It also affects colorectal CSCs-enriched tumoursphere development. These data highlight the relevance to include sphaerococcenol A in further pharmacological studies aiming cancer treatments.

Research paper thumbnail of Marine invasive macroalgae: Turning a real threat into a major opportunity - the biotechnological potential of Sargassum muticum and Asparagopsis armata

Algal Research, 2018

Marine invasive species are widely recognized as one of the worst threats to marine ecosystems in... more Marine invasive species are widely recognized as one of the worst threats to marine ecosystems integrity, unbalancing native communities, which may lead to paramount ecological and economic impacts. Within invasive seaweeds, Sargassum muticum and Asparagopsis armata are recognized as successful invaders in Europe and America. Despite several attempts to control the spread of marine invaders, until now, all have proven to be elusive, and therefore, alternative strategies should be embraced. Worldwide, seaweeds have been increasingly explored due to their ability to produce bioactive compounds. However, one of the main problems associated with the production/extraction of these bioactive compounds for new products development, is the source availability and the potential negative environmental consequences of this exploitation. Within this framework, the use of invasive species to obtain natural bioactive compounds presents us with a two-folded opportunity-high availability of the biological material for the extraction of unique bioactive compounds for new products development, and through specimen collection, mitigating negative effects caused by alien species, contributing for ecosystem integrity and sustainability. Over the last decades, the brown seaweed S. muticum and the red A. armata have been studied all over the world for their capacity to produce bioactive compounds, with main results pointing towards their high potential as producers of antioxidant, antifouling, antimicrobial, and antitumor compounds. The present review summarizes the biotechnological potential of S. muticum and A. armata as producers of bioactive compounds, while addressing the potential use of global threats as important blue growth pawns. 1. State of the art Marine environments are among the richest and most complex ecosystems, encompassing a wide and yet not fully known diversity of species, genetic diversity, and also a vast array of habitats molding organism's presence and responses [1,2]. Normally, these ecosystems are balanced, however with marine resources over-exploration, pollution, and climate changes, marine ecosystems are continuously changing, promoting drivers for invasive species emergence and success. An invasive species was defined as "one that has been introduced by human activity, either deliberately or accidentally, to a new geographic area or ecosystem outside of its natural distribution range, and which has then established and spread" [3-5]. The emergence of invasive species is a serious environmental problem that affects entire biological communities. They compete with native ones (leading to their displacement) and alter habitat's structures promoting biodiversity loss and cascading effects or trophic web shifts that can result in major negative impacts on the ecosystem [6-9]. Ultimately, invasive species can promote the eradication of native ones impoverishing local genetic variability, in a process known as "biotic homogenization" [10]. As a result, invasive seaweeds play a key role in marine ecosystem's equilibrium, structure and function by modifying, creating, maintaining, or

Research paper thumbnail of Adjunctive role of Calyptranthes tricona extract with probiotic Kluyveromyces marxianus on colorectal adenocarcinoma Caco-2 cells

Phytochemistry Letters, 2019

The composition of microbiota may influence the development of colorectal cancer (CRC). In additi... more The composition of microbiota may influence the development of colorectal cancer (CRC). In addition, probiotics can decrease the chance of developing cancer or its progress. For that reason, it is encouraging to assess the influence of plant extracts as adjuvants of the health-promoting effects of probiotics. Thus, this study aimed to investigate the in vitro beneficial properties of Calyptranthes tricona leaf ethanol extract in association or not with the lactic yeast Kluyveromyces marxianus on colon adenocarcinoma Caco-2 cells. C. tricona extract inhibited the in vitro p38α MAPK activity and exhibited immunomodulation on isolated human lymphocytes. Further, the extract did not induce cytotoxicity towards K. marxianus or Caco-2 cells; leading to an increased yeast adhesion to cells in a dose-dependent manner. In conclusion, this preliminary study demonstrates that C. tricona extract has effects on enzyme inhibition and immune function. In addition, when associated with K. marxianus, C. tricona may possess beneficial properties for application as enhancer of probiotic's protective role on CRC cells. However, further studies are necessary in order to elucidate the mechanisms involved.

