The leaves of Nyctanthus arbortristis L. (NA) are reported to be useful in rheumatism, menorrhagia, dysentry, asthma and
allergic reactions. They were proven experimentally to have antibacterial, antiinflammatory
and anthelmintic activity. The aim of the present study was to investigate the effect
of methanolic leaves extraxt (MNA) on immune cells by using in-vitro and in-vivo models. The MNA was examined for the ability to induce secretory and cellular responses
in murine peritoneal macrophages. Macrophages treated with the extract exhibited increased
acid phosphatase and myeloperoxidase activity as well as significant increase in the
production of nitric oxide (NO), hydrogen peroxide (H2O2), and superoxide (O2
–). Hence, in vivo studies were carried out to confirm the immunomodulatory potential of MNA in mice.
Oral administration of MNA at doses of 250 and 500mg/kg, significantly increased in total leukocyte count and in weight of spleen indicating
an uplift of innate immunity. It has significantly increased carbon clearance index
and ovalbumin induced delayed type hypersensitivity (DTH) reactions. It also produced
a significant increase in serum globulin content and specific antibody titer against
ovalbumin. Treatment with MNA increased the number of bone marrow cells positive for
nonspecific esterase and peroxidase activity. Leaves of NA showed the presence of
carbohydrates and glycosides (iridoids glucosides and flavanol glycosides), which
suggest the major role of glycosides for the immunostimulant activity.
In conclusion MNA has shown to stimulate both innate and adaptive immune response
either through stimulation of macrophages or through stimulating the release of factors
that are involved in proliferation of bone marrow cells.
