TOCOTRIENOLS INHIBIT LIVER HMG COA REDUCTASE-ACTIVITY IN THE GUINEA-PIG

Male guinea Digs were treated intraperitoneally with different dosages of tocotrienols isolated from palm oil fatty acid distillate (PFAD) f or 6 consecutive days. Control animals were treated with vitamin E-fre e palm oil triglycerides. Commercial animal pellets and water were giv en ad libitum during the treatment period. The guinea Digs were sacrif iced at around 2400 hr. Liver HMG CoA reductase was assayed by a combi nation of conventional TLC and liquid scintillation spectrophotometry using C-14-HMG CoA as the substrate. Our results show that tocotrienol s isolated from PFAD inhibited liver HMG CoA reductase activity in the guinea Dig and the inhibitory effect of tocotrienols on HMG CoA reduc tase appeared to be dose-dependent. Analysis of the serum tocol profil es indicate that only alpha-tocopherol was found in the serum and ther e was no tocotrienol in the serum after 6 consecutive treatments with tocotrienols. These results indicate a rapid clearance of tocotrienols from the blood circulation. On the contrary, the liver retained much of the tocotrienols administered. The levels of tocotrienols in the li ver appear to increase with increased dosages of tocotrienols in the t reatment.