Loading...
15 results
Search Results
Now showing 1 - 10 of 15
- A biorefinery approach to the biomass of the seaweed Undaria pinnatifida (Harvey Suringar, 1873): obtaining phlorotannins-enriched extracts for wound healingPublication . Ferreira, Carolina A. M.; Félix, Rafael; Félix, Carina; Januário, Adriana P.; Alves, Nuno; Novais, Sara C.; Dias, Juliana R.; Lemos, Marco F.L.Brown seaweeds are recognized sources of compounds with a wide range of properties and applications. Within these compounds, phlorotannins are known to possess several bioactivities (e.g., antioxidant, anti-inflammatory, and antimicrobial) with potential to improve wound healing. To obtain phlorotannins enriched extracts from Undaria pinnatifida, a biorefinery was set using lowcost industry-friendly methodologies, such as sequential solid–liquid extraction and liquid–liquid extraction. The obtained extracts were screened for their antioxidant and antimicrobial activity against five common wound pathogens and for their anti-inflammatory potential. The ethanolic wash fraction (wE100) had the highest antioxidant activity (114.61 +- 10.04 mmol mg-1 extract by Diphenyl-1-picrylhydrazyl (DPPH) and 6.56 +-1.13mMeq. Fe II mg-1 extract by and Ferric Reducing Antioxidant Power (FRAP)), acting efficiently against Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria, and showing a nitric oxide production inhibition over 47% when used at 0.01 ug mL-1. NMR and FTIR chemical characterization suggested that phlorotannins are present. Obtained fraction wE100 proved to be a promising candidate for further inclusion as wound healing agents, while the remaining fractions analyzed are potential sources for other biotechnological applications, giving emphasis to a biorefinery and circular economy framework to add value to this seaweed and the industry.
- Industry-friendly hydroethanolic extraction protocols for Grateloupia turuturu UV-shielding and antioxidant compoundsPublication . Félix, Rafael; Carmona, Ana M.; Félix, Carina; Novais, Sara C.; Lemos, Marco F.L.Grateloupia turuturu is an invasive macroalga on the Iberian coast, known to produce bioactive compounds with di erent cosmeceutical bioactivities, namelyUVshielding and antioxidants. The goal of this study was to optimize the extraction procedure of main bioactivities of this species with cosmetic potential, using Response Surface Methodology. Two Box–Behnken designs were used to evaluate the e ect of ethanol concentration (0–50%), liquid-solid ratio, time, pH, and temperature on yield, UV absorbance, and antioxidant activity. Both optimizations showed a similar trend: aqueous extracts have higher yields and extracts performed with ethanol as part of the solvent have higher activities concerning UV absorbance and antioxidant activity. For all the extracts an absorption peak between 320 and 340 nm was observed. This data now allows further studies by narrowing the extracts worthful of characterization. The development of industry-friendly extraction methods allows the valorization of this invasive species, contributing for the potential creation of natural and eco-friendly products by the cosmetic industry while contributing to the restoration of affected environments.
- Marine macroalgae, a source of natural inhibitors of Fungal PhytopathogensPublication . Vicente, Tânia F. L.; Lemos, Marco F.L.; Valentão, Patrícia; Félix, Rafael; Félix, CarinaFungal phytopathogens are a growing problem all over the world; their propagation causes significant crop losses, affecting the quality of fruits and vegetables, diminishing the availability of food, leading to the loss of billions of euros every year. To control fungal diseases, the use of synthetic chemical fungicides is widely applied; these substances are, however, environmentally damaging. Marine algae, one of the richest marine sources of compounds possessing a wide range of bioactivities, present an eco-friendly alternative in the search for diverse compounds with industrial applications. The synthesis of such bioactive compounds has been recognized as part of microalgal responsiveness to stress conditions, resulting in the production of polyphenols, polysaccharides, lipophilic compounds, and terpenoids, including halogenated compounds, already described as antimicrobial agents. Furthermore, many studies, in vitro or in planta, have demonstrated the inhibitory activity of these compounds with respect to fungal phytopathogens. This review aims to gather the maximum of information addressing macroalgae extracts with potential inhibition against fungal phytopathogens, including the best inhibitory results, while presenting some already reported mechanisms of action.
