Chronic inflammation constitutes one of the major etiologies of degenerative diseases including cancer, and cardiovascular and neurodegenerative diseases; chronic inflammation also contributes to rheumatoid arthritis, asthma and hepatitis. These diseases are among the leading causes of death and disability in the world. During inflammation, several pro-inflammatory mediators including prostaglandin E2 (PGE2) and leukotriene B4 (LTB4), as well as cytokines, such as TNF-alpha, play central roles in regulating inflammatory response and inflammation-mediated damage. Vitamin E comprises eight structurally related molecules, alpha-,beta-, gamma-, delta-tocopherol, and alpha-,beta-, gamma-, delta -tocotrienol. Among them, only alpha -tocopherol (alphaT) has been extensively studied. Recent studies indicate that other forms of vitamin E have unique properties, which are not shared by alphaT, but are important to human disease prevention and therapy. Gamma-Tocopherol (gammaT) and its metabolite, but not aT, exhibit anti-inflammatory effects by inhibiting cyclooxygenase (COX)- catalyzed formation of PGE2. In a rat inflammation model, gammaT inhibits not only PGE2, but also LTB4, and TNF-alpha. These results suggest that gammaT may be superior to some commonly used non-steroid anti-inflammatory drugs (NSAIDs), such as COX inhibitors, most of which only inhibit the COX-mediated pathway. Preliminary studies also indicate that delta- tocopherol and gamma-tocotrienol, compared with gammaT, are even stronger inhibitors of the COX-catalyzed formation of PGE2. These observations led to the current hypothesis that certain forms of vitamin E and their combinations have unique pharmaceutical utility as anti-inflammatory drugs, or as supplements that complement and improve current treatments for inflammatory diseases. This hypothesis will be tested by pursuit of the following Specific Aims in cell culture and animal experiments: 1. Investigate in vitro anti-inflammatory properties of individual vitamin E forms and their combinations; 2. Investigate and compare in vivo anti-inflammatory activities of individual vitamin E forms and their combinations; and 3. Investigate the potentially improved effects of combining certain forms of vitamin E and NSAIDs, such as aspirin, in a rat inflammation model. Our studies may lead to the discovery of novel and better therapy for treating and preventing inflammatory diseases, and provide the scientific rationale, the experimental evidence and the biochemical basis for future human studies.
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