OxyFile #645
AU - Dierickx PJ
AU - Nuffel GV
AU - Alvarez I
TI - Glutathione protection against hydrogen peroxide, tert-
butyl hydroperoxide and diamide cytotoxicity in rat hepatoma-
derived Fa32 cells.
AB - 1. Several ozonides, peroxides and aldehydes are formed
during ozone therapy, recently introduced in medicine.
tert-Butyl hydroperoxide (t-BHP), H2O2 and diamide were
investigated as model substrate in rat hepatoma-derived
Fa32 cells. 2. The cytotoxicity was measured by the neutral
red uptake inhibition assay after 1 h or 24 h treatment.
The relative toxicities were quantified by the determination
of the NI50. This is the concentration of test compound
required to induce an inhibition of 50% in neutral red
uptake as compared to the control cells. All test chemicals
were more toxic after 24 h than after 1 h. 3. The influence
of the glutathione (GSH) alteration on the cytotoxicity
was measured by treating the cells with 2-oxo-4-thiazolidine
carboxylic acid (OTC) or L-buthionine sulfoximine (BSO)
. OTC increased the endogenous GSH content in the cells.
BSO pretreatment strongly decreased the NI50 of the three
chemicals. OTC pretreatment increased the NI50 of H2O2
but not of t-BHP and diamide. This can be explained by
the strong GSH-depletion after 1 h by t-BHP and diamide,
which contrasted with a weak GSH-depletion by H2O2 after
the same time period. 4. The three test chemicals increased
the endogenous GSH content after 24 h. t-BHP and H2O2,
but not diamide, increased the total GSH transferase (GST)
activity. Several alterations of the GST subunits were
observed. Most striking was the increase of class alpha
GST subunits, also for diamide. 5. Since H2O2 and t-BHP
are ozone metabolites thought to be responsible for the
therapeutic effects of well-dosed ozone, the results show
that Fa32 cells can be used as a valuable alternative model
system for studying the effects encountered in human ozone
therapy.
MH - tert-Butylhydroperoxide|PD/*TO
MH - Diamide|PD/*TO
MH - Glutathione|*ME
MH - Hydrogen Peroxide|PD/*TO
MH - Oxidants|*PD
MH - Protective Agents|*ME
SO - Hum Exp Toxicol 1999 Oct; 18(10):627-33
DP - 1999 Oct
TA - Hum Exp Toxicol
PG - 627-33
IP - 10
VI - 18
UI - 20025524