Cytochrome P450 omega-hydroxylase pathway of tocopherol catabolism. Novel mechanism of regulation of vitamin E status.

Cytochrome P450 ω-hydroxylase pathway of tocopherol catabolism: Novel mechanism of regulation of vitamin E status

Long-chain carboxychromanols are the major metabolites of tocopherols and tocotrienols in A549 lung epithelial cells but not HepG2 cells.

Human lung type II cell derived A549 epithelial cancer cells and HepG2 hepatocytes constitutively express cytochrome P4504F2, a P450 we previously identified as a tocopherol-omega-hydroxylase. To determine if A549 cells would metabolize tocochromanols via the omega-hydroxylase pathway, we compared the metabolism of tocopherols (alpha-, gamma-, delta-TOH) and tocotrienols (alpha-, gamma-, delta-...

O-1: Thraputic Effect of Silymarin, Celecoxib and Exogenous Testosterone on Varicocele-Induced Disorders; Possible Mechanisms

Background Varicocele (VCL) is characterized by a progressive disorder which is defined by tortuosity of the pampiniform plexus veins that exerts bilateral impacts. 50-60 percent of males with infertility problems are suffering from VCL. Considering VCL-induced massive problems in human fertilizing potential, investigating different aspects of VCL-induced derangements is gaining considerable at...

Tissue distribution of vitamin E metabolites in rats after oral administration of tocopherol or tocotrienol.

We previously found that 2,7,8-trimethyl-2(2'-carboxyethyl)-6-hydroxychroman (γCEHC), a metabolite of the vitamin E isoforms γ-tocopherol or γ-tocotrienol, accumulated in the rat small intestine. The aim of this study was to evaluate tissue distribution of vitamin E metabolites. A single dose of α-tocopherol, γ-tocopherol or a tocotrienol mixture containing α- and γ-tocotrienol was orally admin...

Regulation of bile acid synthesis.

Bile acids are important physiological agents required for disposal of cholesterol and absorption of vitamins and fats. Bile acids are synthesized from cholesterol in the liver. Enterohepatic circulation of bile acids is very efficient and plays an important physiological role in lipid absorption and secretion, and regulation of bile acid biosynthesis and cholesterol homeostasis. Conversion of ...