Immunostimulant agents from Andrographis paniculata.

EtOH extract and purified diterpene andrographolides of Andrographis paniculata (Acanthaceae) induced significant stimulation of antibody and delayed type hypersensitivity (DTH) response to sheep red blood cells (SRBC) in mice. The plant preparations also stimulated nonspecific immune response of the animals measured in terms of macrophage migration index (MMI) phagocytosis of 14C-leucine labelled Escherichia coli and proliferation of splenic lymphocytes. The stimulation of both antigen specific and nonspecific immune response was, however, of lower order with andrographolide than with the EtOH extract, suggesting thereby that substance(s) other than andrographolide present in the extract may also be contributing towards immunostimulation.