Preliminary insight into the potential antiplasmodial activity and cytotoxicity ofBufo bufoandIncilius alvariuspoison

  • Wells, Mathilde
  • Hambye, Stéphanie
  • Blankert, Bertrand

  • Laboratory of Pharmaceutical Analysis, Faculty of Medicine and Pharmacy, University of Mons, 7000, Mons, Belgium

*Corresponding author.

E-mail addresses:[email protected]; [email protected]; [email protected].

Received January 17, 2023; Received in revised form March 14, 2023; Accepted March 20, 2023.

Handling Editor: Dr. Ray Norton

ARTICLE INFO

Toxicon 227:p 107092, May 2023. | DOI: 10.1016/j.toxicon.2023.107092

The rise and spread of resistant Plasmodium falciparum strains are responsible for an increase in therapeutic failures in many of the regions endemic with malaria. The need for new therapeutic candidates is now more urgent than ever. Animal venoms have long been considered as interesting resources to exploit in terms of potential therapeutic candidates. Among these, the cutaneous secretions of toads constitute a rich and diverse source of bioactive molecules. We focused on two different species: Bufo bufo and Incilius alvarius. The dried secretions underwent a solvent-based extraction and were submitted to a systematic bio-guided fractionation approach using preparative thin-layer chromatography. Initial crude extracts were tested in vitro for their antiplasmodial activity. Based on these results, only crude extracts displaying IC50 < 100 μg/mL were considered for further fractionation. All extracts and fractions, including those that did not display antiplasmodial properties, were characterized by chromatographic (LC-UV/MS) and spectrometric techniques (HRMS). Antiplasmodial activity was evaluated in vitro using a chloroquine-sensitive strain (3D7) and a resistant one (W2). Toxicity was assessed on normal human cells for the samples displaying IC50 < 100 μg/mL. Crude extracts from Bufo bufo secretions exhibited no appreciable antiplasmodial activities. However, the methanol and dichloromethane extracts from Incilius alvarius secretions gave IC50 of (34 ± 4) μg/mL and (50 ± 1) μg/mL respectively when tested on W2 strain. No significant effect was observed on 3D7. This poison would warrant further investigation in terms of its antiplasmodial potential. Following preliminary characterization, it was revealed that the fractions of interest contained mainly bufotoxins, bufagins and alkaloids.

Graphical abstract

Highlights

  • For the first time, Incilius alvarius poison was shown to elicit in vitro antiplasmodial activity against a chloroquine-resistant P. falciparum strain.

  • Bufo bufo extracts showed no antiplasmodial activity.

  • The extracts/fractions were toxic to human cells (IC50 < 100 μg/mL).

Copyright © 2023Elsevier, Inc.
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