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- Efficacy, Stability, and Safety Evaluation of New Polyphenolic Xanthones Towards Identification of Bioactive Compounds to Fight Skin PhotoagingPublication . Resende, Diana I. S. P.; Almeida, Mariana C.; Maciel, Bruna; Carmo, Helena; Lobo, José Sousa; Dal Pozzo, Carlotta; Cravo, Sara M.; Rosa, Gonçalo P.; Kane-Pagès, Aida; Barreto, Maria do Carmo; Almeida, Isabel F.; Sousa, Maria Emília de; Pinto, Madalena M. M.Antioxidants have long been used in the cosmetic industry to prevent skin photoaging, which is mediated by oxidative stress, making the search for new antioxidant compounds highly desirable in this field. Naturally occurring xanthones are polyphenolic compounds that can be found in microorganisms, fungi, lichens, and some higher plants. This class of polyphenols has a privileged scaffold that grants them several biological activities. We have previously identified simple oxygenated xanthones as promising antioxidants and disclosed as hit, 1,2-dihydroxyxanthone (1). Herein, we synthesized and studied the potential of xanthones with different polyoxygenated patterns as skin antiphotoaging ingredients. In the DPPH antioxidant assay, two newly synthesized derivatives showed IC₅₀ values in the same range as ascorbic acid. The synthesized xanthones were discovered to be excellent tyrosinase inhibitors and weak to moderate collagenase and elastase inhibitors but no activity was revealed against hyaluronidase. Their metal-chelating effect (FeCl₃ and CuCl₂) as well as their stability at different pH values were characterized to understand their potential to be used as future cosmetic active agents. Among the synthesized polyoxygenated xanthones, 1,2-dihydroxyxanthone (1) was reinforced as the most promising, exhibiting a dual ability to protect the skin against UV damage by combining antioxidant/metal-chelating properties with UV-filter capacity and revealed to be more stable in the pH range that is close to the pH of the skin. Lastly, the phototoxicity of 1,2-dihydroxyxanthone (1) was evaluated in a human keratinocyte cell line and no phototoxicity was observed in the concentration range tested.
- Chemical Composition and Phytopharmaceuticals : An Overview of the Caulerpa and Cystoseira GeneraPublication . Rosa, Gonçalo P.; Barreto, Maria do Carmo; Seca, Ana M. L.; Pinto, Diana C. G. A.In recent years, macroalgae attracted increasing attention from many industries of diverse branches such as plastics, cosmetics, pharmaceuticals, and food. This interest is due to the diverse chemical composition existing within the various macroalgae classes, which offer the possibility of finding a wide array of primary and secondary metabolites with exciting properties and great potential for pharmacological applications. Caulerpa spp. and Cystoseira spp. produce a wide array of exciting compounds that have been isolated and showed a broad range of biological activities such as anti-inflammatory, antibiotic, antiprotozoal, antitumor, cytotoxic activities, among others. These compounds present high biomedical potential, constituting natural structures that could serve as scaffolds for designing novel leads for pharmacological purposes. However, Caulerpa and Cystoseira species and their cosmetic potential are still understudied, which shows a great research opportunity.
- Seaweed Secondary Metabolites with Beneficial Health Effects : An Overview of Successes in In Vivo Studies and Clinical TrialsPublication . Rosa, Gonçalo P.; Tavares, Wilson R.; Sousa, Pedro M. C.; Pagès, Aida K.; Seca, Ana M. L.; Pinto, Diana C. G. A.Macroalgae are increasingly viewed as a source of secondary metabolites with great potential for the development of new drugs. In this development, in vitro studies are only the first step in a long process, while in vivo studies and clinical trials are the most revealing stages of the true potential and limitations that a given metabolite may have as a new drug. This literature review aims to give a critical overview of the secondary metabolites that reveal the most interesting results in these two steps. Phlorotannins show great pharmaceutical potential in in vivo models and, among the several examples, the anti-dyslipidemia activity of dieckol must be highlighted because it was more effective than lovastatin in an in vivo model. The IRLIIVLMPILMA tridecapeptide that exhibits an in vivo level of activity similar to the hypotensive clinical drug captopril should still be stressed, as well as griffithsin which showed such stunning results over a variety of animal models and which will probably move onto clinical trials soon. Regarding clinical trials, studies with pure algal metabolites are scarce, limited to those carried out with kahalalide F and fucoxanthin. The majority of clinical trials currently aim to ascertain the effect of algae consumption, as extracts or fractions, on obesity and diabetes.
