Avaliação da toxicidade, atividade alelopática e antioxidante do extrato aquoso e do óleo essencial de Croton myrianthus.

Abstract

The article describes a study conducted with the plant Croton myrianthus, where leaves of the plant were collected and subsequently air-dried at room temperature. The essential oils were obtained through hydrodistillation and steam distillation methods. The aqueous extract was obtained by infusing the dried leaves in autoclaved distilled water. The essential oils and the aqueous extract were tested for toxicity using bioassays with Artemia salina (a microcrustacean) and lettuce seeds Lactuca sativa. In the bioassay with Artemia salina, the results showed that all Artemia exposed to the essential oil were dead after 24 hours, indicating high toxicity. On the other hand, all Artemia exposed to the aqueous extract were alive after the same time, demonstrating low toxicity. In the germination test with lettuce seeds, the essential oil of C. myrianthus negatively affected germination, where higher concentrations resulted in a lower percentage of germinated seeds. On the other hand, the aqueous extract did not show significant effects on seed germination. Furthermore, the total phenolic compounds present in the extract were quantified, and the antioxidant activity was evaluated, revealing the ability to neutralize free radicals with IC50 equal to 4,03%. In summary, the study demonstrated that the essential oil of C. myrianthus exhibits high toxicity to Artemia salina and negatively affects lettuce seed germination. On the other hand, the aqueous extract showed low toxicity and did not significantly influence seed germination. The extract also exhibited antioxidant activity, suggesting possible applications as an antioxidant. [resumo fornecido pelo autor]