Immunomodulatory effect of albizzia lebbeck.

The immunomodulatory effect of the bark of Albizzia lebbeck (Sirisha) was evaluated by studying humoral and cell mediated immune responses. The hot aqueous extract and its butanolic fraction were administered once daily for one week in mice, immunised previously with sheep red blood cells (SRBC). At the dose levels tested (6.25, 12.5 and 25 mg/kg, p.o.), A. lebbeck treated mice developed higher serum antibody titres compared to the vehicle treated group and the effect was comparable to the standard drug muramyl dipeptide (MDP). Delayed type hypersensitivity response was suppressed in SRBC immunised mice treated with A. lebbeck extract. The macrophage migration index remained unaltered in both mice and rats. These results are discussed in the light of possible immunopotentiating effects of A. lebbeck.