Various Carbonic Anhydrases in Physiopathological Events, Carbonic Anhydrase Inhibitors, and Hybrid Compounds

Abstract: Enzymes are highly specific catalysts that accelerate reactions in biological systems. Carbonic anhydrase (CA) is an enzyme found in plants, microorganisms, and vertebrates. CA catalyses CO2 hydration/ dehydration. There are different families and isoenzymes of CAs. Fifteen α-CA isoenzymes have been reported in humans. The status of CO2 hydration and dehydration is important for a variety of biological processes. CAs play an important role in many physiological and pathological events in several tissue types. Their levels are increased in some diseases; therefore, CA inhibition has been applied as a therapeutic option. However, the high diversity of these isoenzymes is an important consideration. Isoenzyme- specific CA inhibitors can reduce the side effects of treatment. Some agents containing additional sulfonamides approved for other therapeutic applications, such as topiramate, celecoxib/valdecoxib, sulpiride, and famotidine, have inhibitory effects on CA isoenzymes. These bind to the zinc ion in the CA active site. Recently, research has been conducted on the use of a hybrid form of active ingredient and a CA inhibitor. CA inhibitor-NSAID hybrid compounds demonstrated more efficacy than NSAIDs in arthritis, which has attracted further attention of researchers in conducting research on CA-hybrid drugs.