Evaluation of the in vitro and in vivo inhibitory effects of quercetin on the growth of Babesia and Theileria parasites

Quercetin has antioxidant, anti-inflammatory, antitrypanosomal, and antimalarial activities. The hindering properties of quercetin were appraised for three Babesia species and Theileria equi in vitro and against Babesia microti in mice. Quercetin exhibited substantial growth restraint for Babesia bovis, Babesia bigemina, Babesia caballi, and Theileria equi with IC50 values of 8, 7, 5, and 4 nM, respectively. T. equi growth was suppressed at 50 μM concentration. Parasite regrowth was repressed in the consequent viability test at 100 μM for Babesia bovis and Babesia bigemina and 50 μM for Babesia caballi and Theileria equi. Quercetin at a dose rate of 14.5 mg/kg raised a 77.5 % reticence of Babesia microti progression in BALB/c mice. Quercetin might be of value as a treatment in babesiosis and theileriosis.