Perfil químico e avaliação da atividade farmacológica do extrato seco e da fração acetato de etila obtido das folhas de Mimosa caesalpiniifolia

Abstract

Mimosa caesalpiniifolia (Sansão-do-Campo) is a native species of the caatinga in northeastern Brazil that has been studied for its potential anti-inflammatory and antidepressant activity. The present work was carried out with the aim of promoting the chemical profile and evaluation of the pharmacological activity of the dry extract and the ethyl acetate fraction obtained from the dry leaves of Mimosa caesalpiniifolia. The leaves were collected in the municipality of Alfenas-MG and subjected to drying, followed by division in a knife mill. The preparation of the dry extract was carried out by the extraction method using simple percolation and the fraction obtained by liquidliquid partition. Part of the extractive solution was concentrated in a rotary evaporator followed by a drying process using the spray technique with the addition of colloidal silicon dioxide. The dry extract (33.33%) showed a higher yield in mass when compared to the yield of the ethyl acetate fraction (19.67%). The chemical results were obtained through analysis by HPLC-PDA coupled to a mass spectrometer, enabling the verification of the presence of phenolic acids, flavonoids, aglycones and glycosides, in addition to tannins. This corroborates with data present in the literature for the genus Mimosa sp. Some compounds had their structure determined, where they were identified as catechin (m/z 288.97), cassiaocidentalin A (m/z 560.75) and procyanidin B2 [(epi)catechin–(epi)catechin; m/z 576.83)]. The in vivo pharmacological evaluation was conducted with a total of 82 male Wistar rats that underwent cecal ligation and perforation surgery to induce the inflammatory process. One week after surgery, these animals were treated for 7 days with the dry extract and the ethyl acetate fraction and submitted to behavioral tests (open field and forced swimming). It was found that the animals that were submitted to the treatment did not present statistically significant results, demonstrating that the pharmacological action evaluated in the test was not highlighted in this type of experiment. The groups that underwent treatment had an aggravated locomotor activity. This demonstrates that the depressive-like behavior that was accentuated after the treatment observed in the forced swimming and open field test makes it difficult to draw greater conclusions about the evaluated pharmacological activity. Therefore, the search for new hypotheses or the use of a new study methodology for evaluation is essential. The results found with the chemical study contributed to the knowledge of the plant species studied. On the other hand, further studies are needed to provide a better understanding of the pharmacological evaluation of Mimosa caesalpiniifolia.