Marine Drugs (Dec 2022)

Effect of Phlorotannins from Brown Algae <i>Costaria costata</i> on α-<i>N</i>-Acetylgalactosaminidase Produced by Duodenal Adenocarcinoma and Melanoma Cells

  • Irina Bakunina,
  • Tatiana Imbs,
  • Galina Likhatskaya,
  • Valeria Grigorchuk,
  • Anastasya Zueva,
  • Olesya Malyarenko,
  • Svetlana Ermakova

DOI
https://doi.org/10.3390/md21010033
Journal volume & issue
Vol. 21, no. 1
p. 33

Abstract

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The inhibitor of human α-N-acetylgalactosaminidase (α-NaGalase) was isolated from a water–ethanol extract of the brown algae Costaria costata. Currently, tumor α-NaGalase is considered to be a therapeutic target in the treatment of cancer. According to NMR spectroscopy and mass spectrometric analysis, it is a high-molecular-weight fraction of phlorethols with a degree of polymerization (DP) equaling 11–23 phloroglucinols (CcPh). It was shown that CcPh is a direct inhibitor of α-NaGalases isolated from HuTu 80 and SK-MEL-28 cells (IC50 0.14 ± 0.008 and 0.12 ± 0.004 mg/mL, respectively) and reduces the activity of this enzyme in HuTu 80 and SK-MEL-28 cells up to 50% at concentrations of 15.2 ± 9.5 and 5.7 ± 1.6 μg/mL, respectively. Molecular docking of the putative DP-15 oligophlorethol (P15OPh) and heptaphlorethol (PHPh) with human α-NaGalase (PDB ID 4DO4) showed that this compound forms a complex and interacts directly with the Asp 156 and Asp 217 catalytic residues of the enzyme in question. Thus, brown algae phlorethol CcPh is an effective marine-based natural inhibitor of the α-NaGalase of cancer cells and, therefore, has high therapeutic potential.

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