title: Comparative evaluation of the antioxidant activity of alpha-tocopherol, alpha-tocopherol polyethylene glycol 1000 succinate and alpha-tocopherol succinate in isolated hepatocytes and liver microsomal suspensions.
abstract: The antioxidant activity of alpha-tocopherol polyethylene glycol 1000 succinate (TPGS) and of alpha-tocopherol succinate (TS) has been examined in isolated hepatocytes and microsomal fractions from rat liver. Both TPGS and TS require esterase activity to yield free alpha-tocopherol and, hence, antioxidant activity. TPGS and TS consistently exerted a more effective antioxidant protection than an equivalent amount of directly-added free alpha-tocopherol. The low antioxidant efficiency of directly added free alpha-tocopherol in such water-based experimental systems as used here seems to be due to its extreme hydrophobicity. TPGS, on the other hand, is an extremely hydrophilic compound that is being examined as a useful source of alpha-tocopherol in certain clinical situations and is here shown to be a convenient and effective source for experimental studies into lipid peroxidation and antioxidant mechanisms.
authors.affiliation: Department of Experimental Medicine and Oncology, University of Turin, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Carini
authors.forename: G
authors.initials: G
authors.lastname: Poli
authors.forename: M U
authors.initials: MU
authors.lastname: Dianzani
authors.forename: S P
authors.initials: SP
authors.lastname: Maddix
authors.forename: T F
authors.initials: TF
authors.lastname: Slater
authors.forename: K H
authors.initials: KH
authors.lastname: Cheeseman
mesh_terms: D000818:Animals; D000975:Antioxidants; D015227:Lipid Peroxidation; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008862:Microsomes, Liver / Q000187:drug effects* / Q000378:metabolism; D011092:Polyethylene Glycols; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D024505:Tocopherols; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D014810:Vitamin E; D011092:Polyethylene Glycols; C014225:tocophersolan; D024505:Tocopherols