Trichomonas vaginalis is a protozoan parasite that causes trichomoniasis in humans, the most prevalent non-viral sexually transmitted disease (STD). Imidazole compounds are used for the treatment of trichomoniasis, and metronidazole is the most commonly prescribed. However, these compounds can lead to parasite resistance and unwanted side effects. Therefore, there is a need for an alternative treatment for this disease. Here, we explored the potential of clotrimazole (CTZ) and zinc compounds, as well as CTZ complexed with zinc salts ([1] acetate [Zn(CTZ)2(Ac)2] and [2] a chloride [Zn(CTZ)2Cl2] complexes) against T. vaginalis. We synthesized the zinc complexed CTZ compounds and determined their concentration values that inhibited parasite growth by 50% (IC50). We used scanning and transmission electron microscopy to visualize the ultrastructural alterations induced by CTZ and their zinc complexes. The incubation of the parasites with [Zn(CTZ)2(Ac)2] complex inhibited their growth, yielding an IC50 of 4.9 µm. Moreover, there were changes in the shape of treated parasites, including the formation of surface projections that subsequently detached from the cell, in addition to changes in the hydrogenosomes, endoplasmic reticulum and Golgi complex. We found [Zn(CTZ)2(Ac)2] to be a highly effective compound against T. vaginalis in vitro, suggesting its potential utility as an alternative chemotherapy for trichomoniasis.

Clotrimazole (C22H17ClN2, 1-[(2-chlorophenyl)(diphenyl)methyl]-1H-imidazole) and fluconazole (C13H12F2N6, 2-(2,4-difluorophenyl)-1,3-bis(1H-1,2,4-triazole-1-yl)propan-2-ol) are two active pharmaceutical ingredients commonly used in the treatment and prevention of superficial and systemic fungal infections. The X-ray powder diffraction data and the unit cell parameters of anhydrous clotrimazole [Triclinic, P ${\bar 1}$ , a  = 8.776(1) Å, b  = 10.571(2) Å, c  = 10.622(3) Å, α = 114.08(2)°, β = 96.87(2)°, γ = 97.61(2)°, V = 875.2(2) Å3, Z = 2] and monohydrated fluconazole [Triclinic, P ${\bar 1}$ , a  = 5.6353(4) Å, b  = 11.753(1) Å, c  = 12.326(1) Å, α = 71.220(8)°, β = 79.896(9)°, γ = 84.35(1)°, V = 760.13(9) Å3, Z = 2] are reported.

We evaluated the growth inhibitory efficacy of the imidazole derivatives, clotrimazole (CLT) and ketoconazole (KC), and the herbicide clodinafop-propargyl (CP), in in vitro cultures of Babesia bovis and B. bigemina. Clotrimazole was effective in a dose range of 15 to 60 μM (IC50: 11 and 23·5 μM), followed by KC (50 to 100 μM; IC50: 50 and 32 μM) and CP (500 μM; IC50: 265 and 390 μM). In transmission electron microscopy, extensive damage was observed in the cytoplasm of drug-treated parasites. Combinations of CLT/KC, CLT/CP and CLT/KC/CP acted synergistically in both parasites. In contrast, the combination of KC/CP was exclusively effective in B. bovis, but not in B. bigemina.