# Ethnopharmacology- and Chemotaxonomy-Guided Evaluation of Apuleia leiocarpa Bark and Leaf Extracts against Oropouche, Mayaro, Chikungunya, and Zika Viruses

## TL;DR

This study explores the antiviral potential of Apuleia leiocarpa extracts against four viruses, finding that ethanolic bark extract is particularly effective against Oropouche virus.

## Contribution

The study combines ethnopharmacology and chemotaxonomy to identify a promising natural antiviral source in Apuleia leiocarpa.

## Key findings

- Ethanolic stem bark extract showed potent antiviral activity against Oropouche virus with an EC50 of 14.85 μg/mL.
- Flavonoids, triterpenoids, and phenolic acids were identified in the extracts, linking them to antiviral effects.
- All extracts exhibited antiviral activity against at least one of the four tested viruses.

## Abstract

Apuleia leiocarpa (Vogel)
J.F. Macbr.
(Fabaceae) is traditionally used to treat fever and inflammatory symptoms,
supporting an ethnopharmacological rationale for antiviral investigation.
In addition, the chemotaxonomic context of the genus Apuleia, characterized by the prevalence of flavonoids and triterpenoids
typical of Fabaceae, provides a complementary framework for the selection
of this species. Guided by ethnopharmacological use and chemotaxonomic
evidence, this study evaluated the in vitro antiviral
activity of ethanolic and aqueous extracts obtained from the leaves
and stem bark of A. leiocarpa against
Mayaro, Chikungunya, Zika, and Oropouche viruses. Chemical characterization
of the extracts was performed using liquid chromatography–tandem
mass spectrometry combined with computational metabolomics tools,
including molecular networking and mass spectral database searches.
Flavonoids, triterpenoids, and phenolic acids were putatively annotated
in the extracts, and their presence was interpreted in the context
of antiviral activities previously reported for these chemical classes,
providing a qualitative framework for the observed antiviral responses.
All extracts exhibited antiviral activity against at least one of
the viruses tested. Notably, the ethanolic stem bark extract showed
potent activity against Oropouche virus, with an EC50 value
of 14.85 μg/mL and a selectivity index of 51.50. These results
indicate that the ethanolic bark extract of A. leiocarpa represents a promising and renewable source of natural antiviral
leads.