Background: Angiostrongylus cantonensis is a neurotropic nematode recognized as the leading cause of eosinophilic meningitis worldwide. Despite its growing medical importance, therapeutic options for angiostrongyliasis remain limited, highlighting the need for new anthelmintic agents. Methods: The anthelmintic activity of andrographolide, a diterpene lactone isolated from Cymbopogon schoenanthus, was evaluated against first-stage (L1) larvae, infective third-stage (L3) larvae, and adult worms of A. cantonensis using motility-based phenotypic assays. Toxicity was assessed in mammalian cell models and Caenorhabditis elegans, and drug-likeness and ADMET properties were evaluated using in silico approaches. Results: Andrographolide exhibited concentration-dependent activity across all developmental stages, with EC₅₀ values of 12.5, 11.2, and 7.3 µM for L1, L3, and adult worms, respectively. These EC₅₀ values were similar to those of albendazole, with no statistically significant differences detected for any developmental stage. No toxicity was detected at the highest concentrations tested in mammalian cell models (CC₅₀ > 500 µM) or C. elegans (LD₅₀ > 1000 µM), supporting a preliminary selectivity profile. The in silico analyses predicted compliance with major drug-likeness rules, absence of PAINS alerts, high gastrointestinal absorption, and low probabilities of hepatotoxicity, nephrotoxicity, and neurotoxicity. Conclusions: Andrographolide represents a promising in vitro anthelmintic hit against A. cantonensis and warrants further preclinical investigation.

Angiostrongylus cantonensis is the leading cause of eosinophilic meningitis worldwide, but therapeutic options remain limited. This study investigated the anthelmintic activity and preliminary selectivity of licarin A, a neolignan isolated from Nectandra oppositifolia. The compound was evaluated in vitro against first-stage (L1) larvae, infective third-stage (L3) larvae, and adult worms, using albendazole as the reference drug. Cytotoxicity was assessed in mammalian kidney epithelial, keratinocyte, and neuronal cell models, while whole-organism toxicity was examined in Caenorhabditis elegans. Physicochemical, pharmacokinetic, drug-likeness, and toxicological properties were also predicted computationally. Licarin A was active against L1 and L3 larvae, with EC₅₀ values of 16.8 and 36.4 µM, respectively. Its activity was comparable to albendazole against L1 but lower against L3, and no relevant effect was observed against adult worms (EC₅₀ > 100 µM). No detectable cytotoxicity or lethality was observed in the mammalian cell lines or C. elegans at concentrations up to 500 µM. Computational analyses indicated favorable drug-likeness, high gastrointestinal absorption, blood–brain barrier permeation, lack of recognition as a P-glycoprotein substrate, and generally low predicted toxicity. These findings identify licarin A as a selective, stage-dependent anthelmintic hit and provide a foundation for optimization of its scaffold against parasitic nematodes.