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Percorrer por autor "Hentschke, Guilherme Scotta"

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  • Pigments profile and antioxidant potential of extremophile cyanobacteria isolated from the Mexican Volcanic Lake Chichonal
    Publication . Silva, Raquel; Gonçalves, Talita; Morone, Janaína; Moreira, Gabriela Alves; Morais, João; Hentschke, Guilherme Scotta; Alvarez-Gutierrez, Peggy Elizabeth; Batista-García, Ramon Alberto; Vasconcelos, Vitor; Lopes, Graciliana
    Cyanobacteria are ancient and prolific microorganisms for which the current knowledge remains limited. The present work constitutes the first report on the presence of the cyanobacteria Tolypothrix sp. LEGE 221228, Nostoc sp. LEGE 221229, Scytonema sp. LEGE 221230 and Drouetiella sp. LEGE 221231 in the volcanic crater lake in Chichonal (Chiapas-Mexico), and in the characterization of their pigments profile and antioxidant potential, through the application of biorefinery approaches. The identification of cyanobacteria species was achieved through advanced morphology-based methods for cyanobacterial taxonomy. The HPLC-PDA analysis of the cyanobacteria acetone extracts revealed β-carotene, echinenone and chlorophyll-a as the main pigments. Drouetiella sp. LEGE 221231 presented the highest β-carotene concentration (63.67 μg/mL), total carotenoids (87.92 μg/mL) and chlorophylls (20.88 μg/mL), closely followed by Tolypothrix sp. LEGE 221228 (with 51.37, 75.14 and 14.88 μg/mL, respectively), this being the first report on the carotenoid and chlorophylls profile of these strains. Aqueous extracts revealed the highest content of phycoerythrin in Tolypothrix sp. LEGE 221228 (50.61 mg/g) and of phycocyanin in Nostoc sp. LEGE 221229 (57.66 mg/g), standing out in superoxide anion radical scavenging, while the acetonic ones were more effective in scavenging nitric oxide radical. For both, Tolypothrix sp. LEGE 221228 was the most effective, presenting the lowest IC50 (53.75 and 57.68 μg/mL, respectively). Overall, the present study enriches the knowledge on biodiversity of cyanobacteria from underexplored environments, enhancing their potential biotechnological applications as producers of added value secondary metabolites with interest in food, pharmaceutical and cosmetic industries.
    2024-07Artigo de investigação Acesso embargado Ver mais
  • Secondary metabolites of cyanobacteria from Cape Verde Archipelago act as NO donors with potential application in dermatology and cosmetics
    Publication . Morone, Janaína; Hentschke, Guilherme Scotta; Oliveira, Isabel Benta; Vasconcelos, Vítor; Martins, Rosário; Lopes, Graciliana; Martins, Rosário
    Nitric oxide (NO) is a versatile mediator implicated in a variety of physiological processes, with the ultimate goal of maintaining organism homeostasis. In the present work, aqueous extracts from ten cyanobacteria strains isolated from the Cape Verde archipelago were explored as potential NO donors. None of the strains are toxin producers, as demonstrated by PCR and LC-MS analysis. The extracts were mainly composed by phycobiliproteins (9.1 to 43.8 %), followed by polysaccharides (7.7 to 35.1 %), phenols (1.49 to 3.3 %) and chlorophylls (0 to 0.45 %). All the extracts revealed antioxidant potential, with Salileptolyngbya sp. LEGE 181184 presenting the lowest IC 1 50 value for superoxide anion radical scavenging (46.50 μ g mL ), and ability to inhibit the proinflammatory enzyme lipoxygenase (LOX), Salileptolyngbya sp. LEGE 181150 presenting an IC positive control quercetin (28.49 and 31.77 μ g mL 1 25 similar to the , respectively), highlighting the potential of cyanobacteria extracts as natural ingredients for LOX inhibition. All the extracts were able to increase the NO produced by the macrophage cell line RAW 264.7 through iNOS modulation (from concentrations starting in 12.5 μ g mL 1 ), in a similar mechanism and superior extend to that of LPS. None of the extracts induced cytotoxicity to RAW 264.7 cells and to the endothelial hCMEC/d3, the fibroblast 3 T3/L1 and the keratinocytes HaCaT cell lines, and no environmental hazard is predicted, as demonstrated through the zebrafish (Danio rerio) embryo acute toxicity test (zFET). This pioneer study points-out cyanobacteria aqueous extracts as innovative and biobased natural antimicrobial ingredients which, through a NO-donating mechanism, may potentially act against important antibiotic-resistant strains, thus being worth of consideration as therapeutic agents in dermatology.
    2025-03Artigo de investigação Acesso aberto Ver mais