To date, sixteen CA isoenzymes found in humans belong to α-CA family, which differ in tissue distribution and subcellular localization 5, 6 . These isoenzymes provide carbon dioxide and ion transport, respiration, fluid balance and acid-base balance in many tissues 3 . They are also involved in biosynthetic reactions such as gluconeogenesis, lipogenesis, and urea synthesis as well as in many pathological and physiological events such as tumor formation and calcifica-Abstract: Recently, carbonic anhydrase (CA, E.C.4.2.1.1) inhibitors from natural product have paved the way for novel drug design in the treatment and prevention of some global diseases such as glaucoma, diabetes, and cancer. For this purpose, the inhibition effects of oleuropein and verbascoside from olive (Olea europaea L.) oil on human carbonic anhydrase I, and II (hCA I, and II) isoenzymes were evaluated in the current study. The inhibition effects of both natural compounds were determined by the esterase activity (in vitro). IC 50 value of oleuropein and verbascoside was calculated as 1.57 and 1.73 µM for hCA I isoenzyme, respectively. At the same manner, K i values were determined as 1.25 ± 0.42 and 2.00 ± 0.42 µM, respectively. Then, IC 50 value of each compound for hCA II isoenzyme was calculated as 2.23 and 1.90 µM, respectively. Similarly, K i values were determined as 2.37 ± 0.87 µM and 1.49 ± 0.33 µM, respectively. Also, the inhibitory effects and potent binding mechanisms of oleuropein and verbascoside on hCA I, and II isoenzymes were realized by molecular docking studies. Consequently, both natural phenolic compounds demonstrated the potent inhibition profiles against the both isoenzymes. Therefore, we believe that these results may break new ground in the drug development for the treatment of some global disorders.
