Garcinia cowa bark extract induces oxidative stress mediated cellular apoptosis in Leishmania donovani parasite modulated by its active phytosterol constituent.

Visceral leishmaniasis still remains a leading cause of parasitic deaths, with modern pentavalent antimonials showing limited efficacy and health risks. The methanolic bark extract of the Northeastern Indian plant, Garcinia cowa, demonstrated potent leishmanicidal effects against the parasite Leishmania donovani, demonstrating IC₅₀ values of 20-36 µg/ml, with selective toxicity for parasites over healthy cells. It induced parasite death through elevated oxidative and nitrosative stress elements, reduced arginase activity, nuclear fragmentation, cell cycle arrest, and apoptosis. A GC-MS study and molecular docking identified stigmasterol as a primary component, an antileishmanial compound that inhibits Leishmania donovani parasite efficiently.