Could a common ulcer medication fight parasitic diseases? This research explores the antileishmanial activity of omeprazole, a widely used antiulcer drug, against *Leishmania donovani*, the causative agent of visceral leishmaniasis. The study reveals that omeprazole effectively inhibits the growth of promastigotes and amastigotes, demonstrating its potential as a novel therapeutic agent. Omeprazole's antiparasitic action stems from its inhibition of the P-type K+,H+-ATPase on the surface membrane of *Leishmania*. The drug is effective only at acidic pH, mimicking the conditions within phagolysosomal vesicles where the amastigote form resides. Promastigotes and amastigotes are reduced 90% or more with 150 μM omeprazole. These findings suggest that omeprazole may offer a less toxic alternative to existing chemotherapeutics for leishmaniasis. Its effectiveness at acidic pH makes it particularly promising, targeting the parasite within its natural environment. Further investigation is warranted to explore the clinical potential of omeprazole in treating visceral leishmaniasis.
Published in Antimicrobial Agents and Chemotherapy, this research aligns with the journal's focus on investigating and developing new antimicrobial agents. By demonstrating the antileishmanial activity of omeprazole, the study contributes to the journal's broader exploration of novel therapeutic strategies for infectious diseases. The citations reflect the paper's engagement with existing research in the fields of microbiology and pharmacology.