SPIN-TRAPPING AND DIRECT EPR INVESTIGATIONS ON THE HEPATOTOXIC AND HEPATOCARCINOGENIC ACTIONS OF LUTEOSKYRIN, AN ANTHRAQUINOID MYCOTOXIN PRODUCED BY PENICILLIUM-ISLANDICUM SOPP - GENERATIONS OF SUPEROXIDE ANION AND LUTEOSKYRIN SEMIQUINONE RADICAL IN THE REDOX SYSTEMS CONSISTED OF LUTEOSKYRIN AND LIVER NADPH-DEPENDENT OR NADH-DEPENDENT REDUCTASES
I. Ueno et al., SPIN-TRAPPING AND DIRECT EPR INVESTIGATIONS ON THE HEPATOTOXIC AND HEPATOCARCINOGENIC ACTIONS OF LUTEOSKYRIN, AN ANTHRAQUINOID MYCOTOXIN PRODUCED BY PENICILLIUM-ISLANDICUM SOPP - GENERATIONS OF SUPEROXIDE ANION AND LUTEOSKYRIN SEMIQUINONE RADICAL IN THE REDOX SYSTEMS CONSISTED OF LUTEOSKYRIN AND LIVER NADPH-DEPENDENT OR NADH-DEPENDENT REDUCTASES, Free radical research, 23(1), 1995, pp. 41-50
Luteoskyrin is a hepatotoxic and hepatocarcinogenic bisdihydroanthraqu
inone produced by Penicillium islandicum Sopp. By observing the EPR sp
ectra of DMPO-spin adducts and luteoskyrin semiquinone radical, we inv
estigated in vitro whether luteoskyrin is reduced to its semiquinone r
adical leading to the generation of active oxygen species in redox sys
tems catalyzed by NADPH-dependent cytochrome reductases of the liver.
We found (1) the formation of luteoskyrin semiquinone radical in the N
ADPH-cytochrome P-450 reductase system under anaerobic conditions, (2)
the generation of O-2(-) in the systems composed of luteoskyrin, NAD(
P)H, and either rat liver microsomal NADPH-cytochrome P-450 reductase
or submitochondrial particles and (3) dicoumarol showed no effect on t
he O-2(-) generation in the case of submitochondrial particles. From t
hese results we proposed that luteoskyrin liver injuries are induced b
y the active oxygen species generated in the process of autoxidation o
f luteoskyrin semiquinone radical which is produced in the one-electro
n redox systems catalyzed by the liver NAD(P)H-dependent cytochrome re
ductases.