Toxicological assessment of the Achyrocline satureioides aqueous extract in the Caenorhabditis elegans alternative model.

Achyrocline satureioides , popularly called "marcela" in Brazil, is used in traditional medicine in South America. A. satureioides , inflorescences are used for many conditions, including to minimize the Sars-Cov-2 symptoms. Therefore, the aim of this study was to determine the toxicity profile of A. satureioides aqueous extract (ASAE), using the Caenorhabditis elegans ( C. elegans ) alternative model. Survival, reproduction, development, and transgenerational assays were performed. The effects of ASAE were investigated under conditions of thermal stress and presence of oxidant hydrogen peroxide (H ₂ O ₂ ). In addition, C. elegans strains containing high antioxidant enzyme levels and elevated lineages of daf-16, skn-1 and daf-2 regulatory pathways were examined. The ASAE LC ₅₀ value was found to be 77.3 ± 4 mg/ml. The concentration of ASAE 10 mg/ml (frequently used in humans) did not exhibit a significant reduction in worm survival at either the L1 or L4 stage, after 24 or 72 hr treatment. ASAE did not markedly alter the body area. In N2 strain, ASAE (10 or 25 mg/ml) reversed the damage initiated by H ₂ O ₂ . In addition, ASAE protected the damage produced by H ₂ O ₂ in strains containing significant levels of sod -3, gst -4 and ctl - 1,2,3, suggesting modulation in these antioxidant systems by this plant extract. ASAE exposure activated daf-16 and skn-1 stress response transcriptional pathways independently of daf-2 , even under extreme stress. Data suggest that ASAE, at the concentrations tested in C. elegans , exhibits a reliable toxicity profile, which may contribute to consideration for safe use in humans.