► Antioxidants and prooxidants have been intensively studied over the past few decades. ► Recently, controversy has intensified in this area due to conflicting results. ► Natural and synthetic ...antioxidants both have advantages and disadvantages. ► Many different methods are used to screen matrixes or to find specific antioxidants. ► Due to some limitations, new methodologies are being prepared.
Many studies have been conducted with regard to free radicals, oxidative stress and antioxidant activity of food, giving antioxidants a prominent beneficial role, but, recently many authors have questioned their importance, whilst trying to understand the mechanisms behind oxidative stress. Many scientists defend that regardless of the quantity of ingested antioxidants, the absorption is very limited, and that in some cases prooxidants are beneficial to human health. The detection of antioxidant activity as well as specific antioxidant compounds can be carried out with a large number of different assays, all of them with advantages and disadvantages. The controversy around antioxidant in vivo benefits has become intense in the past few decades and the present review tries to shed some light on research on antioxidants (natural and synthetic) and prooxidants, showing the potential benefits and adverse effects of these opposing events, as well as their mechanisms of action and detection methodologies. It also identifies the limitations of antioxidants and provides a perspective on the likely future trends in this field.
•Three different biopolymeric films composed by chitosan, Peg and gelatin were developed.•Porphyrin dye was successfully incorporated into the different films.•Their spectral-luminescent properties ...were investigated including fluorescence lifetimes, quantum yields, singlet oxygen formation and Triplet–triplet absorption spectra.•Intracellular localization studies of the compounds under study were performed onto HeLa cells.•The anticancer activity of all the generated systems was evaluated.
Porphyrins and some of its derivatives are well known and widely used as photosensitizers (PSs) for Photodynamic Therapy of Cancer (PDT).
The present study regards the characterization and evaluation of a synthesized asymmetric porphyrin dye in solution to be used as PS for PDT. This molecule was also incorporated into biopolymeric films composed by chitosan, polyethylene glycol (PEG) and gelatin in order to overtake some of the disadvantages inherent to the PS, but more important, to evaluate the potential of a system composed by the porphyrin/biopolymer to be applied as localized therapeutic agents.
FTIR spectroscopy showed a strong interaction between the polymers involved in the preparation of the films under study: film 1: chitosan, film 2: chitosan/PEG and film 3: chitosan/gelatin.
Photochemical studies were performed for the dye in solution and into the three different biopolymeric films. Ground state absorption showed the characteristic bands of these kinds of dyes in solution and also incorporated into the films. The films composed by porphyrin/chitosan and porphyrin into chitosan/gelatin, revealed the presence of non-emissive aggregates exhibiting a strong quenching effect in the fluorescence intensity, quantum yields and lifetimes. In this way, the system composed by the porphyrin incorporated into the chitosan/PEG film presents the best fluorescence quantum yield and lifetime.
The transient absorption spectra were obtained for all the systems indicating the formation of an excited triplet state of the porphyrins following excitation, which takes special importance in the generation of phototoxic species namely singlet oxygen.
Singlet oxygen quantum yields were also determined and the results obtained were very promising for the dye in solution but also for the dye into the different substrates. The release of the dye from the three different films onto a buffer solution was evaluated and we conclude that after a few days the dye was completely released by the substrates in acidic conditions.
Confocal microscopy was used for the determination of the intracellular localization of the compound under study onto HeLa cells (human cervical cancer cells line).
The evaluation of the PSs anticancer activity assumes special importance for PDT studies. The system should be less toxic in the dark and more active when irradiated, therefore, toxicity in the dark and phototoxicity studies onto HeLa cells were performed.
Aim and Methods
Although the antimicrobial activity of extracts from several mushroom species has been reported, studies with the individual compounds present in that extracts are scarce. Herein, the ...antimicrobial activity of different phenolic compounds identified and quantified in mushroom species from all over the world was evaluated. Furthermore, a structure–activity relationship (SAR) analysis and molecular docking studies were performed, in order to provide insights into the mechanism of action of potential antimicrobial drugs for resistant micro‐organisms.
