Evaluation of embryotoxicity and teratogenicity of Cenostigma pyramidale (Tul.) fruit extract in zebrafish (Danio rerio).

Cenostigma pyramidale is a plant native to the Caatinga biome of northeastern Brazil, which has been reported to cause congenital malformations, spontaneous abortion, and perinatal mortality in fetuses of goats and sheep. Although several bioactive compounds have been identified in this plant, none have been directly associated with the toxic effects in animals. Therefore, the aim of this study was to evaluate the embryotoxic and teratogenic potential of C. pyramidale extract in zebrafish (Danio rerio) and investigate their association with the plant's bioactive compounds. The aerial parts were extracted with ethanol, and the resulting extracts were successively partitioned with hexane, chloroform, and ethyl acetate. The brine shrimp (Artemia salina) lethality assay was used as a screening method by calculating the median lethal concentration (LC50). The chloroform fraction (CF) of C. pyramidale fruits showed the lowest LC50 (184 ppm) and, therefore, it was used in the identification of compounds by gas chromatography coupled with mass spectrometry and in the Fish Embryo Acute Toxicity test. Superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in the embryos. Dose-dependent lethality, delayed development in viable embryos, bradycardia, and teratogenic defects, such as tail malformations pericardial edema, and scoliosis were observed. CAT activity increased with increasing extract concentration. Among the compounds identified, steroids (sitosterol, campesterol, and cholesterol) and palmitic acid were identified as potential toxic agents. The results show that the CF from C. pyramidale fruits exhibits embryotoxic and teratogenic potential in zebrafish, possibly associated with the isolated or synergistic action of these compounds.