Atividade imunomoduladora de diferentes extratos obtidos da espécie Plukenetia volubilis Linneo (Euphorbiaceae stricto sensu)

Abstract

Inflammation is a response from the organism to aggression and injuries. This process may be finely regulated to prevent the emergence of diseases. Due to the importance of this field, the research of potential plants with immunomodulators activities has receiving an important role. Considering this aspect, in this work it was analyzed the effect of different plant extracts from Plukenetia volubilis L. (Euphorbiaceae stricto sensu ss) for the immunomodulatory activity. In vitro tests were performed using RAW 264.7 macrophages and in vivo tests using BALB/C mice. The results of the present work has shown that the extracts of P. volubilis stimulated the activity of MTT reduction by the mitochondrial dehydrogenases of the macrophages and that there was no cytotoxicity at the concentrations used (100, 250 and 500 μg / mL). Macrophages stimulated with LPS and treated with the different extracts presented a significant reduction in the production of nitric oxide (NO), in comparison with a control group. The percentages of NO production for methanolic (ME), aqueous (AE), hexane (HE), ethanolic (EE) and chloroform (CE) extracts were 56%, 64%, 64.1, 65% and 72% , respectively. Regarding to the cytokine dosage and the quantification of the relative expression of their genes, there has been verified a reduction of the synthesis and expression, exception for TNF-α which presented relative expression above the control after treatment with extracts HE, CE and AE. This extracts probably act by inhibiting COX-2 and iNOS via inhibition of the NfΚB transcription factor, whereas TNF-α mechanism of action is supposed to happen by another independent pathway. AE and EE extracts inhibited the migration of leukocytes to the peritoneal cavity of mice induced to peritonitis, in the in vivo assay. Therefore, the conclusion is that the compounds present in leaf extracts of P. volubilis are promising agents in the development of new alternative forms for the treatment of inflammatory diseases, since they act modulating the inflammatory response by the synthesis of cytokines.