Research paper thumbnail of Antitumor activities of Sphaerococccus coronopifolius bromoditerpenes on in vitro human cancer cell lines

Frontiers in Marine Science, 2018

Research paper thumbnail of Sulfated Polysaccharides from Macroalgae—A Simple Roadmap for Chemical Characterization

Polymers

The marine environment presents itself as a treasure chest, full of a vast diversity of organisms... more The marine environment presents itself as a treasure chest, full of a vast diversity of organisms yet to be explored. Among these organisms, macroalgae stand out as a major source of natural products due to their nature as primary producers and relevance in the sustainability of marine ecosystems. Sulfated polysaccharides (SPs) are a group of polymers biosynthesized by macroalgae, making up part of their cell wall composition. Such compounds are characterized by the presence of sulfate groups and a great structural diversity among the different classes of macroalgae, providing interesting biotechnological and therapeutical applications. However, due to the high complexity of these macromolecules, their chemical characterization is a huge challenge, driving the use of complementary physicochemical techniques to achieve an accurate structural elucidation. This review compiles the reports (2016–2021) of state-of-the-art methodologies used in the chemical characterization of macroalgae ...

Research paper thumbnail of Antioxidant and antimicrobial potential of six Fucoids from the Mediterranean Sea and the Atlantic Ocean

Journal of the Science of Food and Agriculture

BACKGROUD In recent years, research on the bioactive properties of macroalgae has increased, due ... more BACKGROUD In recent years, research on the bioactive properties of macroalgae has increased, due to the great interest in exploring new products that can contribute to improve human health and well-being. In the present study, the antioxidant and antimicrobial potential of six different brown algae of the Fucales order were evaluated, namely Ericaria selaginoides, Ericaria amentacea, Gongolaria baccata, Gongolaria usneoides, Cystoseira compressa and Sargassum vulgare (collected along the Mediterranean and Atlantic coasts). The antioxidant capacity was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, the Oxygen Radical Absorbent Capacity (ORAC) and the Ferric reducing antioxidant power (FRAP) and were related to the total phenolic content (TPC). The antimicrobial activity was evaluated measuring the growth inhibition of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. RESULTS The highest antioxidant capacity was obtained for Ericaria selaginoides revealing the highest capacity to scavenge DPPH radical (EC50 = 27.02 μg/mL), highest FRAP (1761.19 μM FeSO4 E/ g extract), high ORAC (138.92 μmol TE/g extract), alongside to its high TPC (121.5 GAE/ g extract). This species also reported the highest antimicrobial capacity against Staphylococcus aureus (IC50 = 268 μg/mL). CONCLUSIONS Among all studied seaweed, Ericaria selaginoides reveals the highest antioxidant and antimicrobial activities, and thus should be explored as a natural food additive and/or functional ingredient. This article is protected by copyright. All rights reserved.

Research paper thumbnail of Chlorella

Nonvitamin and Nonmineral Nutritional Supplements, 2019

Research paper thumbnail of Boosting Antimicrobial Activity of Ciprofloxacin by Functionalization of Mesoporous Silica Nanoparticles

Pharmaceutics, 2021

Mesoporous silica nanoparticles (MSNs) are very promising nanomaterials for treating bacterial in... more Mesoporous silica nanoparticles (MSNs) are very promising nanomaterials for treating bacterial infections when combined with pharmaceutical drugs. Herein, we report the preparation of two nanomaterials based on the immobilization of ciprofloxacin in mesoporous silica nanoparticles, either as the counter-ion of the choline derivative cation (MSN-[Ch][Cip]) or via anchoring on the surface of amino-group modified MSNs via an amide bond (MSN-Cip). Both nanomaterials were characterized by TEM, FTIR and solution 1H NMR spectroscopies, elemental analysis, XRD and N2 adsorption at 77 K in order to provide the desired structures. No cytotoxicity from the prepared mesoporous nanoparticles on 3T3 murine fibroblasts was observed. The antimicrobial activity of the nanomaterials was determined against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Klebsiella pneumoniae) bacteria and the results were promising against S. aureus. In the case of B. subtilis, both nano...

