<i>In vivo</i> immunosuppressive effect of Ursolic acid.

<p>(A, B) Ursolic acid delayed mortality and weight loss in GVHD mice: Eight million lymphocytes from C57BL/6 donor mice were injected i.v. into immunocompromised Balb/c mice 48 h after WBI (600 cGy). Ten mice were included in each group. Control group mice received vehicle treated cells whereas the UA group received cells treated with 5 µM UA for 4 h. (A) Survival of the immunocompromised mice reconstituted with allogenic lymphocytes treated with UA or vehicle. *p<0.05, as compared to mice injected with vehicle treated allogenic lymphocytes. (B) Changes in the body weight of the mice after allo-transplantation. Data points represent mean±SEM from 10 mice. Changes in levels of IL-2 (C), IL-6 (D) and IFN-γ (E) in serum separated from the blood collected on days 3 and 5 from recipient mice (Balb/c) injected with vehicle treated lymphocytes or UA treated lymphocytes isolated from C57BL/6 mice (F) Ursolic acid inhibits cytokine production in activated lymphocytes. Lymphocytes were stimulated with Con A (5 µg/ml) following which UA (5 µM) was added at the indicated time points and the cells were further cultured for 24 h at 37°C. The concentration of IL-2 cytokines in the culture supernatant was estimated using ELISA. (G) Ursolic acid inhibits Con A induced cytokine production even after washing. Lymphocytes were treated with UA (5 µM)) for 4 h and washed with normal RPMI twice, rested for 48 h and then stimulated with Con A (5 µg/ml) for 24 h at 37°C. The concentration of IL-2 in the culture supernatant was estimated using ELISA. Each bar represents mean±S.E.M. from three replicates and two such independent experiments were carried out. *p<0.01, as compared to vehicle treated cells and #p<0.01, as compared to Con A stimulated cells.