Increase in liver antioxidant enzyme activities in non-alcoholic fatty liver disease.
OBJECTIVE
Steatosis may increase oxidative stress, which is counteracted by cellular enzymatic (cytosolic and mitochondrial superoxide dismutases (Cu/Zn-SOD and Mn-SOD), glutathione peroxidase (GPx), catalase) and non-enzymatic antioxidant systems. We aimed to determine, in patients with non-alcoholic fatty liver disease (NAFLD), the level of antioxidant defenses (1) in liver biopsies, to demonstrate the existence of oxidative stress; (2) in erythrocytes and plasma, to determine whether their antioxidant defenses reflect liver oxidative stress.


METHODS
Erythrocyte and plasma antioxidant defenses were prospectively studied in two groups of 16 patients: patients with NAFLD and controls. Liver biopsies were performed in eight NAFLD patients; liver antioxidant enzyme activities were measured and compared with those in 12 control livers used for transplantation.


RESULTS
Cu/Zn-SOD, GPx and catalase activities were significantly higher in NAFLD livers than in controls whereas no significant differences were observed in Mn-SOD activity, and thiobarbituric acid-reactive substance (TBARS) concentration. No differences were observed in erythrocyte antioxidant enzyme activities (GPx, catalase, Cu/Zn-SOD), erythrocyte TBARS concentration, and plasma alpha-tocopherol concentration.


CONCLUSIONS
Liver antioxidant enzyme activities were high in patients with NAFLD, reflecting an oxidative stress possibly involved in inflammation and fibrogenesis. However, erythrocyte and plasma antioxidant defenses did not reflect intrahepatic peroxidation.
Perlemuter
Gabriel
G
Service d'hépato-gastroentérologie, Hôpital Antoine Béclère, AP-HP, 157 rue de la Porte de Trivaux, 92141 Clamart Cedex, France. gabriel.perlemuter@abc.aphp.fr
Davit-Spraul
Anne
A
Cosson
Claudine
C
Conti
Marc
M
Bigorgne
Amélie
A
Paradis
Valérie
V
Corre
Marie-Pierre
MP
Prat
Lydie
L
Kuoch
Viceth
V
Basdevant
Arnaud
A
Pelletier
Gilles
G
Oppert
Jean-Michel
JM
Buffet
Catherine
C
D000328:Adult; D000368:Aged; D002374:Catalase / Q000378:metabolism*; D004912:Erythrocytes / Q000201:enzymology; D005234:Fatty Liver / Q000201:enzymology*; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase / Q000378:metabolism*
D017382:Reactive Oxygen Species; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase