Toxicity Effect of Bougainvillea glabra (Paper Flower) Water Extracts on Zebrafish Embryo

Background: Bougainvillea glabra, or paper flower, is an ornamental plant known to possess various pharmacological activities. However, there is little information on the potential toxicity of this plant. Therefore, the aim of this study was to assess the acute toxicity and the potential teratogenic activity of water extracts of B. glabra bracts on zebrafish embryos which were selected as the model in this study. Methods: The pink, purple, and dark pink bracts of B. glabra were extracted using the Soxhlet method. Embryos with the same division stage were selected and treated with the extracts (1-300 µg/mL) for 72 h. The mortality of the embryos was recorded and the teratogenicity effect induced by the extracts was identified. The yolk sac area and pigmentation were quantified using Image-J. The data were analyzed by IBM SPSS 22.0. Results: All extracts within the tested concentrations did not induce death in embryo, except the pink bract extract with LC50 of 85.51 µg/mL. In the teratogenicity study, all the extract-treated embryos showed yolk sac edema at different concentrations, and the defect observed was independent of the concentrations. On top of that, the purple bract extract induced hypopigmentation in embryo, significantly at 30 µg/mL compared to control. Conclusion: This study concluded that the water extracts derived from the pink, purple, and dark pink bracts of B. glabra have mild toxicity toward embryo.