In Vitro Evaluation of Farnesyltransferase Inhibitor and its Effect in Combination with 3-Hydroxy-3-Methyl-Glutaryl-CoA Reductase Inhibitor against <i>Naegleria fowleri</i>

Free-living amoeba <i>Naegleria fowleri</i> causes a rapidly fatal infection primary amebic meningoencephalitis (PAM) in children. The drug of choice in treating PAM is amphotericin B, but very few patients treated with amphotericin B have survived PAM. Therefore, development of efficien...

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Bibliographic Details
Main Authors: Hye Jee Hahn, Anjan Debnath
Format: Article
Language:English
Published: MDPI AG 2020-08-01
Series:Pathogens
Subjects:
Online Access:https://www.mdpi.com/2076-0817/9/9/689
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Summary:Free-living amoeba <i>Naegleria fowleri</i> causes a rapidly fatal infection primary amebic meningoencephalitis (PAM) in children. The drug of choice in treating PAM is amphotericin B, but very few patients treated with amphotericin B have survived PAM. Therefore, development of efficient drugs is a critical unmet need. We identified that the FDA-approved pitavastatin, an inhibitor of HMG Co-A reductase involved in the mevalonate pathway, was equipotent to amphotericin B against <i>N. fowleri</i> trophozoites. The genome of <i>N. fowleri</i> contains a gene encoding protein farnesyltransferase (FT), the last common enzyme for products derived from the mevalonate pathway. Here, we show that a clinically advanced FT inhibitor lonafarnib is active against different strains of <i>N. fowleri</i> with EC<sub>50</sub> ranging from 1.5 to 9.2 µM. A combination of lonafarnib and pitavastatin at different ratios led to 95% growth inhibition of trophozoites and the combination achieved a dose reduction of about 2- to 28-fold for lonafarnib and 5- to 30-fold for pitavastatin. No trophozoite with normal morphology was found when trophozoites were treated for 48 h with a combination of 1.7 µM each of lonafarnib and pitavastatin. Combination of lonafarnib and pitavastatin may contribute to the development of a new drug regimen for the treatment of PAM.
ISSN:2076-0817