Simarouba berteroana Krug & Urb. Extracts and Fractions Possess Anthelmintic Activity Against Eggs and Larvae of Multidrug-Resistant Haemonchus contortus

TL;DR

A plant called Simarouba berteroana shows promise as a natural treatment for parasitic worm infections in small ruminants, especially against drug-resistant strains.

Contribution

This study is the first to demonstrate the ovicidal and larval exsheathment inhibition effects of S. berteroana extracts against multidrug-resistant Haemonchus contortus.

Findings

Hydroalcoholic and iso-butanol fractions of S. berteroana significantly inhibited Haemonchus contortus egg hatching.

Extracts and fractions caused structural damage to larvae, including evisceration and cuticle detachment.

Phenolic compounds in the extracts were responsible for inhibiting larval exsheathment.

Abstract

Gastrointestinal nematode infections pose a global threat to small ruminant production, worsened by the growing resistance to existing anthelmintic drugs. This study evaluated the in vitro anthelmintic activity and chemical profile of Simarouba berteroana extracts and fractions. High levels of phenolics, tannins, and flavonoids were quantified in crude extracts and medium- and high-polarity fractions; additionally, quassinoids, terpenoid quinones, phytosterol lipids, alkaloids, and naphthoquinones were annotated. The hydroalcoholic and iso-butanol fractions showed significant inhibitory effects on Haemonchus contortus egg hatching, and the extracts and fractions adhered to eggshells, leading to evisceration and cuticle detachment in larvae. Except for the hexane fraction, all tested extracts and fractions inhibited the exsheathment of third-stage larvae. These findings indicate S. berteroana as a promising source of natural compounds for developing new anthelmintic treatments.

Gastrointestinal nematode infections significantly impact small ruminant production, causing substantial economic losses worldwide. The rising resistance to anthelmintics has led to the search for alternative treatments, including phytotherapeutic approaches. This study investigates the chemical composition and anthelmintic activity of crude extracts and fractions from Simarouba berteroana, an endemic plant from Hispaniola, against a multidrug-resistant isolate of Haemonchus contortus. Chemical analyses revealed high contents of phenolic compounds, tannins, and flavonoids and confirmed the presence of 22 quassinoids, 5 phytosterol lipids, 3 terpenoid quinones, 3 alkaloids, and 1 naphthoquinone. The hydroalcoholic and iso-butanol fractions showed the strongest egg hatching inhibition (IC50 = 0.93 and 1.21 mg/mL, respectively), while hexane fractions were less effective (p < 0.05). Fluorescence microscopy showed that the extracts and fractions adhered to eggshells, causing evisceration and cuticle detachment in hatched larvae. All extracts, except for hexane fractions, inhibited larval exsheathment at 0.3 mg/mL, with phenolic compounds being responsible for this effect. These results provide the first evidence of the ovicidal and larval exsheathment inhibition activities of S. berteroana extracts and fractions against H. contortus, highlighting their potential in managing gastrointestinal nematodes in small ruminants. Further in vivo studies are needed to confirm these findings.

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