CRUZIPAIN INHIBITION BY MONTELUKAST, A LEUKOTRIENE RECEPTOR ANTAGONIST

CAROLINA BELLERA; SBARAGLINI MARIA LAURA; BALCAZAR DARIO; FRACCAROLI LAURA; TALEVI ALAN; CARRILLO CAROLINA

Mar del Plata

Congreso; X Congreso Argentino de Protozoología y Enfermedades Parasitarias; 2014

Sociedad Argentina de Protozoología

Cruzipain (Cz) is the major cystein protease of the hemoflagelate parasite Trypanosomacruzi, etiologic agent of Chagas disease. This enzyme has been validated as drug targetfor novel antichagasic agents, being essential for T. cruzi amastigotes and playing a role inhost-parasite interactions. In the present work, we have applied previously reportedcomputational models to develop a ligand-based virtual screening campaign on twochemical repositories: DrugBank and Merck Index databases. The objective of this work isthe discovery of novel antichagasic therapies in order to overcome the limitations ofcurrently approved therapies, i.e. safety issues and low efficacy in the chronic stage of thedisease. replace current unsatisfactory therapies. Four of the identified drugs, namely: theleukotriene blocker montelukast, the antinociceptive and anti-inflammatory agent atranorin,the synthetic pyrethroid fluvalinate and the calcium blocker methoxyverapamil, wereacquired and tested on Cz activity and epimastigotes proliferative assays. Testing the fourcompounds at a concentration of 100 microM on purified Cz activity it was shown that onlymontelukast and atranorin had and inhibitory effect; however, only the first one maintainedan inhibitory effect in lower concentrations showing a median inhibitory concentration(IC50) of 42.5±6.4 uM. Cultures of T. cruzi epimastigotes in the presence of montelukastshowed inhibitory effects on proliferation, affecting the maximal cell density (treated:29.6±2.8 million parasites/ml vs control: 59.0±9.2 million parasites/ml). This compoundshowed a median lethal dose (LD50) of 71.0±9.8 uM. Finding an a priori unpredictableinhibitory compound applying in silico screening confirms the utility of our models toidentify, through a repurposing strategy, new trypanocidal therapeutics.