Alpha-(13′-hydroxy)-6-hydroxychroman, the main product of alpha-tocopherol metabolism in human hepatocytes, regulates CYP4F2 and PPAR-γ expression

The enzymatic metabolism of vitamin E in liver cells generates long chain metabolites (LCMs) with proposed regulatory activity on inflammatory and atherogenic genes. In this study the LCM formation kinetics was characterized in HepG2 and HepaRG human hepatic cells, supplemented with RRR-α-tocopherol (α-TOH). α-13’OH was the main product of α-TOH metabolism, while α-13’COOH metabolite and the short chain metabolite α-CEHC, were detected only in traces, thus demonstrating the poor efficiency of vitamin E catabolism in these cells. However, this metabolism was significantly simulated when the hepatic cells were challenged with (lipo)toxic agents, such as ethanol or palmitate. Under such condit…