Objectives. To evaluate the immunomodulatory effect on lymphocyte subsets, dendritic cells (DC), Th1 / Th2 / Th17 and inflammatory cytokines on systemic level and/or in the tumor microenvironment of mice with or without melanoma. Materials and methods: Peripheral blood and/or primary tumors samples were obtained of mice with B16 melanoma treated or not with a hydroalcoholic extract of Uncaria tomentosa (UT) with 5.03% of pentacyclic oxindole alkaloids (UT-POA) obtained from the bark of the plant. All cell assays and cytokine measurements were performed by flow cytometry. Results. UT-POA systemically increased CD4/CD8a relation while cell activation was inversely proportional; increased the proportion of DCm; induced a pro-inflammatory Th1 profile and reduced Th17 response. TNF-α and IL-17A positively and negatively correlated with CD4/CD8a relation. Conclusions. The increase of Th1 (TNF-α) may result in the increase of CD4 or M1 macrophage activation. Although UT-POA shows increased DCm, is not dose-dependent. Th17(IL-17A) decreased can support the function of CD8a lymphocytes. UT-POA shows better systemic immunomodulatory effects than intratumoral.