Percorrer por autor "Conde, Tiago"
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- Bioactive lipids in : implications for functional foods and healthPublication . Pais, Rita; Conde, Tiago; Neves, Bruna B.; Pinho, Marisa; Coelho, Marta; Pereira, Hugo; Rodrigues, Alexandre M. C.; Domingues, Pedro; Gomes, Ana Maria; Urbatzka, Ralph; Domingues, Rosário; Melo, TâniaDunaliella salina is a green microalga extensively explored for β-carotene production, while knowledge of its lipid composition is still limited and poorly investigated. Among lipids, polar lipids have been highlighted as bioactive phytochemicals with health-promoting properties. This research aimed to provide an in-depth lipidome profiling of using liquid and gas chromatography coupled with mass spectrometry. The lipid content was 6.8%, including phospholipids, glycolipids, betaine lipids, sphingolipids, triglycerides, diglycerides, and pigments. Among the total esterified fatty acids, 13.6% were 18:3 omega-3 and 14.7% were 18:1 omega-9. The lipid extract of showed anti-inflammatory activity by inhibiting cyclooxygenase-2 activity at 100 µg/mL, dose-dependent antioxidant scavenging activity, and antidiabetic activity by inhibiting α-glucosidase activity at 25 and 125 µg/mL. In conclusion, the lipid extract of has the potential to be used as a functional food ingredient or in the nutraceutical and cosmeceutical industries.
- Comparative analysis of isoprostanoid profiles in Chlorella sorokiniana grown under autotrophic and heterotrophic conditionsPublication . Conde, Tiago; Lopes, Diana; Gros, Valérie; Reversat, Guillaume; Oger, Camille; Galano, Jean-Marie; Vigor, Claire; Rodrigues, Alexandre M. C.; Coelho, Natacha; Cardoso, Helena; Domingues, M. Rosário; Durand, ThierryOxylipins are bioactive lipid mediators derived from polyunsaturated fatty acids (PUFAs), with roles in oxidative stress responses, immunomodulation, and inflammation. While microalgae are recognized as valuable sources of oxylipins, their profiles remain less studied across different species and cultivation conditions. In this study, we characterized the non-enzymatic oxylipin profile of Chlorella sorokiniana grown under autotrophic and heterotrophic conditions to assess the influence of cultivation strategies on their production. A total of 22 isoprostanoids, mainly Phytoprostanes (PhytoP), Phytofurans (PhytoF), Isoprostanes (IsoP), and Neuroprostanes (NeuroP). Autotrophic cultivation resulted in a higher accumulation of isoprostanoids, particularly the alpha-linolenic acid (ALA) derivatives, PhytoP and PhytoF species, likely due to oxidative stress induced by fluctuating light and temperature conditions. In contrast, heterotrophic growth, performed under controlled conditions, yielded lower overall oxylipin levels highlighting the presence of 10(R)-10-F4t-NeuroP which was only present in heterotrophic Chlorella. We observed a correlation between the PUFA composition of Chlorella and its non-enzymatic oxylipin profile. Notably, several oxylipins identified in Chlorella have been associated with antiinflammatory, immunomodulatory, and neuroprotective properties, emphasizing the potential of this micro-alga as a source of high-value bioactive oxylipins. This study paves the way to the utilization of Chlorella as a source of bioactive oxylipins, as well as to develop cultivation strategies to enhance the production of these lipid mediators.
- Evaluation of parental and transgenerational effects of clotrimazole in Daphnia magna — A multi-parametric approachPublication . Ferreira, David; Alkimin, G. D.; Neves, Bruna; Conde, Tiago; Domingues, M. Rosário; Nunes, BrunoAzole antifungals inhibit the cytochrome P450 complex, decreasing the production of ergosterol in fungi, and compromising the biosynthesis of ecdysteroids in crustaceans, which are hormones regulating reproduction and ecdy-sis. The azole antifungal clotrimazole (CLO) raises environmental concerns due its toxicity. This work evaluated the effects on the number of moults, feeding rate, growth, reproduction, transgenerational reproductive effects on two dif-ferent generations (F0, parental generation; and F1, organisms born from F0), and energetic balance in Daphnia magna. Neonates (<24 h) were exposed to sublethal concentrations (0, 2.7, and 3.4 mg/L) of CLO, to assess its effects on the moulting process. Neonates were also exposed to environmentally realistic concentrations of CLO (0, 30,150, 750, and 3750 ng/L) for 24 and 96 h, to assess adverse effects on their feeding behaviour. Effects on energy reserves (fatty acids, glycogen, and protein levels) were also measured in animals exposed to CLO. A reproduction test was carried out to evaluate the amount and size of neonates from F0 and F1 generations. CLO exposure decreased the number of moults, and the size of organisms, but did not alter the feeding pattern of 5 days old individuals. However, neonates (<24 h) exposed to CLO had a significant decrease in their feeding pattern. CLO decreased the fatty acids content in exposed animals, but did not change glycogen and protein. CLO also decreased the size of adult daphnids from the third brood, born from animals exposed in F0; in F1 animals, the size of neonates from the third brood was decreased. This study evidenced the toxic effects caused by CLO on growth, feeding and reproduction of D. magna. Nevertheless, it is not pos-sible to conclude whether the effects are due to the inhibition of cytochrome P450 enzymes, or to unspecific effects caused by general toxic stress and decreased nutrition.
