Supplementation of tocotrienol-rich fraction increases interferon-gamma production in ovalbumin-immunized mice

Palm oil is a rich source of vitamin E. The tocotrienol-rich fraction (TRF) extracted from palm oil contain 70% tocotrienols and 30% tocopherols. The effect of TRF supplementation on the immune modulation was evaluated in 6-wk-old female BALB/c mice immunized with ovalbumin (OVA) adjuvanted with alum. Mice in control and experimental groups were immunized subcutaneously (s.c.) on days 14 and 28 with a single dose of 50 μg OVA. The mice in the experimental group were orally gavaged daily with 1 mg of TRF from palm oil while those in the control group received carrier oil. The results show that mice in the experimental group produced significantly (p<0.05) higher levels of interferon-gamma (IFN-γ) compared to the control group. There was no significant (p>0.05) difference in the levels of interleukin-4 (IL-4) produced between the control and experimental animals. Lymphocyte proliferation in response to mitogen or OVA stimulation was significantly (p<0.05) higher in splenocytes derived from the TRF supplemented mice compared to control mice. These findings show that daily supplementation of palm TRF can induce a strong cell-mediated immune response, i.e., T-helper-1 (Th1) response, which would be beneficial to fight viral infections and cancer.