Allergic disorders are characterized by an abnormal immune response towards non-infectious substances, being associated with life quality reduction and potential life-threatening reactions. The increasing prevalence of allergic disorders demands for new and effective anti-allergic treatments. Here we test the anti-allergic potential of monomeric (juglone, menadione, naphthazarin, plumbagin) and...

It has been demonstrated that perturbation of oxidative balance plays an important role in numerous pathological states as well as in physiological modifications leading to aging. In order to evaluate the role of the oxidative state in cells, biochemical and ultrastructural studies were carried out on K562 and HL-60 cell cultures. Particular attention was given to the transferrin receptor, whic...

Old yellow enzyme (OYE) is an NADPH oxidoreductase which contains flavin mononucleotide as prosthetic group. The X-ray structures of OYE from Trypanosoma cruzi (TcOYE) which produces prostaglandin (PG) F(2α) from PGH(2) have been determined in the presence or absence of menadione. The binding motif of menadione, known as one of the inhibitors for TcOYE, should accelerate the structure-based dev...

Most of the research concerning the biological role of vitamin Kr (2methyl-3-phytyl-l , 4naphthoquinone) has been concerned with its function in blood clotting (1) ; however, substances which possess vitamin K activity are found in organisms such as bacteria and higher plants (1,2) which have no blood-clotting system. The role of the vitamin in these organisms has not been established but may b...

Gentamicin uptake and killing were studied in aminoglycoside-susceptible wild-type Staphylococcus aureus strains and aminoglycoside-resistant small-colony mutants selected by gentamicin from these strains. In wild-type S. aureus three phases of gentamicin accumulation were noted, and killing occurred during the last and most rapid phase of uptake. Uptake and killing were abolished by anaerobic ...

Cell-death programs executed in the pancreas under pathological conditions remain largely undetermined, although the severity of experimental pancreatitis has been found to depend on the ratio of apoptosis to necrosis. We have defined mechanisms by which apoptosis is induced in pancreatic acinar cells by the oxidant stressor menadione. Real-time monitoring of initiator caspase activity showed t...

The results of this study show the quinone-dependent reduction of tertiary amine N-oxides to the corresponding tertiary amines by rat liver preparations. The reduction of imipramine N-oxide to imipramine mediated by liver mitochondria, microsomes, and cytosol proceeded in the presence of both NAD(P)H and menadione under anaerobic conditions. When menadione was replaced with 1, 4-naphthoquinone ...

Mitochondrial particles prepared by exposing mitochondria to sonic oscillation catalyzed the oxidation of reduced nicotinamide adenine dinucleotide by ubiquinone-6, ubiquinone10, the lower homologues of ubiquinone, and menadione. Ubiquinone-6 reduction activity was inhibited completely by rotenone and by amytal. Menadione reduction was also inhibited, but only partially, suggesting multiple sit...

Sovelli (1) described a color reaction for menadione, in which the compound was reacted with 2,4-dinitrophenylhydrazine, after which sodium hydroxide was added to alka1init.y. The green-colored product formed was extracted from the mixture with butyl alcohol. Attempts (24) have been made to apply this reaction quantitatively with variable results. Poor sensitivity, among ot)her things, was the ...