Epiisopilosine alkaloid has activity against schistosoma mansoni in mice without acute toxicity

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSchistosomiasis is a disease caused by parasites of the genus Schistosoma, currently affecting more than 200 million people. Among the various species of this parasite that infect humans, S. mansoni is the most common. Pharmacological treatment is limited135119CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP404134/2012-22014/02282-76, 2016/18023-5, 2016/22488-3The authors are grateful to Phytobios Pesquisa Desenvolvimento e Inovação LTDA.,company of the Centroflora Group, for its support during the realization of this research. SMA is grateful to Conselho Nacional de Desenvolvimento Científico e Tecnológico

Epiisopilosine alkaloid has activity against Schistosoma mansoni in mice without acute toxicity

Schistosomiasis is a disease caused by parasites of the genus Schistosoma, currently affecting more than 200 million people. Among the various species of this parasite that infect humans, S. mansoni is the most common. Pharmacological treatment is limited to the use of a single drug, praziquantel (PZQ), despite reports of parasite resistance and low efficacy. It is therefore necessary to investigate new potential schistosomicidal compounds. In this study, we tested the efficacy of epiisopilosine (EPIIS) in a murine model of schistosomiasis. A single dose of EPIIS (100 or 400 mg/kg) administered orally to mice infected with adult S. mansoni resulted in reduced worm burden and egg production. The treatment with the lower dose of EPIIS (100 mg/kg) significantly reduced total worm burden by 60.61% (P < 0.001), as well as decreasing hepatosplenomegaly and egg excretion. Scanning electron microscopy revealed morphological changes in the worm tegument after treatment. Despite good activity of EPIIS in adult S. mansoni, oral treatment with single dose of EPIIS 100 mg/kg had only moderate effects in mice infected with juvenile S. mansoni. In addition, we performed cytotoxicity and toxicological studies with EPIIS and found no in vitro cytotoxicity (in HaCaT, and NIH-3T3 cells) at a concentration of 512 μg/mL. We also performed in silico analysis of toxicological properties and showed that EPIIS had low predicted toxicity. To confirm this, we investigated systemic acute toxicity in vivo by orally administering a 2000 mg/kg dose to Swiss mice. Treated mice showed no significant changes in hematological, biochemical, or histological parameters compared to non-treated animals. Epiisopilosine showed potential as a schistosomicidal drug: it did not cause acute toxicity and it displayed an acceptable safety profile in the animal model

Hematological parameters of Swiss mice treated with EPIIS by oral route.

<p>Hematological parameters of Swiss mice treated with EPIIS by oral route.</p

<i>In silico</i> analysis of toxicological properties of EPIIS predicted using the pkCSM methodology.

<p><i>In silico</i> analysis of toxicological properties of EPIIS predicted using the pkCSM methodology.</p

Physicochemical parameters through <i>in silico</i> analysis of EPIIS using pkCSM methodology.

<p>Physicochemical parameters through <i>in silico</i> analysis of EPIIS using pkCSM methodology.</p

Antischistosomal effect of a single 100 mg/kg oral dose of EPIIS administered to mice harboring juvenile <i>S</i>. <i>mansoni</i> infection.

<p><b>(A)</b> EPIIS effect on worm burden. <b>(B)</b> EPIIS effect on egg development stages (oogram) <b>(C)</b> Effect on Stoll egg count. Points represent data from individual mice that were infected and treated with EPIIS, or infected and untreated (control). The horizontal bars represent median values. **<i>P</i> < 0.01 and ***<i>P</i> < 0.001 compared with untreated groups.</p

<i>In vitro</i> cytotoxicity assay with EPIIS.

<p>Adhesion indices of NIH-3T3 and HaCaT cells treated with EPIIS. The concentrations of EPIIS were 32 or 512 μg/mL and the adhered cell rates were measured every 30 min for 137 h.</p

Biochemical parameters in sera obtained from Swiss mice treated with EPIIS by oral route.

<p>Biochemical parameters in sera obtained from Swiss mice treated with EPIIS by oral route.</p

Scanning electron microscopy of <i>S</i>. <i>mansoni</i> adults retrieved 48 h after treatment with EPIIS (100 mg/kg).

<p><b>A-D</b>: Control group—untreated; <b>E–L:</b> Male and female worms. The arrows show damage to tegument with reduction in the size of the spines, and damage to the oral and ventral suckers in male worms, followed by body corrugation in female worms. Image bar scale: (<b>A</b>) 100X___10 kv; (<b>B</b>) 120X ___10 kv; (<b>C-D</b>) 180X ___10 kv; (<b>E-F</b>) 127X ___10 kv; (<b>G-H</b>) 250X___10 kv; (<b>I- L)</b> 350X___10 kv.</p

Epiisopilosine alkaloid has activity against <i>Schistosoma mansoni</i> in mice without acute toxicity - Fig 9

<p><b>Photomicrographs of histological sections of liver (A1, A2), spleen (B1, B2), kidney (C1, C2), lung (D1, D2) and brain (E1, E2) obtained from Swiss mice of control group (first column) and group treated with 2000 mg/kg EPIIS (second column).</b> Hematoxylin & eosin, 400 X magnification, bars = 50 μm.</p