Dietary Curcuma xanthorrhiza Roxb. increases mitogenic responses of splenic lymphocytes in rats, and alters populations of the lymphocytes in mice.

Rhizomes of Curcuma xanthorrhiza Roxb. (C. xanthorrhiza), a medicinal plant in Indonesia, has been shown to exert diverse physiological functions. Hitherto, a little attention has been paid to its effect on immune functions. This study was carried out to determine the effect of this medicinal plant on mitogenic response of splenic lymphocytes in rats and population of splenic lymphocytes and macrophages and peripheral blood macrophages in mice. Mitogenic responses of splenocytes to phytohemagglutinin, concanavalin A, and pokeweed mitogens were examined in rat fed C. xanthorrhiza for 3 weeks. The medicinal plant increased the blastogenesis to these mitogens. Flow cytometric analysis was carried out for mice fed the medicinal plant for 3 to 5 weeks. C. xanthorrhiza increased the proportion of the splenic T cells throughout the experimental period, but exerted a variable effect on B cells and T cell subsets, that is, elevations of B cells at 3 weeks and of Th cells at 4 weeks without any elevation of Ts cells. The effect of this medicinal plant on a proportion of macrophages from the spleen and peripheral blood was not consistent. Thus, the present study suggests that C. xanthorrhiza contains some principle(s) activating T and B cell-mediated immune functions.