In Vitro Activity of Pentamidine Isethionate Against Trophozoite and Cyst of Acanthamoeba



Behnia M¹ ; Latifi A¹ ; Rezaian M¹ ; Kharazi S² ; Mohebali M¹ ; Yasami S³ ; Saghafi S⁴ ; Chahardoli R⁵ ; Anasori N¹ ; Torkian H¹ ; Soleimani M⁶ ; Niyyati M⁷ ; Kazemirad E¹ Show Affiliations
Source: Iranian Journal of Parasitology Published:2021

Abstract

Background: Acanthamoebae are a causative agent of Acanthamoeba keratitis (AK) in immu-nocompetent individuals. Since access to propamidine isethionate (Brolene®) as a first-line treatment has been limited in recent years, in the current study, we examined the effects of pentamidine isethionate against trophozoite and cyst forms of Acanthamoeba. Methods: This experimental study was conducted in the Department of Medical Parasitolo-gy and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran, during 2019-2020. Pentamidine isethionate at concentrations of 50, 100, 200, 400, 600, 800, and 1000 µM were tested against trophozoites and cyst stages of T4 genotype, at 24-and 48-hour incubation period, and the viability was determined by trypan blue staining. In addition, the cytotoxic effect of the drug was examined in Vero cells using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Results: The 50% inhibitory concentration (IC50) of pentamidine isethionate on trophozo-ite after 24 and 48h were 97.4 µM and 60.99 µM. These results on cyst after 24 and 48h were 470 µM and 175.5 µM, respectively. In MTT assay, the drug showed an inhibitory effect on Vero cell growth with IC50 values of 115.4 µM and 87.42 µM after 24h and 48h, respective-ly. Conclusion: Pentamidine isethionate exhibited an inhibitory effect on trophozoite and cyst. Given that the trophozoicidal activity of the drug is in the safe dose, it could be suggested as an alternative in patients with AK; however, further investigation is needed in an animal model to confirm the data. © 2021 Behnia et al. Published by Tehran University of Medical Sciences.