Results
2,4‐Dihydroxybenzoic and protocatechuic acids were the phenolic compounds with higher activity against the majority of Gram‐negative and Gram‐positive bacteria. Furthermore, phenolic compounds inhibited more MRSA than methicillin‐susceptible Staphylococcus aureus. MRSA was inhibited by 2,4‐dihydroxybenzoic, vanillic, syringic (MICs = 0·5 mg ml−1) and p‐coumaric (MIC = 1 mg ml−1) acids, while these compounds at the same concentrations had no inhibitory effects against methicillin‐susceptible Staph. aureus.
Conclusions
The presence of carboxylic acid (COOH), two hydroxyl (OH) groups in para and ortho positions of the benzene ring and also a methoxyl (OCH3) group in the meta position seems to be important for anti‐MRSA activity.
Significance and Impact of the Study
Phenolic compounds could be used as antimicrobial agents, namely against some micro‐organisms resistant to commercial antibiotics.
Microalgae productive chains are gaining importance as sustainable alternatives to obtain natural pigments. This work presents a review on the most promising pigments and microalgal sources by ...gathering trends from a 10-year bibliometric survey, a patents search, and an industrial and market analysis built from available market reports, projects and companies' webpages. The performed analysis pointed out chlorophylls, phycocyanin, astaxanthin, and β-carotene as the most relevant pigments, and
,
,
, and
, respectively, as the most studied sources.
is referred in the highest number of patents, corroborating a high technological interest in this microalga. The biorefinery concept, investment in projects and companies related to microalgae cultivation and/or pigment extraction is increasingly growing, particularly, for phycocyanin from
. These pieces of evidence are a step forward to consolidate the microalgal pigments market, which is expected to grow in the coming years, increasing the prospects of replacing synthetic pigments by natural counterparts.
Much recent marine microbial research has focused on sponges, but very little is known about how the sponge microbiome fits in the greater coral reef microbial metacommunity. Here, we present an ...extensive survey of the prokaryote communities of a wide range of biotopes from Indo-Pacific coral reef environments. We find a large variation in operational taxonomic unit (OTU) richness, with algae, chitons, stony corals and sea cucumbers housing the most diverse prokaryote communities. These biotopes share a higher percentage and number of OTUs with sediment and are particularly enriched in members of the phylum Planctomycetes. Despite having lower OTU richness, sponges share the greatest percentage (>90%) of OTUs with >100 sequences with the environment (sediment and/or seawater) although there is considerable variation among sponge species. Our results, furthermore, highlight that prokaryote microorganisms are shared among multiple coral reef biotopes, and that, although compositionally distinct, the sponge prokaryote community does not appear to be as sponge-specific as previously thought.
Nowadays, the food sector is highly concerned with environmental issues and foreseen to develop strategies to reduce waste and losses resulting from activities developed in the food system. An ...approach is to increment added value to the agro-industrial wastes, which might provide economic growth and environmental protection, contributing to a circular economy. Mushroom by-products represent a disposal problem, but they are also promising sources of important compounds, which may be used due to their functional and nutritional properties. Research has been developed in different fields to obtain value added solutions for the by-products generated during mushroom production and processing. Bioactive compounds have been obtained and applied in the development of nutraceutical and pharmaceutical formulations. Additionally, other applications have been explored and include animal feed, fertilizer, bioremediation, energy production, bio-based materials, cosmetics and cosmeceuticals. The main purpose of this review is to highlight the relevant composition of mushroom by-products and discuss their potential as a source of functional compounds and other applications. Future research needs to explore pilot and industrial scale extraction methods to understand the technological feasibility and the economic sustainability of the bioactive compounds extraction and valorization towards different applications.
