Browsing by Author "Andrade, Joana M."
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- In vitro assessment of antimicrobial, antioxidant, and cytotoxic properties of Saccharin-Tetrazolyl and-Thiadiazolyl derivatives: the simple dependence of the pH value on antimicrobial activityPublication . Frija, Luís M. T.; Ntungwe, Epole; Sitarek, Przemysław; Andrade, Joana M.; Toma, Monika; Śliwiński, Tomasz; Cabral, Lília; Cristiano, Maria de Lurdes; Rijo, Patrícia; Pombeiro, Armando J. L.The antimicrobial, antioxidant, and cytotoxic activities of a series of saccharin-tetrazolyl and -thiadiazolyl analogs were examined. The assessment of the antimicrobial properties of the referred-to molecules was completed through an evaluation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against Gram-positive and Gram-negative bacteria and yeasts. Scrutiny of the MIC and MBC values of the compounds at pH 4.0, 7.0, and 9.0 against four Gram-positive strains revealed high values for both the MIC and MBC at pH 4.0 (ranging from 0.98 to 125 µg/mL) and moderate values at pH 7.0 and 9.0, exposing strong antimicrobial activities in an acidic medium. An antioxidant activity analysis of the molecules was performed by using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, which showed high activity for the TSMT (N-(1-methyl-2H-tetrazol-5-yl)-N-(1,1-dioxo-1,2-benzisothiazol-3-yl) amine, 7) derivative (90.29% compared to a butylated hydroxytoluene positive control of 61.96%). Besides, the general toxicity of the saccharin analogs was evaluated in an Artemia salina model, which displayed insignificant toxicity values. In turn, upon an assessment of cell viability, all of the compounds were found to be nontoxic in range concentrations of 0-100 µg/mL in H7PX glioma cells. The tested molecules have inspiring antimicrobial and antioxidant properties that represent potential core structures in the design of new drugs for the treatment of infectious diseases.
- Synchronous insight of in vitro and in vivo biological activities of Sambucus nigra L. extracts for industrial usesPublication . Mota, Ana Henriques; Andrade, Joana M.; Rodrigues, Maria Joao; Custódio, Luísa; Bronze, Maria Rosario; Duarte, Noelia; Baby, Andre; Rocha, Joao; Gaspar, Maria Manuela; Simoes, Sandra; Carvalheiro, Manuela; Fattal, Elias; Almeida, Antonio Jose; Reis, Catarina PintoThere is a re-emerging interest in natural products as reputable sources of new active pharmaceutical ingredients. This study synchronously reports in vitro, with more than one cell line, and in vivo biological activities of extracts obtained from Sambucus nigra. Using several solvents and techniques, eighteen extracts were obtained from fresh and dried berries, and fresh flowers. The flavonoid content and identification were determined using HPLC-MS/MS. The extracts were then screened for antioxidant activity, total polyphenol content, collagenase, elastase, tyrosinase and acetylcholinesterase inhibition as well as photoprotection. In vitro and in vivo (murine model) anti-inflammatory activity and cytotoxicity (skin and monocytic cells) were also studied. The most promising extracts were those obtained from fresh flowers using either ultrasounds or methanol. These extracts showed similar results to positive controls, particularly the antioxidant activity (74.5 +/- 1.6 %), collagenase inhibition (93.6 +/- 0.6 %), photoprotection (Sun Protection Factor > 50), in vitro anti-inflammatory activity (96.9 +/- 2.9 %), as well as oral/topical anti-inflammatory activity. The ultrasounds/ethanol extract of fresh flowers presented higher collagenase inhibition (88.3 +/- 2.8 %) and in vitro anti-inflammatory activity (101.8 +/- 1.5 %). Cytotoxicity testing confirmed the safety. Chemical characterization allowed the deduction of a correlation between extract composition and biological activities, suggesting a straightforward application in the development of novel products subject to further investigation.