- Valorization of Macaronesia Beach-Cast Seaweeds : Secondary Metabolites and Antiaging ActivityPublication . Seca, Ana M. L.; Faustino, Luís M. M.; Viveiros, Mariana Moniz; Rosa, Gonçalo P.; Barreto, Maria do CarmoBeach-cast seaweeds are a seasonal phenomenon consisting of the accumulation of large tons of algae on beaches, which is unpleasant for beach users and affects the tourism industry, mainly because tourists often interpret stranded natural litter as lowering beach quality, especially if the material starts to decompose. These beach casts are always variable mixtures of different species of seagrass and seaweeds. The present work aimed to contribute to the valorisation of this biomass by studying its chemical composition and bioactivities that reveal its potential in the pharmaceutical and/or cosmeceutical industries. […].
- A Green and Simple Protocol for Extraction and Application of a Peroxidase-Rich Enzymatic ExtractPublication . Rosa, Gonçalo P.; Barreto, Maria do Carmo; Pinto, Diana C. G. A.; Seca, Ana M. L.Recently there is a great social expectation that scientists should produce more sustainable and environmentally friendly chemical processes. Within this necessity, biocatalysis presents many attractive features because reactions are often performed in water, under mild conditions, the catalyst is biodegradable and can be obtained from renewable raw materials. In this work, we propose a simple, rapid and low-cost method for the preparation and application of an enzymatic extract from turnip root. The protocol described includes (1) the preparation of the enzymatic extract, (2) the procedure for the assessment of the more favorable working parameters (temperature, pH) and (3) the methodology for the application of the extract as the catalyst for biotransformation reactions. We anticipate that the protocol in this research will provide a simple way for obtaining an enzymatic extract which can operate efficiently under mild conditions and can effectively catalyze the biotransformation of simple phenols.
- Phytochemicals with Added Value from Morella and Myrica SpeciesPublication . Rosa, Gonçalo P.; Silva, Bruno J. C.; Seca, Ana M. L.; Moujir, Laila M.; Barreto, Maria do CarmoTerrestrial plants, due to their sessile nature, are highly exposed to environmental pressure and therefore need to produce very effective molecules that enable them to survive all the threats. Myrica and Morella (Myricaceae) are taxonomically close genera, which include species of trees or shrubs with edible fruits that exhibit relevant uses in traditional medicine. For instance, in Chinese or Japanese folk medicine, they are used to treat diarrhea, digestive problems, headache, burns, and skin diseases. A wide array of compounds isolated from different parts of Myrica and/or Morella species possess several biological activities, like anticancer, antidiabetic, anti-obesity, and cardio-/neuro-/hepatoprotective activities, both in vitro and in vivo, with myricanol, myricitrin, quercitrin, and betulin being the most promising. There are still many other compounds isolated from both genera whose biological activities have not been evaluated, which represents an excellent opportunity to discover new applications for those compounds and valorize Morella/Myrica species.
- Bio-Guided Optimization of Cystoseira abies-marina Cosmeceuticals Extraction by Advanced TechnologiesPublication . Rosa, Gonçalo P.; Peixoto, Andreia F.; Barreto, Maria do Carmo; Seca, Ana M. L.; Pinto, Diana C. G. A.Cystoseira abies-marina (reclassified as Gongolaria abies-marina) is a brown seaweed species rich in meroterpenoids, presenting interesting antioxidant, antitumor, and anti-inflammatory activities. However, there is still a lot to uncover regarding the bioactive potential of this species, as evidenced by the lack of records of antiaging activities from Cystoseira abies-marina, making this macroalga an excellent candidate for studies of its cosmeceutical potential. Ultrasound-(UAE) and microwave-assisted extraction (MAE) are advanced sustainable technologies that are very efficient in enhancing bioactive compound extraction. Applying these extraction techniques to a new biological matrix often calls for optimizing the parameters toward the best extraction yield. Since Cystoseira abies-marina is a new matrix for both UAE and MAE techniques, the present work proposes the optimization of the extraction process, using a novel approach: instead of only focusing on increasing the yield, the goal of this work is to determine the parameters for UAE and MAE that lead to extracts with better antiaging activities. For this bio-guided approach, several Cystoseira abies-marina extracts were prepared by UAE and MAE under varying conditions of solvent, time, and algae/solvent ratios. Their antiaging activities were then determined, and all the results combined to unveil the conditions yielding extracts with higher cosmeceutical potential. Using statistical tools, it was found that, for UAE, the best conditions were ethyl acetate, 15 min, and a ratio of 1:4, which led to an extract with high yield, and causing the strong inhibition of tyrosinase and elastase. In turn, ethanol, 10 min, and a ratio of 1:4 were the best conditions for MAE, leading to the extract with the best antioxidant activity. The results show that the proposed bio-guided approach was effective in obtaining extracts with high cosmeceutical potential, unveiling the possibility of modulating an extract’s activity by changing the extraction method.
