Inhibitory effects of palm alpha-, gamma- and delta-tocotrienol on lipopolysaccharide-induced nitric oxide production in BV2 microglia

Anti-inflammatory actions of the vitamin E fragment tocotrienol have not been described for microglia. Here, we screened palm alpha-, gamma- and delta-tocotrienol isoforms and Tocomin (R) 50% (contains spectrum of tocotrienols and tocopherols) for their ability to limit nitric oxide (NO) production by BV2 microglia. Microglia were treated with varying doses of tocotrienols for 24 h and stimulated with 1 mu g/ml lipopolysaccharide (LPS). All tocotrienol isoforms reduced NO release by LPS-stimulated microglia, with 50 mu M being the most potent tocotrienol dose. Of the isoforms tested, delta-tocotrienol lowered NO levels the most, reducing NO by approximately 50% at 48 h post-LPS treatment (p < .05). None of the tocotrienol doses tested affected microglia viability. (C) 2011 Elsevier Inc. All rights reserved.