RESUMO
The aim of this study was to investigate the effect of Arrabidaea chica (Humb. & Bonpl.) B. Verl., Bignoniaceae, extracts on Ehrlich solid tumor development in Swiss mice. Leaves of A. chica were extracted with two distinct solvents, ethanol and water. The phytochemical analysis of the extracts indicated different classes of secondary metabolites like as anthocyanidins, flavonoids, tannins and saponins. Ethanol (EE) and aqueous (AE) extracts at 30 mg/kg reduced the development of Ehrlich solid tumor after ten days of oral treatment. The EE group presented increase in neutrophil count, α1 and β globulin values, and decrease of α2 globulin values. Furthermore, EE reduced the percentage of CD4+ T cells in blood but did not alter the percentage of inflammatory mononuclear cells associated with tumor suggesting a direct action of EE on tumor cells. Reduced tumor development observed in AE group was accompanied by a lower percentage of CD4+ T lymphocytes in blood. At the tumor microenvironment, this treatment decreased the percentage of CD3+ T cells, especially due to a reduction of CD8+ T subpopulation and NK cells. The antitumor activity presented by the AE is possibly related to an anti-inflammatory activity. None of the extracts produced toxic effects in animals. In conclusion, the ethanol and aqueous extracts of A. chica have immunomodulatory and antitumor activities attributed to the presence of flavonoids, such as kaempferol. These effects appear to be related to different mechanisms of action for each extract. This study demonstrates the potential of A. chica as an antitumor agent confirming its use in traditional popular medicine.