Polyunsaturated fatty acids and regulation of gene expression

It has now long been understood that lipids not only serve as important stores of energy, but also function as ne modulators of cellular signaling and metabolism. Fatty acids and especially polyunsaturated fatty acids (PUFAs) of the n-3 and n-6 series have been implicated in the modulation of various biochemical pathways. PUFAs decrease plasma lipid levels (Rambjor et al., 1996; Harris et al., 1997), improve the immune response (Hwang, 2000; Ntambi et al., 2002a), and increase insulin sensitivity (Storlien et al., 1998; Suresh and Das, 2003). The n-3 PUFAs are also Preventive in several chronic diseases including coronary heart disease and stroke (Siscovick et al., 2000; von Schacky, 2000; Skerrett and Hennekens, 2003), in3 ammatory bowel disease (Kremer, 1996; Beluzzi et al., 2003), lung disease (Schwartz, 2000) as well as certain kinds of cancer such as breast, prostate, and colorectal cancers (Rose, 1997; de Deckere, 1999). Although the bene cial effects of n-3 PUFAs are clear, there is also some concern about possible detrimental effects of n-6 PUFAs due to their known roles in in3 ammatory and aggregatory pathways. Thus, better understanding of the mechanisms by which these fatty acids affect cellular metabolism will be invaluable in establishing a valid dietary n-3/n-6 fatty acid ratio for optimal health (Sampath and Ntambi, 2004).