Investigation in vitro Effects of Rivastigmine and Galantamine Used to Treatment of Alzheimer's Disease on CA Isozymes I and II

The carbonic anhydrases (CA, EC. 4.2.1.1) are an expanding family of zinc-containing enzymes catalyzing the reversible hydration of CO2 in a two-step reaction to yield HCO3-and H+. These enzymes play important roles in several physiological/pathological processes. The aim of this study is to evaluate in vitro the effects of these drug active substances which use which use for treatment of Alzheimer disease on CA I and II isoenzyme. CA I and II isoenzymes from human blood have been purified using Sepharose-4B-l-tyrosine-sulfanilamide affinity chromatography method. The CA I isoenzyme was purified ~122.2-fold with a yield of 61.7%. The CA II isoenzyme was purified ~807.5-fold with a yield of 60%. rivastigmine was showed competitive inhibition and galantamine was showed uncompetitive inhibition for CAI. Both of these drug active substances were showed uncompetitive inhibition for CAII. Ki values were determined for rivastigmine CA I: 0.79 µM; CA II: 1.08 µM and for galantamine CA I: 0.41µM; CA II: 0.40 µM. The results obtained in this study galantamine was identified as the most potent inhibitor.