Research paper thumbnail of Seaweed’s Role in Energetic Transition from Environmental Pollution Challenges to Enhanced Electrochemical Devices

Biology, 2022

Resulting from the growing human population and the long dependency on fossil-based energies, the... more Resulting from the growing human population and the long dependency on fossil-based energies, the planet is facing a critical rise in global temperature, which is affecting all ecosystem networks. With a growing consciousness this issue, the EU has defined several strategies towards environment sustainability, where biodiversity restoration and preservation, pollution reduction, circular economy, and energetic transition are paramount issues. To achieve the ambitious goal of becoming climate-neutral by 2050, it is vital to mitigate the environmental footprint of the energetic transition, namely heavy metal pollution resulting from mining and processing of raw materials and from electronic waste disposal. Additionally, it is vital to find alternative materials to enhance the efficiency of energy storage devices. This review addresses the environmental challenges associated with energetic transition, with particular emphasis on the emergence of new alternative materials for the develo...

Research paper thumbnail of Spirulina

Nonvitamin and Nonmineral Nutritional Supplements, 2019

Research paper thumbnail of Red Algae

Nonvitamin and Nonmineral Nutritional Supplements, 2019

Research paper thumbnail of Reproductive biological characteristics and fatty acid profile of Holothuria mammata ( Grube , 1840 )

In southern Europe, the interest in sea cucumbers is relatively recent, but several fisheries hav... more In southern Europe, the interest in sea cucumbers is relatively recent, but several fisheries have now been developed, as well as aquaculture projects. Holothuria mammata is one of the holothurian species targeted. In this study, some reproductive biological characteristics of H. mammata were studied, such as sex ratio, weight, gonadosomatic index, gonadal tubules morphology, and oocytes diameter in different stages of maturation. The lipid profile was also analysed in order to highlight the fatty acid requirements in a diet for broodstock conditioning. The spring period, from March to April, corresponds to maturation and subsequent spawning. Total fat content was 1.00% ± 2.45, and highest values of fatty acids were obtained for stearic acid (C18:0) (8.91% ± 1.44), arachidonic acid (C20:4 ω6) (19.97% ± 1.30), and eicosapentaenoic acid (C20:5 ω3) (10.85% ± 0.37). The findings lead us to consider higher requirements of long-chain polyunsaturated fatty acids (or LC–PUFAs) in broodstock...

Research paper thumbnail of Marine endophytic fungi associated with Halopteris scoparia (Linnaeus) Sauvageau as producers of bioactive secondary metabolites with potential dermocosmetic application

PLOS ONE, 2021

Marine fungi and, particularly, endophytic species have been recognised as one of the most prolif... more Marine fungi and, particularly, endophytic species have been recognised as one of the most prolific sources of structurally new and diverse bioactive secondary metabolites with multiple biotechnological applications. Despite the increasing number of bioprospecting studies, very few have already evaluated the cosmeceutical potential of marine fungal compounds. Thus, this study focused on a frequent seaweed in the Portuguese coast,Halopteris scoparia, to identify the endophytic marine fungi associated with this host, and assess their ability to biosynthesise secondary metabolites with antioxidative, enzymatic inhibitory (hyaluronidase, collagenase, elastase and tyrosinase), anti-inflammatory, photoprotective, and antimicrobial (Cutibacterium acnes,Staphylococcus epidermidisandMalassezia furfur) activities. The results revealed eight fungal taxa included in the Ascomycota, and in the most representative taxonomic classes in marine ecosystems (Eurotiomycetes,SordariomycetesandDothideomy...

Research paper thumbnail of The marine invasive seaweeds Asparagopsis armata and Sargassum muticum as targets for greener antifouling solutions

Science of The Total Environment, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of Fluoroquinolone-Based Organic Salts and Ionic Liquids as Highly Bioavailable Broad-Spectrum Antimicrobials

Proceedings, 2020

The majority of antibiotics display low oral bioavailability due to reduced solubility in water a... more The majority of antibiotics display low oral bioavailability due to reduced solubility in water and/or inefficient permeability across biological membranes. Their efficiency is further limited by the frequent presence of polymorphic structures with different pharmaceutical activities. In this communication, we present our latest results on the development of organic salts and ionic liquids from fluoroquinolones (FQ-OSILs) as highly efficient ionic formulations of this family of antimicrobials. Ciprofloxacin and norfloxacin were used as anions and as cations, by combination with biocompatible organic counter-ions. In vitro bioavailability studies showed that all prepared FQ-OSILs presented higher solubility in water than the original drugs. All compounds were found to be isomorphic and with tailorable antimicrobial activity according to the cation–anion combination against Staphylococcus aureus, Bacillus subtilis and Klebsiella pneumoniae strains.