Antiparasitic activity of FLLL-32 against four species, , , and , and one species, , and in mice.

FLLL-32, a synthetic analog of curcumin, is a potent inhibitor of STAT3's constitutive activation in a variety of cancer cells, and its anticancer properties have been demonstrated both and . It is also suggested that it might have other pharmacological activities including activity against different parasites. This study therefore investigated the antiparasitic activity of FLLL-32 against four pathogenic species, , , , and , and one species, . anti-Babesia microti activity of FLLL-32 was also evaluated in mice. The FLLL-32, in the growth inhibition assay with a concentration range (0.005-50 μM), was tested for it's activity against these pathogens. The reverse transcription PCR (RT-PCR) assay was used to evaluate the possible effects of FLLL-32 treatment on the mRNA transcription of the target genes including and . The growth of , , , , and was significantly inhibited in a dose-dependent manner (in all cases, < 0.05). FLLL-32 exhibits the highest inhibitory effects on growth , and it's IC value against this species was 9.57 μM. The RT-PCR results showed that FLLL-32 inhibited the transcription of the gene. , the FLLL-32 showed significant inhibition ( < 0.05) of parasitemia in infected mice with results comparable to that of diminazene aceturate. Parasitemia level in -infected mice treated with FLLL-32 from day 12 post infection (pi) was reduced to reach zero level at day 16 pi when compared to the infected non-treated mice. The present study demonstrated the antibabesial properties of FLLL-32 and suggested it's usage in the treatment of babesiosis especially when utilized in combination therapy with other antibabesial drugs.