Saturated fatty acids are synthesized by both plants and animals from acetyl coenzyme A as a form of long-term energy storage. Palmitic acid is a common 16-carbon saturated fat that represents 10-20% of the normal human dietary fat intake, and approximately 25% of the total plasma fatty acids in plasma lipoproteins.{1935} Saturated free fatty acids induce the expression of COX-2.{10646} MP is a fatty acid ester whose concentration in cells is modulated by methanol. In studies with isolated Kupffer cells, MP inhibits phagocytosis and decreases cell viability. In cells treated with lipopolysaccharide, it also decreases secretion of IL-10, TNF-α, NO, and PGE2. This effect is thought to occur by the inhibition of NF-κB.{13763}