RESUMO
In this study, the in vitro effects of 1-(4-dimethylaminobenzylidene)-2-(2-hydroxybenzylidene) hydrazone (L1) and its corresponding copper complex [Cu(L1)], synthesized in our laboratory, were investigated on the proliferative responses, Th1 (interleukin-2 (IL-2), interferon-γ (INFγ)) and Th2 (IL-4) cytokine secretion, adenosine triphosphate (ATP) levels and intracellular redox status of T lymphocytes submitted to H2O2/FeSO4-mediated oxidative stress. T cells were isolated on histopaque density gradient by differential centrifugation, and were cultured with the mitogen concanavalin A (Con A), free radical generator (H2O2/FeSO4) and with different concentrations of L1 and [Cu(L1)] (1 - 100 µM). Proliferation (MTT assay), cytokines (Elisa kits), ATP levels, cytotoxic effect (micronucleus test) and oxidative markers (glutathione, catalase, superoxide dismutase, hydroperoxide and carbonyl protein contents) were investigated after 48-h incubation. Our results showed that H2O2/FeSO4 treatment induced a reduction in T lymphocyte proliferation, cytokine secretion and ATP levels associated to an evident intracellular oxidative stress, inflammatory profile and DNA damage. Addition of L1 at 100 µM was able to increase cell proliferation, IL-2, IL-4 and INFγ secretion and ATP contents and to reduce hydroperoxide and carbonyl protein contents, catalase activity and micronuclei number in lymphocytes under oxidative stress, with a partial protection. The [Cu(L1)] exhibited protective effects in T lymphocytes by inhibiting H2O2/FeSO4 - induced cell proliferation suppression, inflammatory status, ATP loss and oxidative stress generation, whatever the concentration used. In conclusion, in the situation of excessive oxidative stress, [Cu(L1)] treatment improved T lymphocyte proliferation, cytokine production, ATP contents and oxidant/antioxidant status. [Cu(L1)] could be effective at improving oxidative stress and T cell abnormalities.
