Serum biochemical responses under oxidative stress of aspartame in wistar albino rats

Aspartame is widely consumed by humans who are diabetic and who are under weight loss regime. Aspartame (L-aspartyl-L-phenylalanine methyl ester) also known as NutraSweet, after oral administration to humans and experimental animals, aspartame is rapidly and completely metabolized to 50% phenylalanine, 40% aspartic acid and 10% methanol[1]. Methanol is being increasingly recognized as a substance that damages the liver cells where it is oxidized to formaldehyde and later to formate[1]. These processes are accompanied by elevation of NADH level and the formation of superoxide anion, which may be involved in lipid peroxidation[2]. Also, methanol intoxication is associated with mitochondrial damage and increased microsomal proliferation resulting in increased production of oxygen radicals[3]. And these factors together with the excess of formaldehyde formed during acute methanol intoxication cause significant increase in lipid peroxidation[2]. After aspartame consumption, the concentration of its metabolites is increased in blood[4]. There are many enzymes found in the serum that did not originate from the extracellular fluid. During tissue damage, some of these enzymes find their way into the serum through leakage arising from altered membrane permeability. Serum enzymes [alkaline phosphatase (ALP), acid phosphatase (ACP), aspartate PEER REVIEW ABSTRACT