Cosmetics, like any product containing water and organic/inorganic compounds, require preservation against microbial contamination to guarantee consumer’s safety and to increase their shelf-life. The ...microbiological safety has as main goal of consumer protection against potentially pathogenic microorganisms, together with the product’s preservation resulting from biological and physicochemical deterioration. This is ensured by chemical, physical, or physicochemical strategies. The most common strategy is based on the application of antimicrobial agents, either by using synthetic or natural compounds, or even multifunctional ingredients. Current validation of a preservation system follow the application of good manufacturing practices (GMPs), the control of the raw material, and the verification of the preservative effect by suitable methodologies, including the challenge test. Among the preservatives described in the positive lists of regulations, there are parabens, isothiasolinone, organic acids, formaldehyde releasers, triclosan, and chlorhexidine. These chemical agents have different mechanisms of antimicrobial action, depending on their chemical structure and functional group’s reactivity. Preservatives act on several cell targets; however, they might present toxic effects to the consumer. Indeed, their use at high concentrations is more effective from the preservation viewpoint being, however, toxic for the consumer, whereas at low concentrations microbial resistance can develop.
Public-private partnerships (PPPs) are widely spread long-term arrangements between governments and strategic private partner(s). One of their objectives is to reduce the financial pressure on the ...public treasury with regard to new investments. PPPs have been employed within the health care sector which, in turn, carries a huge social burden. In Portugal, for instance, PPPs in health care concern bundling hospital infrastructure and clinical services management. Notwithstanding the need to ensure sustainability and efficient use of hospital resources, it is clearly compulsory to guarantee that patients receive appropriate and timely care, with maximum security, and equitable manner. Still, little or even no attention has been paid in the literature to the clinical response capacity of PPP hospitals and to the populism arguing that these entities have a lower social performance than typical public hospitals. This study uses robust benchmarking methodologies alongside recent data about Portuguese hospitals (FY2012-FY2017) to demystify this idea and to demonstrate that, actually, PPP hospitals can deliver health care services with social performance levels at least as good as public hospitals.
•Social performance is evaluated for both public and PPP hospitals in Portugal.•Social performance levels are compared among both groups of hospitals.•There is no evidence supporting that one group delivers better care than the other.•Both groups of hospitals exhibit similar social performance levels.•Both groups present considerable social inefficiency sources to be corrected.
► Antioxidant potential of the most consumed fungi species was evaluated. ► Fruiting bodies revealed higher antioxidant properties than their mycelia. ► Agaricus bispous (brown) was the mushroom with ...the highest antioxidant potential. ► Lentinula edodes was the mycelium with the highest reducing power. ► Phenolic compounds were detected both in mushrooms and mycelia.
The present study reports a comparison of the antioxidant properties and phenolic profile of the most consumed species as fresh cultivated mushrooms and their mycelia produced in vitro: Agaricus bisporus (white and brown), Pleurotus ostreatus (oyster), Pleurotus eryngii (king oyster) and Lentinula edodes (shiitake). The antioxidant activity was evaluated through reducing power (Folin–Ciocalteu and Ferricyanide/Prussian blue assays), free radical scavenging activity (DPPH assay) and lipid peroxidation inhibition (β-carotene/linoleate and TBARS assays). The analysis of phenolic compounds was performed by HPLC/PAD. The mushroom species with the highest antioxidant potential was Agaricus bispous (brown). However, concerning to the species obtained in vitro, it was L. edodes that demonstrate the highest reducing power. Generally, in vivo samples revealed higher antioxidant properties than their mycelia obtained by in vitro techniques. About the phenolic compounds researched, they were detected both in mushrooms and mycelia without any particular abundance. Results showed that there is no correlation between the studied commercial mushrooms and the corresponding mycelia obtained in vitro. Nevertheless, this study contributes to the rise of data relatively to the species consumed as fresh mushrooms and the possibility of their in vitro production as a source of bioactive compounds.
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