Screening the Medicines for Malaria Venture Pathogen Box against piroplasm parasites. (August 2019)

• Record Type: Journal Article
• Authors: Nugraha, Arifin Budiman; Tuvshintulga, Bumduuren; Guswanto, Azirwan; Tayebwa, Dickson Stuart; Rizk, Mohamed Abdo; Gantuya, Sambuu; El-Saber Batiha, Gaber; Beshbishy, Amany Magdy; Sivakumar, Thillaiampalam; Yokoyama, Naoaki; Igarashi, Ikuo
• Is Part Of: International journal for parasitology. Volume 10(2019)
• Page Start: 84
• Page End: 90
• Publication Date: 2019-08
• Subjects: Pathogen Box -- Drug screening -- Antipiroplasm agent; Parasitic diseases -- Chemotherapy -- Periodicals; Drug resistance -- Periodicals; 616.96061
• DOI: 10.1016/j.ijpddr.2019.06.004
• Languages: English
• ISSNs: 2211-3207

Abstract

Abstract: Diminazene aceturate (DA) and imidocarb dipropionate are commonly used in livestock as antipiroplasm agents. However, toxic side effects are common in animals treated with these two drugs. Therefore, evaluations of novel therapeutic agents with high efficacy against piroplasm parasites and low toxicity to host animals are of paramount importance. In this study, the 400 compounds in the Pathogen Box provided by the Medicines for Malaria Venture foundation were screened against Babesia bovis, Babesia bigemina, Babesia caballi, and Theileria equi . A fluorescence-based method using SYBR Green 1 stain was used for initial in vitro screening and determination of the half maximal inhibitory concentration (IC50). The initial in vitro screening performed using a 1 μM concentration as baseline revealed nine effective compounds against four tested parasites. Two "hit" compounds, namely MMV021057 and MMV675968, that showed IC50 < 0.3 μM and a selectivity index (SI)> 100 were selected. The IC50s of MMV021057 and MMV675968 against B. bovis, B. bigemina, T. equi and B. caballi were 23, 39, 229, and 146 nM, and 2.9, 3, 25.7, and 2.9 nM, respectively. In addition, a combination of MMV021057 and DA showed additive or synergistic effects against four tested parasites, while combinations of MMV021057 with MMV675968 and of MMV675968 with DA showed antagonistic effects. In mice, treated with 50 mg/kg MMV021057 and 25 mg/kg MMV675968 inhibited the growth of Babesia microti by 54 and 64%, respectively, as compared to the untreated group on day 8. Interestingly, a combination treatment with 6.25 mg/kg DA and 25 mg/kg MMV021057 inhibited B. microti by 91.6%, which was a stronger inhibition than that by single treatments with 50 mg/kg MMV021057 and 25 mg/kg DA, which showed 54 and 83% inhibition, respectively. Our findings indicated that MMV021057, MMV675968, and the combination treatment with MMV021057 and DA are prospects for further development of antipiroplasm drugs. Graphical abstract: Image 1 Highlights: Nine of 400 MMV compounds suppressed the in vitro growth of piroplasm parasites. MMV021057 and MMV675968 showed effects similar to those of DA. Combinations of MMV021057 and DA had additive or synergistic effects on parasites. MMV021057 and MMV675968 moderately inhibited the growth of B. microti in mice. A combination treatment with MMV021057 and DA highly inhibited B. microti in mice.