The effects of tocotrienol-rich fraction (TRF), a-tocopherol (T) and a-tocopheryl acetate (TA) on lipopolysaccharide (LPS)-induced inflammatory responses in mouse peritoneal macrophages were examined. Results showed that at 5–30 lg/ml, all test compounds plus 1 lg/ml LPS exhibited no cytotoxic effects on macrophage cells. Compared with T and TA, TRF showed the strongest anti-inflammatory activity as demonstrated by its potency in inhibiting the LPS-induced nitric oxide (NO), prostaglandin E2 (PGE2), and proinflammatory cytokine (TNF-a, IFN-c, IL-1b and IL-6) production. At 10 lg/ml, it signifi-
cantly blocked the LPS induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, but has no effect on cyclooxygenase-1 (COX-1). Furthermore, TRF also showed a greater inhibition on the nuclear factor kappa B (NF-jB) expression than T and TA. These results suggest that TRF could be a better agent than T and TA for use in the prevention of chronic inflammatory diseases.
