Peroxynitrite Scavengers Produced by Filamentous Fungus Used in the Katsuobushi Manufacturing Process

Abstract

Extracts of Aspergillus spp., Monascus purpureus, Rhizopus microsporus, and Eurotium repens, which are filamentous fungi used in the manufacture of fermented foods including sake, shoyu, miso, shochu, tofuyo, tempeh and katsuobushi, were examined for peroxynitrite scavenging activity. Extracts of Eurotium repens, used in the molding step in the manufacture of katsuobushi, exhibited the highest activity of all the tested extracts. Peroxynitrite scavengers were isolated from Eurotium repens extract and were identified as auroglaucin, dihydroauroglaucin, isodihydroauroglaucin, tetrahydroauroglaucin and flavoglaucin. Tetrahydroauroglaucin exhibited the highest peroxynitrite scavenging activity of the isolated compounds, and showed suppressive effects on the expression of blood adhesion molecules, intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1), in human umbilical vein endothelial cells (HUVECs) after induction with tumor necrosis factor (TNF-α).