gamma-tocotrienol and tocotrienol--alpha

Tocotrienols are farnesylated benzopyran natural products that exhibit hypocholesterolemic activity in vitro and in vivo. The mechanism of their hypolipidemic action involves posttranscriptional suppression of HMG-CoA reductase by a process distinct from other known inhibitors of cholesterol biosynthesis. An efficient synthetic route to tocotrienols and their isolation from palm oil distillate using an improved procedure is presented. gamma-Tocotrienol exhibits a 30-fold greater activity toward cholesterol biosynthesis inhibition compared to alpha-tocotrienol in HepG2 cells in vitro. The synthetic (racemic) and natural (chiral) tocotrienols exhibit nearly identical cholesterol biosynthesis inhibition and HMG-CoA reductase suppression properties as demonstrated in vitro and in vivo.

Topics: Animals; Anticholesteremic Agents; Cells, Cultured; Chickens; Cholesterol; Chromans; Humans; Hydroxymethylglutaryl CoA Reductases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Liver; Male; Rats; Rats, Wistar; Tocotrienols; Vitamin E