RESUMO
Jatropha elliptica (Pohl) Oken (Euphorbiaceae) roots are used in folk medicine to treat gastric ulcers. The purpose of this work was to evaluate the gastroprotective activity of ethanol extract (JER) and hexane fraction (ERH) of J. elliptica roots in mice, as well as to analyze the acute toxicity of the extract and identify the potential active compounds. No signs of toxicity were observed in JER. In both acidified ethanol and indometacin-induced gastric ulcer models, all doses tested of JER and ERH significantly reduced gastric lesions. Dereplication of JER was performed by HPLC-DAD-ESI-MS/MS and resulted in the annotation of compounds fraxetin, propacin, jatrophone and jatropholones A and B. GC-MS analysis of ERH revealed the diterpenes jatrophone, jatropholone A and jatropholone B as the major components. The chemical study of this fraction has led to the isolation of these compounds, in addition to the sequiterpene cyperenoic acid and the diterpene 2ß-hydroxyjatrophone, both reported for the first time in J. elliptica. The isolated compounds were tested against L929 cells and only cyperenoic acid and the mixture of jatropholones A and B did not show toxicity, being then selected as good candidates for bioassays using acidified ethanol-induced gastric ulcer model. Cyperenoic acid significantly decreased gastric lesions and preserved gastric mucus layer. The mixture of jatropholones A and B caused a smaller reduction of gastric lesions, without preservation of the gastric mucus layer. The study showed that J. elliptica roots present gastroprotective activity in mice, without causing acute toxic effects. The activity is related, at least in part, to the occurrence of terpenes, mainly the sesquiterpene cyperenoic acid.
