In vitro effect of Derris scandens on normal lymphocyte proliferation and its activities on natural killer cells in normals and HIV-1 infected patients.

We investigated the effect of Derris scandens hydroalcoholic extract on lymphocyte proliferation, natural killer (NK) cell activity and secretion of IL-2 and IL-4. Lymphocyte proliferative response of normal individuals was significantly increased at concentrations of 10 ng/ml, 100 ng/ml, 1 microg/ml and 5 microg/ml, whereas the response was significantly decreased at 100 microg/ml. D. scandens at the concentrations of 10 ng/ml, 100 ng/ml, 1 microg/ml and 10 microg/ml significantly enhanced the function of NK cells of normal individuals. The NK cell activity of HIV-infected individuals was significantly increased at a concentration of 10 microg/ml. Furthermore, the extract was shown to induce the IL-2 secretion from normal peripheral blood mononuclear cells (PBMC), whereas the IL-4 was not induced in the presence of the D. scandens extract. Our data suggested that the hydroalcoholic extract of D. scandens possesses in vitro immunostimulating activity on human immunocompetent and immunocompromised PBMC.