Abstract
Evaluation of novel and effective chemotherapeutic agents for bovine and equine piroplasmosis is urgently
needed because of the toxic side effects of currently available drugs. Heat shock protein 90 (Hsp90)
becomes a promising drug target due to its important roles in protecting the cells. In this study, we report the
in vitro inhibitory effect of gedunin, an Hsp90 inhibitor, on the growth of Babesia bovis, B. bigemina, B.
caballiM, and Theileria equi. The IC50 values of gedunin for four parasites were 21.72 µM, 15.25 µM, 22.1
µM, and 33.21 µM, respectively. Severe morphological changes, such as pyknotic and degenerative change,
were also observed in the parasites treated with gedunin. Although further experiments are required to
evaluate the in vivo activity of gedunin against Babesia and Theileria parasites, the present study indicated
that Hsp90 could be a drug target in bovine and equine piroplasms.