- Cosmeceutical potential of grateloupia turuturu: using low-cost extraction methodologies to obtain added-value extractsPublication . Félix, Carina; Félix, Rafael; Carmona, Ana M.; Januário, Adriana P.; Dias, Pedro D.M.; Vicente, Tânia F. L.; Silva, Joana; Alves, Celso; Pedrosa, Rui; Novais, Sara C.; Lemos, Marco F.L.The invasive macroalga Grateloupia turuturu is known to contain a diversity of bioactive compounds with different potentialities. Among them are compounds with relevant bioactivities for cosmetics. Considering this, this study aimed to screen bioactivities with cosmeceutical potential, namely, antioxidant, UV absorbance, anti-enzymatic, antimicrobial, and anti-inflammatory activities, as well as photoprotection potential. Extractions with higher concentrations of ethanol resulted in extracts with higher antioxidant activities, while for the anti-enzymatic activity, high inhibition percentages were obtained for elastase and hyaluronidase with almost all extracts. Regarding the antimicrobial activity, all extracts showed to be active against E. coli, S. aureus, and C. albicans. Extracts produced with higher percentages of ethanol were more effective against E. coli and with lower percentages against the other two microorganisms. Several concentrations of each extract were found to be safe for fibroblasts, but no photoprotection capacity was observed. However, one of the aqueous extracts was responsible for reducing around 40% of the nitric oxide production on macrophages, showing its anti-inflammatory potential. This work highlights G. turuturu’s potential in the cosmeceutical field, contributing to the further development of natural formulations for skin protection.
- The antiviral potential of algal lectinsPublication . Alvarez, Christian; Félix, Carina; Lemos, Marco F.L.Algae have emerged as fascinating subjects of study due to their vast potential as sources of valuable metabolites with diverse biotechnological applications, including their use as fertilizers, feed, food, and even pharmaceutical precursors. Among the numerous compounds found in algae, lectins have garnered special attention for their unique structures and carbohydrate specificities, distinguishing them from lectins derived from other sources. Here, a comprehensive overview of the latest scientific and technological advancements in the realm of algal lectins with a particular focus on their antiviral properties is provided. These lectins have displayed remarkable effectiveness against a wide range of viruses, thereby holding great promise for various antiviral applications. It is worth noting that several alga species have already been successfully commercialized for their antiviral potential. However, the discovery of a diverse array of lectins with potent antiviral capabilities suggests that the field holds immense untapped potential for further expansion. In conclusion, algae stand as a valuable and versatile resource, and their lectins offer an exciting avenue for developing novel antiviral agents, which may lead to the development of cutting-edge antiviral therapies.
- Seaweed as a natural source against phytopathogenic bacteriaPublication . Vicente, Tânia F.L.; Félix, Carina; Félix, Rafael; Valentão, Patrícia; Lemos, Marco F.L.Plant bacterial pathogens can be devastating and compromise entire crops of fruit and vegetables worldwide. The consequences of bacterial plant infections represent not only relevant economical losses, but also the reduction of food availability. Synthetic bactericides have been the most used tool to control bacterial diseases, representing an expensive investment for the producers, since cyclic applications are usually necessary, and are a potential threat to the environment. The development of greener methodologies is of paramount importance, and some options are already available in the market, usually related to genetic manipulation or plant community modulation, as in the case of biocontrol. Seaweeds are one of the richest sources of bioactive compounds, already being used in different industries such as cosmetics, food, medicine, pharmaceutical investigation, and agriculture, among others. They also arise as an eco-friendly alternative to synthetic bactericides. Several studies have already demonstrated their inhibitory activity over relevant bacterial phytopathogens, some of these compounds are known for their eliciting ability to trigger priming defense mechanisms. The present work aims to gather the available information regarding seaweed extracts/compounds with antibacterial activity and eliciting potential to control bacterial phytopathogens, highlighting the extracts from brown algae with protective properties against microbial attack.
