N-acetylcysteine partially reverses oxidative stress and apoptosis exacerbated by Mg-deficiency culturing conditions in primary cultures of rat and human hepatocytes.
OBJECTIVE
The effects of magnesium (Mg) deficiency on the rate of oxidative stress and apoptosis in primary cultures of human hepatocytes were compared to cultured rat hepatocytes. The possible reversion by N-acetylcysteine (NAC) in Mg-deficient culturing conditions was evaluated.


METHODS
Incubations were conducted for up to 72 h in media containing a deficient (0-0.4 mM) or a physiological (0.8 mM) Mg concentration, and in the presence or absence of NAC after 24 h of culture in these Mg concentration conditions.


RESULTS
We obtained similar profiles in terms of apoptosis and oxidative stress in primary cultures of human hepatocytes, as compared to rat hepatocytes, i.e. a Mg concentration-dependent effect on the caspase-3 activity and GSH levels after 72 h of culture, caspase-3 activity being highest and GSH levels being lowest in Mg-free cultures. The addition of NAC to culture media after the first 24 h of culture increased GSH concentrations. This was accompanied in Mg-deficient cultures by a decrease in both the caspase-3 activity and the lipid peroxidation. However, when culturing hepatocytes with physiological Mg concentrations, an increase in both caspase-3 activity and lipid peroxidation was observed.


CONCLUSIONS
Our results indicate that Mg deficiency exacerbates the rate of apoptosis in cultured hepatocytes, associated with an increase in oxidative stress, the sensitivity of human hepatocytes being equivalent to that of rat hepatocytes. They also indicate a dual role of NAC and/or GSH, i.e. protective for hepatocytes placed in a Mg-deficient environment, while deleterious for hepatocytes placed in a Mg-physiological environment.
Martin
Hélène
H
Laboratoire de Biologie Cellulaire, EA 3921, UFR des Sciences Médicales et Pharmaceutiques, Place Saint-Jacques, 25030 Besançon cedex, France. helene.martin@univ-fcomte.fr
Abadie
Catherine
C
Heyd
Bruno
B
Mantion
Georges
G
Richert
Lysiane
L
Berthelot
Alain
A
D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000502:physiology*; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology*; D008275:Magnesium Deficiency / Q000503:physiopathology*; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats
D016166:Free Radical Scavengers; D053148:Caspase 3; D005978:Glutathione; D008274:Magnesium; D000111:Acetylcysteine