Abstract： Objective To approach the effects of injecting intraperitoneally with curcumin on the survival time of mouse cardiac allografts and the mechanism.Methods Heterotopic cardiac transplantations of mice were done by using 30 C57 mice as donors,and 30 Babl/C mice as recipients.The recipients were classified randomly into three groups:control group,low-dose curcumin group,and high-dose curcumin group.The recipients of the corresponding groups were injected intraperitoneally with sodium chloride,5 μg/μl curcumin,and 10 μg/μl curcumin respectively.The injecting volume of all mice was 20 μl/g.Survival time of transplanted hearts was recorded after the operations.The grafts of 3 mice in each group were harvested for histopathological examination 7 days after the operations,ELISA was used to determine the changes of IL-2,IL-4.IL-10,IFN-γ in peripheral blood of the receptors,the mixed lympholeukocyte reaction was done to inspect responsibility of T lymphocytes of receptors to donor antigen,Western-blot was used to examine nuclear translocation of NF-κB p65 in T cells,and ELISA to analyze DNA binding activity of NF-κB p65 in T cells.Results The average survival time of mouse heart allografts in control group,low-dose curcumin group and high-dose curcumin group was(8.0 ± 3.3),(17.0 ± 2.4),and(23.0 ± 2.2),respectively(P＜0.01).On the 7th day after operations,the grade of rejecting reactions in control group,low-dose curcumin group,and high-dose curcumin group was Ⅱ-Ⅲ,Ⅰ-Ⅱ and 0-Ⅰ,correspondingly.IL-2,and IFN-γ in peripheral blood of receptors in control group,low-dose curcumin group,and high-dose curcumin group were reduced in turn,but IL-4 and IL-10 were increased in turn (P＜0.01).As compared with control group,the proliferation ability of T cells in low-dose curcumin group and high-dose curcumin group was attenuated,especially in high-dose curcumin group,when stimulated with splenocytes of donators.Translocation of NF-κB p65 and NF-κB DNA binding activity of T cells in low-dose curcumin group and high-dose curcumin group were decreased.Conclusion Curcurmin can obviously prolong the survival time of allografts and inhibit the rejecting reactions of mouse cardiac allografts possibly by inhibiting cytokines in Th1 cells and promoting cytokines in Th2 cells,making the receptor immunosuppression against donor antigen.