Comparative effects of tocotrienol-rich fraction, α-tocopherol and α-tocopheryl acetate on inflammatory mediators and nuclear factor kappa B expression in mouse peritoneal macrophages

Abstract

The effects of tocotrienol-rich fraction (TRF), α-tocopherol (T) and α-tocopheryl acetate (TA) on lipopolysaccharide (LPS)-induced inflammatory responses in mouse peritoneal macrophages were examined. Results showed that at 5-30 μg/ml, all test compounds plus 1 μg/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 E(2) (PGE(2)), and proinflammatory cytokine (TNF-α, IFN-γ, IL-1β and IL-6) production. At 10 μg/ml, it significantly 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-κB) 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.