title: Tocotrienols from palm oil as effective inhibitors of protein oxidation and lipid peroxidation in rat liver microsomes.
abstract: Tocotrienols from palm oil showed significant ability to inhibit oxidative damage induced by ascorbate-Fe2+ and photosensitization, involving different mechanisms, in rat liver microsomes. The tocotrienol-rich fraction from palm oil (TRF), being tried as a more economical and efficient substitute for alpha-tocopherol, showed time- and concentration-dependent inhibition of protein oxidation as well as lipid peroxidation. It was more effective against protein oxidation. The extent of inhibition by TRF varied with different peroxidation products such as conjugated dienes, lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS). Among the constituents of TRF, gamma-tocotrienol was the most effective followed by its alpha- and delta-isomers. In general, at a low concentration of 5 microM, TRF was able to prevent oxidative damage to significant extent (37% inhibition of protein oxidation and 27-30% of lipid peroxidation at 1 h of incubation). The protective ability of TRF (30.1% at 5 microM with TBARS formation) was significantly higher than that of the dominant form of vitamin E, alpha-tocopherol (16.5% under same conditions). Hence our studies indicate that this fraction from palm oil can be considered as an effective natural antioxidant supplement capable of protecting cellular membranes against oxidative damage.
authors.affiliation: Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Bombay, India.
authors.forename: J P
authors.initials: JP
authors.lastname: Kamat
authors.forename: H D
authors.initials: HD
authors.lastname: Sarma
authors.forename: T P
authors.initials: TP
authors.lastname: Devasagayam
authors.forename: K
authors.initials: K
authors.lastname: Nesaretnam
authors.forename: Y
authors.initials: Y
authors.lastname: Basiron
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002839:Chromans / Q000494:pharmacology; D005260:Female; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects*; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D000073878:Palm Oil; D010938:Plant Oils; D011506:Proteins / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D024508:Tocotrienols; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D002839:Chromans; D010938:Plant Oils; D011506:Proteins; D017392:Thiobarbituric Acid Reactive Substances; D024508:Tocotrienols; D014810:Vitamin E; C082097:tocotrienol, delta; C013649:plastochromanol 8; D000073878:Palm Oil; C082032:tocotrienol, alpha