Evaluation of chemical constituents in Norantea guianensis aubl. Extracts, embryotoxicity, and acetylcholinesterase inhibitory potential in Danio rerio

Norantea guianensis Aubl., commonly referred to as the parrot flower or macaw-tail vine, is a plant species found in the Brazilian Amazon, Caatinga, and Cerrado biomes. It is used in folk medicine for its anxiolytic properties, as well as its ability to alleviate headaches and reduce fever. Nevertheless, despite its therapeutic benefits, the impact on embryonic development has yet to be fully explained. The objective of this study was to evaluate chemical constituents by HPLC-DAD, UV–visible and classical phytochemistry and the LC50 of ethanolic extracts from the stem and leaves of N. guianensis in Danio rerio after 96 h and to investigate their effect on developmental morphology. The findings were then related to both Acetylcholinesterase (AChE) activity and the plant's chemical composition. Zebrafish embryos were exposed to 0, 20, 40, 60, 80 and 100 mg/L concentrations of stem and leaves extracts. Phytochemical analysis revealed that the stem extract contained predominantly phenolic compounds, tannins, and anthraquinones, while the leaf extract contained alkaloids and flavonoids. The LC50 values for the stem and leaf extracts were 64.55 mg/L and 7.16 mg/L, respectively, being the stem extract was more toxic than the leaf extract. Induced malformations and alterations in the zebrafish development in different concentrations for both extract including pericardial edema, increased heart rate, spinal malformation and equilibrium disruption. Unlike to stem extract, the leaf extract delayed larval hatching and inhibited AChE activity. The findings indicate that the leaf extract possesses higher embryotoxicity and its use should be avoided during pregnancy.