TOCOTRIENOLS FROM PALM OIL AS POTENT INHIBITORS OF LIPID-PEROXIDATIONAND PROTEIN OXIDATION IN RAT-BRAIN MITOCHONDRIA

The tocotrienol-rich-fraction (TRF) from palm oil, being tried as a mo re economical and efficient substitute for alpha-tocopherol, significa ntly inhibited oxidative damage in vitro to both lipids and proteins i n rat brain mitochondria induced by ascorbate-Fe2+, the free radical i nitiator azobis(2-amidopropane)dihydrochloride (AAPH) and photosensiti sation. The observed inhibitory effect was both time-and concentration -dependent. At a low concentration of 5 mu M, TRF can significantly in hibit oxidative damage to both lipids and proteins. The inhibitory eff ect of TRF seems to be mainly due to gamma-tocotrienol and to a lesser extent alpha- and delta-tocotrienols. TRF was significantly more effe ctive than alpha-tocopherol. This fraction from palm oil can be consid ered a natural antioxidant supplement capable of protecting the brain against oxidative damage and thereby from the ensuing adverse alterati ons.