Hydrophilic fraction of Selaginella convoluta (Arn.) Spring shoots extract: Chemical characterization and embryotoxicity in zebrafish (Danio rerio)

As part of our ongoing efforts to better comprehend the species Selaginella convolute (Arn.) Spring, a desiccation-tolerant plant native to the semiarid Caatinga biome, this study aimed to investigate the chemical composition and safety of the hydrophilic fraction (SHF) derived from their shoots extract using the embryotoxicity test in an in vivo model. UPLC-MS/MS analysis revealed an array of phenolic compounds, such as biflavonoids, selaginellins and hydroxycinnamic derivatives. Some, such as selaginpulvilin A and seladoeflavone, are being reported for the first time in S. convoluta. Embryos exposed to concentrations of 2.5, 5.0, and 10.0 mg/ml of the SHF exhibited no signs of toxicity or teratogenicity to zebrafish embryos during the observation period. No mortality was observed among embryos exposed to any concentration of the SHF. However, continuous exposure at a concentration of 10 mg/ml resulted in mortality after 4 hours, with a survival rate below 50 % at 16 hours. The study confirmed the low toxic potential of the SHF during acute exposure and the absence of teratogenic effects across the tested concentrations. A hundred metabolites were detected and just 6.5 % could be annotated regarding online and in-house database. The intriguing chemo diversity of the SHF makes it a promising resource for discovering new chemical entities and developing novel drugs. Moreover, the fraction demonstrates a low toxic potential upon acute exposure in vivo, enhancing its potential for pharmaceutical applications which could drive a biomonitorated isolation to achieve an unequivocal structural assignment.