Abstract

The potent ameliorating effect of ethanol extract of N. sativa seed on the immune system has been assessed in dexamethasone-induced immune-suppressed male rabbits. Fifty mature male rabbits were randomly assigned into five equal groups (control and four treated groups). Animals were daily treated, for 42 days, as follow: C: was orally administered with drinking water; T₁: was orally administered with N.s.S.E. (1.5 g/ kg, b.w.); T₂: was injected with dexamethasone (2 mg/ kg, b.w., im); T₃: was combined treated concomitantly with N.s.S.E. and dexamethasone; T₄: was treated with dexamethasone for 21 days followed by N.s.S.E. for 21 days. The results of body weight gain revealed significant increase in T₁ and significant decrease in T₂ among the experimental groups. Submandibular lymph node weights of T₁, T₂ and T₃ were significantly higher than that of C. Kidneys weights in T₂ and T₃ registered significant increase compared with C. Bone weight in T₁ and T₄ groups was significantly higher than that of other groups. Liver weight in T₂ was significantly higher and in T₄ was significantly lower than other groups. Total leucocytes count and lymphocytes, monocytes and eosinophils percentages were significantly decreased in T₁, while showed no significant differences in T₂, T₃ and T₄ groups compared with that of control. Phagocytes activity and bone marrow mitotic index were significantly reduced in T₂ group, while returned to normal in T₁, T₃ and T₄ groups compared with control. Titers of IgM, IgA, C₃, and C₄ showed no significant differences among groups, while IgG titer was increased in T₁ and T₄ and decreased in T₂. On the basis of the results obtained, it can be concluded that the examined extract showed a certain immunomodulating effect. Of the immunological aspects, cellular immunity was potentially ameliorated in intact and dexamethasone-induced immunosuppressed- male rabbits.