- Pharmacological and Cosmeceutical Potential of Seaweed Beach-Casts of MacaronesiaPublication . Zárate, Rafael; Portillo, Eduardo; Teixidó, Sílvia; Carvalho, Miguel A. A. Pinheiro de; Nunes, Nuno; Ferraz, Sónia; Seca, Ana M. L.; Rosa, Gonçalo P.; Barreto, Maria do CarmoSeaweed beach-casts are a seasonal phenomenon that regularly deposits tons of algae biomass on beaches, which are usually disposed of in landfills. The present work aimed to contribute to the valorization of this biomass by studying bioactivities that reveal its potential in the pharmaceutical and/or cosmeceutical industries. Methanol and ethanol extracts and fractions from 15 beach-casts biomass were tested for a range of bioactivities. Eight of the most active samples exhibit IC50 values between 11.38 µg/mL and 19.28 µg/mL and selectivity indexes higher than 3.8, against NCI-H1299 (lung cancer) and T47D (breast cancer). Concerning antiaging potential, all the extracts tested presented UV protection, with SPF values above 30, like the standard sunscreen. Regarding aging-related enzymes, 24 samples were tyrosinase inhibitors exhibiting IC50 values from 9.01 µg/mL to 200.09 µg/mL. Eight extracts inhibited collagenase (IC50 < 248.76 µg/mL), two of them more actively than positive control EDTA (IC50 = 59.26 µg/mL). In addition to UV protection, the cumulative effect of antityrosinase and anticollagenase activities shown by the samples suggest that they may play a significant role in preventing skin photoaging. The results obtained demonstrate the high potential of beach-cast seaweed biomass as sources of cosmetic bioproducts with antiaging effects, and of selective cytotoxic metabolites.
- GC- and UHPLC-MS Profiles as a Tool to Valorize the Red Alga Asparagopsis armataPublication . Pinto, Diana C. G. A.; Lesenfants, Marie L.; Rosa, Gonçalo P.; Barreto, Maria do Carmo; Silva, Artur M. S.; Seca, Ana M. L.Asparagopsis armata Harvey is a red alga native from the southern hemisphere and then introduced in the Mediterranean Sea and the Atlantic Ocean, including the Azores Archipelago, where it is considered an invasive alga. Some studies show that the extracts exhibit antimicrobial and antifouling activities, and it is incorporated in some commercialized cosmetic products. (e.g., Ysaline®). However, knowledge of this species chemical composition is scarce. The GC-MS and UHPLC-MS profiles of both the nonpolar and polar extracts were established to contribute to this problem solution. According to the results, A. armata is rich in a great structural variety of halogenated lipophilic and aromatic compounds, some of them identified here for the first time. In the lipophilic extract, 25 compounds are identified, being the halogenated compounds and fatty acids, the two major compound families, corresponding to 54.8% and 35.7% of identified compounds (224 and 147 mg/100 g of dry algae, respectively). The 1,4-dibromobuten-1-ol and the palmitic acid are the two most abundant identified compounds (155 and 83.4 mg/100 g of dry algae, respectively). The polar extract demonstrated the richness of this species in brominated phenolics, from which the cinnamic acid derivatives are predominant. The results obtained herein open new perspectives for valuing the A. armata as a source of halogenated compounds and fatty acids, consequently improving its biotechnological and economic potential. Promoting this seaweed and the consequent increase in its demand will contribute to biodiversity conservation and ecosystem sustainability.
- Anti-aging activity of Lobophora variegata ethanolic and methanolic extracts and their fractionsPublication . Rosa, Gonçalo P.; Costa, Ana C.; Medeiros, D.; Seca, Ana M. L.; Barreto, Maria do CarmoSeaweed have promising applications within food, cosmetic and health industries, which led to an increased interest in studying these organisms [1]. In several coastal areas, thousands of tons of macroalgae are cast on beaches and shorelines and it would be very interesting if this biomass could be managed, allowing the extraction of added-value compounds. In this context, polar extracts (methanol and ethanol) of a macroalgal beach cast sample mainly composed of “Lobophora variegate” were prepared and the anti-aging and antioxidant activities were evaluated. The preliminary results showed interesting results, and thus these crude extracts were then fractionated sequentially by their solubility in dichloromethane, acetone and ethyl acetate, resulting in 4 semi-pure fractions each, which were also tested. Fractions A1.1.1 and A1.2.3 were very good tyrosinase inhibitors (IC₅₀ = 37.87 and 24.01 μg/mL, respectively) and fractions A1.1.2 and A1.2.2 presented very good inhibition of elastase (IC₅₀ = 44.76 and 20.86 μg/mL, respectively). However, none of the fractions was active against collagenase. These results show that further purifications of these fractions can lead to the isolation of bioactive added-value compounds.