Dietary effect of tocopherols and tocotrienols on the immune function of spleen and mesenteric lymph node lymphocytes in Brown Norway rats

The immunoregulatory effects of dietary alpha-tocopherol (Toc) and tocotrie nols (T-3) on humoral and cell-mediated immunity and cytokine productions w ere examined in Brown Norway rats. We found that the IgA and IgG productivi ty of spleen and mesenteric lymph node (MLN) lymphocytes was significantly enhanced in the rats fed on Toe: or T-3, irrespective of concanavalin A (Co n A) stimulation of the lymphocytes. On the contrary, the IgE productivity of lymphocytes from the rats fed on Toc or T-3 was: less without Con A stim ulation, but was greater in the presence of Con A, especially in the T-3 gr oup. Toc or T-3 feeding significantly decreased the proportion of CD4(+) T cells and the ratio of CD4(-)/CD8(+) in both spleen and MLN lymphocytes of the rats fed on Toc or T-3. The interferon-gamma productivity of MLN lympho cytes was higher in the rats fed on Toc or T-3 than in those fed on a contr ol diet in the presence of Con A, while that of spleen lymphocytes was lowe r in the rats fed on Toc or T-3. In addition, T-3 feeding decreased the pro ductivity of tumor necrosis factor-alpha of spleen lymphocytes, while it en hanced the productivity of MLN lymphocytes. These results suggest that oral administration of Toc and T-3 affects the proliferation and function of sp leen and MLN lymphocytes.