- Gelidium corneum and its solid by-product from agar extraction are sources of high-value and sustainable lipidsPublication . Batista, Joana; Lopes, Diana; Neves, Bruna B.; Pais, Ana Rita; Pinho, Marisa; Moreira, Ana S. P.; Conde, Tiago; Bonciarelli, Stefano; Goracci, Laura; Dias, João; Aguiar, André; Domingues, Pedro; Pereira, Hugo; Domingues, Maria Rosário; Melo, TâniaThe red alga Gelidium corneum is commonly harvested for agar extraction, producing significant biomass residue that remains underutilized. Gelidium corneum and its residue represent promising sources of high-value compounds, including lipid ingredients, encompassing omega-3 and omega-6 polyunsaturated fatty acids, with potential applications in foods and cosmetics. Algae lipids are quite diverse and complex, however the lipidome of G. corneum and its residue, along with their bioactive potential, remain largely unexplored. This study characterized the lipid signatures of G. corneum and its residue after agar extraction using reversed-phase liquid chromatography-tandem mass spectrometry (C18-RP-HPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) for esterified fatty acids (FAs) profiling. Despite low lipid content (<1% dry weight), G. corneum exhibited a higher glycolipid content, while the residue was richer in phospholipids and triacylglycerols. Nine FAs were identified, with FA 20:4 n-6 and FA 20:5 n-3 more abundant in G. corneum, and FA 18:1 n-9 and FA 18:2 n-6 in the residue, highlighting their nutritional and functional values. Their lipid profile comprised more than 400 lipid molecular species, following the trend of more glycolipids in G. corneum and phospholipids in the residue. Complex lipids with bioactive properties were identified in both matrices, expanding our knowledge of the lipid signature of this seaweed. Gelidium corneum lipids showed higher antioxidant scavenging activity and great anti-inflammatory potential by inhibiting cyclooxygenase-2 activity. Although neither matrix inhibited α-amylase, residue lipids effectively inhibited α-glucosidase activity. These findings emphasize G. corneum and its residue as sources of high-value lipids for sustainable biotechnological applications, including foods, nutraceuticals and cosmetics.
- Insight into the efficiency of microalgae’ lipidic extracts as photosensitizers for Antimicrobial Photodynamic Therapy against Staphylococcus aureusPublication . Mendonça, Inês; Silva, Daniela; Conde, Tiago; Maurício, Tatiana; Cardoso, Helena; Pereira, Hugo; Bartolomeu, Maria; Vieira, Cátia; Domingues, M. Rosário; Almeida, AdelaideAntibacterial resistance causes around 1.27 million deaths annually around the globe and has been recognized as a top 3 priority health threat. Antimicrobial photodynamic therapy (aPDT) is considered a promising alternative to conventional antibiotic treatments. Algal lipid extracts have shown antibacterial effects when used as photosensitizers (PSs) in aPDT. In this work we assessed the photodynamic efficiency of lipidic extracts of microalgae belonging to different phyla (Bacillariophyta, Chlorophyta, Cyanobacteria, Haptophyta, Ochrophyta and Rhodophyta). All the extracts (at 1 mg mL−1) demonstrated a reduction of Staphylococcus aureus >3 log10 (CFU mL−1), exhibiting bactericidal activity. Bacillariophyta and Haptophyta extracts were the top-performing phyla against S. aureus, achieving a reduction >6 log10 (CFU mL−1) with light doses of 60 J cm−2 (Bacillariophyta) and 90 J cm−2 (Haptophyta). The photodynamic properties of the Bacillariophyta Phaeodactylum tricornutum and the Haptophyta Tisochrysis lutea, the best effective microalgae lipid extracts, were also assessed at lower concentrations (75 μg mL−1, 7.5 μg mL−1, and 3.75 μg mL−1), reaching, in general, inactivation rates higher than those obtained with the widely used PSs, such as Methylene Blue and Chlorine e6, at lower concentration and light dose. The presence of chlorophyll c, which can absorb a greater amount of energy than chlorophylls a and b; rich content of polyunsaturated fatty acids (PUFAs) and fucoxanthin, which can also produce ROS, e.g. singlet oxygen (1O2), when photo-energized; a lack of photoprotective carotenoids such as β-carotene, and low content of tocopherol, were associated with the algal extracts with higher antimicrobial activity against S. aureus. The bactericidal activity exhibited by the extracts seems to result from the photooxidation of microalgae PUFAs by the 1O2 and/or other ROS produced by irradiated chlorophylls/carotenoids, which eventually led to bacterial lipid peroxidation and cell death, but further studies are needed to confirm this hypothesis. These results revealed the potential of an unexplored source of natural photosensitizers (microalgae lipid extracts) that can be used as PSs in aPDT as an alternative to conventional antibiotic treatments, and even to conventional PSs, to combat antibacterial resistance.