Newlifeforanolddrug:Invitroandinvivoeffectsoftheanthelminticdrugniclosamideagai
2022-04-15 22:47阅读:
, Xu
Kun Zhang 3,
Bing
Li 1,
Xu
Zheng Zhou 1,
Ji
Yu Zhang 4
Abstract
Toxoplasma gondii is the causative agent of toxoplasmosis and
causes serious public health problems. However, the current
treatment drugs have many limitations, such as serious side
effects. Niclosamide is a salicylanilide drug commonly used to
treat worm infections. Herein, the effectiveness of niclosamide for
the treatment of T. gondii infection was demonstrated. This study
was to evaluate the in vitro and in vivo activities of niclosamide
against T. gondii and to explore its mechanism of action. The in
vitro cytotoxicity of niclosamide on human foreskin fibroblast
cells was evaluated by MTT test. Niclosamide displayed low host
toxicity and its 50% inhibitory concentration was 8.3 μg/mL. The in
vitro anti-proliferation and anti-invasion effects of niclosamide
on T. gondii were determined by quantitative PCR and Giemsa
staining. Niclosamide also inhibited T. gondii tachyzoite
proliferation, with a 50% effective concentration of 45.3 ng/mL,
and reduced the invasion of cells by tachyzoites (17.8% for the
parasite control versus 1.9% for the niclosamide group treated with
100 ng/mL). A model was established by infecting BALB/c mice with
the virulent RH strain of T. gondii and used to determine the in
vivo effects of niclosamide on acute infection. The mice infected
with tachyzoites and treated with 160, 200 or 240 mg/kg·bw
niclosamide for 7 days exhibited 20%, 40% and 50% survival,
respectively. In addition, niclosamide reduced the parasite burden
in the blood and tissues of acutely infected mice, and niclosamide
induced decreases in the mitochondrial membrane potential (ΔΨm) and
adenosine triphosphate (ATP) levels in extracellular tachyzoites,
as assessed by laser confocal microscopy and a multilabel reader.
These findings indicated that the mechanism of action of
niclosamide might be associated with T. gondii mitochondria
oxidative phosphorylation. In conclusion, our results support the
efficacy of niclosamide as a potential compound for the treatment
of T. gondii infection.
Keywords: ATP; Anti-invasion;
Anti-proliferation; In vivo; Niclosamide; T. gondii; ΔΨm.