Potencial tóxico das folhas de esenbeckia pumila Pohl (Rutaceae)

Abstract

Interest in the botanical genus Esenbeckia is based on the chemical and biological potential of its species, as well as other plants of Rutaceae. Therefore, the objective of this work was to evaluate the toxic potential of the leaves of Esenbeckia pumila Pohl (Rutaceae). In the test against Artemia salina, which consisted in the exposure of newly hatched nauplii to the extract and fractions, E. pumila showed to be highly toxic with LC50 values equal to 64 μg.mL -1, 57 μg.mL-1, 65 μg.mL-1 and 149 μg.mL-1 for the ethanolic extract and the dichloromethane, ethyl acetate and hexane fractions, respectively. The cytotoxic effect in the SF-295 (glioblastoma), PC-3 (prostate) and HCT-116 (colon) cultures of the tumor cells was evaluated using the colorimetric MTT reduction method, demonstrated that only the dichloromethane fraction showed a cytotoxic effect against SF-295, inhibiting 75.50% of cells and, notably, against HCT-116, whose inhibition value of cell proliferation was 94.99%. The antibacterial activity of the ethanolic extract and the acetate-ethylic fraction against strains of Staphylococcus aureus and S. epidermidis was evidenced in the Minimum Inhibitory Concentration (MIC) test. In the assay against Atta sexdens rubropilosa, where the toxicity was verified by ingestion of the extract and the fractions, incorporated into the solid artificial diet, all the samples tested, except for the ethanolic extract 0,2 mg, presented significant mortality rates of workers, with a concentration of acetate-ethylic 2,0 mg, which presented 100% mortality on the 21st day and median survival (Md) on the 3rd day (p < 0,05). The results obtained in the biological tests showed the antitumor, antibacterial and formicidal potential of the Esenbeckia pumila Pohl plant. Phytochemical analysis led to the isolation of a mixture of the α-amyrin, β-amyrin and lupeol triterpenes and also of the phytosterol β-sitosterol of the ethyl acetate fraction and the flavonoid rutin of the methanolic fraction.