Brazilin augments cellular immunity in multiple low dose streptozotocin (MLD-STZ) induced type I diabetic mice

Brazilin, an active principle of Caesalprenia sappan, was examined for its immunopotentiating effects in multiple low dose streptozotocin (MLD-STZ) in duced type diabetic mice. Brazilin was intraperitoneally administered for 5 consecutive days to MLD-STZ induced type diabetic mice. Delayed type hyper sensitivity, Con A-induced proliferation of splenocytes and mixed lymphocyt e reaction, which had been decreased in diabetic mice, were significantly r ecovered by the administration of brazilin. Brazilin increased IL-2 product ion without affecting suppressor cell activity. Con A-induced and IL-2-indu ced Expression of high affinity IL-2 receptors were also enhanced by brazil in. These results indicate that brazilin augments cellular immune responses , which are suppressed in the MLD-STZ induced type I diabetic mice, by incr easing IL-2 production and responsiveness of immune cells to IL-2.