In Vitro Anthelmintic Effect of Mexican Plant Extracts and Partitions Against Trichinella spiralis and Strongyloides venezuelensis

Parasitic diseases represent a significant global public health concern. Two clinically important parasites of high prevalence rates are <i>Trichinella spiralis</i> and <i>Strongyloides stercoralis</i>. However, the limitations of currently used nematocidal drugs highlight the urgent need for novel treatment approaches. The present study investigated the in vitro nematocidal activity of methanol extracts from <i>Amphipterygium adstringens</i>, <i>Artemisia ludoviciana</i>, <i>Cymbopogon citratus</i>, <i>Heterotheca inuloides</i>, <i>Jatropha dioica</i>, <i>Justicia spicigera</i>, <i>Larrea tridentata</i>, <i>Mimosa tenuiflora</i>, <i>Psacalium decompositum</i>, <i>Ruta chalepensis</i>, <i>Semialarium mexicanum</i>, and <i>Smilax aspera</i> against <i>T. spiralis</i> L1 and <i>S. venezuelensis</i> L3 (model for <i>S. stercoralis</i>). Most of the plants showed antiparasitic activity, but <i>R. chalepensis</i> crude methanol extract showed the most potent nematocidal activity against both parasites, with a mean lethal concentration (LC₅₀) of 28.2 µg/mL and a selectivity index (SI) of 22.4 for <i>T. spiralis</i> and an LC₅₀ of 244.8 µg/mL and SI of 2.58 for <i>S. venezuelensis</i>. This extract was further separated into <i>n</i>-hexane, chloroform, and methanol partitions by continuous Soxhlet extractions. The <i>n</i>-hexane partition demonstrated the strongest activity against both parasites, with an LC₅₀ of 147.6 µg/mL and an SI of 7.77 against <i>T. spiralis</i> and an LC₅₀ of 39.2 µg/mL and an SI of 3.77 against <i>S. venezuelensis</i>. LC-MS/MS analysis identified coumarins as the main chemical class (53%), and chalepin represented this partition's most abundant compound (29.9%). Overall, this study confirmed the antiparasitic potential of medicinal plants commonly used in Mexico. In addition, it highlights the possibility of obtaining bioactive compounds from plants like <i>R. chalepensis,</i> or the other plants evaluated in this study, as novel treatments against parasitic diseases.