- Red seaweed-derived compounds as a potential new approach for acne vulgaris carePublication . Januário, Adriana P.; Félix, Rafael; Félix, Carina; Reboleira, João; Valentão, Patrícia; Lemos, Marco F.L.Acne vulgaris (AV) is a chronic skin disease of the pilosebaceous unit affecting both adolescents and adults. Its pathophysiology includes processes of inflammation, increased keratinization, sebum production, hormonal dysregulation, and bacterial Cutibacterium acnes proliferation. Common AV has been treated with antibiotics since the 1960s, but strain resistance has emerged and is of paramount concern. Macroalgae are known producers of substances with bioactive properties, including anti-viral, antibacterial, antioxidant, and anti-inflammatory properties, among several others. In particular, red algae are rich in bioactive compounds such as polysaccharides, phenolic compounds, lipids, sterols, alkaloids, and terpenoids, conferring them antioxidant, antimicrobial, and anti-inflammatory activities, among others. Thus, the exploration of compounds from marine resources can be an appealing approach to discover new treatment options against AV. The aim of this work is to provide an overview of the current knowledge of the potentialities of red macroalgae in the treatment of AV by reviewing the main therapeutic targets of this disease, and then the existence of compounds or extracts with bioactive properties against them.
- The biotechnological potential of Asparagopsis armata: what is known of its chemical composition, bioactivities and current market?Publication . Félix, Rafael; Dias, Pedro; Félix, Carina; Cerqueira, Teresa; Andrade, Paula B.; Valentão, Patricia; Lemos, Marco F.L.Marine biomass is a resource with great potential to fuel a circular bioeconomy addressing the current economic and environmental world crisis, while seaweeds are known to be a great source of bioactive compounds with potential use for human and animal nutrition, novel natural preservatives, phytopharmaceuticals, cosmeceuticals, biopharmaceuticals, among others. Asparagopsis armata (Harvey, 1855) is a seaweed with high biomass production and exquisite biotechnological potential due to a myriad of produced secondary metabolites. Furthermore, it is one of the most aggressive invasive seaweed species becoming an economic and ecological problem in Europe. Simultaneously, it is a resource with market demand for its applications in cosmetics and, more recently, for its potential anti-methanogenic activity in ruminants. There is an appreciable amount of literature concerning the chemistry and the bioactivity of this seaweed species (and particularly its gametophyte, the focus of this review), as well as multiple products in the cosmetics market, but all this information is scattered and therefore poorly used. To potentiate the bioindustry of A. armata, the available scientific knowledge is here reviewed and an overview of the market for this species is comprehensively provided. Thus, the chemical composition of A. armata (primary metabolism, polysaccharide characteristics, amino acid profile, and nonhalogenated and halogenated secondary metabolites), its bioactivities (antibacterial, antifungal, antiviral, antiprotozoal, antioxidant, antitumor, anti-inflammatory, among others) and the existent, marketed extracts (cosmetic ingredients) are thoroughly compiled and discussed herein.
- Bioactive carbohydrate polymers: Between myth and realityPublication . Drira, Maroua; Hentati, Faiez; Babich, Olga; Sukhikh, Stanislas; Larina, Viktoria; Sharifian, Sana; Homai, Ahmad; Fendri, Imen; Lemos, Marco F.L.; Félix, Carina; Félix, Rafael; Abdelkafi, Slim; Michaud, PhilippePolysaccharides are complex macromolecules long regarded as energetic storage resources or as components of plant and fungal cell walls. They have also been described as plant mucilages or microbial exopolysaccharides. The development of glycosciences has led to a partial and difficult deciphering of their other biological functions in living organisms. The objectives of glycobiochemistry and glycobiology are currently to correlate some structural features of polysaccharides with some biological responses in the producing organisms or in another one. In this context, the literature focusing on bioactive polysaccharides has increased exponentially during the last two decades, being sometimes very optimistic for some new applications of bioactive polysaccharides, notably in the medical field. Therefore, this review aims to examine bioactive polysaccharide, taking a critical look of the different biological activities reported by authors and the reality of the market. It focuses also on the chemical, biochemical, enzymatic, and physical modifications of these biopolymers to optimize their potential as bioactive agents.
- Marine resources application potential for biotechnological purposesPublication . Lemos, Marco F.L.; Novais, Sara C.; Silva, Susana F.J.; Félix, Carina