Yes this is expected ,Ethanol intoxication can lead to tissue injury ,inflammation and consequent complications . Oxidative stress is mostly joined to inflammations,proinflammatory cytokines.

Accordingly oxidative stress can consume significant amount of antioxidant Enzymes, this may be an explination

Thanks a lot Dr. Elseweidy, your explanation is very useful. 

Best Regards

Metabolism of ethanol by microsomal ethanol oxidation system MEOS result in significant increase in free radicals including superoxide  hydrogen peroxide so and hydroxy radicals which in turn diminished reduced glutathione and other oxidative defense system which also associated with harmful processes including inflammation tissue injury and damage etc. due to imbalance between ROS production and  enzymatic and none enzymatic antioxidants defense mechanisms. Good luck

I found the same as you in rat model of  voluntary a prolonged alcohol intake. It seems to me, that the long during free radicals production damages DNA and proteins, including enzymes. This may result in any events: production of antioxidant enzymes with altered molecular structure, structural damage of normally synthesized enzymes, etc. The cumulative result of all these processes will be decreased enzymatic activity. 

Thank Dr. Traykova and Ahmad Hunaiti ·for your answers