Tocotrienols are part of the vitamin E family and are largely found in palm oil, rice bran and annatto. However, tocotrienols are less popular and not as comprehensively studied in comparison to tocopherols, which is the other isomer of vitamin E. Tocotrienols are similar to tocopherols in which alpha, beta, gamma and delta subtypes of both forms of vitamin E exist naturally. Tocotrienols are unsaturated and contain isoprenoid side chains, which differentiates them from tocopherols. Previous studies indicated that tocotrienols have superior antioxidant and biological effects against chronic diseases compared to tocopherols. The liver is the major powerhouse organ involved in metabolism and thus very susceptible to injury caused by xenobiotics, harmful chemicals and toxic metabolites. Uncontrolled levels of these reactive molecules leads to increased oxidative stress in the liver environment, which is thought to be the major aetiology of liver toxicity and liver cancer. This review will discuss the antioxidant activity of tocotrienols and the potential molecular targets of tocotrienols in the liver. The role of tocotrienols in the prevention of liver toxicity and liver cancer will also be discussed.
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